Selective Carbonyl−C(sp<sup>3</sup>) Bond Cleavage To Construct Ynamides, Ynoates, and Ynones by Photoredox Catalysis
作者:Kunfang Jia、Yue Pan、Yiyun Chen
DOI:10.1002/anie.201611897
日期:2017.2.20
Carbon–carbonbondcleavage/functionalization is synthetically valuable, and selective carbonyl−C(sp3) bondcleavage/alkynylation presents a new perspective in constructing ynamides, ynoates, and ynones. Reported here is the first alkoxyl‐radical‐enabled carbonyl−C(sp3) bondcleavage/alkynylation reaction by photoredox catalysis. The use of novel cyclic iodine(III) reagents are essential for β‐carbonyl
High enantioselectivity (up to 94% ee) has been achieved in the protonation of samarium enolates which were generated by SmI2-mediated reduction of 2-aryl-2-methoxycyclohexanones using a C2-symmetric chiral diol as a protonsource.
Samarium diiodide-promoted electrophilic amination of ketone enolates: efficient synthesis of quaternary carbon-containing α-aminated ketones
作者:Xing-Wen Sun、Wei Wang、Ming-Hua Xu、Guo-Qiang Lin
DOI:10.1016/j.tetlet.2008.07.123
日期:2008.9
An efficient and practical electrophilic amination method that allows the preparation of useful quaternary carbon-containing alpha-aminoketones was developed. The reaction proceeds regiospecifically via a samarium enolate intermediate at room temperature in the presence of mild reducing agent SmI2. Unlike the most reported lithium enolate cases, this new amination method does not require the use of strong base such as BuLi or LDA. (C) 2008 Elsevier Ltd. All rights reserved.