Conformational analysis of 3,3-dimethyl-3-silathiane, 2,3,3-trimethyl-3-silathiane and 2-trimethylsilyl-3,3-dimethyl-3-silathiane-preferred conformers, barriers to ring inversion and substituent effects
作者:Svetlana V. Kirpichenko、Erich Kleinpeter、Bagrat A. Shainyan
DOI:10.1002/poc.1677
日期:2010.9
The first conformational analysis of 3‐silathiane and its C‐substituted derivatives, namely, 3,3‐dimethyl‐3‐silathiane 1, 2,3,3‐trimethyl‐3‐silathiane 2, and 2‐trimethylsilyl‐3,3‐dimethyl‐3‐silathiane 3 was performed by using dynamic NMR spectroscopy and B3LYP/6‐311G(d,p) quantum chemical calculations. From coalescence temperatures, ring inversion barriers ΔG≠ for 1 and 2 were estimated to be 6.3 and
3- silathiane和其C-取代的衍生物,即,3,3-二甲基-3- silathiane的第一构象分析1,2,3,3-三甲基-3- silathiane 2,和2-三甲基甲硅烷基-3,3-通过使用动态NMR光谱和B3LYP / 6-311G(d,p)量子化学计算来执行2-3-3-silathiane 3。从聚结的温度下,环反转障碍Δ ģ ≠为1和2被估计为分别为6.3和6.8千卡/摩尔。这些值大大低于硫代环己烷(9.4 kcal / mol),但略高于1,1-二甲基硅环己烷(5.5 kcal / mol)之一。构象自由能为甲基基团在2(-Δ由低温13 C NMR数据得出的G °= 0.35 kcal / mol)与计算值相当一致。对于化合物2,理论计算得到Δ ë接近零的值的之间的平衡2 -Me斧和2个-Me当量构象异构体。在三甲基甲硅烷基团的所计算出的赤道偏好3是更明显(-Δ ģ °=