Visible-Light-Mediated Cross Dehydrogenative Coupling of Thiols with Aldehydes: Metal-Free Synthesis of Thioesters at Room Temperature
作者:Vishal Jyoti Roy、Partha Pratim Sen、Sudipta Raha Roy
DOI:10.1021/acs.joc.1c02111
日期:2021.12.3
is also found to be scalable with good efficiency. Mechanistic investigations reveal that under this photochemical condition, the formation of acyl radical can be achieved from aldehyde. This acyl radical was further intercepted with an intermediate disulfide, generated in situ via the dehydrogenation of thiol to give the desired thioester. Moreover, disulfides, which are relatively easier to handle
硫酯在生物系统中起着至关重要的作用,是有机合成的重要组成部分。在此,Eosin Y 和 TBHP 介导的原料醛和硫醇之间的光化学交叉脱氢偶联 (PCCDC) 已被描述在室温下合成硫酯。该硫酯化方案顺利进行,通过烷基/芳基醛与各种烷基/芳基硫醇的合适 PCDC 以良好至极好的收率得到所需产物,并生成水和tBuOH 作为绿色副产品。还发现该方法具有良好的可扩展性。机理研究表明,在这种光化学条件下,醛可以形成酰基自由基。该酰基进一步被中间体二硫化物拦截,中间体二硫化物通过硫醇的脱氢原位生成,得到所需的硫酯。此外,相对更容易处理的二硫化物在优化的反应条件下也提供了良好的收率。该协议进一步扩展到更具挑战性的醇到硫酯的直接转化。