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24.04.18 Seemingly Trivial Functional Group Transformation

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Automatisierte Medienanalyse

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welcome to part 5 off the lecturer of all about competing reactions subject of today a seemingly trivial functional group transformations while in densely functionalized molecules rather often you have a problem with all of firm on competing reactions for instance this then and oxidation you have in this molecule what at least 3 positions which could be easy the oxidized the elder height the nitrogen could be transformed to monoxide and of course an olefin you could also oxidized to oxide or to a dialed and so on in this case it was too soon for those started to appear in the Paul Greco's group this this doctoral student William A. Carroll Floyd was performed or pursue will be finished in 1992 to and published in 1993 well to last steps the gist oxidizing this al diet functionally teams 1st of all oxidizing 2nd key and S. tariffication of to get those target product to natural product and its name is pseudo Tabas owning while they couldn't go for really harsh forcing oxidizing conditions because of those competing reactions but after a all the al the height usually is very easy to be oxidized unfortunately not in this case it just didn't work uptake normally be could imagine steric reasons yeah electronic reasons 1 main reason should be electronica here because such that conjugated to the hired his all because of the stabilization through conjugation is more reluctant for being on oxidized and what you can see that as the land VN unit goes form white a kind of cell for nitrogen would be directly attached of a covenant group it would be a former might and this was this conjugated double Lucas so it didn't work pretty should walls of all meant to be the final steps of the BEH DEC users of William Carroll and you pursue me said dont it doesn't work you and then he went for 1 of eternity he said all I should get rid of that carbon my group get rid of the Benson Group and put on the ester functionality in 1 step and the decay finished that's and for those past set but the following reaction conditions 1st to normal C. at 100 degrees of course you have to pressurize the flounce 2nd king treatment the neutral aluminum oxide on isolated the intermediary product the next stage this 81 per cent YouTube and as the 3rd step while for certain using I will provide the name down at the lithium all 4 prime dying tension worry new child by senate th out 87 per cent you'd what they isolated duty was the structure we talked about as indeed he get rid of a benzyl group and that from your functionality Christians how does that work actually these reaction conditions just H. C. L. 110 trend 2 degrees of the reaction conditions for that D. cobble mutilation getting rid of the Allied functionality a neutral aluminum oxide this just treating purification neutralization since you have been been found highly acidic environment and of course this tool basic highly basic centers you know mean and that 1 you have to neutralize so OK this is 1st exercise after dating peace trying to figure out the mechanism how old back bond here is cleaved and the full moon group this exchange against the hydrogen mechanistically under these reaction conditions specific try
so let's try to find the solution together but 1st of all he should assess followed this reaction since as explained this doesn't work cell how OK that said that a partial structure again the problem we have to solve is how can all the ball into C-C bond cleavage here take place the presence of HCl and want to find the mechanism although there are 2 ways to solve the problem has Avila do you think about where is that structure protonated on the other hand we could also think about 2 if the would start the this molecule and want to introduce the full moon group how would the formulation mechanistic could the work and since all of those steps presumably optics librium reactions than if you make a mechanism for the formulation of this compound and read it back backwards than we have the mechanism of the deconvolution so what do we have here as I said before this is the the newly grows carboxylic MIT and carboxylic alliance in thick Valerian prefer emotionally protonated at the cover not oxygen science is that you have that nice conjugated system the cat ionic charge is stabilized by the Miss America system so k and that's put on the the true arrow out since it's an extended RAM chloride an iron
Thailand these numeric structures OK let's put on just 1 this was well the clue alright and iron is the nucleophile present in close proximity had been excluded Briand every now and then on the crew alright who be attached here and in England in this form the next step we are still in strongly acidic solution HCl temperature once again H. C. L. so now we have here this I mean common as of strongly basic position here it is preferentially protonated so not to forget the clue alright counter an iron know also
