Very Strong and Confined Chiral Acids: Universal Catalysts for Asymmetric Synthesis?

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Very Strong and Confined Chiral Acids: Universal Catalysts for Asymmetric Synthesis?
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2019
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English

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Abstract
Strong acids not only dissolve metals but are also broadly useful, perhaps universal catalysts for chemical synthesis. Indeed, acid catalysis enables key transformations, such as the Diels–Alder and Friedel–Crafts reactions, and various aldol, Mannich, and Michael reactions. Some of these processes are conducted on a multi-million ton scale. Consequently, substantial efforts have been directed towards the development of enantiopure acids, especially Lewis acids, which facilitate important asymmetric variations of such reactions. Despite the plethora of elegant catalysts and methodologies developed in this context however, a key limitation of enantioselective Lewis acid catalysis is the frequent need for relatively high catalyst loadings (10-20 mol%), which result from issues such as insufficient Lewis acidity, product inhibition, hydrolytic instability, and background catalysis. Recently, we proposed a new design for asymmetric acid catalysis. We have developed in situ silylated organic acids, which address some of the above problems in various highly enantioselective reactions involving silicon-containing nucleophiles with unprecedentedly low catalyst loadings. As an example of asymmetric counteranion-directed catalysis (ACDC), these reactions proceed via silylation of an electrophile, generating a cationic reactive species that ion-pairs with an enantiopure counteranion and reacts with a silylated nucleophile. We are currently expanding this “silylium-ACDC” concept to, in principle, all types of Lewis acid catalyzed reactions, including those that do not involve silylated reagents. In my presentation, I will discuss how the concept of using very strong and confined acids has led to the development of novel, extremely active organic Lewis acid catalysts that enable asymmetric versions of highly challenging Diels–Alder reactions. The confined acids that form the basis of our latest catalyst design not only enable the utilization of small and unbiased substrates but, because of their high acidity, also the activation of previously inaccessible substrates for organocatalysis.
Stereoselektive Synthese Physical chemistry Chemical element Materials science Pharmaceutical drug Acid Chemist
Stereoselektive Synthese Germanic peoples Abiogenesis Chemische Energie Data conversion Photosynthesis Topicity Acid Food
Stereoselektive Synthese Germanic peoples Acid Ammonia
Stereoselektive Synthese Germanic peoples Materials science Plastic Zunderbeständigkeit Stream bed Acid
Molecularity Functional group Protein Transport Topicity Transport Solution Solution Wine tasting descriptors Catalytic converter
Organokatalyse Organische Chemie Transformation <Genetik> Acetaldehyde
Übergangszustand Organokatalyse Enzyme Proline Multiprotein complex Chemist Process (computing)
Area Organokatalyse Gesundheitsstörung Acid Chemist Process (computing)
Lewis acids and bases Famotidine Candy Watt Chemical reaction Acid Process (computing) Schwefelblüte
Lewis acids and bases Petroleum Zunderbeständigkeit Acid Electronic cigarette Chemistry
Stereoselektive Synthese Naturstoff Lewis acids and bases Collecting Acid Chemistry Process (computing)
Stereoselektive Synthese Lewis acids and bases Recreational drug use Walking Fenofibrate Zunderbeständigkeit Sea level Acid
Metal Sense District Enzyme inhibitor Weinfehler Asset Multiprotein complex Acid Stereoselektive Synthese Enantiomere Lewis acids and bases Acid Volumetric flow rate Oxide
Neutralization (chemistry) Systemic therapy Lewis acids and bases Acid Volumetric flow rate Base (chemistry) Multiprotein complex Acid Enantiomere Chemistry
Lewis acids and bases Vulcanization Lewis acids and bases Volumetric flow rate Chemical compound Aluminium Fenofibrate Ausgangsgestein Substrat <Chemie> Acid Enantiomere
