Oxidative Cross-Coupling of Cysteamine with Secondary Phosphine Chalcogenides: Aspects of Reaction Chemoselectivity

Cysteamine (2-aminoethanethiol) undergoes oxidative cross-coupling with secondary phosphine sulfides and phosphine selenides under mild conditions (room temperature, 2–5 h, CCl4/Et3N) to give products of monocoupling at the amino group (ethylchalcogenophosphinic amides with free SH functions) and dicoupling (l-chalcogenophosphorylamino-2-chalcogenothioethanes) in 72–85% total yield. Under similar conditions, stirring an equimolar mixture of bis(2-phenylethyl)phosphine sulfide (or selenide), 1-butylamine, and 1-butanethiol leads to the chemoselective formation of the corresponding chalcogenophosphinic amides in high yield.