Cyclotrimerization of alkynes using a multicatalytic system, Pd(II)/chlorohydroquinone/NPMoV, under dioxygen

Article abstract of DOI:10.1016/S0040-4039(97)00780-6

Cyclotrimerization of internal and terminal alkynes was performed using a new triple catalytic system, Pd(II)/chlorohydroquinone/NPMoV, under atmospheric oxygen. Internal alkynes such as 3-hexyne and 4-octyne were converted into hexaethyl- and hexapropylbenzenes in quantitative yields. Terminal alkyne, t-butylacetylene, afforded 1,3,5-tri-t-butylbenzene without formation of unsymmetrical tri-t-butylbenzenes. The reaction did not take place in the absence of oxygen.