Alkylation of Rink's amide linker on polystyrene resin: A reductive amination approach to modified amine-linkers for the solid phase synthesis of N-substituted amide derivatives

Reductive amination of aldehydes and ketones using sodium cyanoborohydride and Rink's 4-(2',4'-dimethoxyphenyl-aminomethyl)-phenoxymethyl-linked polystyrene resin [Rink's amine linker on copoly-(styrene-1%-divinylbenzene)](1) 2 affords high yields of linker-bound, N-alkyl amines with excellent chemical selectivity. Subsequent coupling with acid derivatives gave derivatized N-substituted amides in excellent yields after cleavage from the solid-support. (C) 1997 Elsevier Science Ltd.