Highly Selective Phosphinotelluration of Terminal Alkynes Using a (Ph2P)2−(PhTe)2 Mixed System upon Visible Light Irradiation: Straightforward Access to 1-Phosphino-2-telluro-alkenes

Simultaneous and regioselective introduction of both phosphino and telluro groups into carbon−carbon triple bonds has been attained successfully by using a novel mixed system of diphosphine and ditelluride under visible light irradiation conditions. Upon irradiation with a xenon lamp (500 W) through the filter (hν > 400 nm), terminal alkynes undergo highly selective phosphinotelluration in the presence of tetraphenyldiphosphine and diphenyl ditelluride, affording 1-(diphenylphosphino)-2-(phenyltelluro)alkenes, regioselectively, in moderate to good yields. The regioselectivity of this phosphinotelluration of terminal alkynes is discussed by comparison with those of the thiophosphination using a (Ph2P)2−(PhS)2 binary system and the selenophosphination using a (Ph2P)2−(PhSe)2 binary system.