Reactions of tert-butyl trimethylsilyl carbonate and of bistrialkylsilyl carbonates with amino acids. Carbon-13 chemical shifts in carbonates and silyl carbonate derivatives
Reactions of tert-butyl trimethylsilyl carbonate and of bistrialkylsilyl carbonates with amino acids. Carbon-13 chemical shifts in carbonates and silyl carbonate derivatives
复制标题
叔丁基三甲基甲硅烷基碳酸酯和双三烷基甲硅烷基碳酸酯与氨基酸的反应。
DOI：
10.1021/jo00954a021
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发表时间：
1973
期刊：
影响因子：
--
通讯作者：
B. M. Pope
中科院分区：
文献类型：
--
作者：
Yutaka Yamamoto;D. Tarbell;J. R. Fehlner;B. M. Pope
合成了一系列双三烷基硅基碳酸酯RsSiOC（= 0）OSiR 3。最近描述的叔丁基三甲基甲硅烷基碳酸酯（Ia）已被证明与氨基酸酯反应形成相应的甲硅烷基氨基甲酸酯RC（NHCOOR '）HCOOR”，其中R'= Si（CH 3）3。在更剧烈的条件下，形成完全甲硅烷基化的氨基酸衍生物。所有的甲硅烷基化的衍生物被湿醚水解为母体氨基酸或酯;与L-酪氨酸，完全甲硅烷基化，然后用湿醚水解再生L-酪氨酸，没有外消旋的证据。碳酸双三乙基甲硅烷基酯（3c）和碳酸叔丁基三乙基甲硅烷基酯（Ib）由甘氨酸乙酯产生相同的甲硅烷基氨基甲酸酯。测定了一系列碳酸酯、二碳酸酯、三碳酸酯、碳酸甲硅酯和-BOC及其它由甘氨酸乙酯衍生的化合物的~（13）C化学位移，并将化学位移归属于特定类型的碳。随着分子中碳酸酯基团数目的增加，羰基碳的化学位移向高场移动。羰基碳旁边的硫（代替氧）的存在使其化学位移向低场移动~ 16-18 ppm。其他的注意事项。
A number of bistrialkylsilyl carbonates, RsSiOC (= 0) OSiR3have been prepared. Therecently described íerí-butyl trimethylsilyl carbonate (la) has been shown to react with-amino acid esters to form the correspond-ing silylurethanes, RC (NHCOOR') HCOOR", where R'= Si (CH3) 3. Under more drastic conditions, the completely silylated amino acid derivatives are formed. All of the silylated derivatives are hydrolyzed by moist ether to the parent amino acids or esters; with L-tyrosine, complete silylation followed by hydrolysis with moist ether regenerates the L-tyrosine, with no evidence of racemization. Bistriethylsilyl carbonate (3c) and íerí-butyl triethylsilyl carbonate (lb) yield the same silylurethane from glycine ethyl ester. 13C chemical shifts have been measured, and assignments of chemical shifts to specific types of carbon havebeen made for a series of car-bonate esters, di-and tricarbonates, silyl carbonates, and-BOC and other urethanes derived from glycine ethyl ester. As thenumber of carbonate groups in the moleculeincreases, the chemical shifts of the carbonyl carbons move to higher field. The presence ofsulfur (in place of oxygen) next to the carbonyl carbon moves its chemical shift downfield~ 16-18 ppm. Other regularities are noted.