16765-79-0Relevant articles and documents
Synthesis of β-carbolines via a silver-mediated oxidation of tetrahydro-β-carbolines
Durham, Sierra D.,Sierra, Brianna,Gomez, Maximillian J.,Tran, Jennifer K.,Anderson, Marc O.,Whittington-Davis, Nick A.,Eagon, Scott
, p. 2747 - 2750 (2017)
The oxidation of tetrahydro-β-carbolines to β-carbolines using silver carbonate was developed as an alternative to current methods. The oxidation is extremely mild and provides the products in modest to good yields after purification. A number of functional groups are tolerated by this methodology, including reduction-sensitive groups which are often cleaved with other methods. Though the mechanism is not fully understood, the reaction proceeds in an open flask, is not sensitive to light or moisture, and provides a viable synthetic route to compounds that are not easily prepared via other methodologies.
Proton-transfer tautomerism of ?2-carbolines mediated by hydrogen-bonded complexes
Chou, Pi-Tai,Liu, Yun-I,Wu, Guo-Ray,Shiao, Mei-Ying,Yu, Wei-Shan,Cheng, Chung-Chih,Chang, Chen-Pin
, p. 10674 - 10683 (2001)
The carboxylic acid catalyzed excited-state amino-imino tautomerism for ?2-carboline (?2-CB) and its analogues has been investigated. Thermodynamics and microsolvation (i.e., stoichiometry of the complex formation) of various ?2-CB/acetic acid complexes in nonpolar solvents have been studied by means of absorption and emission titration experiments. Supplementary support of the stoichiometric ratio and structure for the hydrogen-bonding formation was provided by molecular design and syntheses of various ?2-CB analogues incorporating either only one hydrogen bonding site or dual hydrogen bonding sites where interplay between two sites are sterically prohibited. The results in combination with time-resolved measurements and theoretical approaches suggest the 1:2 ?2-CB/acetic acid complex with a structure of triple hydrogen bonding formation to be responsible for the excited-state proton-transfer tautomerism in cyclohexane. The proton transfer time is beyond the response limit of the detecting system of 15 ps, indicating that only a negligibly small geometry adjustment is required for the guest molecule (i.e., acetic acid) to a correct geometry, i.e., a hydrogen-bond relay configuration, for the triple proton transfer to proceed. In comparison, for the 1:1 ?2-CB/acetic acid non-hydrogen-bond relayed complexes, amino-imino tautomerism is prohibited during the excited-state lifetime, giving rise to a normal Stokes shifted emission. The results provide detailed ground-state thermodynamics of ?2-CB HB complexes as well as the dynamics of proton-transfer tautomerism mediated by the hydrogen-bonding structures.
Facile synthesis of isoquinolines, β-carbolines, and 3-deazapurines
Huang, Wenhua,Li, Jingyi,Ou, Lihua
, p. 2137 - 2143 (2007)
Isoquinoline, β-carbolines, and 3-deazapurines were prepared in 52-81% yields via oxidative decarboxylation of cyclic α-amino acids using ammonium persulfate as an oxidant in the presence of catalytic silver. Copyright Taylor & Francis Group, LLC.
Selectivity-tunable oxidation of tetrahydro-β-carboline over an OMS-2 composite catalyst: preparation and catalytic performance
Bi, Xiuru,Tao, Luyao,Yao, Nan,Gou, Mingxia,Chen, Gexin,Meng, Xu,Zhao, Peiqing
, p. 3682 - 3692 (2021/03/22)
Controlling the reaction selectivity of organic transformations without losing high conversion is always a challenge in catalytic processes. In this work, a H3PO4·12WO3/OMS-2 nanocomposite catalyst ([PW]-OMS-2) was prepared through the oxidation of a Mn(ii) salt with sodium phosphotungstate by KMnO4. Comprehensive characterization indicates that different Mn2+precursors significantly affected the crystalline phase and morphology of the as-synthesized catalysts and only MnSO4·H2O as the precursor could lead to a cryptomelane phase. Moreover, [PW]-OMS-2 demonstrated excellent catalytic activity toward aerobic oxidative dehydrogenation of tetrahydro-β-carbolines due to mixed crystalline phases, enhanced surface areas, rich surface oxygen vacancies and labile lattice oxygen species. In particular, β-carbolines and 3,4-dihydro-β-carbolines could be obtained from tetrahydro-β-carbolines with very high selectivity (up to 99%) over [PW]-OMS-2viatuning the reaction solvent and temperature. Under the present catalytic system, scalable synthesis of a β-carboline was achieved and the composite catalyst showed good stability and recyclability. This work not only clarified the structure-activity relationship of the catalyst, but also provided a practical pathway to achieve flexible, controllable synthesis of functional N-heterocycles.
A convenient synthesis of β-carbolines by iron-catalyzed aerobic decarboxylative/dehydrogenative aromatization of tetrahydro-β-carbolines under air
Mohamad Arshad, Ahmad Saifuddin,Meesala, Ramu,Hanapi, Nur Aziah,Mordi, Mohd Nizam
, (2021/02/12)
A convenient synthesis for the conversion of various substituted tetrahydro-β-carbolines has been developed by iron-catalyzed decarboxylative/dehydrogenative aromatization to construct aromatic β-carbolines under air atmosphere. In the presence of a FeCl3 catalyst, this reaction exhibited a good functional group tolerance to produce corresponding β-carbolines in good yields in the absence of any additive. Additionally, the utility of the method was highlighted in the gram-scale synthesis of important natural β-carboline synthons norharmane (2a) and harmane (2b), which the latter provide practical access towards eudistomin N and nostocarboline.
