Reactivity of some tertiary chlorides with olefinic and methoxy neighboring groups. A case of extended ?, n-participation
作者:Sandra Juri?、Olga Kronja
DOI:10.1002/poc.492
日期:2002.8
Tertiary 2-chloro-2-methyl-5-methoxypentane (2) solvolyzes with a significantly reduced secondary β-deuterium kinetic isotopeeffect (substrate with two trideuteromethyl groups), and with smaller entropy and enthalpy of activation than the reference saturated analog 4 [kH/kD = 1.35 ± 0.01 VS kH/kD = 1.79 ± 0.01; ΔΔH≠ = −11 kJ mol−1; ΔΔS≠ = −30 J mol−1 K−1, in 80% (v/v) aqueous ethanol], indicating
Evidence for extended ?,n-participation in solvolysis of some benzyl chlorides
作者:Sandra Juri?、Anita Filipovi?、Olga Kronja
DOI:10.1002/poc.687
日期:2003.12
Chlorides 3 (1-aryl-1-chloro-4-methyl-7-methoxy-4-heptene) and 4 (1-aryl-1-chloro-4-methyl-4-hexene) with various phenyl substituents were prepared (Y=p-OCH3, p-CH3, H and m-Br) and the solvolysis rates were measured in 80% (v/v) aqueous ethanol. The rate constants of 3 correlate well with σ+, and the ϱ+ value obtained is −1.45±0.15, whereas with 4 breakdown of the Hammett plot occurs, and the ϱ+ value