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10.04.18 Competing Reactions

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so coming to the lecturer upon you competing reactions back when we all synthesizing hardened compound you of course are always aiming for the high you to this bell as the high purity both could be a problem but most often by height year to this problem so achieving a high unit wall for achieving IUD can optimize can try to optimize reaction conditions to optimize the working up procedure usually you will build the some of fewer units during working up it's clear even a simple of column chromatography usually you you you lose the ball 10 % of few of material on the wall a really good buy idea this to avoid side reactions the competing reactions and those competing reactions having a closer look on what is going on within your reaction flask this this is the main subject of this lecture of the semester lecture it is important of calls in academic labs but even more important in maps in industry just of course to avoid vase and to optimize your your your industrial process so there is a lecture room will be accompanied by a the book of an industrial medicine chemist Saragossa do of alter the the title at this site reactions in organic synthesis and of calls it I will put an end to his lecture on you more information from recent original papers connected to this this subject so let us 1st have a look on the lessons we have learned in the preceding semester but balls the lecture in designing organic synthesis reaches true synthesis who a few has to listen to of that kind of of lecture last semester or maybe a couple of years ago and at least some of you know OK so but the plan and a good plan for the synthesis of a target compound tries to mini mize the steps
every single step usually news material archaic so minimizing the steps because 100 % selectivity is very seldom maybe never reached at all so actually there are only the very few really reliable good reactions in organic synthesis well at least of the famous chemist Berry shop was was claiming this information and he wrote them rather important optical which is interesting to read and you should look that up so you from Sharpless the optical click chemistry actually the name click chemistry was introduced this this article in I'm going to chemistry click chemistry divers chemical function from you know good reactions so what our these few reactions shop this would be to classify as good so the examples the 1st of all Psychlo addition reactions for instance well the assault of cause you all know what you saw the reaction for instance Eitel painted I mean and such an acrylic aster at lower temperature usually and selective would give those by psychic products or of being the 1 3 dipolar cycloaddition it was sometimes called yes good reaction named after Professor this going from Nick University and 1 prominent example is of calls the food 1st step this in the boson Nola's adding those zone to an olefin but nowadays the reaction to his skin reaction that has been most made use of is the following and the kind plows than eighties I very often the 4 cop on mediated mediated 2 cycloaddition giving rise to such that triazole salts
evokes an excellent unit and nowadays some people forget the bollard once 3 dipolar cycloaddition this can reaction and call this process the click reactions a BIG this article about click chemistry mate this reaction famous again and more and more people may noticed that if they have an all kind of something on the and an eighties I'd have something else on there's very reliable you could put those 2 components together and having the poll violent whatever in between cooking and it almost doesn't matter what you have on 1 side and on the other hand on the other side you can you can connect that by that click of clicked reaction or better go forward on this can type of reaction not biologists and biochemists make use of that type of process so Psychlo editions they than in addition reactions see seeing multiple bonds double or triple bonds for instance in case of olefins electron-rich olefins the app oxidation and the dihydroxylation I hope you remember that the as the metric cis dihydroxylation was also invented by Barry Sharpless who won the nobel prize for all this of a highly useful on synthetic procedure that look at your FedEx substitution abbreviated free of the status the actual especially ad AP oxide that epoxides his bald in Sharpless list of those few good reactions goggle-eyed chemistry especially non Algol Coburn chemistry for instance condensation reaction off the mountain I mean and now the heart you re of formation lots of examples that the easy 1 would be this my cyanate plus I mean also indirectly via a reaction that proceeds said nicely usually the very very
