四种生物碱:(R)-(+)-地平A 5,(R)-(+)-八氢吲哚并[2,3- a ]喹唑烷8,(R)-(+)-毒品19和(R)-(通过前手性烯胺(亚胺盐)的不对称转移氢化反应制备了+)-去溴阿糖胞苷22。根据在(+)-(R)-叔存在下测得的1 H NMR光谱确定分离出的生物碱的对映体过量-丁基苯基膦硫基(硒)酸作为手性溶剂。在所有情况下,通过X射线晶体学证实了新产生的立体碳原子上的绝对构型。
A Highly Enantioselective Access to Tetrahydroisoquinoline and β-Carboline Alkaloids with Simple Noyori-Type Catalysts in Aqueous Media
作者:Laurent Evanno、Joel Ormala、Petriâ M. Pihko
DOI:10.1002/chem.200902289
日期:2009.12.7
enhancement: A very convenient modified protocol for the enantioselective transfer hydrogenation of dihydroisoquinoline skeletons under aqueous conditions is reported. Unmodified Noyori ligands can be used and the activity of the catalyst is greatly enhanced with silver additives (see scheme). The protocol was used in a very short synthesis of the alkaloids (S)‐harmicine and (S)‐crispine.