BETA,BETA'-FUNCTIONALIZED N,N-DIVINYL-N-TRIMETHYLSILYLOXYAMINES VIA SILYLATION OF BETA-SUBSTITUTED ALIPHATIC NITRO-COMPOUNDS - THE INVESTIGATION OF THE MECHANISM OF THE PROCESS USING SELECTIVE TRAPPING REAGENTS

Hitherto unknown N,N-divinyl-N-trimethylsilyloxyamines of the general formula [XC(R)=CH](2)NOSiMe3 (X = CO2Me, CN, 5-methyloxycarbonylisoxaz olin-3 yl; R = H, Me, CH(Me)CO2Me) were obtained with moderate to good yields by silylation of nitro compounds XCH(R)CH2NO2 with N,O-bis(tri methylsilyl)acetamide. The mechanism of this reaction was studied by t he example of silylation of methyl 3-nitropropionate using selective t rapping reagents. Trimethylsilyl ester of the starting aci-nitro compo und and methyl 2-nitroso acrylate were intercepted as consecutive inte rmediates. Thus, the silylation of beta-functionalized nitro compounds could be presented as a convenient route to practically unknown beta- substituted nitroso-alkenes XC(R)=CHNO which behave as active 1,3-hete rodienes towards ethyl vinyl ether used as trapping reagent. (C) 1997 Elsevier Science Ltd.