Facile One-Pot Procedure for Et<sub>3</sub>Al-Promoted Asymmetric Pinacol-Type Rearrangement
作者:Keisuke Suzuki、Tomoichi Shionhara
DOI:10.1055/s-2003-36266
日期:——
A facile procedure for the synthesis of enantiomerically pure α-substituted ketones is described. The pinacol-type 1,2-shift of sec-tert 1,2-diols could be effected by performing the following two processes in a one pot procedure, (1) regioselective methanesulfonylation, and (2) direct treatment of the resulting mesylate with Et3Al. This procedure allowed 1,2-shift reactions of various groups, including vinyl, aryl, and heteroaromatic groups, giving enantiomerically pure ketones in high yields.
is challenging, especially in asymmetric transformations. With each step in the catalytic cycle promoted by its privileged ligand and different steps well-connected by dynamic ligand exchange, synergistic combination of multiple ligands could potentially enhance the catalytic efficiency and selectivity. Now, this concept has been applied to the NiH-catalyzed asymmetric remote hydroacylation of olefins
Nickel‐Catalyzed Enantioselective Decarboxylative Acylation: Rapid, Modular Access to α‐Amino Ketones**
作者:Yang Gao、Phil S. Baran
DOI:10.1002/anie.202315203
日期:2023.12.11
A new approach to the enantiocontrolled synthesis of α-amino ketone derivatives is disclosed by employing a nickel-catalyzed decarboxylative acylation strategy. Starting from readily available acyl chlorides and α-amino acids-derived redox-active esters, the reaction exhibits broad substrate scope, easy scalability, and is applied to dramatically simplify the synthesis of several known structures.
作者:Seunghwan Byun、Meemie U. Hwang、Henry R. Wise、Anna V. Bay、Paul H.‐Y. Cheong、Karl A. Scheidt
DOI:10.1002/anie.202312829
日期:2023.12.4
An enantioselective radical-radical coupling using combined photoredox/N-heterocyclic carbene (NHC) catalysis was developed. The coupling of a ketyl radical and an sp3-carbon radical allows access to α-chiral ketones in moderate-to-good yields and enantioselectivities. Computational investigations reveal the N-heterocyclic carbene controls the double-facial selectivity of the ketyl radical and the
Photoredox/nickel-catalyzed enantioconvergent acylcross-coupling of carboxylic derivatives with racemic secondary organotrifluoroborate was developed for the synthesis of an enolizable chiral α-aryl ketone under mild neutral conditions. Moderate to high yields and good enantioselectivities were achieved.