title: The isolation and characterization of a rhodacycle intermediate implicated in metal-catalyzed reactions of alkylidenecyclopropanes.
abstract: The isolation and characterization of a rhodacycle intermediate implicated in rhodium-catalyzed reactions of alkylidenecyclopropanes (ACPs) is described. The structure of the metallacycle was unambiguously determined by X-ray crystallography and is catalytically competent in the rhodium-catalyzed carbocyclization and ene-cycloisomerization reactions of ACPs. This work represents a rare example of the isolation of a metallacycle in a metal-catalyzed higher-order carbocyclization reaction and thereby provides important insight into the ligand requirements for the insertion of π-components. Furthermore, it serves as a convenient synthon for the development of challenging higher-order carbocyclization reactions, as exemplified by the reaction with an activated allene.
authors.affiliation: Department of Chemistry, University of Liverpool, Crown Street, L69 7ZD (UK).
authors.forename: Phillip A
authors.initials: PA
authors.lastname: Inglesby
authors.forename: John
authors.initials: J
authors.lastname: Bacsa
authors.forename: Daniela E
authors.initials: DE
authors.lastname: Negru
authors.forename: P Andrew
authors.initials: PA
authors.lastname: Evans
keywords: carbocyclization; ene-cycloisomerization; reactive intermediates; rhodium; π-allyl ligands