Theoretical studies of the ring opening metathesis reaction of 3,3-dimethyl cyclopropene with molybdenum catalyst

Ring opening metathesis reaction of 3,3-dimethyl cyclopropene with catalyst Mo(NH)(CH2)(OCH3)2 alkylidene has been studied computationally using DFT method. The complete catalytic cycle proceeds in two steps i.e. cycloaddition and ring opening. Each step involved a distorted trigonal bipyramidal transition structure. Cyclopropene may be either syn or anti to the NH group of the alkylidene but syn orientation is more favorable for product formation. With the molybdenum model catalyst, the energy barriers of the syn cycloaddition and syn ring opening reactions are 7.6 and 5.97 kcal/mol respectively. The ring opening step has lower energy barrier than the cycloaddition reaction. Thermodynamically the syn ring opening product is significantly more stable than the anti product by 2.04 kcal/mol.