描述了 Tepe 的人类蛋白酶体调节剂的第一个对映选择性和非对映选择性合成。这种和其他高度取代的手性咪唑啉的路线通常会产生外消旋材料。这里公开的路线的关键是α-烷基 α-硝基酯亲核试剂的克级抗选择性氮杂-亨利反应,由双(脒)[BAM] 手性质子配合物催化,以高产率提供关键中间体作为单一的立体异构体。加合物被还原为氨基酯并转化为咪唑啉。
Diastereo- and enantioselective additions of α-nitro esters to imines for <i>anti</i>-α,β-diamino acid synthesis with α-alkyl-substitution
作者:Daniel J. Sprague、Anand Singh、Jeffrey N. Johnston
DOI:10.1039/c7sc05176j
日期:——
The discovery that a C2-symmetric bis(AMidine) [BAM] catalyst promotes an anti-selectiveaddition of α-substituted α-nitro esters to imines is described, providing α-substituted α,β-diamino ester products with high diastereo- and enantioselectivity. When compared to the function of a BAM catalyst reported previously, the pair offer a rare example of diastereodivergence using a bifunctional Brønsted