Dominguez-Molano P, Solé-Daura A, Carbó JJ, Fernández E. Remote 1,4-Carbon-to-Carbon Boryl Migration: From a Mechanistic Challenge to a Valuable Synthetic Application of Bicycles.
ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024;
11:e2309779. [PMID:
38361396 DOI:
10.1002/advs.202309779]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 01/25/2024] [Indexed: 02/17/2024]
Abstract
The present paper reports a remote carbon-to-carbon boryl migration via an intramolecular 1,4-B/Cu shift, which establishes an in situ stereospecific electrophilic trap on the alkene moiety. The synthetic application is developed to prepare functionalized cyclopentenes by means of a palladium-catalyzed regioselective intramolecular coupling that completes a strategic cyclopropanation and generates valuable structural bicyclic systems. The mechanism is characterized by DFT (density functional theory) calculations which showed that the 1,4-migration proceeds through an intramolecular, nucleophilic attack of the copper-alkyl moiety on the boron atom bonded to the C(sp2), leading to a 5-membered boracycle structure. The computation of the 1,3- and 1,4-B/Cu shifts is also compared as is the impact of the endo- or exocyclic alkene on the reaction kinetics.
Collapse