high unit the that's that more examples here and next ization while an example heating up such a a 1 who got his substituted on carboxylic acid heating it up and a bit of of catalytic as at lot actually you already have the there it's a carboxylic acid on the wall the readily undergo a condensation the action to form the lactam ring and at our reading formation well maybe you should think about various had to reading formations so you will know all that's the 1
example this condensation reaction for the formation of a few run so the spurs the list that has been originally on shown in that seminal publications what we should ask why our rules reactions so reliable before high yields obviously they are highly selective because of a high selectivity you can achieve I used and this has of course something to do with the energetics off frozen things so important is the thermodynamic driving force the emotional in battle bigger than the 20 K Calif come on and this this reached there there's some that extra energy profit this in the reaction compared to tools other normal processes in the range of 50 to 60 % you so us I think the bulge what this the extra energy profit in those examples have a look at the do folders reaction a concerted process their knowledge the single bond is formed but true C-C bonds formant simultaneously so 1 conjugated double bond is broken but in this at the same time 1 you double double bond is formed and to see see what's but only 1 bond is formed to gains more energy I can't here this 1 3 dipolar cycloaddition process while in principle the same as the case time covalent bonds from this nitrogen to that nitrogen tree and the is formed but in this at the same time this profits from parameterization vistas hatchery are the same as here at every information profiting from aromatization the next 1 so epoxidation and dihydroxylation to see bonds formed simultaneously actually the dihydroxylation Call proceeds usually also virus clue addition reaction in the 1st step if you have a closer look to Mecham's then cover like chemistry OK but well at least profits and also from entropy no no know OK the entropy profit the f you have here the within the lectern ization cell kinetic it's easy because this can intron monocolor pro-science I'm done all from 1 molecule 2 molecules formed and entropy goes up so on the higher the temperature of on fiery entropy gain is also profit in the net energy I think so this explanation why the mean formation that is so good 1 of I must admit I care don't have the precise answers hit but at least this those and equilibrium reaction added the thin vehicle of every an acute librium reaction although we'll be able from traps the water for instance of an stock unveil falls on driving the reaction almost to completion play so will you re formation this reaction clearly profits energetic cozy by the formation of the boom a tour except to cysteine conjugation this also energetically problem no so if in that seminal paper show up brought a nice example
where through the couple of steps although working very well because they are from this list of your good reactions you can follow the all building up of a high complexity but step by step moved very nice unit always around 90 per cent at least more than 80 per so that's ever look at this example from the US cyclohexyl dying and you should all know this is so made by a brooch reduction of benzene that double at oxidation forming this double tap oxide while there here Sharpless didn't give the unit because of you'll get a mixtures of St you you are isomers archaic so the overall unit of this this epoxide regardless Mystere chemistry is also above 80 percent but you have that since 1 and you have the transform all the trans want Israel's major isomer a ball of but under certain reaction conditions you can get this up to close to 50 percent OK this this epoxide there's learning treated the so do you own 80 ZEIT ammonium chloride in water under reflux temperature from there on highly stereoselective this double these this produced live the 90 seven percent unit the next step offering acetylene died carboxylic acid die full pasture for all the this going cycloaddition permanent tool try trials world's formed all the ethyl ester those the brief begin breviate I just eat this step also works the 90 7 CPUs that catalytic amounts in this case is all a stereo coding handle it I mean as the base by ISO PropU f over a million if a remember it correctly Mrs. Calton who unique base not misconstrue peak unique was a famous professor at book so this 1 85 per cent of both the lectern ization product so that could collect ization take place intramolecular S formation lists as students to move forward from that about 1 cleared but this 1 it's from a close OK so there this the place where the aster formation will take place ceremony this year remains unchanged but here this is a newly formed luck tone functionality then last step of the synthesis reported there's
