18034-03-2Relevant articles and documents
TOTAL SYNTHESIS OF N-NORNITIDINE
Rigby, James H.,Holsworth, Daniel D.
, p. 5757 - 5760 (1991)
The benzophenanthridine alkaloid, N-nornitidine has been synthesized employing a benzyne-vinyl isocyanate cycloaddition as the key transformation.
Reagent-Free C?H/N?H Cross-Coupling: Regioselective Synthesis of N-Heteroaromatics from Biaryl Aldehydes and NH3
Zhao, Huai-Bo,Liu, Zhan-Jiang,Song, Jinshuai,Xu, Hai-Chao
, p. 12732 - 12735 (2017)
An unprecedented synthesis of N-heteroaromatics from biaryl aldehydes and NH3 through reagent-free C?H/N?H cross-coupling has been developed. The electrosynthesis uses NH3 as an inexpensive and atom-economic nitrogen donor, requires no oxidizing agents, and allows efficient and regioselective access to a wide range of phenanthridines and structurally related polycyclic N-heteroaromatic products.
Divergent total syntheses of pseudoberberine and nitidine through C[sbnd]H vinylation and switchable 6π electrocyclizations
Jiang, Xunjin,Zeng, Zhixiong,Shi, Dong,Liu, Chenguang,Zhang, Yandong
, (2021)
Quaternary protoberberine alkaloids and quaternary benzophenanthridine alkaloids are two biosynthetically related natural product families of biological importance. Although significant advances have been achieved in the synthetic chemistry of these alkal
A concise synthesis of nornitidine via nickel- or palladium-catalyzed annulation
Luo, Yu,Mei, Yuhua,Zhang, Jianbo,Lu, Wei,Tang, Jie
, p. 9131 - 9134 (2006)
A concise method to synthesize benzo[c]phenanthridine alkaloid, nornitidine, was developed utilizing nickel- or palladium-catalyzed iminoannulation of an internal alkyne. The advantages of this strategy included readily available starting materials, inexp
A Short Total Synthesis of Benzophenanthridine Alkaloids via a Rhodium(III)-Catalyzed C-H Ring-Opening Reaction
Aravindan, Narasingan,Jeganmohan, Masilamani
, p. 14826 - 14843 (2021/10/20)
The biologically important naturally available benzophenanthridines were prepared efficiently in three steps with overall good yields. A new synthetic methodology involving a rhodium(III) catalyzed redox-neutral ring-opening of 7-azabenzonorbornadienes with aromatic aldoximes is developed to synthesize the target molecules. The developed C-H ring-opening reaction is highly diastereoselective and compatible with various sensitive functional group substituted aromatic aldoximes as well as substituted 7-azabenzonorbornadienes. The ring-opening products were transformed into highly sensitive 13,14-dehydrobenzo phenanthridine derivatives by HCl hydrolysis. Subsequently, 13,14-dehydrobenzophenanthridines were converted into biologically important benzophenanthridine alkaloids in the presence of DDQ. A possible reaction mechanism was proposed for the C-H ring-opening reaction and supported by the deuterium labeling studies.
The Aryne aza-Diels-Alder Reaction: Flexible Syntheses of Isoquinolines
Castillo, Juan-Carlos,Quiroga, Jairo,Abonia, Rodrigo,Rodriguez, Jean,Coquerel, Yoann
supporting information, p. 3374 - 3377 (2015/07/15)
(Chemical Equation Presented). Two cascade reactions have been developed for the time-efficient preparation of a variety of functionalized aromatic heterocyclic products exhibiting an isoquinoline core. The approach is based on the normal electron-demand
Visible-light-promoted iminyl-radical formation from Acyl oximes: A unified approach to pyridines, quinolines, and phenanthridines
Jiang, Heng,An, Xiaode,Tong, Kun,Zheng, Tianyi,Zhang, Yan,Yu, Shouyun
, p. 4055 - 4059 (2015/03/30)
A unified strategy involving visible-light-induced iminyl-radical formation has been established for the construction of pyridines, quinolines, and phenanthridines from acyl oximes. With fac-[Ir(ppy)3] as a photoredox catalyst, the acyl oximes were converted by 1 e- reduction into iminyl radical intermediates, which then underwent intramolecular homolytic aromatic substitution (HAS) to give the N-containing arenes. These reactions proceeded with a broad range of substrates at room temperature in high yield. This strategy of visible-light-induced iminyl-radical formation was successfully applied to a five-step concise synthesis of benzo[c]phenanthridine alkaloids.
Rapid and convergent assembly of natural benzo[c]phenanthridines by palladium/norbornene catalysis
Deyris, Pierre-Alexandre,Caneque-Cobo, Tatiana,Gomes, Filipe,Narbonne, Vanessa,Maestri, Giovanni,Malacria, Max
, p. 807 - 815 (2016/09/09)
A straightforward total synthesis of a small panel of natural benzo[c]phenanthridines is described. The selective coupling of an aryl triflate with a bromobenzylamine by means of palladium/norbornene joint catalysis and a sequential transfer hydrogenation
Expeditious approach to pyrrolophenanthridones, phenanthridines, and benzo[ c ]phenanthridines via organocatalytic direct biaryl-coupling promoted by potassium tert -butoxide
De, Subhadip,Mishra, Sourabh,Kakde, Badrinath N.,Dey, Dhananjay,Bisai, Alakesh
, p. 7823 - 7844 (2013/09/12)
A methodology involving a "transition metal-free" intramolecular biaryl-coupling of o-halo-N-arylbenzylamines has been developed in the presence of potassium tert-butoxide and an organic molecule as catalyst. The reaction appears to proceed through KOtBu-promoted intramolecular homolytic aromatic substitution (HAS). Interestingly, this biaryl coupling also works in the presence of potassium tert-butoxide as sole promoter. On extending our approach further, we found that N-acyl 2-bromo-N-arylbenzylamines undergo a one-pot N-deprotection/biaryl coupling followed by oxidation, thus offering an expeditious route to the phenanthridine and benzo[c]phenanthridine skeletons. The strategy has been applied to a concise synthesis of Amaryllidaceae alkaloids viz. oxoassoanine (1b), anhydrolycorinone (1d), 5,6-dihydrobicolorine (2d), trispheridine (2b), and benzo[c]phenanthridines alkaloids dihydronitidine (3b), dihydrochelerythidine (3d), dihydroavicine (3f), nornitidine (3h), and norchelerythrine (3j).
Formal synthesis of nitidine and NK109 via palladium-catalyzed domino direct arylation/N-arylation of aryl triflates
Blanchot, Mathieu,Candito, David A.,Larnaud, Florent,Lautens, Mark
, p. 1486 - 1489 (2011/06/09)
The use of aryl triflates as reaction partners in a palladium-catalyzed domino direct arylation/N-arylation provides a great advantage due to the availability of starting materials. Furthermore, it allows expedient access to biologically interesting benzo
