The stabilization and reactivity of strained cyclic alkynes on transition metal centres

Abstract

Small cycloalkynes that are short-lived or unknown in the free state can be stabilized by coordination to low-valent transition metal fragments such as ML 2 (M = Ni, Pt; L = various tertiary phosphines) or ZrCp 2 (PMe 3). The preparation and reactivity of some of the resulting compounds, including Pt(PPh 3) 2 (cyclopentyne), ZrCp 2 (benzyne)(PMe 3), ML 2 (benzyne) (M = Ni, Pt; L = PEt 3, PPrt 3, PCy 3), and Ni 2 (Cy 2 PCH 2 CH 2 PCy 2) 2 (u-l,4-benzdiyne), are discussed. © 1989 IUPAC