In this investigation, we describe solvent effect on the ethylene insertion into Cu–B bond in a (NHC)Cu(boryl) complex using MPW1PW91 quantum chemical methods. Solvent effects were explored by using the self-consistent reaction field (SCRF) method based on polarizable continuum model (PCM) in cyclopentanol, acetone, methanol, nitromethane, and dimethylsulfoxide. The progress of the reaction was quantitatively studied using the bond orders of the C–C bond of ethylene, and the percentages of bond cleavage (BCCC) of C–C bond at the transition state were described. The linear correlations between barrier energy, bond distances variations and thermodynamic parameters with dielectric constants of solvents were investigated. Rate constant of the title reaction over the temperature range of 200–1200 K was calculated in gas phase.