57259-32-2Relevant academic research and scientific papers
From Prochiral N-Heterocyclic Carbenes to Optically Pure Metal Complexes: New Opportunities in Asymmetric Catalysis
Kong, Lingyu,Morvan, Jennifer,Pichon, Delphine,Jean, Marion,Albalat, Muriel,Vives, Thomas,Colombel-Rouen, Sophie,Giorgi, Michel,Dorcet, Vincent,Roisnel, Thierry,Crévisy, Christophe,Nuel, Didier,Nava, Paola,Humbel, Stéphane,Vanthuyne, Nicolas,Mauduit, Marc,Clavier, Hervé
, p. 93 - 98 (2020/01/09)
Well-defined optically pure transition metal (TM) complexes bearing C1- and C2-symmetric N-heterocyclic carbene (NHC) ligands were prepared from prochiral NHC precursors. As predicted by DFT calculations, our strategy capitalizes on
Organocatalytic Atroposelective Construction of Axially Chiral N-Aryl Benzimidazoles Involving Carbon-Carbon Bond Cleavage
Man, Ningning,Lou, Zhenbang,Li, Yuming,Yang, Haijun,Zhao, Yufen,Fu, Hua
, p. 6382 - 6387 (2020/09/02)
Axially chiral compounds widely occur in natural products, biologically active molecules, ligands, and catalysts, and their efficient and enantioselective synthesis is highly desirable. Herein, we report a novel method for the atroposelective construction of axially chiral N-aryl benzimidazoles with chiral phosphoric acid as the organocatalyst via reaction of N1-(aryl)benzene-1,2-diamines with multicarbonyl compounds. The present method provided the target products in high yields (up to 89percent) with excellent enantioselectivity (up to 98percent ee).
Copper-Catalyzed One-Pot Synthesis of Dibenzofurans, Xanthenes, and Xanthones from Cyclic Diphenyl Iodoniums
Zhu, Daqian,Li, Min,Wu, Zhouming,Du, Yongliang,Luo, Bingling,Huang, Peng,Wen, Shijun
, p. 4566 - 4571 (2019/07/09)
Oxygenation of cyclic diphenyl iodoniums (CDPIs) with varied medium-ring sizes has been fully investigated. This practical copper-catalyzed tandem reaction of CDPIs with water as the oxygen source enables the construction of derivatised dibenzofurans and xanthenes at moderate to good yields. Moreover, structurally important xanthones are also successfully accessed under the oxygenation conditions with additional TEMPO.
Gold(i)-catalysed high-yielding synthesis of indenes by direct Csp3-H bond activation
Nahide, Pradip D.,Jiménez-Halla, J. Oscar C.,Wrobel, Katarzyna,Solorio-Alvarado, César R.,Ortiz Alvarado, Rafael,Yahuaca-Juárez, Berenice
, p. 7330 - 7335 (2018/10/24)
A catalytic, practical and high-yielding procedure for the synthesis of indenes by direct Csp3-H activation under gold(i) catalysis was developed. The scope of the protocol was determined by synthesizing some electron-neutral, electr
Intramolecular addition of triarylmethanes to alkynes promoted by KOtBu/DMF: A synthetic approach to indene derivatives
Chen, Yan-Yan,Chen, Zhen-Yu,Zhang, Niu-Niu,Chen, Jia-Hua,Zhang, Xue-Jing,Yan, Ming
, p. 599 - 606 (2016/02/19)
A method for the intramolecular addition of triarylmethanes to alkynes has been developed. The reaction was efficiently promoted by KOtBu/DMF without any transition-metal catalyst. A variety of indene derivatives were prepared in moderate to good yields. A cascade cyclization of 2-alkyl-substituted substrates at elevated reaction temperature gave bicyclic indene derivatives. The reaction is proposed to proceed through the generation of a triphenylmethyl radical. Indene derivatives were prepared by the intramolecular addition of triarylmethanes to alkynes promoted by KOtBu/DMF. A cascade cyclization of 2-alkyl-substituted substrates at elevated reaction temperature gave bicyclic indene derivatives. A free-radical reaction mechanism is proposed.
Domino reactions initiated by intramolecular hydride transfers from tri(di)arylmethane fragments to ketenimine and carbodiimide functions
Alajarin, Mateo,Bonillo, Baltasar,Ortin, Maria-Mar,Sanchez-Andrada, Pilar,Vidal, Angel,Orenes, Raul-Angel
supporting information; experimental part, p. 4690 - 4700 (2010/11/24)
The ability of triarylmethane and diarylmethane fragments to behave as hydride donors participating in thermal [1,5]-H shift/6π-ERC tandem processes involving ketenimine and carbodiimide functions is disclosed. C-Alkyl-C-phenyl ketenimines N-substituted by a triarylmethane substructure convert into a variety of 3,3,4,4-tetrasubstituted-3,4-dihydroquinolines, as structurally related carbodiimides transform into 3,4,4-trisubstituted-3,4- dihydroquinazolines via transient ortho-azaxylylenes. The first step of these one-pot conversions, the [1,5]-H shift, is considered to be a hydride migration on the basis of the known hydricity of the tri(di)arylmethane fragment and the electrophilicity of the central heterocumulenic carbon atom, whereas the final electrocyclization involves the formation of a sterically congested C-C or C-N bond. In the cases of C,C-diphenyl substituted triarylmethane-ketenimines the usual 6π-ERC becomes prohibited by the presence of two phenyl rings at each end of the azatrienic system. This situation opens new reaction channels: (a) following the initial hydride shift, the tandem sequence continues with an alternative electrocyclization mode to give 9,10-dihydroacridines, (b) the full sequence is initiated by a rare 1,5 migration of an electron-rich aryl group, followed by a 6π-ERC which leads to 2-aryl-3,4-dihydroquinolines, or (c) a different [1,5]-H shift/6π-ERC sequence involving the initial migration of a hydrogen atom from a methyl group at the ortho position to the nitrogen atom of the ketenimine function. Diarylmethane-ketenimines bearing a methyl group at the benzylic carbon atom experience a tandem double [1,5]-H shift, the first one being the usual benzylic hydride transfer whereas the second one involves the methyl group at the initial benzylic carbon atom, the reaction products being 2-aminostyrenes. Diarylmethane-ketenimines lacking such a methyl group convert into 3,4-dihydroquinolines by the habitual tandem [1,5]-H shift/6π-ERC processes.
Aryl ring migration reaction in the synthesis of 2,4-diaryl-4H-3,1- benzothiazines
Butin, Alexander V.,Tsiunchik, Fatima A.,Abaev, Vladimir T.,Gutnov, Andrey V.,Cheshkov, Dmitry A.
scheme or table, p. 2616 - 2626 (2010/02/16)
A new rearrangement of 1-(diarylmethyl)-2-isothiocyanatobenzenes into 2,4-diaryl-4H-3,1-benzothiazine derivatives is described. Treatment of the starting compounds with aluminum trichloride under Friedel-Crafts conditions leads to migration of an aryl sub
Mass Spectral and Pyrolitic Studies of Some 4,4-Disubstituted 1,4-Dihydro-2H-3,1-benzoxazin-2-ones
Acharya, Baman Prasad,Misra, Bijaya Kumar,Rao, Yerramalli Ramachandra
, p. 4417 - 4420 (2007/10/02)
Pyrolysis of 4,4-diaryl-1,4-dihydro-2H-3,1-benzoxazin-2-ones at 230-240 deg C gives 9-arylacridines and (2-aminophenyl)diarylmethanes.Their formation correlates well with the mass fragmentation of the respective parent compounds.
