Copper-Catalyzed Borrowing Hydrogen
Reaction for α-Alkylation of Amides with Alcohols
Qiuling Xia,
Yulong Miao, Yue Hu, Yinjun Xie,* and Junfei Luo*
School
of Materials Science and Chemical Engineering, Ningbo University, Ningbo, 315211,
P. R. China
—J. Org. Chem., 2024, DOI:
10.1021/acs.joc.4c00404.
Recommended by Chaoyou Liu _ PDM
ABSTRACT:Authors
report the first example of copper-catalyzed α-alkylation of acetamides with
alcohols via a borrowing hydrogen strategy. Catalyzed by the in situ-generated
copper particles, acetamides and various substituted benzyl or alkyl alcohols
were transformed into functionalized amides in good yields with excellent
selectivity. Compared with previous work, this process is simple using
commercially available Cu(OAc)2 as a precatalyst, without an additional ligand or a metal
complex, and easier. Mechanistic studies revealed that aldehyde and α,β-
unsaturated amides were the intermediates of this reaction and also disclosed
the role of copper in alcohol dehydrogenation and C=C bond hydrogenation.
Background
Substrate Scope
Gram-scale Reaction
Plausible
Mechanism
Summary and Comments
In summary, authors have developed a
novel copper-catalyzed selective α-alkylation of unactivated amides with alcohols via
a borrowing hydrogen strategy to produce functional amides.This reaction is easy to handle, quite
compatible with a wide range of substrates, environmentally friendly with water
as the only byproduct, and inexpensive with the
use of commercially available copper salt Cu(OAc)2 as aprecatalyst without any organic ligand or inorganic support. In addition, a plausible
mechanism is proposed on the basis of a preliminary mechanistic study.