Copper-Catalyzed Enantioselective Synthesis of trans-1-Alkyl-2-substituted Cyclopropanes via Tandem Conjugate Addition-Intramolecular Enolate Trapping
Tim den Hartog, Alena Rudolph, Beatriz Maci, Adriaan J. Minnaard* and Ben L. Feringa*
*Stratingh Institute for Chemistry, University of Groningen,
Nijenborgh 4, 9747 AG Groningen, The Netherlands, Email: b.l.feringa
rug.nl,
a.j.minnaardrug.nl
T. den Hartog, A. Rudolph, B. Maci, A. J. Minnaard, B. L. Feringa, J. Am. Chem. Soc., 2010, 132, 14349-14351.
DOI: 10.1021/ja105704m
Abstract
Cu-TolBINAP-catalyzed conjugate addition of alkyl Grignard reagents to 4-chloro-α,β-unsaturated esters, thioesters, and ketones leads to trans-1-alkyl-2-substituted cyclopropanes in good yield and high enantioselectivity. The versatility of this reaction is illustrated by the formation of key intermediates for the formal syntheses of cascarillic acid and grenadamide.
see article for more examples
Key Words
ID: J48-Y2010-2820
