Effective preparation of olivacine and ellipticine via late-stage D-ring cyclization is described. Key features of the synthetic routes include trifluoroacetic acid-mediated formation of a lactone that is fused to a tetrahydrocarbazole derivative and its one-pot two-step ring opening and aromatization mediated by para-toluenesulfonic acid and palladium on carbon, respectively.
Enantioselective Synthesis of 1- and 4-Hydroxytetrahydrocarbazoles through Asymmetric Transfer Hydrogenation
作者:Erkan Ertürk、Ömer Dilek、Süleyman Patir
DOI:10.1055/s-0037-1610351
日期:2019.1
the corresponding 1- and 4-oxotetrahydrocarbazoles through asymmetrictransferhydrogenation by using the commercially available Noyori–Ikariya ruthenium catalyst. The immediate use of the freshly prepared catalyst and the use of a HCO2H–DABCO (11:6) mixture as the hydrogen source are crucial for achieving high activity and enantioselectivity. In this way, a tetrahydrocarbazole heterocycle fused to a
types of reactions. Further studies on the reaction of α-chloroformylarylhydrazines 1 with thiourea compounds confirmed a novel cyclization and de-cyclization mechanism, which led to give 2-arylhydrazinecarboximidamides 5 and 1,3,4-thiadiazolin-5-ones 6. In addition, various 1,3,4-oxadiazines 9 were obtained by reacting α-chloroformylarylhydrazines with α-cyclodiketones, showing ring cyclization was involved
A novel CAN-SiO2-mediated one-pot oxidation of 1-keto-1,2,3,4-tetrahydrocarbazoles to carbazoloquinones: Efficient syntheses of murrayaquinone A and koeniginequinone A
作者:Suchandra Chakraborty、Gautam Chattopadhyay、Chandan Saha
DOI:10.1002/jhet.561
日期:2011.3
1‐keto‐1,2,3,4‐tetrahydrocarbazoles (1) to carbazole‐1,4‐quinones (2) are efficiently carried out by CAN‐SiO2‐mediated reaction. This generalized protocol was successfully extended to the synthesis of two naturally occurring carbazoloquinones: murrayaquinone A (2b) and koeniginequinone A (2g). A plausible mechanism for this novel reaction involves formation of a 9‐hydroxy‐2,3,4,9‐tetrahydro‐1H‐carbazole‐1‐one
Selective Synthesis and X-Ray Structural Analysis of a Pyridocarbazole Derivative
作者:N. Sampath、Rita Mathews、M. N. Ponnuswamy
DOI:10.1007/s10870-010-9801-z
日期:2010.12
Pyridocarbazole possesses many biological activities such as antimicrobial and antitumor properties. It also serves as a selective inhibitor for cyclic GMP phosphodiesterase (cGMP-PDE) enzyme. Since it is very similar to ellipticine and olivacine, its derivatives are endowed with DNA intercalating properties. One of the pyridocarbazoles, MCDDC, has been synthesized and its stereochemistry has been proven by X-ray crystallographic study. The crystal belongs to the monoclinic space group, P21/a, with cell parameters a = 11.771(3) Å, b = 14.557(3) Å, c = 11.869(1) Å and β = 101.80(2)°. According to the X-ray structure, the entire MCDDC molecule adopts a planar conformation except for the dichlorophenyl ring, which is almost orthogonal to the pyridine ring. Molecules are tightly bound by the N–H···N type hydrogen bonds and weak C–H···π interactions also help in packing stabilization. One of the pyridocarbazoles, MCDDC, has been synthesized and its selectivity has been proved by X-ray crystallographic study.
哒螨唑具有多种生物活性,如抗菌和抗肿瘤特性。它还是环 GMP 磷酸二酯酶(cGMP-PDE)的选择性抑制剂。由于它与椭圆氨酸和橄榄氨酸非常相似,其衍生物具有 DNA 插层特性。其中一种吡啶咔唑 MCDDC 已经合成,其立体化学结构已通过 X 射线晶体学研究得到证实。该晶体属于单斜空间群 P21/a,晶胞参数 a = 11.771(3) Å, b = 14.557(3) Å, c = 11.869(1) Å 和 β = 101.80(2)° 。根据 X 射线结构,除二氯苯基环与吡啶环几乎正交外,整个 MCDDC 分子均呈平面构象。分子通过 N-H-N 型氢键紧密结合,微弱的 C-H--π 相互作用也有助于填料的稳定。我们已经合成了其中一种吡啶咔唑--MCDDC,并通过 X 射线晶体学研究证明了它的选择性。