offering this secondary I mean as a nucleophile and again in 85 per cent viewed still 1 the component the the reactor at the the most reactive 2 functionality and to 2 is this what luck chose the scope of began and you know do is it already takes some time to draw that final product due to rob or high complexity so on and then 85 per cent under originally they started to 5 when 0 grams of Vive and could isolate at the and 20 point 2 grams calls that 1 certainly far former biological testing of that highly functionalized molecule so then the there proceedings semester we went through the lecturer designing organic synthesis really true synthesis and 2 that suffer look about the essentials what we have learned there
all the thin reaches synthetic and others the task of the year that the convergent strategy is usually much better than the linear should check strategy so convergent of strategy usually superior to a linear 1 except you can do every single step above 95 per cent and half a synthesis Robert like a few synthesis or something like that of course but generally convergent strategy let us assume you have thank think have those building blocks for all synthesis from 80 to page cell and interviews that he put together and being having than the bobolink bond between C and D you can have and you can't age then sorry putting this building block together with his money on that before the last 1 having gone to bigger building blocks and in the last step Walcott's clear this is our target molecule and and let us assume that every single step Burks there's 1 realistic 80 % need than the convergent synthesis though delivery this product 50 1 % here the determinative pop grace it was putting together a and B the next step plus C next stop plus D. and so on until we finally reached the target molecule the over all you'd it's easy to calculate who would be around only 20 on South this illustrates convergence strategy generally that is superior let's have a look that I Elias and proper easy reach a synthetic analysis she can make acid it's an important intermediate in the biosynthesis of sup aromatic amino acids actually drawn to the blackboard now there's the unnatural monster so it should cubic passage so making use of those though no 1 good reactions the reaches synthetic analysis this is the very true synthesis so be disconnecting strategic bonds strategic bonds along as ch can be easy won't band dis- connecting it the thing it doesn't can experiment there leads to a simpler structure and I don't even go on all OK you have 3 hydroxide groups here getting rid of true of those would be a good idea of simplifying the structure since the cis dihydroxylation is 1 of those good to excellent reactions and those 2 on the same side of ring will clearly should be a good idea true cooperate this reach rule cis dihydroxylation that in mind but the floor while ADD mix as a metric dihydroxylation that is such a mixture you can can already by for instance of all retro hover companies we have thus intermediate OK thinking about this molecule how could be simply 5 and of course good the elimidate now water done we have from much simpler structure water and benzoic acid that's not a good idea of the thing that really true synthesis because you have no idea how true do this reaction selectively script kind so but imagine that this molecule heard the rise from this 1 and let's draw batch somewhat nicer that we have this structure of and all this is a long 1 5 already drawn to the Blackboard there a prey reach road use all the what and then we have a simple starting material we should keep in mind VAD during the various some symphysis the should work with some protective groups otherwise we get into problems for instance from such a structure so water
would be indeed easier read he eliminated and then the out and that's thermodynamic sink when I so how was the synthesis and the other way around actually done so this started indeed form for an and to sum up from unique acid derivatives OK it's put on on the whole that's a bit more complicated on than the the Kiral Lewis acid anuncio selectively the formation office and older product was achieved 67 % while have to use it problem lodged except the excess of the this 1 astonishing sort of 97 per cent Munson excess of callers nicely optimize reaction conditions of an optimized who is possible so the as Starrett Kodi hindered babies the lithium diesel etc. in th f that no temperature minus 78 degrees what will happen the most acidic proton this was will be extracted and that could low temperatures would oxen agent bridge will be opened and then we are in danger of the