Reactions of carboxamides with vinylsilanes under oxidative conditions

A B S T R A C T The reactions of acetamide, benzamide and trifluoroacetamide with trimethyl(vinyl)-, triphenyl(vinyl)-, dimethyl(divinyl)-and diphenyl(divinyl)silanes in the presence of oxidants (t-BuOCl + NaI) or N-bromosuccinimide (NBS) in acetonitrile have been studied. Generally, all unsaturated silanes react with trifluoroacetamide to give the products of haloamidation, whereas with acetamide or benzamide the re -action affords mainly the products of halogenation. The formation of bromoamination product containing the MeCONH moiety in the NBS-induced reaction of trimethylvinylsilane with all studied amides clearly indicates that the reaction proceeds with the solvent (MeCN) interception rather than by the attack of the amide nucleophile. The product of bromoamidation from the NBS-promoted reaction undergoes a base-induced cyclization to the corresponding 1,3-oxazoline in quantitative yield. (c) 2022 Elsevier B.V. All rights reserved.