Umpolung Synthesis\nof Selenoesters and Telluroesters\nvia the Photoinduced Coupling of Acylsilanes with Electrophilic Chalcogen\nReagents

A novel\nsynthesis of selenoesters and telluroesters based\non the\nreactions of nucleophilic siloxycarbenes, which were generated by\nthe visible-light-induced isomerization of the corresponding aroyl-,\nheteroaroyl-, or alkenoylsilanes, with electrophilic chalcogen reagents\nwas developed. The use of appropriate selenides or ditellurides/Lewis\nacids enabled the coupling at temperatures below ambient temperature\nwith a broad substrate scope and high functional-group tolerance.\nTo the best of our knowledge, this is the first example of a synthetic\nmethod for selenoesters and telluroesters involving the combination\nof an acylanion equivalent and cationic chalcogen synthons.