Li C, Zhou Z, Ma S. A Pd-catalyzed highly selective three-component protocol for trisubstituted allenes.
Chem Sci 2023;
14:7709-7715. [PMID:
37476716 PMCID:
PMC10355113 DOI:
10.1039/d3sc01849k]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2023] [Accepted: 06/20/2023] [Indexed: 07/22/2023] Open
Abstract
Herein we report the first example of a Pd-catalyzed highly selective three-component reaction of alkynyl-1,4-diol dicarbonates, organoboronic acids, and malonate anions for the efficient synthesis of trisubstituted 2,3-allenyl malonates not readily available by the known protocols. The reaction demonstrates an excellent regio- and chemo-selectivity for both the oxidative addition referring to the two C-O bonds and the subsequent coupling with the nucleophile with a remarkable functional group compatibility. A series of control experiments confirm a unique mechanism involving β-O elimination forming alka-1,2,3-triene and the subsequent insertion of its terminal C[double bond, length as m-dash]C bond into the Ar-Pd bond.
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