could say part maybe this is protonated here archaic and then we get essentially to the same structure but here known Noll's nicely this is this Union can find this electron deficient here this those electron rich on the fragmentation could take place like Lech so that said have you have full mood chloride and in principle adding full moon chloride to and even and means in the presence of HCl pass from kind of Friedel-Crafts catalysts his is of Friedel-Crafts acylation centrally you could go through that mechanism in this direction and to here actually not of HCl but of aluminum chloride so aluminum chloride H. C. L. cabinet on oxide that this mixture of reactive electron-rich parametric systems that and that to this the gut among cough formulation former relational reaction and Friedel-Crafts catalysts HCl and carbon monoxide on the high pressure this there's the industrial we to produce GPU grows our diets the avoid that in the latter since you don't want to set up a reaction with HCl mom and carbon-monoxide bombed button pressurized that it's much easier to do of food smile formulation fits my opt formulation just a further force Foxy crow right and so on has and FTNS and force for oxychloride so the problem is this reagent at this acid chloride of formic acid but you can't buy that this is rob lot sensitive and decomposes already at minus 40 degrees repetition 1st the test being proven that they had it in flask in solution in the by the famous Professor stops and Heidelberg published in 1963 in under onto the 1st simple tied to form you chloride that was the title of this paper and how they did it therefore and adds to of it was known about on the H C L those those react giving committed sodium chloride discrepant which crystallizes out plus the acid chlorides this was already known of various substituents and they tried it if a hydrogen here in chloroform solution and when keeping that and doing the reaction add minus 60 degrees keeping about for few hours at minus 60 degrees than than adding methanol then another the form 8 formant time that it warm up to minus 40 degrees and then adding methanol almost no ester formation was a scene that means the minus 40 degrees already decrepit decomposition of that into H C L and covered 1 so plot back to he calls and Caro's symphysis offered the root tab mean the next step that you treatment all right the Stewart Benson made it the bend sedated and then sedated molecule the this reagent what normally bends you protecting groups
you are get rid of them had the further Palladio hydrogen on cockle cockle and flung hydrogen that of pressure well the problem you would have there was additional olefins that Châu should be hydrogen it under these conditions 7 this of reducing agent that's which there's 2 full suitable also for that deepens relations 87 per cent you'd is good the next exercise please try to figure out the structure of a compound so that deep-tissue tissue brew trial by from light 1st of all we biphenyl and in fall for Prime if potentially will groups and this should be then an iron where the lithium counted cat on iron and this means we have the radical and pine OK you could draw rose pies systems Dr. Ch throughout badge sometimes you see that so the and ionic charge and radical is is not localized at a certain position on this there's pomp ball follow for activation very similar to hold that system take Naftalin and so doing and th to move around handles a green color of 2 years all of radical and iron off enough to and the bit it behaves fly go solvated electrons very nice reducing agent quality of following we talked about that in the lecture of structural metric strip fumitory Gunnel italics for instance 1 could use that these as reducing agents all of producing the weaker metals having that in solution and having some sold solubilized source of some metals reducing that in solution and then you have 4 or find small particles of the metal hide the active OK the next example for this seemingly trivial functional group transformation we have in this molecule here it's the ball that olefin just hydrogen nation or better reductions have double bond group fat undertook that's and fuses of course try it the normal high pressure hydrogen nation the palladium 1 car cold maybe platinum oxide also it didn't work no sign of that reduced should be staring at reasons calls such Octane octal cycle it is not flat and then you have in addition some knowledge also side chains and indeed if you imagine but the usual hydrogenation palladium-catalyzed hodoud nation is had to Regina's reaction and the reactor center has to come close to about surface could be a problem however there are some interesting my faults there's farm very small hydrogen transfer reagents but actually it should not be that sensitive bald steric hindrance on day all the most prominent of that this be d die in light and that's it indeed as the