Area Reaction mechanism Transformation <Genetik> Substrat <Chemie> Stereoselectivity
Stereoselektive Synthese Systemic therapy Naturstoff Lewis acids and bases Acid Reaction mechanism Aldosterone Base (chemistry) Multiprotein complex Wursthülle Acid
Stereoselektive Synthese Systemic therapy Lewis acids and bases Species Lactitol Aldosterone Sea level Cobaltoxide Chemical reaction Solution Acid
Stereoselektive Synthese Lewis acids and bases Zearalenone Reaction mechanism Aldosterone Calcium ammonium nitrate Multiprotein complex Solution Acid
Stereoselektive Synthese Wine tasting descriptors Island Ice Lewis acids and bases Fermium Cryogenics Aldosterone Solution Acid Common land Stereoselektive Synthese
Wine tasting descriptors Protein Aldosterone Desalination Thermoforming
Acid Species Glasses Chemical structure Exciter (effect) Hope, Arkansas
Stereoselektive Synthese Setzen <Verfahrenstechnik> Lewis acids and bases Transformation <Genetik> Acid
Stereoselektive Synthese Lewis acids and bases Zearalenone Weakness Exciter (effect) Zunderbeständigkeit Addition reaction Chemical reaction Acid
Stereoselektive Synthese Lewis acids and bases Chain (unit) Yield (engineering) Assimilation (biology) Orlistat Trimethylsilyl Elektronentransfer Angiotensin-converting enzyme Acid Thermoforming
Stereoselektive Synthese Sense District Process (computing) Potenz <Homöopathie> Lewis acids and bases Substrat <Chemie> Acid
Anomalie <Medizin> Übergangszustand Molecule Process (computing) Enzyme Recreational drug use Chloral Ursodesoxycholsäure Acid
Process (computing) Phosphorous acid Chiralität <Chemie> Ursodesoxycholsäure Acid Steric effects
Systemic therapy Substrat <Chemie> Hydroxyl Transformation <Genetik> CHARGE syndrome
Naturstoff Systemic therapy Pheromone Functional group Colourant Phosphorous acid Food
Naturstoff Paste (rheology) Process (computing) Ageing Functional group
Acyl Paste (rheology) Potenz <Homöopathie> Sedation Functional group Jasmonate Transformation <Genetik> ISO-Komplex-Heilweise Chemical reaction Multiple chemical sensitivity Stereoselektive Synthese Electronic cigarette
Acid Recreational drug use Functional group Fazies Cobaltoxide Angiotensin-converting enzyme Wursthülle Solution Multiple chemical sensitivity Chemistry Electronic cigarette Curie temperature
Klinisches Experiment Perfume Acid
Naturstoff Island FDP.The Liberals Dye penetrant inspection Elephantiasis Acid
Setzen <Verfahrenstechnik> Substitutionsreaktion Jasmonate Katalase Wursthülle Solution Acid Klinisches Experiment Enzyme Azo coupling Substrat <Chemie> Angiotensin-converting enzyme Perfume
Systemic therapy Bearing (mechanical) Polymorphism (biology) Ketone Yield (engineering) Substitutionsreaktion Jasmonate Substrat <Chemie> Chemical reaction Chemistry Catalytic converter
Organische Chemie FDP.The Liberals Yield (engineering) Jasmonate Pharmaceutical drug Cycloalkane Zunderbeständigkeit Dye penetrant inspection Sea level Chemical reaction Chemistry Multiple chemical sensitivity
Naturstoff Starvation response Setzen <Verfahrenstechnik> Aldehyde Chemical engineering Aldosterone Solution Solution Chemistry Branch (computer science) Systemic therapy Functional group Materials science Silencer (DNA) Yield (engineering) Pharmaceutics Polymer Sodium borohydride Dye penetrant inspection Farmer
Chlorhexidine Simulation Chemical engineering Chemical structure Substrat <Chemie> Dye penetrant inspection Chemical reaction Solution
Stop codon Metal Precursor (chemistry) Systemic therapy Ageing Functional group Brown adipose tissue Tube (container) Elektronentransfer Chemical structure Substrat <Chemie> Silicon Base (chemistry) Hydrophobic effect
Digital elevation model Sense District Substitutionsreaktion Phosphorous acid Acid Stereoselektive Synthese Combine harvester Acid Solvent Simulation Hydroxybuttersäure <gamma-> Gemstone Elektronentransfer Zunderbeständigkeit Dye penetrant inspection Permaculture
Sense District Dyeing Molecule Oxalate Transformation <Genetik> Solution Chemical reaction Acid Chemistry
Setzen <Verfahrenstechnik> Ionenbindung Organische Chemie Coral reef Jasmonate Katalase Wursthülle Acid Wine tasting descriptors Ether Block (periodic table) Chemistry Alkene Water Island Polymorphism (biology) Octane Protein Derivative (chemistry) Barrel (unit) Substrat <Chemie> Mixture Chemist
