Synthesis and reactivity of selenium functionalised allylidynes and propargylidynes†
Abstract
The reactions of the trimethylsilylpropargylidyne [W(CCCSiMe3)(CO)2(Tp*)] (1: Tp* = hydrotris(dimethylpyrazolyl)borate) towards selenium centred reagents when treated with tetrabutylammonium fluoride (TBAF) were explored in order to prepare alkynylselenolato propargylidynes, e.g., [W(CCCSePh)(CO)2(Tp*)]. Treating 1 with TBAF and PhSeSePh resulted in E and Z isomers of the vinylcarbyne (allylidyne) complex [W{CC(SePh)CHSePh}(CO)2(Tp*)] in addition to traces of the trisubstituted derivative [W{CC(SePh)C(SePh)2}(CO)2(Tp*)]. Reactions with PhSeCl resulted in the isolation of bimetallic bis-substituted allylidyne complex [(Tp*)(CO)2WCC(SePh)C(SePh)CCCW(CO)2(CO)2(Tp*)] as well as the desired selenolatopropargylidyne [W(CCCSePh)(CO)2(Tp*)].