A Green Chemistry Approach to a More Efficient Asymmetric Catalyst: Solvent-Free and Highly Concentrated Alkyl Additions to Ketones

Sang-Jin Jeon, Hongmei Li and Patrick J. Walsh*

*Department of Chemistry, P. Roy and Diana T. Vagelos Laboratories, University of Pennsylvania, Philadelphia, Pennsylvania 19104, Email: pwalshsas.upenn.edu

S.-J. Jeon, H. Li, P. J. Walsh, J. Am. Chem. Soc., 2005, 127, 16416-16425.

DOI: 10.1021/ja052200m

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Abstract

The catalytic asymmetric addition of alkyl groups to ketones under highly concentrated and solvent-free conditions permits reduction in catalyst loading by a factor of 2- to 40-fold compared with standard reaction conditions employing toluene and hexanes. Using cyclic conjugated enones, solvent-free asymmetric addition followed by a diastereoselective epoxidation using 5.5 M decane solution of tert-butyl hydroperoxide generated epoxy alcohols.

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Asymmetric Addition of Alkylzinc Reagents to Cyclic α,β-Unsaturated Ketones and a Tandem Enantioselective Addition/Diastereoselective Epoxidation with Dioxygen

S.-J. Jeon, P. J. Walsh, J. Am. Chem. Soc., 2003, 125, 9544-9545.

Highly Enantioselective Catalytic Phenylation of Ketones with a Constrained Geometry Titanium Catalyst

C. Garcia, P. J. Walsh, Org. Lett., 2003, 5, 3641-3644.

Key Words

1,2-addition, epoxidation, tert-butyl hydroperoxide, green chemistry

ID: J48-Y2005-2750