摘要

The solvent effect on the reaction mechanism of the Pd(II)-catalyzed cycloisomerization of 4-aza-1-cyclopropyl-1,6-enyne toward 3-aza-bicyclo[4.1.0]heptene and homo-ene product was investigated via density functional theory. Four different Pd complexes, PdCl2{P(OPh)(3)}, PdCl2(PPh3), Pd{P(OPh)(3)}, and Pd(PPh3) as hypothetical active catalyst species were applied to (E)-N-(but-2-ynyl)-N-(3-cyclopropylallyl) amine model substrate in 1,4-dioxane and dichloroethane solvent environment. Reaction pathways toward (Z)-3-((Z)-buta-1,3-dien-1-yl)-4-ethylidenepyrrolidine (homo-ene product) and 7-cyclopropyl-6-methyl-3azabicyclo[4.1.0]hept-4-ene were obtained and energetic differences were compared. The selective formation of 3-aza-bicyclo[4.1.0] heptenes in toluene at 130 degrees C that was not reproduced in other solvents at lower temperatures was likely because of the catalyst effect rather than the solvent effect.

  • 出版日期2016-6