Visible-Light-Induced Chemoselective Deboronative Alkynylation under Biomolecule-Compatible Conditions

Here, we report a visible-light-induced deboronative alkynylation reaction, which is redox-neutral and works with primary, secondary and tertiary alkyl trifluoroborates or boronic acids to generate aryl, alkyl and silyl substituted alkynes. This reaction is highly chemoselective and performs well on substrates containing alkenes, alkynes, aldehydes, ketones, esters, nitriles, azides, aryl halides, alkyl halides, alcohols, and indoles, with no detectable occurrence of side reactions. The mechanism of this novel C(sp(3))-C(sp) bond coupling reaction was investigated by luminescence quenching, radical trapping, on-off light, and C-13-isotopic-labeling experiments. This reaction can be performed in neutral aqueous conditions, and it is compatible with amino acids, nucleosides, oligosaccharides, nucleic acids, proteins, and cell lysates.