Solid-phase synthesis of 4-methylene pyrrolidines and allylic amines using palladium-activated allylic linkers.
The solid-phase synthesis of 4-methylene pyrrolidines and allylic amines has been achieved using palladium-catalysed nucleophilic cleavage of allylic linkages. Six pyrrolidines were synthesised in five steps from a carboxyethyl resin 20, where the key transformations included a Lewis-acid promoted imino-Sakurai type reaction and reductive alkylation prior to the final palladium-catalysed cyclisation cleavage of the allylic carboxylate linkage. Allylic carboxylate resin 22 was also shown to undergo "traceless" cleavage using various hydride sources in the presence of catalytic palladium. A more robust allylic ether linkage was also investigated. Starting from a phenol resin 36, a number of 3-aryl-allylamines were prepared using a palladium-catalysed nucleophilic cleavage reaction.
Brown
Richard C D
RC
Department of Chemistry, University of Southampton, Highfield, Southampton, UK S017 1BJ. rcb1@soton.ac.uk
Fisher
Martyn L
ML
Brown
Lynda J
LJ