Asymmetric Synthesis of 2-Arylpyrrolidines by Cationic Cyclization
作者:Iain Coldham、Steven Robinson、Carl Baxter
DOI:10.1055/s-0032-1317114
日期:——
amines were prepared by asymmetricdeprotonation of benzylamines using n-BuLi and (–)-sparteine to give chiral organolithiums to which were added prenyl bromide. Removal of the Boc protecting group gave anilines that were found to undergo Bronsted acid catalyzed or iodine-mediated cyclization to give aryl-substituted pyrrolidine heterocyclic products with high enantioselectivity.
Asymmetric Lithiation−Substitution of Amines Involving Rearrangement of Borates
作者:Iain Coldham、Jignesh J. Patel、Sophie Raimbault、David T. E. Whittaker、Harry Adams、Guang Y. Fang、Varinder K. Aggarwal
DOI:10.1021/ol702734u
日期:2008.1.1
Asymmetric lithiation of substituted benzylamines, N-Boc-pyrrolidine, or N-Boc-indoline using Beak's methodology was followed by electrophilic quench with trialkylboranes. The resulting borate intermediates rearrange with concomitant C-N bond breakage to give, after oxidation, chiral secondary alcohols with high enantioselectivity.