Acidities of stable simple enols and bond dissociation enthalpies of their H-O bonds in DMSO

被引:11
作者
Bordwell, FG [1 ]
Zhang, SZ [1 ]
Eventova, I [1 ]
Rappoport, Z [1 ]
机构
[1] HEBREW UNIV JERUSALEM,DEPT ORGAN CHEM,IL-91904 JERUSALEM,ISRAEL
关键词
D O I
10.1021/jo970404i
中图分类号
O62 [有机化学];
学科分类号
070303 ; 081704 ;
摘要
The PKHA values for eight stable enols and the oxidation potentials of their anions, E-OX(A(-)), were determined in DMSO, and the bond dissociation enthalpies (BDE) of their O-H bonds were estimated using the equation, BDEHA = 1.37pK(HA) + 23.1E(OX)(A(-)) + 73.3 kcal/mol (1). For Mes(2)C=C-(OH)R enols the PKHA's increase with the bulk of R from 17.8 for R = H to 19.9 for R = t-Bu; the E-OX(A(-)) values become more negative, and the BDEs decrease from 82.2 kcal/mol for R = H to 78.3 for R = t-Bu. The PKHA values roughly parallel the association constants of the enols with the DMSO solvent. These values are discussed in terms of steric and electronic effects.
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收藏
页码:5371 / 5373
页数:3
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