subsequent elimination will take place that and at least acidifying recruit product so be reformed out called assume out correlate has to be trapped the 4 side to protecting group and this is done by that by adding TVs true float trough late so who protecting group with an additional added base present 206 rooted in nitrogen heterocycle at low temperature and that that sided oxy group sits at the only remaining or yeah the only remaining cows center indeed the the hat 3 Carleson does here we have only 1 doesn't matter because that 1 but since dihydroxylation will take place on the opposite side of the ring and while since they had already VAT deRiel chemical control element and was not necessary to would take 80 makes as emitted you go oxidation mixture containing already the color information is not necessary in we have already color informational molecules so osmium TechWorks it's and as oxidizing agent 0 of degrees the island than the S 2 could be isolated hard realization of the Esther and D. protecting here then produced the finally the end she can make as as have 1 other very important terms you have learnt and V to see there semester was with 2 and 3 truck the so if you remember of those who attended that remember certain remember about such the cyclo hicks seen moiety if you notice the cyclo exceeding moiety the thing you would target molecule you should think about applying the dues all the reaction for the synthesis of this molecule because having this as a partial structure I strongly suggest that you should make this week was emphatic transformation the other around actually using found Piazzolla reaction and even if you don't have that Psychlo exceed just the cycle hexane moiety you could think about within your reach a synthetic analysis and the other thing functionality that you then generates the re this is the really trying all of videos all reactions you can do so because you know the simple and reliable enough to get rid of the double bond simply catalytic Cartesian nation so we have the preceding semester talked about the all of the oxycodone rearrangement cell what is an obstacle arrangement the tears that go prearrangement the and alcohol laid at this position usually a potassium over correlate and already the will 25 degrees but for sure the of 55 degrees that felt free arrangement would take place please remember that normal cope rearrangements take please above 160 do use of so acidifying who and give
rise to this the final product so what about to read from of the UK Puxico prearrangement you notice who are target structure such commodity the delta epsilon unsaturated carbon on that you should take into consideration but this could be formed by an Moxico prearrangement starting from that this but be it might be much simpler to synthesized and lack in this case it it is so rather complicated to have the overview and therefore it makes sense to put in numbers to the position this to help to solve related problems
also in this case 1 could think about having for instance something like that he turned off a chain like that if you don't have a double bond there the same the euro reaches static analysis you could also say well that's introduce the spend then we have a possibility to do that cause you will find the very after maybe protecting that carbon our group to hydrogen at that or making use continuous synthesis of so the the here we have the target molecule of so and the vendor reaches syntactic analysis of this target molecule some chemists all you about the Reed of the oxic goal plea arrangement got the idea that for doing such or applying in their oxic prearrangement they had to introduce both in addition the carbon of functionality and an olefin to make it easier to find the solution Ivan Châu at which position they decided to do that here the olefins they become a so actually this falls down in the group of new pocket the most famous natural product synthesis group color made extensive use of optical pre arrangements so the novelist
exercise please try to figure out how could you make use of an obstacle prearrangement for synthesizing destroyer psychic system I know it's easier for those who already went through the lecture on reach synthetic analysis but nevertheless it's it's a nice exercise but that fits in said makes sense to have those numbers here because the solve problem that it really helps drawing by numbers or enjoyment modern knocked silent so let's try at here where do we have the position 1 so please keep in mind you noticed we have a carbon our group here and the olefin there on the wall position 1 of those the cover called we have no other choice 1 2 3 4 5 6 this 1 possibility 1 2 3 4 5 6 of this the 2nd possibility for each rescinded it and is both our right but no 1 will lead us to open much simpler structure and the