Photoinduced group transfer radical addition of carbamotelluroates to acetylenes

[GRAPHICS] Te-Phenyl carbamotelluroates 1 add to acetylenes under irradiation of visib le light to yield beta -telluroacrylamides 2 regioselectively. This reactio n would be initialed by homolytic cleavage of the carbamoyl carbon-telluriu m bond, producing carbamoyl and PhTe radicals, The addition reaction procee ds via a radical chain mechanism comprising two processes: (i) addition of carbamoyl radicals at the terminal carbon of the triple bond, giving vinyli c radicals, and (ii) S(H)2 reaction on the Te atom caused by the attack of the vinyl radicals to 1.