Azo coupling
Ice Gesundheitsstörung Materials science Transformation <Genetik> Tetrahydrobiopterin Mixture Lambic Process (computing)
Ice Compacted graphite iron Azo coupling Stereoselectivity
Pharmacology Chemist Chemistry
but when i come to meetings like this one international sciences meetings like getting to a meeting or in the u.s. it's kind of similar i noticed that we chemists seemed to be in a kind of introspective face these days and we search for for.
and challenges that are not borrowed from our neighbouring disciplines like biology medicine in physics all materials science as we try to find a real chemical grand challenges and i don't know how this was imposed on us if we were if it was alone decision or the funding agency or politicians and you can argue with.
no not this is useful. i think some great concept came out of this think about for example camec chemical energy conversion i think this is an outstanding grand challenge that we keep us busy for for this century or think about the original of life another you know brilliant and purely chemical problem very exciting. however i think one of the i would argue the grandest of all challenges has been overlooked somehow maybe because it's so obvious to all of us and that's the grand challenge of can tell us this the future of can tell us as i think very i mean of course this is a little bit biased but i think there is no more fast.
donating topic to think about them can tell us as just think about photosynthesis for example catalyst in a bow the production of food for us to eat and air for us to breathe i mean is there anything more important at least from a human perspective in this universe but the beauty of can tell us is is that it is all.
also always a technology i would see the enabling technology of mankind which is some sometimes forgotten but you clearly without one hundred fifty million tons of ammonia every years have produced by our part about bosh it would mean nine billion of us it or think about.
fuel that is produced on a billion taiwan scale by catalytic cracking of plastic that was just mentioned by bed and materials that are producing hundreds of millions of times through the help of can tell us so callous as he is the enabling technology or do you know anything else that contributes to over one third of the.
global domestic product kind of amazing this fascinating number of seventy six trillion us dollars in in two thousand and thirteen and it is also clear in my opinion that could tell us as we'd be.
take part of the solutions to these problems that we're facing right now major challenges such as you know how to feed and and provide help for growing world population energy have cost a big topic transportation and of cause climate change so they are really really big problems mankind are facing it is clear that they can only be so.
of with can tell us and so my group were interested in can tell us the scenes in almost twenty years and we started out with organic a talent is pushing this a little bit for what as a field and discovering a protein catalyse into molecular although reaction out of which many interesting concept a rosy mean calluses.
amina a mediocre palaces in many mine activation an asymmetric brands as it could houses but also interesting another transformation said were sort of an era of president to be for using acetaldehyde for example as a nuclear five and so on and in fact it turns out twenty years ago organic intelligence wasn't even existing as.
the field and now it's literally number one in a symmetric synthesis its dominating now the feud in over any other approach including enzymes and transition matter complexes kind of fascinating and also their more and more industrial processes nowadays using organic catalyst this is one that uses appalling catalyzed into molecular reaction to make.
could an antiviral agent or one of you this is actually also very interesting story that hiv is now not really curable but people are the patients live a relatively normal live thanks to chemicals made by chemists kind of amazing and a great success story that people are not so were off sometimes.
