Affiliations: Dipartimento di Chimica “G.Ciamician”, Universita' di Bologna, via Selmi 2, 40126 Bologna, Italy
Correspondence:
[2]
Corresponding author.
Note: [1] andrea@ciamserv.ciam.unibo.it.
Note: [3] nando@ciamserv.ciam.unibo.it.
Note: [4] giampi@ciamserv.ciam.unibo.it.
Abstract: In this paper we have reported the results of theoretical investigations at the DFT level on the mechanism of some representative organometallic reactions. In all cases the non-local hybrid B3LYP functional has been used. The reactions examined here are: (a) the cyclopropanation reactions promoted by transition metal complexes and (b) the nickel-catalyzed carbonylation reactions. In the former case we have considered in details the Simmons-Smith reaction and the cyclopropanation promoted by palladium complexes. It has been found that the active cyclopropanating reagent is always a carbenoid species [L]-M-CH2-X (I., X = ligands) and that the cyclopropanation promoted by palladium complexes proceeds either via a concerted mechanism or a multi-step mechanism involving palladacyclobutane intermediates. For the carbonylation reactions we have examined in details the mechanism of the insertion of a CO molecule into a nickel-carbon bond. This step corresponds to a complicated process involving either four-coordinated or five-coordinated nickel complexes.
Keywords: Organometallic reactivity, Reaction mechanism, Potential energy surface, DFT computations
