Efficient chirality switching in the asymmetric addition of indole to N-tosylarylimines in the presence of axially chiral cyclometalated bidentate N-heterocyclic carbene palladium(II) complexes
作者:Zhen Liu、Min Shi
DOI:10.1016/j.tetasy.2008.11.015
日期:2009.1
Efficient dual stereocontrol can be achieved by using axially chiral cyclometalated bidentate N-heterocyclic carbene palladium(II) complexes for the addition of indole to N-tosylarylimines simply by the adjustment of the R group on the benzene rings of the NHC-Pd(II) complexes. (C) 2008 Elsevier Ltd. All rights reserved.
Asymmetric Friedel−Crafts Addition of Indoles to <i>N</i>-Sulfonyl Aldimines: A Simple Approach to Optically Active 3-Indolyl-methanamine Derivatives
[reaction: see text] The enantioselective copper(II)-catalyzed Friedel-Crafts addition of indoles to N-sulfonyl aldimines was developed using chiral bisoxazoline as ligands, and high enantioselectivities (up to 96% ee) were achieved.
Jnsymmetrical arylbis(3-indolyl)methanes have been synthesized via a Bronsted acid catalyzed Friedel-Crafts alkylation of α-(3-indolyl)benzylamines with N-methylindole. With 5 mol% of the catalyst, the reaction proceeds smoothly under mild conditions, affording the unsymmetrical triarylmethanes in excellent yields (up to 98%).