so with this in mind we became interested in seeing in pushing the front years for their of of organic at thousand seeing can it be really also like air like a chemical good talus us to have to make you know one of these movie million tones care process ease in the area we focused on in recent years.
may surprise you a little bit is new is acid could houses and it's not because it's a fundamentally novel activation lot of course it could be far from nothing could be far from true use as it could tell us this is probably the single most established approach to could tell us as there is it's also i would argue the most power.
awful approach to to a callous as there is and the most general approach to alice's serious and i would say the majority off all catalyze of the reactions can be catalyze by louis s's and this has also found its way of cause in to pick industrial processes free to craft a creations the other reactions but also.
this reaction catalytic wrecking using his elide is done on a billion town scale kind of remarkable right so the first things crude oil sees a catalyst and end of the second thing is is this the allied to to produce fuel.
so this is an established area in industrial and also in in academic could tell us as but the surprising observation that we made was why this is like a brick scale chemistry when it comes to in until selective louise s. it could tell us as people have developed a very nice catalyst over the years and this is just as.
small arbitrarily told the collection very powerful very useful in academic natural products as up occasions for example this chemistry for some reason never essentially made it into industrial processes and i'm not in this to provide industrial processes don't get me wrong but somehow it reflects.
on usefulness i would argue and the question is then why is nobody using this to make you know drugs on scale even organic intelligence is used more frequently nowadays then in this one step is to approach of his magic was as it does and we thought about this and i think the reason is kind of obvious it's the catalyst boarding why aluminum tricor.
but free to craft a patient is used people on ppm level this is not a typical ten more percent catalyst daunting and this is you know as i said rather common in a symmetrical was as it can tell us as and so the question then is why is that why do you need such a high catalyst voting and we thought about this for a while and people have already.
post different problems an asymmetric was as it can tell us but i would argue that there is probably a fundamental design flaw in how we make these cairo lewis assets and the way we make them is we start from a metal on the tabloid and oxidation state higher than zero so it's its positively charged and has a contract i am. my own and this is not lose as it right and how do you make of car well let's add a little this is how we always have done it and it makes a lot of sense right because lewis acid happily craves for lewis be significant and this is like a like a sort of instantaneous reaction that occurs and you find these cairo complexes however there is also.
also a problem and that problem has somewhat be overlooked and that is if you makes a base and an acid as we all know from our first said mr studying chemistry neutralisation happens and this is also true for you he systems with pairs right so of course the resulting complex when you at a base to it we.
be less lewis's citic then the parent compound and this has been called league in the sept deceleration but it's kind of interesting that lead an accelerated calluses is more sort of an established as a concept but this is probably at least as common as as league and acceleration and so idea and was very simple how can we solve this well.
remove the league and entirely and put the car elegy onto the county high into the count time right account to enter cairo an eye on and then hopefully retain this district mad agree activity of aluminium tricor right or be of three of the like but n n in activating your lewis basic substrate.
but still achieve high and onto selectivity by virtue now have i in perry so now it's not a call and kind of mechanism but the counter and i own in design pairing phenomenon induces asymmetry in a transformation that occurs with you activated substrate. and so we wondered if organic intelligence perhaps can help in this in this area and specifically wanted to start with the tradition own who is acid catalyzed reaction it's the book i am i all reaction known since the seventy's and look i am i am self and it's not that there are only.
if you catalyst available the dozens of of very efficient highly anticipated catalyst and newquay i'm self even develop one of those.
very nice and reliable and used a natural product but again you see this is sort of ridiculous the high catalyst building and in this case again you have a base at an acid and of course the corresponding complex is it is that we can lose as it and that in part explains the high catalyst daunting but there's another problem with this system in that comes from the mechanism this new is.
it now activates the other hide you few more law the system nuclear file can detect and you from this species now and then all that has to take place is the solution mind helping from one oxygen to the other oxygen giving the elder product and regenerating the news as it and the problem is now hear this species itself can act as a loser. yes it but not delivering the cairo who is as it did you have sort of assembled here but another one the equivalent off trimesters to lose your mind and this is a very very active catalyst trams and solid triplett interest we made extremely important catalyst of carlisle reactions used up down two ppm levels so.
