REACTION OF THE GROUP-15 METALLOID AMIDES WITH DIKETENE BY 1,4-ADDITION MODE

(Dialkylamino)dimethylarsines, (dimethylamino)diphenylarsine, and (dialkylamino)dimethylstibines react with diketene to yield N,N-dialkyl-4-dimethylarsino-3-oxobutanamides, N,N-dimethyl-4-diphenylarsino-3-oxobutanamide, and N,N-dialkyl-4-dimethylstibino-3-oxobutanamides, respectively. These group 15 metalloid-substituted 3-oxobutanamides exist as keto-enol tautomers and the keto isomers are predominant in solution or in neat state. This reaction is the first example of 1,4-addition of heteroatom-nitrogen bond to diketene.