Paul Suvam, Das Sourav, Choudhuri Tathagata, Sikdar Papiya, Bagdi Avik Kumar
Department of Chemistry, University of Kalyani, Kalyani 741235, India.
J Org Chem. 2023 Apr 7;88(7):4187-4198. doi: 10.1021/acs.joc.2c02665. Epub 2023 Mar 13.
A visible-light-induced cross-dehydrogenative methodology has been developed for the regioselective sulfenylation of pyrazolo[1,5-]pyrimidine derivatives. Rose bengal, blue LEDs, KI, KSO, and DMSO are all essential for this photocatalytic transformation. The protocol is applicable for the synthesis of a library of 3-(aryl/heteroaryl thio)pyrazolo[1,5-]pyrimidine derivatives with broad functionalities. The selectivity and scalability of the methodology have been also demonstrated. Moreover, the efficiency of this strategy for sulfenylation of pyrazoles, indole, imidazoheterocycles, and 4-hydroxy coumarin has been proven. The mechanistic investigation revealed the radical-based mechanism and formation of diaryl disulfide as a key intermediate for this cross-dehydrogenative coupling reaction.
已开发出一种可见光诱导的交叉脱氢方法，用于吡唑并[1,5 - ]嘧啶衍生物的区域选择性亚磺酰化。孟加拉玫瑰红、蓝色发光二极管、碘化钾、硫酸钾和二甲基亚砜对于这种光催化转化都是必不可少的。该方案适用于合成具有广泛官能团的一系列3 - （芳基/杂芳基硫代）吡唑并[1,5 - ]嘧啶衍生物。该方法的选择性和可扩展性也得到了证明。此外，该策略用于吡唑、吲哚、咪唑杂环和4 - 羟基香豆素亚磺酰化的效率也得到了证实。机理研究揭示了基于自由基的机理以及二芳基二硫醚作为这种交叉脱氢偶联反应的关键中间体的形成。
