Stereoselective Copper-Catalyzed Olefination of Imines.

Alkenes are an important class of organic molecules found among synthetic intermediates and bioactive compounds. They are commonly synthesized through stoichiometric Wittig-type olefination of carbonyls and imines, using ylides or their equivalents. Despite the importance of Wittig-type olefination reactions, their catalytic variants remain underdeveloped. We explored the use of transition metal catalysis to form ylide equivalents from readily available starting materials. Our investigation led to a new copper-catalyzed olefination of imines with alkenyl boronate esters as coupling partners. We identified a heterobimetallic complex, obtained by hydrocupration of the alkenyl boronate esters, as the key catalytic intermediate that serves as an ylide equivalent. The high E-selectivity observed in the reaction is due to the stereoselective addition of this intermediate to an imine, followed by stereospecific anti-elimination. © 2023 Wiley-VCH GmbH.

Citation

James E Baumann, Crystal P Chung, Gojko Lalic. Stereoselective Copper-Catalyzed Olefination of Imines. Angewandte Chemie (International ed. in English). 2024 Feb 05;63(6):e202316521

PMID: 38100274

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