An experimental and computational investigation of the mechanism of the deoxygenation of THF by atomic carbon

Article abstract of DOI:10.1021/ja00165a017

An ab initio investigation (MP2/6-31G*//3-21G) of the deoxygenation of tetrahydrofuran (1) to ethylene and CO by atomic carbon reveals a low-energy concerted pathway, which yields the products directly in a 3-bond cleavage. The geometry of the transition state for this process, calculated at the HF/3-21G level, indicates a nonsynchronous process in which the C-O bonds are cleaved to a greater extent than the C-C bond. When C atoms are reacted with a 1:1 mixture of 1 and 1-d₈, the products are ethylene and ethylene-d₄ in a 2.1:1 ratio. This ratio represents a mean secondary kinetic isotope effect (KIE) k(H)/k(D) = 1.13 per H and is close to a value of 1.12 calculated from the computed amount of rehybridization in the transition state and the corresponding equilibrium isotope effects.