Enantioselective synthesis of some tetrahydroisoquinoline and tetrahydro-β-carboline alkaloids
作者:Joanna Szawkało、Stefan J. Czarnocki、Anna Zawadzka、Krystyna Wojtasiewicz、Andrzej Leniewski、Jan K. Maurin、Zbigniew Czarnocki、Józef Drabowicz
DOI:10.1016/j.tetasy.2007.01.014
日期:2007.2
Four alkaloids: (R)-(+)-cryspine A 5, (R)-(+)-octahydroindolo[2,3-a]quinolizidine 8, (R)-(+)-harmicine 19 and (R)-(+)-desbromoarborescidine 22 were prepared via the asymmetric transfer hydrogenation reaction of a prochiral enamine (iminium salt). The enantiomeric excesses of the isolated alkaloids were determined from their 1H NMR spectra measured in the presence of (+)-(R)-tert-butylphenylphosphinothio(seleno)ic
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。
Syntheses of (RS)- and (S)-(−)-Nazlinin and (RS)- and (+)-6-Azacyclodeca[5,4-b]indol-1-amine
(RS)‐1‐(4‐Aminobutyl)‐1,2,3,4‐tetrahydro‐β‐carboline ((RS)‐1) was synthesized in two different ways. The preparation of (S)‐(−)‐1 was performed both by asymmetric reduction with ⩾ 95% ee and by synthesis from (S)‐(+)‐3. From this compound also (+)‐6‐azacyclodeca[5,4‐b]indol‐1‐amine ((+)‐2) was prepared with high enantioselectivity.