水催化2个酯分子相互转化反应的理论研究  

Theoretical Studies on Water Catalysis of Two Esters Interconversion Reaction

作　　者：蒋举兴[1,2] 王家俊[1,2] 段焰青[1,2] 刘亚[1,2] 王文元[1,2] 吴少华[3] 

机构地区：[1]云南中烟工业有限责任公司技术中心,昆明650202 [2]红云红河烟草(集团)有限责任公司技术中心,昆明650202 [3]云南大学云南省微生物研究所、育部微生物重点实验室,昆明650091

出　　处：《高等学校化学学报》2014年第9期1919-1925,共7页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金(批准号:21062027);云南中烟基金(批准号:2011JC08);国家烟草专卖局基金(批准号:110201201009 BR-03)资助~~

摘　　要：从印楝植物内生真菌Phomopsis sp.培养液中分离得到的4-acetoxymultiplolide(1)和1-acetoxymultiplolide(2)在室温及水存在下能够相互转化.提出二者相互转化最可能的4个途径(机理A^D).在B3LYP/6-311+G(d,p)水平进行气相条件的优化,结果表明,无水催化的机理A中TS1和TS2的活化能均显著大于120 kJ/mol,2个分子水催化的机理D中TS1和TS2的活化能则显著降低.计算结果显示水的溶剂化效应能进一步降低机理D中TS1和TS2的活化能.在MP2/6-311++G(2d,2p)//B3LYP/6-311+G(d,p)水平计算了单点能,得到在水相时机理D中TS1和TS2的活化能分别为106.24和107.37 kJ/mol.因此,机理D是化合物1和2在室温下及水存在时相互转化最可能的途径,该途径是一种特殊的水催化分子内酯的醇解反应,也是一种经典的亲核加成反应,通过一种新的叔醇中间体实现.Compounds 1 and 2 could interconverse to each other at room temperature when water was encoun-tered. Four possible interconversion mechanisms, A, B, C and D, were put up. At B3LYP/6-311＋G（d,p） level in gas phase, the optimized activation energies of TS1 and TS2 in mechanism A were all distinctively more than 120 kJ/mol. But as for mechanism D, the optimized activation energies of TS1 and TS2 were dra-matically decreased. Further results showed that the solvation effects of water also reduced the activation ener-gy. Meanwhile, the single point energy were calculated at MP2/6-311＋＋G（2d,2p）//B3LYP/6-311＋G（d,p） level. Finally the activation energies of TS1 and TS2 in mechanism D were 106. 24 and 107. 37 kJ/mol, re-spectively. Therefore, mechanism D was the most possible pathway for the interconversion between compounds 1 and 2 at room temperature. This preferred mechanism pathway was a special water-catalyzed intramolecular oxoester alcoholysis, which also was a conventional nucleophilic addition, producing a novel tetrahedral alco-holic intermediate.

关 键 词：分子内酯交换反应 水催化 活化能 密度泛函理论计算 二级微扰理论计算 

分 类 号：O641.12[理学—物理化学]