Modular Enantioselective Synthesis of cis-Cyclopropanes through Self-Sensitized Stereoselective Photodecarboxylation
Matteo Costantini1, Abraham Mendoza1
1Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, 106 91 Stockholm, Sweden.
Abstract:
Chiral cis-cyclopropanes are strained rigid analogues of alkyl chains, whose study and application are limited by their difficult synthesis. A modular approach from olefin materials is enabled by the discovery of the electron donor-acceptor (EDA) interaction between 2-substituted benzothiazolines and N-hydroxyphthalimide esters. These complexes are activated by visible light without photocatalysts, and the benzothiazoline reagent plays a triple role as a photoreductant, a stereoselective hydrogen-atom donor, and a Brønsted acid. Beyond the enantioselective synthesis of cis-cyclopropanes, these results introduce benzothiazolines as accessible and easily tunable self-sensitized photoreductants.
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