The influence of chiral auxiliaries and catalysts on the selectivity of intramolecular conjugate additions of pyrrole to N-tethered Michael acceptors
作者:Martin G. Banwell、Daniel A. S. Beck、Jason A. Smith
DOI:10.1039/b312552a
日期:——
A series of pyrroles incorporating N-tethered acrylates and related groups has been prepared and examined for their capacity to undergo intramolecular Michael addition reactions to form, in a diastereo- or enantio-selective fashion, the corresponding 8-substituted tetrahydroindolizidine or homologues thereof.
Radical difluoromethylthiolation of aromatics enabled by visible light
作者:Jianbin Li、Dianhu Zhu、Leiyang Lv、Chao-Jun Li
DOI:10.1039/c8sc01669k
日期:——
Direct introduction of a difluoromethylthio group (–SCF2H) to arenes represents an efficient route to access a valuable catalogue of organofluorines; however, to realize this transformation under metal-free and mild conditions still remains challenging and rarely reported. Herein, a metal-catalyst-free and redox-neutral innate difluoromethylthiolation method with a shelf-stable and readily available
Asymmetric Palladium‐Catalyzed Oxycarbonylation of Terminal Alkenes: Efficient Access to β‐Hydroxy Alkylcarboxylic Acids
作者:Bing Tian、Xiang Li、Pinhong Chen、Guosheng Liu
DOI:10.1002/anie.202104252
日期:2021.6.25
leading to high reactivity and excellent enantioselective control. Compared to the conventional methods, the reaction itself features alkenes as easily prepared starting materials, mild and operationally simple reaction conditions, and insensitivities to air and water. Moreover, this method allows for broad alkene substrate scope, excellent regio- and enantioselectivities, scalabilities and a wide array
Asymmetric intramolecular Friedel–Crafts reaction catalyzed by a spiropyrrolidine organocatalyst: Enantioselective construction of indolizine and azepine frameworks
The asymmetric intramolecular Friedel–Crafts type Michael reaction of α,β-unsaturated aldehyde with pyrrole, catalyzed by a spiropyrrolidine (SP)-type organocatalyst, has been accomplished, which allows the construction of a series of azepine and indolizine frameworks with high to excellent enantioselectivities (up to 98% ee). Moreover, the substrate scope could be extended to generate a quaternary
Palladium(II)-Catalyzed Enantioselective Hydrooxygenation of Unactivated Terminal Alkenes
作者:Xintuo Yang、Xiang Li、Pinhong Chen、Guosheng Liu
DOI:10.1021/jacs.2c02753
日期:2022.5.11
A novel Pd(II)-catalyzed enantioselective Markovnikov hydrooxygenation of unactivated terminal alkenes using a substituted pyridinyl oxazoline (Pyox) ligand has been developed. Herein it was discovered that the (EtO)2MeSiH/BQ redoxsystem is vital for the highly selective and efficient hydrooxygenation, where the alkylpalladium(II) species generated from enantioselective oxypalladation step is reduced