Enantioselective Tail-to-Head Cyclizations Catalyzed by Dual-Hydrogen-Bond Donors.

J Am Chem Soc

Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States.

Published: April 2020

Chiral urea derivatives are shown to catalyze enantioselective tail-to-head cyclization reactions of neryl chloride analogues. Experimental data are consistent with a mechanism in which π-participation by the nucleophilic olefin facilitates chloride ionization and thereby circumvents simple elimination pathways. Kinetic and computational studies support a cooperative mode of catalysis wherein two molecules of the urea catalyst engage the substrate and induce enantioselectivity through selective transition state stabilization.

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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7293861PMC
http://dx.doi.org/10.1021/jacs.0c02665DOI Listing

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