title: A bimetallic hydroformylation catalyst: high regioselectivity and reactivity through homobimetallic cooperativity.
abstract: The racemic and meso diastereomers of an electron-rich binucleating tetraphosphine ligand have been used to prepare homobimetallic rhodium norbornadiene complexes. The racemic bimetallic Rh complex is an excellent hydroformylation catalyst for 1-alkenes, giving both a high rate of reaction and high regioselectivity for linear aldehydes, whereas the meso complex is considerably slower and less selective. A mechanism involving bimetallic cooperativity between the two rhodium centers in the form of an intramolecular hydride transfer is proposed. Mono- and bimetallic model complexes in which the possibility for bimetallic cooperativity has been reduced or eliminated are very poor catalysts.
authors.forename: M E
authors.initials: ME
authors.lastname: Broussard
authors.forename: B
authors.initials: B
authors.lastname: Juma
authors.forename: S G
authors.initials: SG
authors.lastname: Train
authors.forename: W J
authors.initials: WJ
authors.lastname: Peng
authors.forename: S A
authors.initials: SA
authors.lastname: Laneman
authors.forename: G G
authors.initials: GG
authors.lastname: Stanley