now you have this problem in addition to this sort of we can with the city of your complex that you have a competing very very active catalyst in this solution and that's a cairo and so of course then when you lower the catalyst loading they don't just activity falls apart.
that's the problem of the uk a mile or action of course our solution then was what appears we just used his inherent thousands of the maya mallory actually and at a cairo counter and i own and then benefit from this but was what used to be an annoying background can tell us this mechanism and used is now as a productive can.
politics cycle and so we did ten years ago we introduced a new class of carl lewis as it's where you have a cairo ice to form it as the counter an island and the equivalent of a solution on as as the real catalyst and indeed these turned out to be very very effective catalyst a low temperature low catalyst loading you get. very good enough to selectively and most importantly already at the time the catalyst loading could be really reduced to zero point zero five more percent without affecting healed and in adjusted activity of quite don't have to say this was by far the lowest catalyst loading ever used in any catalytic asymmetric mile reaction so we were.
onto something here and the question then was how does it work.
and in fact it works by you can just use the free aesthetic from the brands that as a form of the catalyst in this reaction which in principle you can imagine as acting as a brand said as it but that's not what happens what happens is a proto desalination of your nuclear five takes place this is the most basic thing around gets protein aged and in return on gives back the.
your mind and then you have what you can see an m.r.i. and also in x. rays the structures you have an insulated version and and also related version of this species now you this is your actual louise acid transferring now the salute your mind on to the outside loring takes place in look if i can detect now in this i'm perry us and pair scenario. giving the simulated algal and then the cinema and i hope speck on to the counter and i always used in an abbreviated catalytic cycle to reactivate the other this is how this works and new strategy a new platform for asymmetrical was as it can tell us is that was kind of exciting for us and over the years than funded by a generous of by a generous.
and from the european research concert weeks brought the scope of this type of reactive he invariance video was obese been enormous and and similar type can tie type of transformations methyl allegations allows only sucker i do kind of had reduced other reactions with danny chesty dying in our lives.
abramoff reactions still a sign asians and all sorts that can be done on i'm muti graham scale actually have greater than hundred gram ninety nine has it to one iata and all sorts of addition reactions to events that was an exciting time for all editorial we published many many papers as you can see here but he at some point we realized there is a little weak.
miss about this kid has a strategy as exciting as we were as as it is and the weakness can sounds the substrate school so yes this is a new approach to is meant to be was cut as it can tell us but the truth turned out to be it's a new approach to his much it was as it can tell us of reactions involving left outside so if you have a problem with nafta and had were really good at solving the.
his but when it comes to more realistic allies are probably on al hide or you know this longer chain are corralled hide unfortunate doesn't work anymore in a just an activity essentially falls apart and also the yield ghost town because you get transfer assimilation form that you know silent of this in allies about al hide so this was a disaster in.
in that sense that you if you want to provide something useful you better make sure the scope of the methodology is reasonable and people can use it beyond an afterthought hide.
and so this was hunting us for a while and we thought about this what's the problem of are catalysts design and our thinking is basically summarized in his power point here what's going on is that these catalysts have infected relatively open active side and open and shallow active side and open and shallow active sides will accommodate.
but i would suggest variety and and and diversity of transition state confirmations and this will ultimately with small substrates with small unbiased our lives let's say and this will ultimately boy down into low in hunter said activity so what was needed in our opinion was.
sort of in taking inspiration from enzymes and q eating a confined space around your active side and in this confined space of cost effects abilities much less pronounced with small molecule and you should be able to get high interest in activity and so we designed this new class off catalysts carol me to die for states.
two of the phosphoric acid sprinted over an immediate nitrogen and that creates a lot of stereo hinderance around the active side confines the active side and indeed you go from this opened shape now to confine shape of the catalyst so how do they perform actually nice you can.