equilibrium slow transformation from the trends die in mind Cooper Zuse of the cis 1 those who want but nicely transfers that's hydrogens to olefins and other kinds the truth transferred wall forming molecular nitrogen that this this quiet this reagent is quite easy produced consider the motion you don't want to have that in gram quantities pure please don't want that but you can produce that generate that in situ the amazing if you start from had isn't having oxygen respective leeches air copper sulfate then half a mole page to hold their power NIESR on to practical then organic syntheses the ch ara very nice to you worked all at in detail and all very safe and easy to follow from organic syntheses this the example of hydrogen 18 this macrocycle very referred to trans olefins and 1 cis olefin and 2nd selectively have a nice you'd the trans olefins are hydrogen it'd be faster compared to the cis 1 and this could be isolated the well 1 example that was tried in my group a couple of years ago OF the Union with this region and you die they might there's this molecule open for but since hydrogen nation had this olefin but all 5 Our groups the those from proxy groups on the same side of a cycle contain brain but you can imagine that this is then sterically really overcrowded and to be made some my calculations that then the Mean 18 hydrogen going back roads it is I'm exergonic so and therefore the do die out it might Our reduction didn't work in this case not so surprisingly but it the surprisingly it also didn't broke here in this case so how did that group then manage to synthesize that molecule well how they took the open chain component hydrogenated batch the normal conditions just 1 atmosphere pressure hydrogen 10 per cent palladium on got cold got nicely the hydrogenated product photo of calls them facing the problem all of having to do actualization to a medium-sized rings this is always the problem indeed need
special a reaction conditions optimizing that aren't and to of conditions there were using Borland's to reduce the di sulfide no died died to reduce di sulfide this structure therefore 1 equivalent of try for a new of the and in this case if sorry the
mixed file you'll and hydraulic is produced plus try centers of phosphine oxides the and now
this has to be activated as the leaving group and this activation those achieved by treating this with a sulfur and to a Silicon so the that show from oral borate then totally insane reflux temperature and I all a unit of 70 3 per cent for the 8 members the brain structural but what OK I think this is enough for today we go on to moral God of problems with this deRiel chemistry thanks for listening to you to more often the
Single electron transfer
Transformation <Genetik>
Orlistat
Kohlenstofffaser
Zusatzstoff
Stickstoff
Werkzeugstahl
Geröll
Chemische Struktur
Menschenversuch
Reaktionsmechanismus
Säure
Chemische Bindung
Alkoholgehalt
Benzylierung
Molekül
Funktionelle Gruppe
Biomolekül
Konjugate
Zelle
Neutralisation <Chemie>
Hydrierung
Reaktionsführung
Oxidschicht
Gangart <Erzlagerstätte>
Verstümmelung
Fluoralkene
Energiearmes Lebensmittel
Radioaktiver Stoff
Ester
Aufbereitung
Oxide
Bukett <Wein>
Thermoformen
Lithium
Krankheit
Abschrecken
Tonerde
Chloride
Bukett <Wein>
Lösung
Rückfaltung
Graukäse
Chemische Struktur
Eisenherstellung
Formulierung <Technische Chemie>
Reaktionsmechanismus
Körpertemperatur
Chemische Bindung
Spaltfläche
Säure
Funktionelle Gruppe
Systemische Therapie <Pharmakologie>
Carboxylierung
Konjugate
Zelle
Chlorwasserstoff
Gangart <Erzlagerstätte>
Katalase
Legieren
Bukett <Wein>
Thermoformen
Colamin
Sauerstoffverbindungen
Metallatom
Natriumchlorid
Verrottung
Fettsäuremethylester
Doppelbindung
Sterische Hinderung
Reaktionsmechanismus
Säure
Oberflächenchemie
Alkoholgehalt
Molekül
Terminations-Codon
Solvatisiertes Elektron
Strippen
Elektron <Legierung>
Reaktionsführung
Aluminiumchlorid
Reaktivität
Chloridion
Weinkrankheit
Ester
Fremdstoff
Thermoformen
Mischen
Octane
Krankheit
Interkristalline Korrosion
Chloride
Brauwissenschaft
Transformation <Genetik>
Chloroform
Verteilungschromatographie
Druckausgleich
Klinisches Experiment
Chemische Verbindungen
Lösung
Landwirtschaft
Chemische Struktur
Wasserfall
Eisenherstellung
Reduktionsmittel
Formulierung <Technische Chemie>
Nanopartikel
Getränkedose
Elektronentransfer
Koch
Seitenkette
Funktionelle Gruppe
Substituent
Systemische Therapie <Pharmakologie>
Platin
Hydrierung
Aktivität <Konzentration>
Chemischer Reaktor
Setzen <Verfahrenstechnik>
Quellgebiet
Gangart <Erzlagerstätte>
Ameisensäure
Acylgruppe
Fluoralkene
Kohlenmonoxid
Energiearmes Lebensmittel
Katalase
Methanol
Oxide
Lithium
Farbenindustrie
Palladium
Kupfer
Hydrierung
Reaktionsführung
Arachidonsäure
Potenz <Homöopathie>
Carcinoma in situ
Transformation <Genetik>
Makrocyclische Verbindungen
Fluoralkene
Stickstoff
Konkrement <Innere Medizin>
Azokupplung
Chemische Struktur
Fed-batch-Verfahren
Reduktionsmittel
Bewegung
Photosynthese
Krankheit
Kettenlänge <Makromolekül>
Elektronentransfer
Molekül
Funktionelle Gruppe
Palladium
Sauerstoffverbindungen
Chemische Forschung
Chemische Struktur
Mischanlage
Aktivität <Konzentration>
Körpertemperatur
Silicone
Funktionelle Gruppe
Sulfur
Phosphin

Metadaten

Formale Metadaten

Titel 24.04.18 Seemingly Trivial Functional Group Transformation
Serientitel Lecture Competing Reactions
Teil 5
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 10.5446/38588
Herausgeber Ruhr-Universität Bochum (RUB), Fakultät für Chemie und Biochemie
Erscheinungsjahr 2018
Sprache Englisch

Inhaltliche Metadaten

Fachgebiet Chemie
Abstract Decarbonylation, Formyl Chloride, Diimide Reduction

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