Allyl system Amides

The tertiary amines 303 and the acid chlorides 304 (X = Cl) initially formed acylammonium salts 305, which underwent a von Braun type degradation by an attack of the nucleophilic chloride ion at the allyl system to give allyl chlorides 306/307 and carboxylic acid amide functions. 

The third mechanism starts with addition of the AT-allylamine 103 to the cumulated acceptor system of an allene carbonester 108 (Acc=CHC02Me) to form an intermediate iV-allyl ammonium amide enolate 109 (allene carbonester Claisen rearrangement). The anion stabilizing group is exclusively placed... 

The palladium catalysed substitution reaction of allylic systems has also been utilised in the formation of five membered rings. Intramolecular nucleophilic attack of the amide nitrogen atom on the allylpalladium complex formed in the oxidative addition of the allyl acetate moiety on the catalyst led to the formation of the five membered ring (3.63.). In the presence of a copper(II) salt the intermediate pyrroline derivative oxidized to pyrrole.80... 

Little is known about transition metal catalyzed epoxidation of simple allylic amides. The easily removable trichloroacetyl group is suitable as /V-substituent in the molybdenum-catalyzed epoxidation of (Z)-allylic systems with rm-butyl hydroperoxide, which produces the. sv -com-pound with appreciable selectivity21. 

One way in which allyl lithiums can be made by direct deprotonation is when the allyl system has a substituent not at one end but in the middle, and when the substituent is of the kind we used in chapter 7 for directing aromatic lithiation. The simplest examples are amides such as 48 that react with two molecules of BuLi to give a dilithium derivative11 often represented as an allyl complex 50b though it is probably a lithium o-complex 50a. These amide derivatives react with aldehydes and ketones to give lactones,12 e.g. 53 via adducts such as 52. 

A similar mechanism was proposed by Lindow et al. (II) for the biphenyl system. However, biphenyl provides much less dialkylation (Table I) than either naphthalene or anthracene under normal quenching conditions. Perhaps the amide deprotonation is slower in this case because of the reduced acidity of the doubly allylic system (i.e., 1,4-dihydrobiphenyl) in comparison with the allylic-benzylic or doubly benzylic systems (i.e., dihydronaphthalene or dihydroanthracene, respectively). 

The bottom face of the allylic system R is hindered by the amide group... 

In studies not yet published (66), the A/-acyl-oxazolidine-2-one 62 has been found to exhibit exceptionally high levels of (Z)-enolization stereoselection with either amide bases (LDA, THF, -78°C) or boryl triflates [(n-C4H9)2BOTf, CH2CI2, -78°C] in the presence of diiso-propylethylamine (DPEA). Upon aldol condensation, the enolates 63a and 63b afford the aldolates 64 (Scheme 11), which react readily with nucleophiles at the carbonyl function (Table 22). As discussed earlier, the large preference for (Z)-enolate formation in this system can be attributed to allylic strain considerations (37)... 

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