Rhodium-catalyzed phenylation of N-arylsulfonyl aldimines with sodium tetraphenylborate or trimethyl(phenyl)stannane

The rhodium-catalyzed addition reactions of trimethyl(phenyl)stannane and sodium tetraphenylborate to N-phenylsulfonyl aldimines RCH=NSO2Ph (R = alkyl and aryl) provided R(Ph)CHNHSO2Ph in high yields. A cationic and free phosphine complex [Rh(cod)(MeCN)(2)]BF4 was found to be an efficient catalyst for the addition of PhSnMe3, whereas [Rh(cod)(MeCN)(2)]BF4/dppb catalyzed the addition of Ph4BNa to various N-sulfonyl aldimines in dioxane at 90 degrees C. The scope and limitations of the reactions, as well as the effect of varying the reaction conditions, are discussed. (C) 2000 Elsevier Science S.A. All rights reserved.