Visible-light induced click reactions of acylsilanes with pyruvate electrophiles

Siloxycarbene intermediates induced via the visible light irradiation of acylsilanes undergo highly efficient benzoin-type click reactions with pyruvate derivatives. This process requires no reagents other than visible light, proceeds with high efficiency and is tolerant of a wide range of functional groups. Pyruvate esters, thioesters, amides, nitriles and phosphonates were all identified as suitable electrophiles including those tethered to complex drug or biomolecule scaffolds. The visible-light induced carbon-carbon bond forming process was scalable using both batch and flow methodologies, accompanied by diversification studies on the corresponding addition products. Mechanistic insights into siloxycarbene reactivity were also obtained by DFT analysis.