effective direct hydrogen‐atom transfer catalyst for C−H activation. Using the alkylation of C−Hbonds with electron‐deficient alkenes as a model study revealed an extremely broad substrate scope, enabling easy access to a variety of important synthons. This eosin Y‐based photocatalytic hydrogen‐atom transfer strategy is promising for diverse functionalization of a wide range of native C−Hbonds in a green
Base-Promoted Three-Component Cascade Reaction of α-Hydroxy Ketones, Malonodinitrile, and Alcohols: Direct Access to Tetrasubstituted N<i>H</i>-Pyrroles
malonodinitrile, and alcohols has been developed, providing a direct and efficient route to a range of structurally diverse and synthetically useful 2-alkyloxy-1H-pyrrole-3-carbonitrile derivatives. The reaction involved three different bond (C–C, C–O, and C–N) formations in a single step, and its regioselectivity was depended on the structure of the α-hydroxy ketones employed. The use of easily available
Catalytic Acceptorless Dehydrogenation of Aliphatic Alcohols
作者:Hiromu Fuse、Harunobu Mitsunuma、Motomu Kanai
DOI:10.1021/jacs.0c00123
日期:2020.3.4
aliphatic secondary alcohols to ketones undervisiblelight irradiation at room temperature by devising a ternary hybrid catalyst system comprising a photoredox catalyst, a thiophosphate organocatalyst, and a nickel catalyst. The reaction proceeded through three main steps: hydrogen atom transfer from the α-C-H bond of an alcohol substrate to the thiyl radical of the photo-oxidized organocatalyst, interception
Aerobic C–H Functionalization Using Pyrenedione as the Photocatalyst
作者:Jie Wu、Dejiang Huang、Yuannian Zhang、Xin Yang
DOI:10.1055/s-0040-1707135
日期:2020.9
disclose a visible-light-promoted aerobic alkylation of activated C(sp3)–H bonds using pyrenedione (PYD) as the photocatalyst. Direct C–H bond alkylation of tetrahydrofuran with alkylidenemalononitriles is accomplished in over 90% yield in the presence of 5 mol% of PYD and 18 W blue LED light under ambient conditions. The substrate scope is extended to ethers, thioethers, and allylic C–H bonds in reactions
Novel radical transfer reagentsunder photoirradiation conditions were developed by the use of benzothiazoline derivatives. These reagents enabled both hydroalkylation and hydroacylation of alkenes underneutralconditions at ambient temperature without any toxic reagents or an excess amount of metals. A mechanistic study was carried out to elucidate the radical process.