Synlett 2001; 2001(12): 1889-1892
DOI: 10.1055/s-2001-18770
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Titanium 3,3′-Modified-Biphenolate Complexes Atropisomerically Controlled by TADDOLs: Novel Chiral Lewis Acid Catalysts for Asymmetric Methylation with an Achiral Methyl-Titanium Reagent

Makoto Ueki* , Yosuke Matsumoto, Jonathan J. Jodry, Koichi Mikami
  • * Department of Applied Chemistry, Tokyo Institute of Technology O-okayama, Meguro-ku, Tokyo 152-8552, Japan; Fax: + 81(3)57342776; E-mail: kmikami@o.cc.titech.ac.jp
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Publication History

Publication Date:
04 December 2001 (online)

Chiral Ti complexes, which are constituted of 3,3′-modified-biphenolate (BIPOLate) ligands atropisomerically controlled by (R)-TADDOLs, are shown to be novel chiral Lewis acid catalysts for the methylation reaction of aldehydes with an achiral methyl-titanium reagent. Thus, the chiral 3,3′-modified BIPOLate/TADDOLate-Ti complexes give enhanced enantioselectivities up to 100% enantiomeric excess.