Enantioselective Synthesis of Tetra-ortho-Substituted Axially Chiral Biaryls through Rhodium-Catalyzed Double [2 + 2 + 2] Cycloaddition.

Org Lett

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

Published: August 2006

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[reaction: see text] We have established an enantioselective synthesis of both C2 symmetric and unsymmetric tetra-ortho-substituted axially chiral biaryls through rhodium-catalyzed double [2 + 2 + 2] cycloaddition (up to >99% ee). This method serves as an attractive new route to enantioenriched tetra-ortho-substituted axially chiral biaryls in view of the one-step access to substrate diynes and tetraynes starting from readily available alkynes.

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http://dx.doi.org/10.1021/ol0611550DOI Listing

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