The Experts below are selected from a list of 303 Experts worldwide ranked by ideXlab platform
Seong Gyoung Gang - One of the best experts on this subject based on the ideXlab platform.
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a facile synthesis of benzo c Phenanthridine alkaloids oxynitidine and oxysanguinarine using lithiated toluamide benzonitrile cycloaddition
Tetrahedron Letters, 2004Co-Authors: Thanh Nguyen Le, Seong Gyoung GangAbstract:Abstract Benzo[c]Phenanthridine alkaloids oxynitidine and oxysanguinarine were synthesized from easily available starting benzonitrile 5 and toluamide 6 using toluamide–benzonitrile cycloaddition reaction in six steps. This method is so highly efficient that it could be a more useful way for preparing fully aromatized benzo[c]Phenanthridine compounds.
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a versatile total synthesis of benzo c Phenanthridine and protoberberine alkaloids using lithiated toluamide benzonitrile cycloaddition
Journal of Organic Chemistry, 2004Co-Authors: Thanh Nguyen Le, Seong Gyoung GangAbstract:A new versatile synthesis of benzo[c]Phenanthridine and protoberberine alkaloids using lithiated toluamide−benzonitrile cycloaddition was carried out. The coupling reaction between benzonitrile 6 with o-toluamides (8a−c) afforded 3-arylisoquinolines (9a−c) that were transformed to the protoberberines (11a−c) or benzo[c]Phenanthridines (14a−c). These compounds were synthesized by ring closure of the two-carbon chain on either position 2 or 4 of the 3-arylisoquinolinone (9a−c). Several kinds of substituted benzo[c]Phenanthridine alkaloids such as oxysanguinarine, oxyavicine, and oxynitidine as well as protoberberines such as 8-oxocoptisine, 8-oxopseudoberberine, and 8-oxopseudocoptisine were synthesized.
Thanh Nguyen Le - One of the best experts on this subject based on the ideXlab platform.
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Total synthesis of oxyfagaronine, phenolic benzo[c]Phenanthridine and general synthetic way of 2,3,7,8- and 2,3,8,9-tetrasubstituted benzo[c]Phenanthridine alkaloids.
Chemical & Pharmaceutical Bulletin, 2006Co-Authors: Thanh Nguyen LeAbstract:Benzo[c]Phenanthridine alkaloids such as oxynitidine, oxysanguinarine, oxyavicine and phenolic oxyfagaronine were synthesized from easily available starting benzonitriles 5 and toluamides 6 using a lithiated toluamide-benzonitrile cycloaddition reaction. The coupling reaction provided 3-arylisoquinolinones that were transformed to the benzo[c]phenanthridones. This method is highly efficient and could be useful for preparing diverse substituted aromatic benzo[c]Phenanthridine compounds on a multi gram scale.
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synthesis of oxychelerythrine using lithiated toluamide benzonitrile cycloaddition
Chemical & Pharmaceutical Bulletin, 2005Co-Authors: Thanh Nguyen LeAbstract:Oxychelerythrine, benzo[c]Phenanthridine alkaloid, was synthesized from easily available starting toluamide 5 and benzonitrile 6 using toluamide-benzonitrile cycloaddition reaction in 6 steps.
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a facile synthesis of benzo c Phenanthridine alkaloids oxynitidine and oxysanguinarine using lithiated toluamide benzonitrile cycloaddition
Tetrahedron Letters, 2004Co-Authors: Thanh Nguyen Le, Seong Gyoung GangAbstract:Abstract Benzo[c]Phenanthridine alkaloids oxynitidine and oxysanguinarine were synthesized from easily available starting benzonitrile 5 and toluamide 6 using toluamide–benzonitrile cycloaddition reaction in six steps. This method is so highly efficient that it could be a more useful way for preparing fully aromatized benzo[c]Phenanthridine compounds.
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a versatile total synthesis of benzo c Phenanthridine and protoberberine alkaloids using lithiated toluamide benzonitrile cycloaddition
Journal of Organic Chemistry, 2004Co-Authors: Thanh Nguyen Le, Seong Gyoung GangAbstract:A new versatile synthesis of benzo[c]Phenanthridine and protoberberine alkaloids using lithiated toluamide−benzonitrile cycloaddition was carried out. The coupling reaction between benzonitrile 6 with o-toluamides (8a−c) afforded 3-arylisoquinolines (9a−c) that were transformed to the protoberberines (11a−c) or benzo[c]Phenanthridines (14a−c). These compounds were synthesized by ring closure of the two-carbon chain on either position 2 or 4 of the 3-arylisoquinolinone (9a−c). Several kinds of substituted benzo[c]Phenanthridine alkaloids such as oxysanguinarine, oxyavicine, and oxynitidine as well as protoberberines such as 8-oxocoptisine, 8-oxopseudoberberine, and 8-oxopseudocoptisine were synthesized.
