The pKa of 2-, 3-and 4-substituted quinuclidinium perchlorates and the solvolysis rates of the corresponding bicyclo[2.2.2loctyl-l-pnitrobenzenesulfonates reveal the dispersal of charge in ammonium ions and carbocations. Recent studies1 have shown that the solvolysis rates (log k) of several substi
Inductivity and Bridging in 2-Bicyclo[2.2.2]octyl Cations. Polar Effects, Part 11
β Scribed by Cyril A. Grob; Pawel Sawlewicz
- Publisher
- John Wiley and Sons
- Year
- 1984
- Tongue
- German
- Weight
- 616 KB
- Volume
- 67
- Category
- Article
- ISSN
- 0018-019X
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β¦ Synopsis
Inductivity was defined as thc reaction constant p, in the equation log (klk,) = pluq, where k and k, are fmt-order rate consmiits for the substitutcd and unsubstituted tosylates, respectively, in 80% EtOH and u? i s the corresponding inductive substituent constant [3]. For recent reviews, see [2]. X-ray data [&I] show that the C(2)-C(7) distance (2.40 A) in 2 is actually shorter than the C(2)-C(6) distancc (2.50 A) in 1.
π SIMILAR VOLUMES
As derived from the Hammetr equation log k/ko = pI 'cr ? where k and ko are rate constants for substituted and unsubstituted tosylates, respectively, and u? are inductive substituent constants [2]. The p , values for C(1) in 3 and 4 are presented and discussed in this communication. The dotted lines
Standard deviations of the pK,, upon which n? values are based, and of the conductometric rate measurements, as well uncertainties regarding the orientation of dipolar substituents, contribute to this limitation, as in most Hammett treatments. The I3C-NMR signals for the a-, /3-, and r-C-atoms in th
The effects of substituents at C5, C6 and C7 on the solvolysis rates of 2-norbornyl p-toluene sulfonates confirm that through space induction is directional and depends on distance and bridging strain.
Hydrolysisofbicyclo[2.2.2]octylp-nitrobenzenesulfonate (14a,X =p-N02C6H4S03), and nineteen 4-R-substituted derivatives 14b-14 t in 70% aqueous dioxane yield the corresponding bicyclo [2.2.2]octanols 14 (X = OH), exclusively. The 7-center fragmentation to 1,4-dimethylidene-cyclohexane (15) is not obs
## Abstract The rate constants (log __k__) for the solvolysis of 4^e^βsubstituted 2^e^β and 2^a^βadamantyl __p__βnitrobenzenesulfonates **14** and **15**, respectively, in 80% EtOH correlate linearly with the respective inductive substituent constants Ο. Therefore, relative rates are controlled by