Solvolysis of 2-aryl-2-adamantyl p-nitrobenzoates and some tertiary benzylic p-nitrobenzoates. YBnOPNB and YxBnOPNB scales

✍ Scribed by Kwang-Ting Liu; Chih-Wei Chang; Hung-I Chen; Chien-Pu Chin; Yeh-Fang Duann

• Book ID: 101289041
• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 66 KB
• Volume: 13
• Category: Article
• ISSN: 0894-3230
• DOI: 10.1002/(sici)1099-1395(200004)13:4<203::aid-poc230>3.0.co;2-9

✦ Synopsis

Solvolysis rate constants for a number of tertiary benzylic p-nitrobenzoate esters in a wide range of solvents were measured. New scales of solvent ionizing power for Grunwald-Winstein-type correlation analyses, Y BnOPNB from 2-phenyl-2-adamantyl p-nitrobenzoate and Y xBnOPNB from 2-(6-methoxy-2-naphthyl)-2-adamantyl p-nitrobenzoate, were developed for the mechanistic study of solvent effects on the solvolytic reactivity of benzylic p-nitrobenzoates. The excellent linear log k -Y BnOPNB plot for 2-(4-methylphenyl)-2-propyl p-nitrobenzoate indicated a limiting S N 1 mechanism. The solvolytic transition state for 9-phenyl-9-fluorenyl p-nitrobenzoate and that for 1,1-diphenylethyl p-nitrobenzoate were considered to involve extended positive charge delocalizations from the observation of linear relationships between log k and Y xBnOPNB . The ambiguity in the case of 2, 2-dimethyl-1-(4methoxyphenyl)-1-phenyl-1-propyl p-nitrobenzoate is discussed.