Search results for "Nitrile ylide"
showing 2 items of 2 documents
A new model for C–C bond formation processes derived from the Molecular Electron Density Theory in the study of the mechanism of [3+2] cycloaddition …
2016
Abstract The [3+2] cycloaddition (32CA) reactions of the nitrile ylide (NY) with ethylene and with dicyanoethylene (DCE) have been studied using the Molecular Electron Density Theory through DFT calculations at the MPWB1K/6-31G(d) level. The analysis of the electronic structure of NY indicates that it presents a carbenoid structure with an sp 2 lone pair at the carbon atom. While the 32CA reaction with ethylene presents a low activation energy, 6.1 kcal mol −1 , the transition state structure associated with the 32CA reaction of NY with DCE is located 7.5 kcal mol −1 below the reagents, the reaction being completely regioselective. The topological analysis of the Electron Localisation Funct…
An MEDT study of the carbenoid-type [3 + 2] cycloaddition reactions of nitrile ylides with electron-deficient chiral oxazolidinones.
2016
The molecular mechanism of the carbenoid-type [3 + 2] cycloaddition (32CA) reactions of a nitrile ylide (NY) with a non-chiral and a chiral oxazolidinone has been studied within Molecular Electron Density Theory (MEDT) at the MPWB1K/6-31G(d) computational level. Topological analysis of the Electron Localisation Function (ELF) of the NY shows that it presents a carbenoid structure. The high nucleophilic character of the NY together with the electrophilic character of the non-chiral oxazolidinone favour a polar 32CA reaction with a very low activation energy, the reaction being completely meta/endo selective. A Bonding Evolution Theory (BET) study of the molecular mechanism makes it possible …