Reaction Rate Acceleration Enabled by Tethered Lewis Acid-Lewis Base Bifunctional Catalysis: A Catalytic, Enantioselective [2+2] Ketene Aldehyde Cycloaddition Reaction
Sridhar Chidara, Yun-Ming Lin*
*Department of Chemistry, University of Toledo, 2801 W. Bancroft Street, Toledo, OH 43606, USA, Email: Yun-Ming.LinUtoledo.edu
S. Chidara, Y.-M. Lin, Synlett, 2009, 1675-1679.
A quinine tethered Co(III)-salen complex promotes as a Lewis acid-Lewis base (LA*-LB*) bifunctional catalyst a rapid asymmetric [2+2] cycloaddition reaction between ketene and aldehydes to produce C4-substituted β-lactones in uniformly >99% ee and high isolated yields.
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Lewis acids, Lewis bases, bifunctional catalysts, rate acceleration, enantioselectivity, lactones