Department of Chemical Sciences, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, U.K.
J Org Chem. 2023 Feb 3;88(3):1424-1433. doi: 10.1021/acs.joc.2c02309. Epub 2023 Jan 23.
A simple catalytic electrosynthetic protocol for oxidative transformations mediated by hypervalent iodine reagents has been developed. In this protocol, electricity drives the iodine(I)/iodine(III) catalytic cycle enabling catalysis with generated hypervalent iodine species, thereby eliminating chemical oxidants and the inevitable chemical waste associated with their mode of action. In addition, no added electrolytic salts are needed in this process. The developed method has been validated using two different hypervalent iodine-mediated transformations: (i) the oxidative cyclization of -allylic and -homoallylic amides to the corresponding dihydrooxazole and dihydro-1,3-oxazine derivatives, respectively, and (ii) the α-tosyloxylation of ketones. Both reactions proceeded smoothly under the developed catalytic electrosynthetic conditions without reoptimization, featuring a wide substrate scope and excellent functional group tolerance. In addition, scale-up to gram-scale and catalyst recovery were easily achieved maintaining the high efficiency of the process.
已开发出一种简单的电催化合成协议,用于介导高价碘试剂的氧化转化。在该协议中,电力驱动碘(I)/碘(III)催化循环,从而能够利用生成的高价碘物种进行催化,从而消除了化学氧化剂及其作用模式所带来的不可避免的化学废物。此外,该过程不需要添加任何额外的电解质盐。该方法已通过两种不同的高价碘介导的转化得到验证:(i) -烯丙基和 -同烯丙基酰胺的氧化环化分别生成相应的二氢恶唑和二氢-1,3-恶嗪衍生物,以及(ii) 酮的α-对甲苯磺酰氧基化。在开发的催化电化学合成条件下,这两种反应均顺利进行,无需重新优化,具有广泛的底物范围和出色的官能团耐受性。此外,很容易实现扩大到克级规模和催化剂回收,保持了该过程的高效率。