Theoretical Studies on Hatero Diels-Alder Reactions of Sulfur Dimides

초록

The gas-phase hetero Diels-Alder cycloaddition reactions of slfur dimides, HN=S+-N-X where X=CH3,H,Cl,CN and NO2, with 1,3-butadiene are investigated theoretically at the B3LYP/6-31G* level. The most stable isomers of sulfur dimides have Z,Z-forms which are more stable than the least stable E,E-forms by 6 ~11 kcal mol-1. The reactions proceed mostly with HN= S+-N-X (2) rather than HN--S+=NX (2?, even with an electron-donor X (=CH3). The activation energy (DG? is the lower, the stronger the electron-accepting ability of X.