other way this 1 through including complicated structure so let's follow the therefore this route and some of you will have followed that route that could then compare and the others who did this route could also make at home this 1 and and compare so 1 2 3 full of 5 6 so here we have the redrawing of the oxic cope prearrangement so let's draw all that structure once again and just following the numbers by adding something will wiping something node so once again 1 2 3 4 5 6 and now we have always to compare here in the the division positions 1 6 no bonds but here we have a bond so in reaches synthetic analysis we have to form the bond between 1 and 6 and form the no age group here but let us start with the old age group here so from common I'm true or H the between 5 and 6 the bondage this bond those who migrate to the position 4 and 5 between 4 and 5 here we would have the double bond don't worry about that 5 bonded call them you have to eliminate Nobel between 3 and 4 this bond is I got we have to form a single bond between the position 1 and 6 and we have to form the double bond between 2 and 3 and P is P is the problem that method OK that's wiped out the muscle groups just what they don't have to look can be introduced that selectively and OK so let us translate that called if you would put that up into common of false view computer model here and dropped them and push the optimized but what will happen by psychic system would be drawn so where do we have the muffled groups he and there are lot so and therefore maybe but disunity would talk so I and you in a dead then this should be being transformed that me this product and from here to there and you have to solve a problem how to add the muffler group hawker area facility problem but hopefully we find an appropriate to selectively deprotonated here and then just still not fully think so now all the next step should be thinking disconnect here plus some organic lithium compound compassion her thinking about how to
synthesize the molecule like that actually in the preceding semester we had a similar problem to be discussed 1 could could think about making it used all or reaction the half the cycle exceeding moiety but within the reach a synthetic analysis this would mean and we should make use of this die the in class that keep clean bird unfortunately the what key tedious just don't undergo 4 plus 2 cycloaddition reactions but true plus 2 cycloaddition reaction and can solve the problem if 1 changes to that 1 the paper they can use called a reaction on that and have an alpha crural Sino- compound and exchanging the chloride and the gains in wage group and linear for cyano hydrogen on the well if you had was that in the key to on line corn rather complicated and while in addition 1 should think about the OK it it it should have the right to read you read you selectivity for we cycloaddition however the Paquette group all Khot BI DO YOU words another protocol what another route so very happy dear that let's change oxidation state that various positions let's go back to the alchohol functionality here having an out cold here whatever studio chemistry and such the bonked could have been formed this is the idea how do the dishes but of course you don't need the Cabinet group while the K changed oxidation state here like back OK that ritual all needs to this color what if you have that all core functionality here could is protected regions that want to eliminate tear having their the olefin deep protect and van oxidize there are case this would be a synthesis how could you get something like that knowledge here while whispers a classic I do having and oolitic functionality at this position and from here to there it's than those analysis how could you introduce that other groups there while should be something related to some kind of my quote addition process and the best me here there's the Sakurai the reaction maybe you have heard about large Sakurai reaction it is and although the sign Lane on that as a catalyst titanium Tuchel chloride or of or of movies acid which activates which coordinates to recover my group activates the electoral felicity of this position than this this long nucleophilic center and reaction undergoes before the elimination here so master steps how could be synthesized while an Alpha Beta's unsaturated keto on 1 should always think of calls the Boucher and I'll go the condensation of so and finishing the reaches synthetic analysis while disconnecting here for the Michael type prose since then you have that and here you would have an alphabet unsaturated ke tone OK that you would notice that different aldehyde it wouldn't work very well because the other died has the highest all through the city and at the same time wise common-law activity so you wouldn't choose the elder hired as really look you files so what you need this the soon from like that 2 major reactivity here and the synthesis equivalent and most of these could the antinomian bopper so I hope this our examples from retrosynthetic analysis had to those to remember what we have learned in the preceding semester and motivate others sooner or later that take a close in because syntactic analysis thanks for listening see you to moral and the same lecture all but already at 3 PM what search the
