Further observations on the dimerisation of alkynes on triruthenium clusters

• Published in: Journal of organometallic chemistry 1998-02, Vol.552 (1), p.109-125
• Main Authors: Bruce, Michael I, Hinchliffe, Jonathan R, Humphrey, Paul A, Surynt, Richard J, Skelton, Brian W, White, Allan H
• Format: Article
• Language: English
• Subjects: Alkynes; Dimerisation; Triruthenium clusters
• ISSN: 0022-328X; 1872-8561
• DOI: 10.1016/S0022-328X(97)00492-0

The reaction between Ru 3{ μ 3-PPhCH 2PPh(C 6H 4)}(CO) 9 ( 2) and HC 2Ph resulted in insertion of a diene formed by coupling of the alkyne into an Ru–P(phosphido) bond to give a PPh(C 6H 4)CH 2PPh(C 4H 2Ph 2) ligand. Thermolysis regenerated the original phosphido–phosphine ligand and the alkyne dimer, which was coordinated in the usual 2 η 1: η 4-mode. Similar metallacyclopentadiene complexes were obtained from 2 and HC 2CO 2Me, from Ru 3{ μ 3-RC 2(CO 2Me)}( μ-dppm)( μ-CO)(CO) 7 and C 2Ph 2 [R=CO 2Me, H (2 isomers)], and from [Ru 3( μ 3-PPhCH 2PPh 2)(CO) 9] − and C 2Ph 2, followed by protonation. X-ray structures are reported for the complexes Ru 3{ μ 3-C 2Ph 2C 2(CO 2Me) 2}( μ-dppm)(CO) 6 ( 5) and two isomers of Ru 3{ μ 3-C 2Ph 2 CHC(CO 2Me)}( μ-dppm)(CO) 6 ( 8a and 8b), Ru 3{ μ 3-PPh(C 6H 4)CH 2PPh(C 4H 2Ph 2)}( μ-CO)(CO) 6 ( 9) and Ru 3( μ-H)( μ 3-PPhCH 2PPh 2)( μ-C 4Ph 4)(CO) 6 ( 12). In 5, 8a and 8b, one of the ester CO groups is bonded to an Ru atom also coordinated to phosphorus.