Coordinatively unsaturated alkyne complexes: synthesis of mono and bis-alkyne complexes of tungsten (II)

Abstract

Abstract [WBr 2 (CO 4 ] n reacts with alkynes to give complexes [WBr 2 CO(RCCR) 2 ] 2 (1) (R = R′ = Me, Et, Ph; R = Me, R′ = Ph), which react with nucleophiles L{L = CNBu t , PPh 3 , or P(OMe) 3 } to give monoalkyne derivatives (WBr 2 (CO)(RCCR′)L 2 ](2). An intermediate bis-alkyne adduct [WBr 2 CO(MeCCMe) 2 (CNBu t )] (3) was isolated in the reaction of [WBr 2 CO(MeCCMe) 2 ] 2 with CNBu t illustrating that cleavage of the dimer (1) is the first stage in these reactions.