Visible light-induced hydrogen atom transfer trifluoromethylthiolation of aldehydes with bismuth catalyst.

By using a combination of BiCl3 and TBACl as a ligand-to-metal charge transfer (LMCT) photocatalyst, hydrogen atom transfer trifluoromethylthiolation of aldehydes was achieved under visible light irradiation. The present method provides economical and operationally simple access to trifluoromethylthioesters using low toxicity and cost-effective bismuth catalysts under mild reaction conditions. Based on the radical trapping experiments, the direct conversion of aldehydes to acyl radicals via chlorine radicals as HAT reagents was proposed as the reaction mechanism.

Photocatalyst-free visible light driven synthesis of gem-dihaloenones from alkynes, tetrahalomethanes and water.

Photocatalytic reactions, in particular, processes without photosensitisers, have attracted increased attention due to their green aspect and high economic value and are considered valuable tools in organic synthesis. A new practical photocatalytic system was investigated in this study, and it can efficiently produce gem-dihaloenones by combining terminal alkynes with tetrahalomethanes (BrCCl3 and CBr4) and water without a photocatalyst, and the yield can reach up to 87%. The catalytic system is straightforward, the raw materials are inexpensive and easy to obtain, and the operation is simple.