Pharmazeutische Chemie
Präparative Chemie
Biologisches Lebensmittel
Säulenchromatographie
Reaktionsführung
Gangart <Erzlagerstätte>
Chemische Verbindungen
Azokupplung
Replikationsursprung
Menschenversuch
Krankheit
Chemischer Prozess
Aktives Zentrum
Biosynthese
Chemische Forschung
Stereoselektivität
Carcinoma in situ
Kochsalz
Fettsäuremethylester
Dipol <1,3->
Fremdstoff
Additionsreaktion
Mannose
Körpertemperatur
Nobelium
Atombindung
Funktionelle Gruppe
Dreifachbindung
Citronensäurezyklus
Biosynthese
Biologisches Lebensmittel
Click-Chemie
Acetylsalicylsäure
Reaktionsführung
Oxidschicht
Permakultur
Setzen <Verfahrenstechnik>
Gangart <Erzlagerstätte>
Fluoralkene
Fremdstoff
Cycloaddition
Oxide
Bukett <Wein>
Harnstoff
Kondensationsreaktion
Pharmazie
Feinkost
Chemische Bindung
Chemischer Prozess
Lactame
Setzen <Verfahrenstechnik>
Chromosomenkondensation
Carbonsäuren
Stereoselektivität
Fettsäuremethylester
Wasser
Stickstoff
Doppelbindung
Falle <Kohlenwasserstofflagerstätte>
Chemische Bindung
Durchfluss
Molekül
Intron
Epoxide
Zelle
Acetylsalicylsäure
Reaktionsführung
Oxidschicht
Chemieingenieurin
Bildungsentropie
Base
Isomer
Gekochter Schinken
Cycloaddition
Fließgrenze
Mischen
Krankheit
Benzolring
Multiple chemical sensitivity
Aromatizität
Chemische Forschung
Enzymkinetik
Dipol <1,3->
Dauerwelle
Epoxidation
Klinisches Experiment
Werkzeugstahl
Stockfisch
Additionsreaktion
Reduktionsmittel
Körpertemperatur
Sammler <Technik>
Cyclohexan
Atombindung
Funktionelle Gruppe
Ammoniumchlorid
Weibliche Tote
Carbonsäuren
Biosynthese
Konjugate
Pasteurisieren
Komplexbildungsreaktion
Setzen <Verfahrenstechnik>
Gangart <Erzlagerstätte>
Essigsäureester
Acetylen
Azokupplung
Oxide
Harnstoff
Kondensationsreaktion
Chemischer Prozess
Homöostase
Mischanlage
Schutzgruppe
Carcinoma in situ
Verschleiß
Hydroxide
Wasser
Benzoesäure
Altern
Chemische Struktur
Fed-batch-Verfahren
Säure
Chemische Bindung
Molekül
f-Element
Funktionelle Gruppe
Terminations-Codon
Biosynthese
Zelle
Reaktionsführung
Komplexbildungsreaktion
Chemischer Reaktor
Gangart <Erzlagerstätte>
Syntheseöl
Säure
Arzneiverordnung
Flüssigkeitsfilm
Mischen
Aminosäuren
Aromatizität
Alkohol
Cope-Umlagerung
Transformation <Genetik>
Trog
Stickstoff
Doppelbindung
Transponierbares Element
Formaldehyd
Oxycodon
Chemische Struktur
Derivatisierung
Körpertemperatur
Säure
Alkoholgehalt
Hexane
Umlagerung
Molekül
Funktionelle Gruppe
Biosynthese
Kalium
Insel
Destillateur
Zelle
Ketone
Reaktionsführung
Oxidschicht
Setzen <Verfahrenstechnik>
Cycloalkane
Tieftemperaturtechnik
Base
Eliminierungsreaktion <alpha->
Osmium
Heterocyclische Verbindungen
Protonierung
Thermoformen
Mischen
Lithium
Farbenindustrie
Krankheit
Biodiesel
Biomolekül
Hydrierung
Kohlenstofffaser
Fettsäuremethylester
Fluoralkene
Lösung
Doppelbindung
Chemische Struktur
Oxygenierung
Sense
Farbenindustrie
Pharmazie
Kettenlänge <Makromolekül>
Molekül
Delta
Funktionelle Gruppe
Biosynthese
Chemische Forschung
Chloride
Stereoselektivität
Vancomycin
Titanchloride
Cope-Umlagerung
Kohlenstofffaser
Alphaspektroskopie
Chemische Verbindungen
Doppelbindung
Cyanidion
Altern
Retrosynthese
Chemische Struktur
Sense
Nobelium
Aldehyde
Chemische Bindung
Säure
Chromosomenkondensation
Allmende
Molekül
Funktionelle Gruppe
Systemische Therapie <Pharmakologie>
Biosynthese
Biologisches Lebensmittel
Hydrierung
Aktivität <Konzentration>
Ketone
Reaktionsführung
Oxidschicht
Reaktivität
Querprofil
Gangart <Erzlagerstätte>
Eliminierungsreaktion <alpha->
Syntheseöl
Fluoralkene
Hydrophobe Wechselwirkung
Oxygenierung
Cycloaddition
Bukett <Wein>
Lithium
Farbenindustrie
Advanced glycosylation end products
Alkohole <tertiär->
Chemischer Prozess

Metadaten

Formale Metadaten

Titel 10.04.18 Competing Reactions
Serientitel Lecture Competing Reactions
Teil 1
Anzahl der Teile 9
Autor Dyker, Gerald
Lizenz CC-Namensnennung 3.0 Deutschland:
Sie dürfen das Werk bzw. den Inhalt zu jedem legalen Zweck nutzen, verändern und in unveränderter oder veränderter Form vervielfältigen, verbreiten und öffentlich zugänglich machen, sofern Sie den Namen des Autors/Rechteinhabers in der von ihm festgelegten Weise nennen.
DOI 10.5446/38584
Herausgeber Ruhr-Universität Bochum (RUB), Fakultät für Chemie und Biochemie
Erscheinungsjahr 2018
Sprache Englisch

Inhaltliche Metadaten

Fachgebiet Chemie
Abstract Click Chemistry, Convergent Strategy, Retron

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