Pattanayak Paramita, Satyanarayana Appanapalli N V, Chatterjee Tanmay
Department of Chemistry, Birla Institute of Technology and Science, Pilani (BITS Pilani), Hyderabad Campus, Jawahar Nagar, Hyderabad 500078, Telangana, India.
J Org Chem. 2024 Sep 20;89(18):13215-13223. doi: 10.1021/acs.joc.4c01344. Epub 2024 Sep 11.
Herein, we report a metal-free, organophotoredox-catalyzed sustainable C-H thiocyanation of a biologically active class of N-heterocycles, pyrazolo[1,5-]pyrimidines, with potassium thiocyanate (KSCN) using 9-mesityl-10-methylacridinium perchlorate as the photocatalyst (PC) and molecular oxygen as the terminal oxidant under blue-light-emitting diode irradiation at room temperature. The developed catalytic protocol features mild reaction conditions, a broad substrate scope, a high yield of products, and a straightforward scalability. Mechanistic studies revealed a radical pathway involving reductive quenching of the PC by KSCN.
在此，我们报道了一种无金属、有机光氧化还原催化的可持续反应，即在室温下蓝光发光二极管照射下，以高氯酸9-均三甲苯基-10-甲基吖啶鎓作为光催化剂（PC），分子氧作为终端氧化剂，使具有生物活性的一类氮杂环化合物吡唑并[1,5 -]嘧啶与硫氰酸钾（KSCN）进行C-H硫氰化反应。所开发的催化方法具有反应条件温和、底物范围广、产物收率高以及易于放大等特点。机理研究揭示了一条涉及KSCN对PC进行还原猝灭的自由基途径。
