Yang Y, Liu S, Li S, Liu Z, Liao P, Sivaguru P, Lu Y, Gao J, Bi X. Site-Selective C-H Allylation of Alkanes: Facile Access to Allylic Quaternary sp
3 -Carbon Centers.
Angew Chem Int Ed Engl 2023;
62:e202214519. [PMID:
36428220 DOI:
10.1002/anie.202214519]
[Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 11/24/2022] [Accepted: 11/25/2022] [Indexed: 11/27/2022]
Abstract
The construction of allylic quaternary sp3 -carbon centers has long been a formidable challenge in transition-metal-catalyzed alkyl-allyl coupling reactions due to the severe steric hindrance. Herein, we report an effective carbene strategy that employs well-defined vinyl-N-triftosylhydrazones as a versatile allylating reagent to enable direct assembly of these medicinally desirable structural elements from low-cost alkane feedstocks. The reaction exhibited excellent site selectivity for tertiary C-H bonds, broad scope (>60 examples and >20 : 1:0 r. r.) and good efficiency, even on a gram-scale, making it a convenient alternative to the well-known Trost-Tsuji allylation reaction for the formation of alkyl-allyl bonds. Combined experimental and computational studies were employed to unravel the mechanism and origin of site- and chemoselectivity of the reaction.
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