STABLE CARBOCATIONS .286. C-13-NMR SPECTROSCOPIC STUDY OF 2-[1-(TRIMETHYLSILYL)VINYL]-2-ADAMANTYL CATION, THE 1ST BETA-SILYL-SUBSTITUTED CARBOCATION

被引：43

作者：

PRAKASH, GKS

REDDY, VP

RASUL, G

CASANOVA, J

OLAH, GA

机构：

[1] UNIV SO CALIF,DEPT CHEM,LOS ANGELES,CA 90089

[2] CALIF STATE UNIV LOS ANGELES,DEPT CHEM,LOS ANGELES,CA 90032

来源：

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY | 1992年 / 114卷 / 08期

关键词：

D O I：

10.1021/ja00034a047

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

2-[1-(Trimethylsilyl)vinyl]-2-adamantyl cation (2) was prepared by the ionization of 2-[1-(trimethylsilyl)vinyl]-2-adamantanol in FSO3H/SO2CF at -130-degrees-C and was characterized by C-13 NMR spectroscopy. For comparison, the 2-vinyl-2-adamantyl cation (4) was similarly prepared and characterized. The cationic center of 2 is deshielded by 11.5 ppm over that of 4, indicating no beta-silyl stabilization effect (either inductive or hyperconjugative). However, the low barrier for rotation across the C2-C1' bond in 2 indeed supports the intermediate perpendicular cation being stabilized by beta-silyl effect. The results are rationalized by MM2, ab initio, and IGLO calculations.

引用

页码：3076 / 3078

页数：3

共 22 条

[1] APELOIG Y, 1985, J AM CHEM SOC, V107, P2807
[2] BASSINDALE AR, 1989, CHEM ORGANIC SILICON, pCH14
[3] BROOK MA, 1991, J ORG CHEM, V56, P2274
[4] CARTLEDGE FK, 1971, TETRAHEDRON LETT, P2193
[5] Colvin E. W., 1981, SILICON ORGANIC SYNT
[6] ORGANOSILICON COMPOUNDS .48. EFFECTS OF ALPHA-TRIMETHYLSILYL GROUPS ON RATES OF REACTION AT CARBON-HALOGEN BONDS
COOK, MA
EABORN, C
WALTON, DRM
[J]. JOURNAL OF ORGANOMETALLIC CHEMISTRY, 1971, 29 (03) : 389 - &
[7] STRUCTURE AND STABILITY OF SILYL-SUBSTITUTED CARBONIUM-IONS
EABORN, C
FEICHTMA.F
HORN, M
MURRELL, JN
[J]. JOURNAL OF ORGANOMETALLIC CHEMISTRY, 1974, 77 (01) : 39 - 43
[8] EABORN C, 1968, ORGANOMETALLIC COM 1, V1, P464
[9] EABORN C, 1960, ORGANOSILICON COMPOU, P433
[10] FRISCH MJ, 1984, AB INITIO CALCULATIO

← 1 2 3 →