| Abstract: | Reactions involving the (4 + 2)-cycloaddition of phosphaalkenes to 1,3-butadiene have been characterized in the framework of the frontier-orbital approach. MNDO and nonempirical calculations in the 4-31G basis have shown that most of these reactions take place under normal electronic conditions. The  -electronic stabilization energies of the transition states of the reactions have been evaluated. The influence of substituents on the relative rate and regioselectivity of the reactions of phosphaalkenes with derivatives of 1,3-butadiene has been considered.Institute of Organic Chemistry, Academy of Sciences of the Ukrainian SSR, Kiev. Scientific-Research Institute of Technical Physics, Far-Eastern University. Vladivostok. Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 27, No. 4, pp. 462–466, July–August, 1991. Original article submitted October 12, 1990. |
