Yongsheng Zhang,[b] Jordan Diaz,[b] Sudip Senapati,[c] Kannika La-ongthong,[b][d] Yeong Chyuan Ung,[b] Chutima Kuhakarn,[d] Jianwen Jin,[a][b],* Rene M. Koenigs,[c],* and Philip Wai Hong Chan[b],*

[a] Institute for Advanced and Applied Chemical Synthesis, College of Pharmacy, Jinan University, Guangzhou, Guangdong 510632, China

[b] School of Chemistry, Monash University, Clayton, Victoria 3800, Australia

[c] University of Bayreuth, Organic Chemistry II, Universitätsstr. 30, 95447 Bayreuth, Germany

[d] Department of Chemistry and Center of Excellence for Innovation in Chemistry (PERCH-CIC), Faculty of Science, Mahidol University, Bangkok 10400, Thailand

A photoinitiated synthetic method for the site-selective chlorination at the unactivated secondary and tertiary -C(sp3)–H bond of ketones and (E)-1,3-enones, and -position of alkylbenzenes by chloramine-T (CAT) and N-chlorosuccinimide (NCS) under blue LED (max = 456 nm) light irradiation was developed. The reaction proceeded via a radical mechanism where the chlorination reagent dichloramine-T (DCT) is generated in situ from the reaction of CAT with NCS. The developed protocol operates under mild reaction conditions at room temperature and demonstrates excellent functional group tolerance as exemplified by the site-selective -C(sp³)–H bond chlorination of carboxylic esters and amides, and late-stage functionalization of several bioactive natural products and drug molecules.

Zhang, Y.; Diaz, J.; Senapati, S.; La-ongthong, K.; Ung, Y.C.; Kuhakarn, C.; Jin, J.; Koenigs, R. M.; Chan, P.W.H. Chin. J. Chem. 2026, 44, 377-364. DOI: 10.1002/cjoc.70367