Towards Functionalized Silicon-Containingα-Amino Acids: Asymmetric Syntheses of Sila Analogs of Homoserine and Homomethionine
作者:Richard J. Smith、Stefan Bienz
DOI:10.1002/hlca.200490152
日期:2004.7
The homoserine and homomethionine sila analogs, (R)-HOSi(Me2)CH2CH(NH2)CO2H ((R)-21) and (R)-MeSCH2Si(Me2)CH2CH(NH2)CO2H ((R)-24), respectively, were each synthesized in nine steps and in 30 and 23% overall yield, respectively, from commercially available ClSiMe2CH2Cl. The key step of both syntheses was the asymmetric α-bromination of an Evans amide to introduce the stereogenic center of the amino
高丝氨酸和高蛋氨酸的sila类似物(R)-HOSi(Me 2)CH 2 CH(NH 2)CO 2 H((R)-21)和(R)-MeSCH 2 Si(Me 2)CH 2 CH(NH)2)CO 2 H((R)-24)分别由九个步骤合成,总收率分别为30%和23%,由可商购的ClSiMe 2 CH 2 Cl合成。两种合成方法的关键步骤是埃文斯分子的不对称α-溴化反应酰胺引入具有确定的绝对构型的氨基酸的立体异构中心。虽然高甲硫氨酸类似物(R)-24的制备遵循预期的途径,但是在N 3 CH 2取代的硅烷衍生物的催化加氢过程中出乎意料地形成了高丝氨酸(R)-21的硅烷类似物。