Ag-catalyzed difluorohydration of b-alkynyl ketones for diastereoselective synthesis of 1,5-diconboyl compounds

Yi-Long Zhu, Ai-Fang Wang, Jian-Yu Du, Bo-Rong Leng, Shu-Jiang Tu*, De-Cai Wang, Ping Wei*, Wen-Juan Hao,  Bo Jiang*

A new catalytic difluorohydration of b-alkynyl ketones using NFSI as the fluorinating reagent has been established, diastereoselectively furnishing a range of structurally diverse difluoride 1,5-dicarbonyl products through C(sp³)-H fluorination. Notably, the sterically encumbered t-butyl functionality located at a-position of carbonyl group of substrates behaved the excellent diastereoselectivity (up to >99:1 dr). The reaction enabled multiple bond-forming events including two C(sp³)–F formation through Ag-catalysis to provide a high-efficient and practical method toward difluoride 1,5-dicarbonyls, some of which were successfully converted into difluorinated isoquinolines.

Chem. Commun. 2017, 54, 6397-6400 (Inside Front Cover)