Somsak Ruchirawat - One of the best experts on this subject based on the ideXlab platform.
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a new synthetic approach to 6 unsubstituted Phenanthridine and Phenanthridine like compounds under mild and metal free conditions
Organic and Biomolecular Chemistry, 2014Co-Authors: Jumreang Tummatorn, Suppachai Krajangsri, Krissada Norseeda, Charnsak Thongsornkleeb, Somsak RuchirawatAbstract:A new and mild synthetic approach for the synthesis of 6-unsubstituted Phenanthridine and Phenanthridine-like compounds under metal-free conditions at room temperature has been developed. The strategy involved a tandem azide rearrangement/intramolecular annulation and oxidation reactions of biarylmethyl azide precursors to obtain the desired products in up to 99% yields with high regioselectivity.
Jianguo Zeng - One of the best experts on this subject based on the ideXlab platform.
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Metal-Free Photoredox Catalyzed Cyclization of O-(2,4-Dinitrophenyl)oximes to Phenanthridines
Molecules, 2016Co-Authors: Zhixing Qing, Pi Cheng, Xinyu Zheng, Jianguo ZengAbstract:A metal-free visible-light photoredox-catalyzed intermolecular cyclization reaction of O-2,4-dinitrophenyl oximes to Phenanthridines was developed. In this study, the organic dye eosin Y and i-Pr2NEt were used as photocatalyst and terminal reductant, respectively. The oxime substrates were transformed into iminyl radical intermediates by single-electron reduction, which then underwent intermolecular homolytic aromatic substitution (HAS) reactions to give Phenanthridine derivatives.
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regiospecific minisci acylation of Phenanthridine via thermolysis or photolysis
ChemInform, 2015Co-Authors: Pi Cheng, Zhixing Qing, Jianguo ZengAbstract:The method is applicable to the acylation of Phenanthridine with aryl and alkyl aldehydes, but fails for alkenyl aldehydes.
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regiospecific minisci acylation of Phenanthridine via thermolysis or photolysis
Tetrahedron Letters, 2014Co-Authors: Pi Cheng, Zhixing Qing, Jianguo ZengAbstract:Abstract In this study, a new type of Minisci reaction for regiospecific acylation of Phenanthridine has been developed based on cross dehydrogenative coupling (CDC) strategy. Using substoichiometric amount of TBAB (tetrabutylammonium bromide, 30 mol %) and K 2 S 2 O 8 as an oxidant, acyl radicals generate from aldehyde substrates under thermal conditions followed by a regiospecific intermolecular acylation with Phenanthridine. Furthermore, a preliminary research has indicated that the acylation reaction can be carried out at room temperature when K 2 S 2 O 8 /TBAB is displaced by (NH 4 ) 2 S 2 O 8 and another 5 mol % of fac -Ir(ppy) 3 is used as photocatalyst under irradiation of visible light. This intermolecular acylation reaction provides an easy access to 6-acylated Phenanthridine derivatives.
Bijoy Kundu - One of the best experts on this subject based on the ideXlab platform.
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synthesis of 8 aryl substituted benzo a Phenanthridine derivatives by consecutive three component tandem reaction and 6 endo carbocyclization
ChemInform, 2013Co-Authors: Anil K Mandadapu, Meena D Dathi, Rajesh K Arigela, Bijoy KunduAbstract:The ICl-promoted reaction of quinolines (I) introduces a 7-iodo substituent into the benzo[a]Phenanthridine skeleton and allows further functionalization by Pd-catalyzed coupling reactions.
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a new entry to Phenanthridine ring systems via sequential application of suzuki and the modified pictet spengler reactions
Organic and Biomolecular Chemistry, 2009Co-Authors: Anil K Mandadapu, Mohammad Saifuddin, Piyush K Agarwal, Bijoy KunduAbstract:A mild, efficient and versatile method has been developed for the two step synthesis of Phenanthridine ring systems using the Suzuki and the modified Pictet–Spengler strategy. The strategy involves synthesis of a substrate in which an aryl amine is tethered to an activated arene ring at the carbon ortho to the activated carbon nucleophile so as to facilitate the formation of Phenanthridine ring viaπ-cyclization.
