AbstractAn enantioselective protonation by means of chiral scandium complex‐catalyzed aza‐Michael reaction was realized. A series of α‐aryl‐substituted vinyl ketones reacted with pyrazoles smoothly, affording the corresponding enantiomerically enriched pyrazole derivatives with excellent results (up to 99% yield, 94% ee). Water and hydrogen chloride were found to accelerate the protonation process.magnified image
Direct α-Acylation of Alkenes via N-Heterocyclic Carbene, Sulfinate, and Photoredox Cooperative Triple Catalysis
作者:Kun Liu、Armido Studer
DOI:10.1021/jacs.1c01022
日期:2021.4.7
excellent functional group tolerance. Mechanistic studies reveal that these cascades proceed through a sequential radical addition/coupling/elimination process. In contrast to known triple catalysis processes that operate via two sets of interwoven catalysiscycles, in the introduced process, all three cycles are interwoven.
Ligand-Free Palladium-Catalyzed Carbonylative Suzuki Couplings of Vinyl Iodides with Arylboronic Acids under Substoichiometric Base Conditions
作者:Zhiyuan Yang、Pei-Xue Gong、Wei Han、Junjie Chen、Jie Zhang、Xu Gong
DOI:10.1055/a-1511-0435
日期:2021.7
A ligand-free palladium-catalyzedcarbonylation of vinyl iodides with arylboronic acids, permitting the synthesis of chalcones and α-branched enones, has been established. This reaction proceeds smoothly at ambient pressure and temperature, and works well even with a substoichiometric amount of base. Importantly, this mild, efficient, and operationally simple protocol is suitable for the late-stage
A novel enantioselective protonation protocol that is triggered by reductive cross coupling of olefins is reported. When under cooperative photoredox and chiral hydrogen-bonding catalytic conditions and using a terminal reductant, various α-branched vinylketones with diverse vinylazaarenes could provide important enantioenriched azaarene derivatives containing tertiary stereocenters at their remote
Enantioselectivecyclopropanation and C–H insertion reactions of α-substituted vinyl ketones with α-diazoesters have been accomplished using a N,N′-dioxide-scandium(III) complex catalyst. Various tetrasubstituted cyclopropanes and E-enone derivatives bearing a chiral ester substituent were obtained simultaneously with good yields and excellent enantioselectivities.