Base-catalyzed stereoselective thiosulfonylation of ynones for the facile synthesis of thio-functionalized vinyl sulfones†
Abstract
The first catalytic vicinal thiosulfonylation of ynones has been developed. Under the catalysis of 1–20 mol% Cs2CO3, various ynones underwent the Michael addition/nucleophilic substitution tandem reaction with different thiosulfonates to form C–SO2 and C–S bonds simultaneously and produced thio-functionalized vinyl sulfones in high yields and with excellent E-selectivity. In addition, on using K3PO4 as the base, ynones can couple with trifluoromethyl thiosulfonates through a similar tandem process to afford the corresponding trifluoromethylthiolated products in good to high yields with excellent stereoselectivity.