Water-promoted regioselective hydrothiolation of alkynes

Water promotes hydrothiolation of unactivated alkynes efficiently without any catalyst or additive. The reaction at room temperature furnishes vinyl sulfides with high regioselectivity via anti-Markovnikov addition. The terminal alkynes provide dithiolanes at 80[degrees]C by bis-addition. The reactions are very clean and high yielding. Key words: alkynes, hydrothiolation, vinyl sulfides, regioselectivity, water. L'eau favorise l'hydrothiolation des alcynes non actives d'une facon efficace, sans catalyseur ou additif. A la temperature ambiante, la reaction conduit a la formation de sulfures de vinyle, avec une regioselectivite par le biais d'une addition anti-Markovnikov. Les additions a 80[grados]C sur des alcynes terminaux conduisent a des dithiolanes resultant d'une bis-addition. Les reactions sont tres propres et les rendements sont eleves. Mots-cles : alcynes, hydrothiolation, sulfures de vinyle, regioselectivite, eau. [Traduit par la Redaction]
Introduction The hydrothiolation of alkynes by thiols is a very interesting and challenging reaction being associated with mono- and bis-condensation, Markovnikov and (or) anti-Markovnikov addition, and stereoselectivity. This reaction is [...]