Bowen J, Slebodnick C, Santos WL. Phosphine-catalyzed hydroboration of propiolonitriles: access to (
E)-1,2-vinylcyanotrifluoroborate derivatives.
Chem Commun (Camb) 2022;
58:5984-5987. [PMID:
35481802 DOI:
10.1039/d2cc00603k]
[Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report an organocatalytic trans hydroboration of 3-substituted-propiolonitriles. In the presence of catalytic amounts of tributylphosphine and pinacolborane, regioselective hydroboration of the internal triple bond proceeded in a stereoselective fashion under mild conditions to afford the corresponding (E)-1,2-vinylcyanoborane derivatives. The mechanism is proposed to occur through a 1,2-phosphine addition instead of a canonical 1,4-conjugate addition pathway.
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