- FeCl3-Promoted ring size-dictating diversity-oriented synthesis (DOS) of N-heterocycles using: In situ -generated cyclic imines and enamines
-
The FeCl3-promoted ring size-controlled oxidative activation of o-alkynylanilines opens up a complementary appealing protocol for poly-N-heterocycle synthesis. When electron-poor π-alkyne iron species combine with cyclic enamines obtained from cyclohexanone and β-tetralone, they undergo a regioselective 6-exo-dig cyclization to afford the corresponding dibenzo[b,j][1,10]phenanthrolines and 12-benzoylated dihydrobenzo[a]acridine skeletons. Later, these acridine motifs become completely unsaturated due to dehydrogenative aromatization via the aza-allyl oxidation intermediate. We obtained all quaternary carbon centre pseudoindoxyls through the Mannich-type alkylation of 2,3-dihydro-1H-inden-1-one with cyclic ketimines generated from the in situ intramolecular nucleophilic cyclization of o-alkynylanilines.
- Dhandabani, Ganesh Kumar,Mutra, Mohana Reddy,Wang, Jeh-Jeng
-
-
Read Online
- Ortho-Quinone Methide Driven Synthesis of New O,N- or N,N-Heterocycles
-
To synthesize functionalized Mannich bases that can serve two different types of ortho-quinone methide (o-QM) intermediates, 2-naphthol and 6-hydroxyquinoline were reacted with salicylic aldehyde in the presence of morpholine. The Mannich bases that can form o-QM and aza-o-QM were also synthesized by mixing 2-naphthol, 2-nitrobenzaldehyde, and morpholine followed by reduction of the nitro group. The highly functionalized aminonaphthol derivatives were then tested in [4+2] cycloaddition with different cyclic imines. The reaction proved to be both regio- and diastereoselective. In all cases, only one reaction product was obtained. Detailed structural analyses of the new polyheterocycles as well as conformational studies including DFT modelling were performed. The relative stability of o-QMs/aza-o-QM were also calculated, and the regioselectivity of the reactions could be explained only when the cycloaddition started from aminodiol 4. It was summarized that starting from diaminonaphthol 25, the regioselectivity of the reaction is driven by the higher nucleophilicity of the amino group compared with the hydroxy group. 12H-benzo[a]xanthen-12-one (11), formed via o-QM formation, was isolated as a side product. The proton NMR spectrum of 11 proved to be very unique from NMR point of view. The reason for the extreme low-field position of proton H-1 could be accounted for by theoretical calculation of structure and spatial magnetic properties of the compound in combination of ring current effects of the aromatic moieties and steric compression within the heavily hindered H(1)-C(1)-C(12b)-C(12a)-C(12)=O structural fragment.
- Szatmári, István,Belasri, Khadija,Heydenreich, Matthias,Koch, Andreas,Kleinpeter, Erich,Fül?p, Ferenc
-
-
Read Online
- Nitrogen-Iodine Exchange of Diaryliodonium Salts: Access to Acridine and Carbazole
-
A nitrogen-iodine exchange protocol of diaryliodonium salts with sodium azide salt is developed for general construction of significant functional acridines and carbazoles, in which introduction of nitrogen at a late stage was successfully established avoiding heteroatom incompatibility. Inorganic sodium azide served as the sole nitrogen atom source in this transformation. The diversiform functional acridines and carbazoles were comprehensively achieved through annulated diaryliodonium salts, respectively. Notably, Acridine orange (a fluorescent indicator for cell lysosomal dye) and Carprofen (a nonsteroidal anti-inflammatory drug) were efficiently established through this protocol.
- Wang, Ming,Fan, Qiaoling,Jiang, Xuefeng
-
p. 216 - 219
(2018/01/17)
-
- Nitrogen anthracene class compound and its synthetic method and application (by machine translation)
-
The invention discloses a formula (2) shown in nitrogen anthracene class of compound and its synthetic method, high Iodized salt as reaction raw material, in the inorganic nitrogen reagent, additive, water, alkali, under the action of the metal catalyst, in the 80 - 150 °C conditions, reacts in a solvent 12 - 60 hours to obtain various nitrogen anthracene class compounds. The invention by post method of introducing nitrogen atoms, to avoid the early stage in the reaction of the nitrogen heterocyclic to metal catalyst of the reaction conditions such as not compatibility; in addition, high Iodized salt in the full utilization of the two aryl, shows that the method of the invention atom economy. Prepared by the method of the invention can be further applied [...] compound of the fluorescent indicator acridine orange synthesis. (by machine translation)
- -
-
Paragraph 0103-0106
(2018/05/16)
-
- Facile synthesis of acridine derivatives by ZnCl2-promoted intramolecular cyclization of o -arylaminophenyl schiff bases
-
A concise and efficient method for the synthesis of a wide range of acridine derivatives and polycyclic aza-aromatic compounds from a ZnCl 2-promoted cyclization reaction of readily available o-arylaminophenyl Schiff base compounds under convenient conditions was developed. Reaction conditions and scope of the new method were examined in detail.
- Su, Qing,Li, Pei,He, Mina,Wu, Qiaolin,Ye, Ling,Mu, Ying
-
supporting information
p. 18 - 21
(2014/01/23)
-
- A General and Practicable Synthesis of Polycyclic Heteroaromatic Compounds. Part 4. A Rationale for the Mechanism of the Synthesis
-
Studies on aspects of the mechanism of our general synthesis of polycyclic heteroaromatic compounds suggest that the reaction sequence outlined in Scheme 2 is followed.Under the conditions of our synthesis, the ortho-rearrangement (8) --> (9) is preferred to the para-rearrangement which is known to occur in acid conditions.Aniline Mannich bases (29) are converted to benzacridines (30) in an intermolecular reaction.The synthesis appears to be restricted to substrates where the putative intermediate (9) is not part of an amide group.In the course of these studies effective syntheses of the tricyclic compounds (24) and (25) have been discovered.
- Asherson, Janet L.,Bilgic, Orhan,Young, Douglas W.
-
p. 3041 - 3047
(2007/10/02)
-
- A General and Practicable Synthesis of Polycyclic Heteroaromatic Compounds. Part 3. Extension of the Synthesis to 'Quinone Methides' of Naphthalene, Phenanthrene, and Benzene
-
The general synthesis of polycyclic heteroaromatic compounds by generation of a quinone methide in the presence of an aromatic amine has been successfully extended to naphthalene and phenanthrene 'quinone methides'.Whereas yields had been highest when the putative quinone methides of less aromatic compounds were generated by a retro-Diels-Alder process, this method was inappropriate for the 'quinone methides' of more aromatic compounds.Good yields were obtained for the naphthalene and phenanthrene series when the 'quinone methides' were generated by pyrolysis of a Mannich base.Attempts to extend the synthesis of benzenoid quinone methides gave low yields of the polycyclic heteroaromatic product
- Bilgic, Orhan,Young, Douglas W.
-
p. 1233 - 1239
(2007/10/02)
-
