Electrochemical pinacol coupling of carbonyl compounds in an undivided cell with a sacrificial anode would be a promising approach toward synthetically valuable vic-1,2-diol scaffolds without using low-valent metal reductants. However, sacrificial anodes produce an equimolar amount of metal waste, which may be a major issue in terms of sustainable chemistry. Herein, we report a sacrificial anode-free electrochemical protocol for the synthesis of pinacol-type vic-1,2-diols from sec-alcohols, namely benzyl alcohol derivatives and ethyl lactate. The corresponding vic-1,2-diols are obtained in moderate to good yields, and good to high levels of stereoselectivity are observed for sec-benzyl alcohol derivatives. The present transformations smoothly proceed in a simple undivided cell under constant current conditions without the use of external chemical oxidants/reductants, and transition-metal catalysts.
在带有牺牲阳极的不分化电池中进行羰基化合物的电
化学嚬哪醇偶联,是在不使用低价
金属还原剂的情况下合成有价值的沧-1,2
-二醇支架的一种可行方法。然而,牺牲阳极会产生等摩尔量的
金属废物,这可能是可持续
化学方面的一个主要问题。在此,我们报告了一种以仲醇(即
苄醇衍
生物和
乳酸乙酯)为原料合成
频哪醇型沧海1,2
-二醇的无牺牲阳极电
化学方案。相应的沧海-1,2
-二醇的收率从中等到良好,仲
苄基醇衍
生物的立体选择性从良好到较高。在恒流条件下,无需使用外部
化学氧化剂/还原剂和过渡
金属催化剂,即可在一个简单的未分割电池中顺利进行上述转化。