Practical enantioselective synthesis of axially chiral biaryl diphosphonates and dicarboxylates by cationic rhodium(I)/Segphos-catalyzed double [2 + 2 + 2] cycloaddition

Goushi Nishida; Shuichiro Ogaki; Yukinori Yusa; Tohru Yokozawa; Keiichi Noguchi; Ken Tanaka

doi:10.1021/ol801013v

Practical enantioselective synthesis of axially chiral biaryl diphosphonates and dicarboxylates by cationic rhodium(I)/Segphos-catalyzed double [2 + 2 + 2] cycloaddition

Org Lett. 2008 Jul 3;10(13):2849-52. doi: 10.1021/ol801013v. Epub 2008 Jun 7.

Authors

Goushi Nishida¹, Shuichiro Ogaki, Yukinori Yusa, Tohru Yokozawa, Keiichi Noguchi, Ken Tanaka

Affiliation

¹ Department of Applied Chemistry, Graduate School of Engineering, and Instrumentation Analysis Center, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588, Japan.

PMID: 18537257
DOI: 10.1021/ol801013v

Abstract

A cationic rhodium(I)/Segphos complex catalyzes a [2 + 2 + 2] cycloaddition of internal 1,6-diynes with a phosphonate- or ester-substituted 1,3-butadiyne leading to C(2)-symmetric axially chiral biaryl diphosphonates or dicarboxylates, respectively, in high yields with outstanding ee's. The use of a phosphonate- or ester-substituted 1,3-butadiyne as a cycloaddition partner and Segphos as a ligand is crucial for the success of this transformation.