and for example catalyze the first could litigation that expire us to tell his agent in charge a graduate student in my laboratory at the time no system professor dirie discovered this transformation and you can use substance that offer the unmodified just the you know either is there that gets proto unaided and this hydroxyl group that cyclists into this giving this cairo action.
this is a natural product if the pheromone used by the food fly called only and that you can get for the first time in a color to gaze magic fashion so that was exciting but really the sort of paradigm shift in my laboratory at least came subsequently when another group published how for a year later a paper injects called catalytic.
they symmetric spire us television and guess which catalyst they use they use trip over phosphoric acid is open active side and it also worked so what was the difference to our system the difference was rather and then sort of new buildings sophisticated catalyst what these people what these people did and i have to say we also did.
you know in the past a lot and and i feel somehow little bit bad about it the engineer at the substrate right so you just put to federal groups year and then you also have a nice catalytic a summit expire us to his age with trip unfortunately of course the product is not a natural product anymore and and into the flies was certainly not not smell it so.
you can see my sort of disrespect about this style of its much you can tell us as i said and i am but i'm blaming myself my group has done this in the past a lot and but we try to really go away from this now work on making sophisticated heavily engineered catalyst rather than creating our substrates and over the years then we.
have shown this is a general catalyst very very powerful in a number of different transformations for example suffolk sedation is of our higher end era sulphides a possible with financial activity completely organic so for sedation reactions catalytic asymmetric s. to tell his nation's a possible the referees no to these companies are completely useless why are you doing them we were to. you know some are fascinated with this idea that the symmetric as intel is asians a possible company inside as a shoes and all sorts of prints reaction became possible in this was also an exciting time so we could benefit from the power of this new design now handling really small on by subject however unfortunately once again.
we didn't really solve the problem because these catalyst are simply not a civic enough to engage in this kind of louise acid activation that we wanted them to to engage in right so they do not catalyzed ok i must a chemistry.
little problem and so we thought about this for a while how can a actually many years it took i don't have five or six years to solve this problem and it was very simple solution how can we city five these catalyst how can we make much stronger as it would put my drug was here that didn't really help a lot and ultimately the solution was very simple just exchanging these. to oxygen's here to entry frugal this is an old trick in brown said asad chemistry how you can signify oxygen based brands as it's just exchange the oxygen to entry for a group and we did this twice or in this active side so it had a dramatic effect i talk about the case at the end of my talk this is ten million times more acidic.
and the i.d.p. catalyst they called me to die foster in the dates and i'm extremely strong as its approaching like trip limit in this city are and catalyze some of our dream reaction for example those on the second trial ation not only have enough to hide but also of simple are corralled hides with very high and just elect. city actually we still have to say this in parentheses we submitted this to a higher ranking journal because we're really excited to solve this problem and the referees get back to us saying well you know kind of nice but they are already catalyst for this reaction and it's a problem of the eighty's and it didn't help that i said it's a problem of the eighty's.
because nobody have soft it it wasn't islands off problem of the eighty's since the eighty's people have not been able to handle elephant exception in this was always our corral elation it's also the reason why a natural products as you always see stocky metric iraq zero is a disparity agent in making these kind of her mollycoddled but.
this is now for the first time a solution to this problem and these catalyst really trial to be a breakthrough in my laboratory and you almost the my entire let works with these catalyst we have solved the problems that were completely on soft before for example handing cyclicality fighting oaxaca be new mines in a symmetrical as a cat on that was in. never even not handled by enzymes or any other type of catalyst unless you have bent on your nationwide roxy called substitutions he also be kept could catalyze him ok i'm up michael type addition i know this looks like something not special ride but it was not it seems that catalyst that could handle these kind of substrates and it was kind. interesting when i would this paper appeared just a couple of weeks before habit my heirs published about how kyson mates and and pointed out that they are the weakest electrified in michael editions so in this case actually this is a problem of the eighteen eighty's when michael discovered his reaction using a car it's an amazing fact.
