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Enantioselective Alkynylation of Pyrazole-4,5-diones with Terminal Alkynes Catalyzed by Copper/PyBisulidine. | LitMetric

A copper/PyBisulidine-catalyzed enantioselective alkynylation of electrophilic pyrazole-4,5-dione with terminal alkynes has been developed. Chiral tertiary propargylic alcohols bearing the pyrazolone motif were prepared with yields (up to 99%) and enantioselectivities (up to 99% ee). The prominent feature of this protocol includes its mild reaction conditions and good stereoselectivities. The nonlinear effect study showed that the catalytically active specie was a monomeric catalyst and that the excess copper activated the alkynes through the π-system.

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http://dx.doi.org/10.1021/acs.joc.3c01338DOI Listing

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