SILICON EFFECTS .6. BETA-SILICON EFFECT OF VARIOUS SILYL GROUPS IN SOLVOLYSIS FOR ALPHA-ALKYLBENZYL AND ALPHA-SILYBENZYL SYSTEMS

Authors
SHIMIZU N WATANABE S HAYAKAWA F YASUHARA S TSUNO Y INAZU T
Citation
N. Shimizu et al., SILICON EFFECTS .6. BETA-SILICON EFFECT OF VARIOUS SILYL GROUPS IN SOLVOLYSIS FOR ALPHA-ALKYLBENZYL AND ALPHA-SILYBENZYL SYSTEMS, Bulletin of the Chemical Society of Japan, 67(2), 1994, pp. 500-504
Citations number
33
Categorie Soggetti
Chemistry
Journal title
Bulletin of the Chemical Society of Japan → ACNP
ISSN journal
00092673
Volume
67
Issue
2
Year of publication
1994
Pages
500 - 504
Database
ISI
SICI code
0009-2673(1994)67:2<500:SE.BEO>2.0.ZU;2-T
Abstract
The kinetic beta-silicon effects of various silyl groups including Me3 Si, Me3SiMe2Si, (C6H5)Me2Si, (i-PrO)Me2Si, and (CH3OCH2)Me2Si were mea sured in k(c) solvolysis of two different benzylic systems of the type s, ArCH(OCOCF3)CH2R (3: Ar=phenyl or 3,5-dichlorophenyl, R=silyl group ) and C6H5CH(CI)SiMe2R (4: R=silyl group). The relative beta-silyl acc elerations were 1.0: 5.57:0.309 for R=Me3Si; Me3SiMe2Si, and (C6H5)Me2 Si, respectively, for the system 3, and 1.0:7.65:0.502:0.289 for R=Me3 Si, Me3SiMe2Si, (i-PrO)Me2Si, and (CH3OCH2)Me2Si, respectively, for th e system 4. The variation of the beta-silicon effect with gamma-substi tuents was interpreted as reflecting changes in hyperconjugating abili ties of beta-C-Si and beta-Si-Si sigma-bonds mainly due to the inducti ve effect of the gamma-substituent groups.