- 作者: 蔡增光 ; 游靜惠
- 作者服務機構: 清華大學化學系
- 中文摘要: Semiempirical calculations of activation energies confirm the importance of orbital overlap effect on thermal reverse homo-Diels-Alder reactions and intramolecular reverse ene reactions. Computations of the transition states of cis-3,6-dimethyl-3,6- dihdropyridazine, 2,5- dimethyl-3,4-diaza bicyclo [ 4.1.0 ] hept-3-ene, 2,5- dimethyl-3,4-diaza bicyclo [ 4.2.0 ] oct-3-ene and (cis-2(S)-(2(S)-isopropyl-1-d/sub 3/)-1(S)-(1(E)-propenyl-2-d) cyclopropane indicate that activation energies are considerably decreased when optimal overlap is accomplished. The orbital overlap effect overcomes the steric effect in intramolecular reverse ene reaction of compounds such as(cis-3-R-2(S)-(2(S)-isopropyl-1-d/sub 3/)-1(S)-(1(E)- propenyl-2-d) cyclopropane in which R is a chlorine atom or a methyl group.
- 英文摘要: --
- 中文關鍵字: Activation Energy; Orbital Overlap Effect; Thermal Reverse Homo-Diels-Alder Reaction; Intramolecular Reverse Ene Reaction; Steric Effect
- 英文關鍵字: 活化能;軌域重疊效應;熱可逆同Diels-Alder反應;分子內可逆烯反應;立體效應