Computational study of the CO elimination reaction of cyclopropylmethoxy carbenes

Abstract The (CO) elimination reaction of cyclopropylmethoxy (fluoro/chloro) carbenes ( C – X , X = H , F , Cl ) and its consequent rearrangement products are studied computationally using B3LYP/6-311++G** method. Results of this study show that the reaction proceeds via a first TS corresponding to the cyclopropylmethoxy (chloro/fluoro) carbenes ( C – X , X = H , F , Cl ). The negative mode of this TS species corresponds to the elimination of the CO molecule, consistent with the experimentally proposed mechanism. Effects of the X substitution on the electronic and energetic properties of this conversion which is an intermediate step of the conversion of 3-cyclopropylmethoxy-3-(fluoro/chloro) diazirines ( D – X , X = H , F , Cl ) to different products are also investigated. Calculations are also carried out for reactants and products of this reaction at the same level of theory. Nuclear quadrupole coupling constants and asymmetry parameter of the 35 Cl and 14 N nuclei have also been calculated and analyzed for reactants, TSs and products, as probes of the reaction coordinate.