irradiation. Ketyl radicals, generated by single-electron reduction of aldehydes through proton-coupled electron transfer (PCET), reacted with electrophilic alkynylsulfones. Sterically demanding bulky aldehydes reacted smoothly under the Umpolung reaction conditions. Moreover, the alkynylation proceeded chemoselectively with an aryl aldehyde group in the presence of other carbonyl groups including an aliphatic
通过 Umpolung 方法对醛进行还原性炔基化是在蓝色 LED 照射下使用光氧化还原催化剂开发的。通过质子耦合电子转移 (PCET) 醛的单电子还原产生的酮基自由基与亲电子炔基砜反应。空间要求高的大体积醛在 Umpolung 反应条件下反应平稳。此外,在包括脂肪族醛基在内的其他羰基存在下,炔基化与芳基醛基
化学选择性地进行。