Hydrative trimerization of acetylene into 2-vinyloxy-1,3-butadiene in the KOH/DMSO system: a quantum chemical insight

The previously described one-pot hydrative trimerization of acetylene to give 2-vinyloxy-1,3-butadiene in the KOH/DMSO superbase system has been studied using the MP2/6-311++G**//B3LYP/6-31+G* quantum chemical framework in which the superbase system was modeled by nDMSO center dot KOH complexes (n = 1 or 5). According to the results obtained, initial formation of acetaldehyde and its ethynylation to give acetylenic alcohol occurs in the coordination sphere of the K+ cation. The rate-determining step is the addition of the hydroxide ion to the acetylene molecule. (C) 2015 Elsevier Ltd. All rights reserved.