A General Organocatalytic System for Enantioselective Radical Conjugate Additions to Enals
作者:Emilien Le Saux、Dengke Ma、Pablo Bonilla、Catherine M. Holden、Danilo Lustosa、Paolo Melchiorre
DOI:10.1002/anie.202014876
日期:2021.3
enantioselective conjugate addition of carbon‐centered radicals to aliphatic and aromatic enals. The process uses an organic photoredox catalyst, which absorbs blue light to generate radicalsfrom stable precursors, in combination with a chiral amine catalyst, which secures a consistently high level of stereoselectivity. The generality of this catalytic platform is demonstrated by the stereoselective interception
Visible-light excitation of iminium ions enables the enantioselective catalytic β-alkylation of enals
作者:Mattia Silvi、Charlie Verrier、Yannick P. Rey、Luca Buzzetti、Paolo Melchiorre
DOI:10.1038/nchem.2748
日期:2017.9
organisms. Herein we demonstrate that the direct excitation of chiral iminium ions can unlock unconventional reaction pathways, enablingenantioselective catalytic photochemical β-alkylations of enals that cannot be realized via thermal activation. The chemistry uses readily available alkyl silanes, which are recalcitrant to classical conjugateadditions, and occurs under illumination by visible-light-emitting
Asymmetric Photocatalytic C–H Functionalization of Toluene and Derivatives
作者:Daniele Mazzarella、Giacomo E. M. Crisenza、Paolo Melchiorre
DOI:10.1021/jacs.8b05240
日期:2018.7.11
from the corresponding enals. The process combines the oxidative power of a chiral excited-state iminium ion and the basic nature of its counteranion to trigger the generation of benzylic radicals by means of a sequential multisite proton-coupled electron transfer mechanism. This study shows that feedstock chemicals generally used as solvents, such as toluene and xylene derivatives, can be used as
Fluorinated Sulfinates as Source of Alkyl Radicals in the Photo‐Enantiocontrolled β‐Functionalization of Enals
作者:Ricardo I. Rodríguez、Marina Sicignano、José Alemán
DOI:10.1002/anie.202112632
日期:2022.2.21
use of gem-difluoro sulfinates in visible-light photocatalysis for the construction of new C−C bonds in a chiral fashion is presented. This was tackled by rerouting the chemical pathway of alkyl sulfonyl radicals from traditional sulfonylation to alkylation performance. The efficacy of these sulfinates for assisting SO2 extrusion is shown by allowing the installation of CF2-bearing scaffolds, a modern
介绍了宝石-二氟亚磺酸盐在可见光光催化中前所未有的用途,用于以手性方式构建新的 C-C 键。这是通过将烷基磺酰基自由基的化学途径从传统的磺酰化重新路由到烷基化性能来解决的。这些亚磺酸盐有助于 SO 2挤出的功效通过允许安装带有 CF 2的支架来显示,这是制药领域的一项现代任务。
α-Photooxygenation of chiral aldehydes with singlet oxygen
Organocatalytic α-oxygenation of chiralaldehydes with photochemically generated singlet oxygen allows synthesizing chiral 3-substituted 1,2-diols. Stereochemical results indicate that the reaction in the presence of diarylprolinol silyl ethers is highly diastereoselective and that the configuration of a newly created stereocenter at the α-position depends predominantly on the catalyst structure. The