Reference

The importance of the s*-p* orbital mixing for the nucleophilic displacement on the unsaturated carbon

The importance of the s*-p* orbital mixing for the nucleophilic displacement on the unsaturated carbon. Yamabe, Shinichi; Minato, Tsutomu; Kawabata, Yumi (Dep. Chem., Nara Univ. Educ., Nara 630, Japan). 50-00-0 and 75-36-5 are cas registry numbers. These chemicals are also mentioned in this article. Can. J. Chem., 62(2), 235-40 (English) 1984. CODEN: CJCHAG. ISSN: 0008-4042. DOCUMENT TYPE: Journal CA Section: 22 (Physical Organic Chemistry) The reactivity of carbonyl and arom. compds. toward nucleophilic displacement is studied theor. The LUMO obtained by mixing the p* with the s* MO is a uniform criterion of the relative reactivity of substrates. The presence or absence of a tetrahedral intermediate depends on the energy difference between the p* and s* MO's. .

Transition-state structural features for anilide hydrolysis from b-deuterium isotope effects

Transition-state structural features for anilide hydrolysis from b-deuterium isotope effects. Stein, Ross L.; Fujihara, Hisashi; Quinn, Daniel M.; Fischer, G.; Kuellertz, G.; Barth, A.In this study， 88548-58-7 and 75-36-5 are also used.; Schowen, Richard L. (Dep. Chem., Univ. Kansas, Lawrence, KS 66045, USA). J. Am. Chem. Soc., 106(5), 1457-61 (English) 1984. CODEN: JACSAT. ISSN: 0002-7863. DOCUMENT TYPE: Journal CA Section: 22 (Physical Organic Chemistry) The D isotope effect on the alk. hydrolysis of p-O2NC6H4NHCOR (I; R = Me, CD3) is at a max. at OH- concn. ~ 0.03M as the reaction involves a base-dependent mixt. of rate-limiting transition states. At the lowest OH- concns. decompn. of a unineg. tetrahedral adduct predominates. In the intermediate range decompn. of a dineg. adduct is important and at the highest OH- concns. nucleophilic substitution of OH- on I is the major path. These isotope effects are consistent with quasi-tetrahedral transition states for formation and decompn. of the unineg. adduct and with rate-limiting trapping or diffusional sepn. of AcO- and p-O2NC6H4NH- for decompn. of the dineg. adduct. The temp. dependence of the isotope effect at 0.208 M OH- concn. is consistent with a shift in limitation away from the nucleophilic substitution transition state towards the dineg. adduct transition state, as the temp. is raised, and with simple zero-point-energy origins for the individual isotope effects. .