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• 555-16-8 4-nitrobenzaldehdye 
• 54-12-6 Trp 
• 139655-01-9 tryptamine 
• 3380-77-6 rac-1-(4-nitrophenyl)-2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indole hydrochloride 
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• 209169-31-3 1-(4-nitro-phenyl)-2,3,4,9-tetrahydro-1H-β-carboline-3-carboxylic acid 
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• 1381771-01-2 N-(4-(9H-pyrido[3,4-b]indol-1-yl)phenyl)thiophene-2-carboxamide 
• 771533-61-0 4-(9H-pyrido[3,4-b]indol-1-yl)aniline 

Relevant academic research and scientific papers

A convenient synthesis of β-carbolines by iron-catalyzed aerobic decarboxylative/dehydrogenative aromatization of tetrahydro-β-carbolines under air

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.

Reusable, homogeneous water soluble photoredox catalyzed oxidative dehydrogenation of N-heterocycles in a biphasic system: Application to the synthesis of biologically active natural products

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.

Metal free one pot synthesis of Β-carbolines via a domino Pictet-Spengler reaction and aromatization

A convenient and efficient metal free, atom economical flexible synthesis of β-carbolines involving a domino Pictet-Spengler reaction and aromatization in oxygen atmosphere in N-methyl-2-pyrollidone (NMP) is described. Variety of aryl, heteroaryl and aliphatic aldehydes were found to be good substrates for this methodology. Several β-carbolines (6a-6t) and β-carboline methyl esters (7a-7e) were synthesized using this methodology.The same reaction carried out in argon atmosphere in the presence of catalytic amount of acid in NMP furnished, tetrahydro-β-carbolines (4a-4g).

Cu-catalyzed mild and efficient oxidation of THβCs using air: Application in practical total syntheses of perlolyrine and flazin

A mild, efficient and environmentally benign method for synthesis of aromatic β-carbolines via Cu(ii)-catalyzed oxidation of 1,2,3,4-tetrahydro-β-carbolines (THβCs) was developed, in which air (O2) was used as the clean oxidant. This method has advantages such as environmentally friendliness, mildness, very good tolerance of functional groups, high yielding and easy experiment operation. In addition, this new methodology was successfully applied in the efficient and practical total syntheses of β-carboline alkaloids perlolyrine and flazin.

Synthesis of β-carbolines via a silver-mediated oxidation of tetrahydro-β-carbolines

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.

Dehydrogenation of 1-aryl(hetaryl)-1,2,3,4-tetrahydro-9H-β-carboline-3-carboxylic acids and their esters with dimethyl sulfoxide

Oxidative dehydrogenation of 1-aryl(hetaryl)-1,2,3,4-tetrahydro-9Н-β-carboline-3-carboxylic acids derivatives with dimethyl sulfoxide leads to the formation of 1-aryl(hetaryl)-9Н-β-carbolines. Simultaneously with the dehydrogenation decarboxylation occurs

Ru(II)-catalyzed β-carboline directed C-H arylation and isolation of its cycloruthenated intermediates

A Ru(II)-catalyzed C-H arylation approach has been developed utilizing β-carboline alkaloids as the directing group. Selective formations of diarylated products from moderate to excellent yields were accomplished. Broad substrate scope with excellent functional group tolerance for C1-phenyl/thienyl/PAHs-β-carbolines was demonstrated. X-ray crystal structure of cycloruthenated complex 2cr and no arylation reaction with model substrate 13 strongly suggests that N2 is the directing group than N9 in C1-aryl-β-carbolines. Catalytic properties and stability of the cycloruthenated complexes have been explored. Library of biologically relevant new β-carboline derivatives and isolation of its cycloruthenated intermediates are the highlights of this work.

Decarboxylative aromatization of β-carbolines by using metal free catalysis and efficient synthesis of β-carboline derivatives

A new novel metal-free decarboxylative and aromatized β-carboline (5a-j) derivatives were synthesized by one-pot reaction. In all cases, resulting β-carboline derivatives with above 90 % yield.

An efficient one-pot decarboxylative aromatization of tetrahydro-β-carbolines by using N-chlorosuccinimide: total synthesis of norharmane, harmane and eudistomins

A facile method for the synthesis of a variety of β-carbolines and their natural products such as norharmane (2a), harmane (2b), eudistomins I, N, T, and U (6, 7, 9 and 10, respectively) has been successfully developed via a decorboxylative aromatization tool by employing N-chlorosuccinimide (NCS) as a mild and efficient reagent. Gratifyingly, this reagent system proceeds in a one-pot manner and converted all the tetrahydro-β-carboline acids into their corresponding decorboxylative aromatic products with good to excellent yields. Additionally, this system works well in the case of tetrahydro-β-carboline esters to produce their aromatic partners in high yields.

PhI(OAc)2-mediated one-pot oxidative decarboxylation and aromatization of tetrahydro-β-carbolines: Synthesis of norharmane, harmane, eudistomin U and eudistomin i

Iodobenzene diacetate was employed as a mild and efficient reagent for one-pot oxidative decarboxylation of tetrahydro-β-carboline acids and dehydrogenation of tetrahydro-β-carbolines to access the corresponding aromatic β-carbolines. To the best of our knowledge this is the first synthesis of β-carbolines via a one-pot oxidative decarboxylation at ambient temperature. The utility of this protocol has been demonstrated in the synthesis of β-carboline alkaloids norharmane (2o), harmane (2p), eudistomin U (9) and eudistomin I (12).