Synfacts 2011(1): 0057-0057  
DOI: 10.1055/s-0030-1259163
Metal-Catalyzed Asymmetric Synthesis and Stereoselective Reactions
© Georg Thieme Verlag Stuttgart ˙ New York

Enantioselective Synthesis of trans-1-Alkyl-
2-Substituted Cyclopropanes

Contributor(s): Hisashi Yamamoto, Jiajing Tan
T. den Hartog, A. Rudolph, B. Maciá, A. J. Minnaard*, B. L. Feringa*
University of Groningen, The Netherlands
Further Information

Publication History

Publication Date:
21 December 2010 (online)


The asymmetric synthesis of trans-1-alkyl-2-substituted cyclopropanes has traditionally been based on the well-known Simmons-Smith ­cyclopropanation. However, a stoichio­metric amount of a chiral dioxaborolane is needed and efficient catalytic methods are very rare. The authors represent a catalytic asymmetric tandem conjugate addition-intramolecular enolate trapping reaction by using the Cu-TolBINAP complex. Reactions of various Grignard reagents to 4-Cl-α,β-unsaturated esters, thioesters, and ­ketones provide highly functionalized cyclopropanes in excellent yields and enantioselectivities.