Palladium-catalyzed asymmetric tandem allylic substitution using chiral 2-(phosphinophenyl)pyridine ligand
作者:Katsuji Ito、Yoshikatsu Imahayashi、Tomomi Kuroda、Shuuichiro Eno、Bunnai Saito、Tsutomu Katsuki
DOI:10.1016/j.tetlet.2004.08.014
日期:2004.9
Palladium-catalyzed asymmetric tandem allylic substitution of (Z)-1,4-diacyloxy- and (Z)-1,4-bis(alkoxycarbonyloxy)-2-utene (2a-c) using 2-(phosphinophenyl)pyridine 1 as chiral ligand provided optically active six-membered 2-vinyl-1,4-diheterocyclic compounds with good to high enantioselectivity. For example, the reactions with catechol, 2-(benzylamino) phenol, or 1,2-bis(benzylamino)ethane as a nucleophile gave 2-vinyl-1,4-benzodioxane (71% ee), 4-benzyl-2-vinyl-1,4-benzoxazine (86% ee), and 1,4-dibenzyl-2-vinylpiperazine (86% ee), respectively. (C) 2004 Elsevier Ltd. All rights reserved.