Asymmetric C–H Dehydrogenative Allylic Alkylation by Ternary Photoredox-Cobalt-Chiral Primary Amine Catalysis under Visible Light
作者:Zongbin Jia、Long Zhang、Sanzhong Luo
DOI:10.1021/jacs.2c03299
日期:2022.6.22
We report herein an asymmetric C–H dehydrogenative allylic alkylation by a synergistic catalytic system involving a chiral primary amine, a photoredox catalyst, and a cobaloxime cocatalyst. The ternary catalytic system enables the coupling of β-ketocarbonyls and olefins with good yields and high enantioselectivities. Mechanism studies disclosed a cooperative radical addition process with a chiral α-imino
Substrate Range of the Titanium TADDOLate Catalyzed Asymmetric Fluorination of Activated Carbonyl Compounds
作者:Andreas Bertogg、Lukas Hintermann、Dominique P. Huber、Mauro Perseghini、Maria Sanna、Antonio Togni
DOI:10.1002/hlca.201100375
日期:2012.3
4‐diazoniabicyclo[2.2.2]octane bis‐[tetrafluoroborate]) at room temperature. A series of α‐methylated β‐keto esters (3‐oxobutanoates, 3‐oxopentanoates) with bulky benzyl ester groups (60–90% ee) or phenyl ester (67–88% ee) have been fluorinated readily, whereas α‐acyl lactones were also readily fluorinated, but gave lower inductions (13–46% ee). Double stereochemical differentiation in β‐keto esters with chiral
Chiral Primary Amine/Ketone Cooperative Catalysis for Asymmetric α-Hydroxylation with Hydrogen Peroxide
作者:Mao Cai、Kaini Xu、Yuze Li、Zongxiu Nie、Long Zhang、Sanzhong Luo
DOI:10.1021/jacs.0c11787
日期:2021.1.20
catalytic strategies, aminocatalysis and carbonyl catalysis do not coexist well, and, as such, a cooperative amine/carbonyl dual catalysis remains essentially unknown. Here we report a cooperative primary amine and ketone dual catalytic approach for the asymmetric α-hydroxylation of β-ketocarbonyls with H2O2. Besides participating in the typical enamine catalytic cycle, the chiral primary amine catalyst