Catalyst‐Free Decarboxylation of Carboxylic Acids and Deoxygenation of Alcohols by Electro‐Induced Radical Formation
作者:Xiaoping Chen、Xiaosheng Luo、Xiao Peng、Jiaojiao Guo、Jiantao Zai、Ping Wang
DOI:10.1002/chem.201905224
日期:2020.3.12
derived from naturally abundant carboxylic acids and alcohols provides a sustainable and inexpensive approach to radical formation via undivided electrochemical cells. The resulting radicals are trapped by an electron-poor olefin or hydrogen atom source to furnish the Giese reaction or reductive decarboxylation products, respectively. A broad range of carboxylic acid (1°, 2°, and 3°) and alcohol (2° and
Based on the DFT calculations, the sulfonamide was explored as an efficient hydrogen-atomtransfer catalyst for the C(sp3)–H alkylation. The combination of a metal-free photoredox catalyst and a sulfonamide catalyst enables highly regioselective alkylation of the C–H bonds adjacent to heteroatoms, which features broad substrate scope and excellent functional group compatibility. Remarkably, the sulfonamide
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
Electrophotocatalytic C–H Functionalization of Ethers with High Regioselectivity
作者:He Huang、Zack M. Strater、Tristan H. Lambert
DOI:10.1021/jacs.9b11472
日期:2020.1.29
The highly regioselective electrophotocatalytic C-H functionalization of ethers is described. These reactions are catalyzed by a trisaminocyclopropenium (TAC) ion in a mild electrochemical potential with visible light irradiation. Ethers undergo oxidant-free coupling with isoquinolines, alkenes, alkynes, pyrazoles, and purines with typically high regioselectivity for the less-hindered α-position. The
Radical conjugate addition onto vinyl sulfones was achieved by means of a convenient, tin-free procedure. This was based on the photocatalyzed CH bond activation in aldehydes, amides, ethers and even cycloalkanes by using tetrabutylammonium decatungstate (TBADT). The reaction was likewise effective for the functionalization of β-substituted vinyl sulfones. The products are useful building blocks and