The separation of polar and steric effects. Part 14. Kinetics of the reactions of benzoic acid and of ortho-substituted benzoic acids with diazodiphenylmethane in various alcohols

Influence of ortho substituents on 17O NMR chemical shifts in phenyl esters of substituted benzoic acids

“…[41,42] In the previous papers we found that in substituted phenyl benzoates, (X-C 6 H 4 CO 2 C 6 H 5 , C 6 H 5 CO 2 C 6 H 4 -X) the influence of ortho substituents on the log k values in the alkaline hydrolysis, [1][2][3][4][5][6][7] the carbonyl carbon 13 C NMR chemical shifts, δ CO , [8] and the carbonyl carbon infrared stretching frequencies, ν CO , [9] was precisely described with the Charton equation [45] using the inductive, σ I , [8,46] resonance, σ°R, [8,47] and steric, E S B , [6,48] substituent constants. Nearly the same results were obtained when for ortho substituents the Charton steric scale, υ, [49] based on van der Waals radii, was used. In the phenyl esters of ortho-substituted benzoic acids (X-C 6 H 4 CO 2 C 6 H 5 ) the contribution of ortho inductive and ortho steric components were found to be the dominant factors in the alkaline hydrolysis in F o r P e e r R e v i e w 3 water, [6] the carbonyl carbon infrared stretching frequencies, ν CO , [1,9] for cis conformers as well as in the 13 C NMR chemical shifts, δ CO : [8] log k ortho (H 2 In reaction series considered (Eqns (1)- (2)) the resonance term was negligible.…”

“…21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 [2] . Charton's modified steric constants, υ, [6,8,49] were used. B , (R = 0.976, n = 10) using steric constant, υ = 1.22 [60] for OC(CH 3 ) 3 substituent.…”

“…As the steric constants for ortho substituents two steric scales were employed: the E s B constants and the Charton scale of υ. [49,60,61] The steric constants, E s B , determined on the basis of the acid hydrolysis of ortho-substitued phenyl benzoates, C 6 H 5 CO 2 C 6 H 4 -X, [6,48] in the case of substituents X = H, F, Cl, Br, I, CH 3 , C(CH 3 ) 3 , CF 3 , were found to be nearly linear function of the υ values, calculated on the bases of van der Waals radii, r v .…”

Marvin Charton - Correlation Analyst Par Excellence

“…In the early 1980s he joined in the work of Chapman and Shorter's research group in Hull on the rates of reaction of a large number of ortho-substituted benzoic acids with diazodiphenylmethane in a wide range of solvents, a collaboration which led to several papers [16,17]. A short time earlier he had contributed a long chapter on the Applications of Linear Free Energy Relationships to Polycyclic Arenes and to Heterocyclic Compounds in the Chapman-Shorter volume on "Correlation Analysis in Chemistry -Recent Advances," [18].…”

Correlation analysis of IR, 1H NMR and UV spectral data of alkyl and aryl 4,6-disubstituted-3-cyano-2-pyridones. Part I

“…On certain occasions, when other models failed, combined multiparameter equations were applied, the method known to be used before 17,18 , and with the same precision as obtained here. …”