Correlation of the Rates of Solvolysis of Isopropyl Fluoroformate Using the Extended Grunwald-Winstein Equation

Bulletin of the Korean chemical society

Chan Joo Rhu¹  Dennis N. Kevill¹  Jin Burm Kyong¹  Dong Kook Kim¹  So Hee Lee¹ 

关键词: Isopropyl fluoroformate;    Addition-elimination;    Grunwald-Winstein equation;   

DOI  :  

学科分类：化学（综合）

来源: Korean Chemical Society

【 摘 要 】

The specific rates of solvolysis of isopropyl fluoroformate are well correlated using the extended Grunwald-Winstein equation, with a sensitivity (l ) to changes in solvent nucleophilicity (N_T) and a sensitivity (m) to changes in solvent ionizing power (Y_Cl). The sensitivities (l = 1.59 �? 0.16 and m = 0.80 �? 0.06) toward changes in solvent nucleophilicity and solvent ionizing power, and the k_F/k_Cl values are very similar to those for solvolyses of n-octyl fluoroformate, suggesting that the addition step of an addition-elimination mechanism is rate-determining. For methanolysis, a solvent deuterium isotope effect of 2.53 is compatible with the incorporation of general-base catalysis into the substitution process. The large negative values for the entropies of activation are consistent with the bimolecular nature of the proposed rate-determining step. These observations are also compared with those previously reported for the corresponding chloroformate and fluoroformate esters.

【 授权许可】

Unknown