Work

Regioselective C‐H Thio‐ and Selenocyanation of Pyrazolo[1,5‐a]pyrimidines

Year: 2025

Type: article

Abstract: Herein, we report a metal-free, N-chlorosuccinamide (NCS)-mediated, highly efficient, and regioselective C-H thio- and selenocyanation of pyrazolo[1,5-a]pyrimidines using KSCN and KSeCN respectively. The transformation required only NCS (1 equiv) and operated under mild conditions such as ambient temperature and aerobic atmosphere. This method was found to be highly efficient for the C-H thiocyanation of pyrazolo[1,5-a]pyrimidines as compared to our previously developed photocatalytic strategy and also enabled the C-H selenocyanation of the substrates to access 3-selenocyanatopyrazolo[1,5-a]pyrimidines, for the first time, which was unexplored or unsuccessful so far. A wide variety of new pyrazolo[1,5-a]pyrimidines bearing -SCN or -SeCN functional groups were synthesized in good to excellent yield. The developed protocol features a broad substrate scope, high functional group tolerance, mild conditions, high to excellent yield of products, efficient scalability, and synthetic diversifications of products. Mechanistic studies revealed an ionic pathway for this reaction.

Source: Chemistry - An Asian Journal

DOI: 10.1002/asia.202401610

Authors: Paramita Pattanayak, Harshil Khandelwal, Shreeja Basappa, Tanmay Chatterjee

Institutions: Birla Institute of Technology and Science - Hyderabad Campus, Birla Institute of Technology and Science, Pilani

Language: English

Topic: Sulfur-Based Synthesis Techniques

Subfield: Organic Chemistry

Field: Chemistry

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $4,520

Funders: Department of Science and Technology, Ministry of Science and Technology, India, Council of Scientific and Industrial Research, India, Birla Institute of Technology and Science, Pilani, Science and Engineering Research Board