Dichlorocarbene reaction with amides

Amides [41,44], thioamides [41 ] and amidines [45] are converted into nitriles by the reaction with dichlorocarbenes generated by Makosza s procedure (Table 7.16). Under similar conditions, monosubstituted and A.A-disubstituted ureas are converted into cyanamides (Table 7.17) JV,(V -disubstituted ureas produce carbodi-imides in low yield [41,46,47]. /V-Carbamoyl derivatives of dibenzo[/ /]diazepines and the related 10, l l-oxirane derivatives are converted into the corresponding... 

The reaction of dichlorocarbene with A, A -diethyl-3-methyl-2-butenamine (100) produced A V-diethyl-4-methyl-2-pentenamide (103) as the major product.51 The formation of this material was attributed to the generation of ammonium ylide 101 followed by a [l,2]-allylic shift to give intermediate 102 which then hydrolyzed during workup to produce amide 103. No product resulting from a [2,3]-sigmatropic rearrangement of ylide 101 was detected in the crude reaction mixture. 

Thus, investigation of the reaction of dichlorocarbene with 2-phenylsulfonyl-2-aza-bicyclo[3.2.1]octa-3,6-diene showed that this carbene primarily undergoes addition to the en-amide double bond, and that the stereochemistry of the product, e.g. 7-11, depends on the substituent at... 

The reactions of dichlorocarbene with a variety of olefinic and acetylenic substrates have been discussed in Chap. 2. We wish now to turn our attention to the reactions of this species with a number of other substrates which either are non-olefmic or contain double bonds which do not constitute the major reactive function. The substrates considered here are alcohols, imines, amines, amides, thioethers, and hydrocarbons. With the exception of the latter, all of these species appear to react by initial coordination of the electrophilic carbene with a Lewis basic site. Subsequent reactions attributable to differences in the basic function or involvement with other reactive sites lead to differences in the chemistry of each substrate, and each is therefore considered separately. 

The reaction of dichlorocarbene with primary amides, amidines, thioamides, and aldoximes all yield the corresponding nitriles. N,N-Disubstituted ureas likewise yield the corresponding N,N-disubstituted amine nitrile. This reaction amounts to a dehydration in the case of primary amides, aldoximes, and N,N-disubstituted ureas the elements of hydrogen sulfide are lost from thioamides, and HCN from amidines. 

The reaction of iminium salts such as 66 with salts of trichloroacetic acid has been shown to yield amides such as 84 on hydrolysis 126). It was suggested that the reaction proceeds by addition of dichlorocarbene to give an aziridinium intermediate (85), which was opened by trichloroacetate followed by hydrolysis to give the observed products 126). The observed products from the reaction can be accounted for by formation of CCI3,... 

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See also in sourсe #XX -- [ ]

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