Computational Insight Concerning Catalytic Decision Points of the Transition Metal Catalyzed [2 + 2 + 1] Cyclocarbonylation Reaction of Allenes.

ABSTRACT: Rhodium and molybdenum catalyzed allenic [2 + 2 + 1] cycloaddition reactions give 4-alkylidene and α-alkylidene cylopentenones, respectively. The selective reaction of one double bond of the allene over another is controlled by the transition metal and not the substrate structure. Calculations were performed to explain this unique control element using the B3LYP functional as implemented in Gaussian 03. The 6-31G(d) basis set was applied to all elements except rhodium, which is described with the LANL2 effective core potential and the LANL2DZ basis set. The product-determining step for both reaction pathways is oxidative addition of the metal to the alkynyl allene to form the corresponding metallocycles B and B'. The transition state calculations strongly suggest that geometry constraints

SUBMITTER: Bayden AS 

PROVIDER: S-EPMC4441411 | biostudies-literature | 2006 Oct

REPOSITORIES: biostudies-literature