Catalytic Enantioselective Synthesis of 3,4-Unsubstituted Thiochromenes through Sulfa-Michael/Julia-Kocienski Olefination Cascade Reaction
Amit Kumar Simlandy and Santanu Mukherjee*
*Department of Organic Chemistry, Indian Institute of Science, Bangalore 560 012, India, Email: smorgchem.iisc.ernet.in
A. K. Simlandy, S. Mukherjee, J. Org. Chem., 2017, 82, 4851-4858.
DOI: 10.1021/acs.joc.7b00579 (free Supporting Information)
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A highly enantioselective cascade sulfa-Michael/Julia-Kocienski olefination reaction between 2-mercaptobenzaldehydes and β-substituted vinyl PT-sulfones provies a wide range of 3,4-unsubstituted 2H-thiochromenes with excellent enantioselectivities. This reaction is catalyzed by diphenylprolinol TMS ether and proceeds through an aromatic iminium intermediate.
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