Selective construction of alkaloid scaffolds by alcohol-based direct and mild aerobic oxidative Pictet-Spengler reactions
Han, Feng,Li, Huan,Liu, Haicheng,Liu, Jianping,Xu, Qing
, p. 7079 - 7085 (2020/10/02)
Employing TBN/TEMPO as the catalysts and oxygen as the oxidant, the biologically and pharmaceutically significant tetrahydro-β-carboline and β-carboline alkaloid scaffolds that used to be obtained by multi-step processes can now be selectively obtained in only one-stepviadirect aerobic oxidative Pictet-Spengler reactions of tryptamines with alcohols under mild conditions, with water generated as the byproduct. In this reaction, TBN/TEMPO was interestingly found to be able to facilitate the cyclization step of the whole reaction. This method tolerates a variety ofC- andN-substituted tryptamines, and both the more reactive benzylic and allylic alcohols and the less reactive aliphatic alcohols. This method can also be extended to dihydro-β-carboline synthesis and applied to the more available and more economical tryptophan for β-carboline synthesis, revealing its broad substrate scope and potential in synthetic applications.
Bifunctional thiosquaramide catalyzed asymmetric reduction of dihydro-β-carbolines and enantioselective synthesis of (-)-coerulescine and (-)-horsfiline by oxidative rearrangement
Nachtigall, Fabiane M.,Santos, Leonardo S.,Sathish, Manda
, p. 38672 - 38677 (2020/11/05)
Tetrahydro-β-carboline (THBC) is a tricyclic ring system that can be found in a large number of bioactive alkaloids. Herein, we report a simple and efficient method for the synthesis of enantiopure THBCs through a chiral thiosquaramide (11b) catalyzed imine reduction of dihydro-β-carbolines (17a-f). The in situ generated Pd-H employed as hydride source in the reaction of differently substituted chiral THBCs (18a-f) afforded high selectivities (R isomers, up to 96% ee) and good isolated yields (up to 88%). Moreover, the chiral thiosquaramide used also afforded exceptional catalyst activity in the syntheses of (-)-coerulescine (5) and (-)-horsfiline (6) with excellent enantioselectivities up to 98% and 93% ee, respectively, via an enantioselective oxidative rearrangement approach.
Reusable, homogeneous water soluble photoredox catalyzed oxidative dehydrogenation of N-heterocycles in a biphasic system: Application to the synthesis of biologically active natural products
Abinaya, R.,Baskar, B.,Mariappan, M.,Prasanth, Arun,Sridhar, R.,Srinath, S.
, p. 2575 - 2587 (2020/05/13)
Herein, a simple and efficient method for the oxidative dehydrogenation (ODH) of tetrahydro-β-carbolines, indolines and tetrahydro-(iso)quinolines is described using a reusable, homogeneous cobalt-phthalocyanine photoredox catalyst in a biphasic medium. A biphasic system offers an advantage of easy separation of the product and an efficient reusability of the homogeneous photoredox catalyst. Also, the current system significantly helps to overcome the solubility issue of the substrate and catalyst at room temperature. Its potential applications to organic transformations are demonstrated by the synthesis of various biologically active N-heterocycles such as indoles, (iso)quinolines and β-carbolines and natural products such as eudistomin U, norharmane, and harmane and precursors to perlolyrine and flazin. Without isolation and purification, the catalyst solution can be reused up to 5 times with almost comparable reactivity. Furthermore, the efficiency of the reaction was demonstrated on a gram scale. To the best of our knowledge, this is the first report on ODH reactions using a non noble, reusable and homogeneous cobalt photoredox catalyst under environmentally friendly conditions.
Organic base-promoted efficient dehydrogenative/decarboxylative aromatization of tetrahydro-β-carbolines into β-carbolines under air
Zhao, Ziquan,Sun, Yan,Wang, Lilin,Chen, Xuan,Sun, Yanpei,Lin, Long,Tang, Yulin,Li, Fei,Chen, Dongyin
, p. 800 - 804 (2019/02/16)
Organic base DBN has been identified as an efficient reagent for promoting the dehydrogenative/decarboxylative aromatization of tetrahydro-β-carbolines under air atmosphere, to access the corresponding β-carbolines in moderate to good yields. The utility of this protocol for the gram-scale synthesis of β-carboline alkaloids eudistomin U (7) and harmane (10) has also been demonstrated.
Organic light-emitting compound, preparation and application thereof and light-emitting device containing organic light-emitting compound
-
, (2019/04/26)
The invention discloses an organic light-emitting compound. The organic light-emitting compound has a structural formula represented in a following figure. The organic light-emitting compound has chemical stability, and a material containing the organic light-emitting compound has high glass transition temperature and high decomposition temperature, and is an OLED material with excellent performance. The synthetic route of the material has simple and easy operation and high reaction yield, the preparation cost of the OLED material can be reduced, and therefore the material has a good industrialization prospect. The OLED material can be used as a dopant of a light-emitting layer in an organic light-emitting device, effects of high brightness, high efficiency and low voltage can be achievedthrough an organic light-emitting diode prepared by using the OLED material, and screen dark spots can be avoided effectively; and superior performance is achieved.