until the first asymmetric variant of this reaction came out so people before had always had another substitute and he had to do for withdraw electron density from the system also still work on an elder or reactions but now for example with ketones this was published last year with hundred on bear post-op from korea now assistant professor.
there. in nature chemistry but not now with their dogma graham quantities and and twenty more percent like like ok i'm a before but with ppm loadings point four million grant to convert ten grams of this key tone into to twenty two grams of this compiled here and that's not the high school we have a whole substrate scope table with graham.
stick scale reactions and ppm level catalyst loading high scores this one you can use now one milligram of our catalyst of these i have the catalyst up to two thousand grams per more to make a more off the product and so if you would upscale this this would mean one kilogram of our catalyst is enough.
to make three hundred thirty four tones of a product which is sort of the world demand of a blockbuster drug showing your the power of of what has happened now in the meantime with organic catalyst in the last twenty years very very active highly in under selective cadmus another little problem that we have worked on.
the psni was my dream out all reaction and that would be making such aloes hate you that i stream valuable for the experts a lot in natural products into this but also in in pharmaceuticals and this is to making his elbows directly from an alcoholic and the eagles silent have a seat idea that would be kind of the dream reaction of for me. the but of course it's a bit naive to do this disconnection because you have an brand and difficult to hide in the starting material and in and branch and effective study materials the product and not surprisingly this is a known polymer ization reaction so you can easily polymer rise by lock see silence with this way making making kind of. farmers because of course the nuclear file with for the attack here and yamamoto has provided a solution to this again by engineering the substrate putting these to pursue groups here on the you know silent and then you have a very big nuclear file in a very big electrify and they just don't find each other anymore and the reaction stops year and the id paice. no different you don't have to decorate the subsidy you can use commercially available in all silence t.b.s. protect their very cheap and easy to make from thx f x actually and also the test you know silent and reacting with all sorts of different al to hide and if addict on branch to branch of hide and aromatic other high. it's and get high not just an activity and once again this is scalable to move the grahams the catalyst can be recycled the reaction times a short and you can make very nice pharmaceuticals with this chemistry so this is we have a new catalyst system a new type of who is as an activation mode but they still a week this and i'm sure many of us have identified.
i said the majority of all catalyze where we actually can be catalyze with was as if it's true but i'm only showing use those reactions that involved so you can transfer right our substrates are always structure metric lee simulated and the question then is how general is this principle if you have to always use elated substrates and so team got some my eye.
found in my group together with minor fund cameron system in which you can now use the silicon as a stop structure metric reagent as a core catalyst in india's either reaction in a very challenging to use either reaction again because this is a very very bad that you know file these are causing limits and those are now converted into the details of the product with high. university to be using a different more city brown said as a precursor to see age as a base bought based a catalyst so that was nice but it again required a little bit of substrate decoration specifically we need to use these groups here the flu or new math also protecting tube it's not so. bad to bring in and also easy to create of but still somebody has to do it and my point is whenever you have to modify your substrates to do a catalytic asymmetric or any catalytic reaction then you may as well use the evans of surgery like what's the point of sort of faking asymmetrical palaces when you have to do to modify your substrate i did you want to use the.
it's substrates and so to me later did and we couldn't handle the simple archive a sudden it's not as pacific the metal sudden mates even ethel is not so great anymore but all sorts of metal of a button said treated as does a card substituted or old substituted and very very low catalyst loadings i don't have to enforce.
