69035-30-9Relevant academic research and scientific papers
The cooperative effect of Lewis pairs in the Friedel-Crafts hydroxyalkylation reaction: A simple and effective route for the synthesis of (±)-carbinoxamine
Harikrishnan, Adhikesavan,Sanjeevi, Jayakumar,Ramanathan, Chinnasamy Ramaraj
, p. 3633 - 3647 (2015/03/30)
An efficient C-C bond formation strategy between aromatic/heteroaromatic π-nucleophiles and Lewis acid activated aldehydes is described. This aromatic electrophilic substitution reaction of arenes or heteroarenes is facilitated by Lewis acid AlBr3. Aromatic rings with electron donating substituents are excellent nucleophilic counterparts in this reaction, generating carbinols in excellent yields (61-94%). The formation of triarylmethanes is also witnessed in the case of certain reactive aldehydes and aromatic π-nucleophiles through reactive carbocation formation. The formation of triarylmethane is reduced to a greater extent via retardation of the second π-nucleophile addition through a Lewis base, for example, pyridine, coordination with an aluminium alkoxide intermediate. Various aliphatic aldehydes also underwent Friedel-Crafts type hydroxyalkylation and generated the expected carbinols in moderate yields (41-53%) in the presence of AlBr3. This protocol has been successfully applied to the synthesize of the (±)-carbinoxamine, a therapeutically important histamine H1 antagonist, in a one-pot manner.
Room-temperature bismuth-catalyzed bis-arylation of carbonyl compounds with aryl ethers and phenols
Liu, Congrong,Li, Manbo
, p. 1274 - 1278 (2013/11/06)
Using Bi2(SO4)3 as the catalyst and TMSCl as the additive, a wide variety of aldehydes, ketones, and acetals were smoothly condensed with aryl ethers at room temperature to provide the corresponding diarylmethanes and triarylmethanes selectively in good to excellent yields. Using Bi2(SO4)3 as the catalyst and TMSCl as the additive, a wide variety of aldehydes, ketones, and acetals were smoothly condensed with aryl ethers at room temperature to selectively provide the corresponding diarylmethanes and triarylmethanes in good to excellent yields. Copyright
Friedel-Crafts hydroxyalkylation through activation of a carbonyl group using AlBr3: An easy access to pyridyl aryl/heteroaryl carbinols
Harikrishnan, Adhikesavan,Selvakumar, Jayaraman,Gnanamani, Elumalai,Bhattacharya, Suman,Ramanathan, Chinnasamy Ramaraj
supporting information, p. 563 - 567 (2013/04/10)
Aromatic electrophilic substitution of aromatic/electron rich heteroaromatic compounds with AlBr3 activated aldehydes/ketone to afford pyridyl aryl/heteroaryl or diaryl carbinols is described. The strong electron donating group dictates the regiochemical outcome of the product.
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.
Catalytic selective bis-arylation of imines with anisole, phenol, thioanisole and analogues
Liu, Cong-Rong,Li, Man-Bo,Yang, Cui-Feng,Tian, Shi-Kai
, p. 1249 - 1251 (2008/12/21)
The first highly efficient double Friedel-Crafts reaction of N-tosyl imines with anisole, phenol, thioanisole and analogues has been developed to produce the corresponding symmetric diarylmethanes and triarylmethanes with high regioselectivity in the presence of a catalytic amount of Bi2(SO 4)3-TMSCl at room temperature. The Royal Society of Chemistry.
