50892-81-4Relevant articles and documents
Visible light mediated selective oxidation of alcohols and oxidative dehydrogenation of N-heterocycles using scalable and reusable La-doped NiWO4nanoparticles
Abinaya, R.,Balasubramaniam, K. K.,Baskar, B.,Divya, P.,Mani Rahulan, K.,Rahman, Abdul,Sridhar, R.,Srinath, S.
, p. 5990 - 6007 (2021/08/24)
Visible light-mediated selective and efficient oxidation of various primary/secondary benzyl alcohols to aldehydes/ketones and oxidative dehydrogenation (ODH) of partially saturated heterocycles using a scalable and reusable heterogeneous photoredox catalyst in aqueous medium are described. A systematic study led to a selective synthesis of aldehydes under an argon atmosphere while the ODH of partially saturated heterocycles under an oxygen atmosphere resulted in very good to excellent yields. The methodology is atom economical and exhibits excellent tolerance towards various functional groups, and broad substrate scope. Furthermore, a one-pot procedure was developed for the sequential oxidation of benzyl alcohols and heteroaryl carbinols followed by the Pictet-Spengler cyclization and then aromatization to obtain the β-carbolines in high isolated yields. This methodology was found to be suitable for scale up and reusability. To the best of our knowledge, this is the first report on the oxidation of structurally diverse aryl carbinols and ODH of partially saturated N-heterocycles using a recyclable and heterogeneous photoredox catalyst under environmentally friendly conditions.
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.
Application of metal free aromatization to total synthesis of perlolyrin, flazin, eudistomin U and harmane
Santhanam, Srinath,Ramu, Abinaya,Baburaj, Baskar,Kalpatu Kuppusamy, Balasubramanian
, p. 2121 - 2127 (2020/03/04)
Application of our recently reported metal free reaction conditions to the total synthesis of the four different and selective biologically interesting β-carboline natural products is reported. Using this simple methodology, flazin, perlolyrine, eudistomin U and harmane containing heteroaryl and alkyl substituents at C1 position were synthesized in good yields. (Figure presented.).
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
supporting information, 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.
Metal free one pot synthesis of Β-carbolines via a domino Pictet-Spengler reaction and aromatization
Ramu,Srinath,kumar, A. Aswin,Baskar,Ilango,Balasubramanian
, p. 86 - 93 (2019/02/27)
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
Zheng, Bo,Trieu, Tien Ha,Meng, Tian-Zhuo,Lu, Xia,Dong, Jing,Zhang, Qiang,Shi, Xiao-Xin
, p. 6834 - 6839 (2018/02/23)
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.
Design, synthesis and biological evaluations of quaternization harman analogues as potential antibacterial agents
Dai, Jiangkun,Dan, Wenjia,Ren, Siyu,Shang, Congguo,Wang, Junru
, p. 23 - 36 (2018/10/20)
Thirty-three new quaternization harman analogues were synthesized and their antibacterial activity against four Gram-positive and two Gram-negative bacteria were evaluated. The structure–activity relationships were summarized and compounds 4f, 4i, 4l, 4u,
Direct Biomimetic Synthesis of β-Carboline Alkaloids from Two Amino Acids
Wang, Zi-Xuan,Xiang, Jia-Chen,Cheng, Yan,Ma, Jin-Tian,Wu, Yan-Dong,Wu, An-Xin
, p. 12247 - 12254 (2018/09/21)
The increasing importance of enzyme mimics in organic synthesis inspired us to design a novel biomimetic synthesis of β-carboline alkaloids directly from tryptophan and a second amino acid. This novel one-pot protocol utilizes abundant and readily available starting materials and thus presents a green and user-friendly alternative to conventional methods that rely on stepwise synthesis. Driven by molecular iodine and TFA, decarboxylation, deamination, Pictet-Spengler reaction, and oxidation reactions proceeded sequentially, transforming biomass amino acids into value-added alkaloid motifs.
Isolation of mutagenic β-carboline derivatives after nitrite treatment of maillard reaction mixtures and analysis of these compounds from foodstuffs and human urine
Masuda, Shuichi,Kanamori, Hisayuki,Kinae, Naohide
, p. 2232 - 2235 (2008/02/03)
Mixtures of carbohydrate decomposition products and L-tryptophan were incubated at pH 7.0 and 37°C for 4 weeks. These mixtures exhibited mutagenic activity toward S. typhimurium TA 100 without metabolic activation after a nitrite treatment at pH 4.0. Four β-carboline derivatives were isolated as premutagens from mixtures of methylglyoxal and furfural. These premutagens were also found to be contained in daily foodstuffs and human urine samples.
Efficient one-pot synthesis of anti-HIV and anti-tumour β-carbolines
Kusurkar, Radhika S.,Goswami, Shailesh K.
, p. 5315 - 5318 (2007/10/03)
Thermal electrocyclisation of the azahexatriene system has been used as a key step for the synthesis of anti-HIV and anti-tumour compounds, harman, derivatives of harman and 1-aryl-β-carbolines. A one-pot reaction sequence was used to furnish these compounds in good yield.
