Applications of 1-Alkenyl-1,1-Heterobimetallics in the Stereoselective Synthesis of Cyclopropylboronate Esters, Trisubstituted Cyclopropanols and 2,3-Disubstituted Cyclobutanones

Mahmud M. Hussain, Hongmei Li, Nusrah Hussain, Mercedes Ureña, Patrick J. Carroll and Patrick J. Walsh*

*P. Roy and Diana T. Vagelos Laboratories, University of Pennsylvania, Department of Chemistry, 231 South 34th Street, Philadelphia, Pennsylvania 19104-6323, Email: pwalshsas.upenn.edu

M. M. Hussain, H. Li, N. Hussain, M. Ureña, P. J. Carroll, P. J. Walsh, J. Am. Chem. Soc., 2009, 131, 6516-6524.

DOI: 10.1021/ja900147s

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Abstract

Hydroboration of 1-alkynyl-1-boronate esters and in situ transmetalation furnishes 1-alkenyl-1,1-borozinc heterobimetallic intermediates. Reaction with aldehydes and in situ cyclopropanation generates B(pin) substituted cyclopropyl carbinols with excellent diastereoselectivities. Oxidation provides trisubstituted α-hydroxycyclopropyl carbinols, that allow access to both cis- and trans-2,3-disubstituted cyclobutanones via a facile pinacol-type rearrangement.

see article for more examples

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Highly Enantio- and Diastereoselective Tandem Generation of Cyclopropyl Alcohols with up to Four Contiguous Stereocenters

H. Y. Kim, A. E. Lurain, P. Garcia-Carcia, P. J. Carroll, P. J. Walsh, J. Am. Chem. Soc., 2005, 127, 13138-13139.

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Key Words

cyclopropanes, cyclopropanols, cyclobutanones, Pinacol rearrangement, sodium perborate

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ID: J48-Y2009-1460