size this is unprecedented not even the very best child was as it could handle some of the substance combination this is like a new maturity as other ricky for which no other catalyst was even available this is a really we expanded sort of the deals other world with this kind of cattle assisted the id pies as a sort now i would say. this is a new and general approach to asymmetric was as it can tell business but before finishing let me tell you just one edition aspect of of this catalyst class which you might find interesting and that is in need to die for streaming dates id pie catalyst by the way were currently of commercialising them very strong as its. and this is a peak a scale that we like to use of my laboratories to see tonight try scare it makes a lot of sense of correlates with we activity in organic solvents that we that we see and just for comparison i have a few a car as it's here and then you can see try for a sikh acid twelve point six trip to a ritual phosphoric acid catalyst for my labrador thirty. it's a slightly less acidic the i.d.p. catalyst a slightly more siddig so this is kind of the to fable ballpark the cyclists are again one thousand times more acidic than the i.d.p. said this is where news as it can tell us a starts and this is as a city has partially and so forth as it and the id pike at least come in this zone. here where you don't even have a lot of of commonly used a car brands that acids and the piquet of this fellow substituted i'd pikas four point five and date when you start decorating these callous with flu in substitutions this was the limit of all measurement capabilities in stone yet with evil i talk and he said this is like as a civic his trip from it.
so you can envision these catalyst as like traffic as it or triplet made in a cairo cage and there were behaved the bench stable and we could keep them at were at room temperature for months now eleven tory in very very powerful brand said asad in a building transformations once again for which no other solution existed for example had audiences.
the reactions to plus for cycling visions not off cry oxalate with the danny chest the dying ok that's was a soft problem in the eighty's but now with any die even and any other hide aromatic or and offended and you can make sense molecules that are made by b.s. after telling show you a little bit how how far this chemistry as has moved forward.
now by chemicals from ba is engaged in these asymmetric catalytic four plus to cycling destruction of the very broad scope and finally we can also solve what i think is a big grand challenge of organic and talents as and that is the activation of all the fans we cannot protein made simple olefins barrel our cars subsidy. rooted in these hydrox the show high draw ether if occasionally actions in th f. all hirings with very high and to selectively a huge substrates go in this case the the referees actually didn't sleep and they pointed out we should also do an intellectual a variant we somewhat prematurely published this year but it tells you also a weather. this is going you can imagine what my people not doing in my love of her work with one octane and water for example this is kind of the reef to believe we have now and i think my time is up so i cannot speak intensely about the last problem i would like to speak about something and publish the big to pay big debate i would just very briefly mention this to you there was. this observation by saul when stein with that when you start with these and and to pure turpin derivatives and you you subject them to solve all his it's what happens is you get a result make a mixture of product and this has cost the big debate because so when start proposed that there's a sick not be localized breached intermediate with.
there are three center to electron bonds that was unusual in in chemistry and was immediately contested by brown heavily surprisingly also because brown should have been sort of no use at a very familiar to this kind of warning scenario but he said no this is a classic a cat island you have this block them they have on type ressam ization that.
it's happening and then later all are by and i'm very recently crossing in germany by x. ray showed actually wins time was right and these are really non classic a couple carry on but when steins observation that you start within a new pew material and generate arrested made was of course interesting to us and the question then was can we reverse this can we.
maybe take a mixture of ice immersed subject them to it to solve all is his have a nuclear five coming in now and with account controlled by the car can try and generate enough to pure materials sort of a nun to converge in transformation and indeed about a patsy and and got great support my laboratory after eight years of really tough for. this experiment was actually suggested by peter china to us i should also give him some credit here found that when you start now within a job market pew material subjected to this free to craft conditions with an id pike at least you get the this xo i summer ninety six to three point five yard so you could see just a little loss of corona to hear but the beauty is if you takes the.
ressam made you get the same in ensure selectivity in this and still high conversion and if even if you take the ante part of this ice summer you get the same product with the same manager selectivity strongly suggesting this sort of well on tresco couple counted immediate allied with that i would like to stop i don't know why this is black.
i would like to thank my heroes of my talk and fogerty this picture got lost i sent this by e-mail but they all here beautiful chemists from all over the world very much evaded brilliant scientist i would like to thank all of them this is a chore action and money are fundamentally that you can see in for a glider the the initial heroes funding agencies you. noticed all we've moved from pharma to chemistry which is exciting and these are companies but also of i would like to think the funding agency the used in research concert and of cause i'm very very privileged in the uk banks packs blank society to be able to do it really what i like to do until i retire this is.
very very exciting and a few honored to be part of this the clip thank you very much for your kind of tension and patients.
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