Enantioselective Sulfoxidation and Kinetic Resolution Combined Protocol Mediated by a Functionalized (S)-Norcamphor-Based Hydroperoxide/Titanium(IV) Isopropoxide System
hydroperoxide derived from (S)-norcamphor has been easily synthesized in good yield and in a highly diastereoselective manner. Good to highenantioselectivities (up to 99 % ee) and acceptable to good yields (up to 86 %) were achieved for the sulfoxides, by tandem stereoconvergent asymmetric sulfoxidation and kineticresolution when using the novel hydroperoxide as oxygen donor and chirality source in
A Study of Factors Affecting Enantioselectivity in the Oxidation of Aryl Benzyl Sulfides in the Presence of Chiral Titanium Catalysts
作者:Maria Annunziata M. Capozzi、Caterina Centrone、Giuseppe Fracchiolla、Francesco Naso、Cosimo Cardellicchio
DOI:10.1002/ejoc.201100310
日期:2011.8
explain the highly enantioselectiveoxidation of aryl benzyl sulfides with tert-butyl hydroperoxide in the presence of a complex between titanium and (S,S)- or (R,R)-hydrobenzoin. The studied variations involved the sulfides, the ligands, and the order of addition of reactants. The reaction path predicted by our model was confirmed in every experiment. In particular, aryl benzyl sulfides behaved as the