Synthesis of 2-((2-(Benzo[d]oxazol-2-yl)-2H-imidazol -4-yl)amino)-phenols from 2-((5H-1,2,3-Dithiazol -5-ylidene)amino)phenols through Unprecedented Formation of Imidazole Ring from Two Methanimino Groups
A new synthetic pathway to four substituted imidazoles from readily available 2-((4-aryl (thienyl)-5H-1,2,3-dithiazol-5-ylidene)amino)phenols has been developed. Benzo[d]oxazol-2-yl(aryl (thienyl))methanimines were proved as key intermediates in their synthesis. The formation of an imidazole ring from two methanimine derivatives likely includes the opening of one benzoxazole ring followed by ring closure by intermolecular nucleophilic attack of the N-methanimine atom to a carbon atom of another methanimine.
Baranovsky, Ilia V.,Konstantinova, Lidia S.,Tolmachev, Mikhail A.,Popov, Vadim V.,Lyssenko, Konstantin A.,Rakitin, Oleg A.
(2020/09/04)
Acid-Catalyzed Condensation of o-Phenylenediammines and o-Aminophenols with α-Oxodithioesters: A Divergent and Regio? selective Synthesis of 2-Methylthio-3-Aryl/Heteroarylquinoxalines and 2-Acylbenzoxazoles
o-Phenylenediammines and o-Aminophenols were reacted with α-oxodithioesters in a highly regioselective fashion to give 2-methylthio-3-Aryl/heteroarylquinoxalines and 2-Acylbenzoxazoles in 55-94percent and 45-86percent, respectively, in the presence of p-T
Palladium(II)/N-heterocyclic carbene-catalyzed direct C-H acylation of heteroarenes with N-acylsaccharins
N-Acylsaccharin represents a facile acyl group transfer agent to heteroarenes in the presence of Pd(II)/NHC complexes appended with a pyrene unit. Catalytic acylation of heteroarenes was enhanced by the noncovalent interaction between the pyrene unit and
Karthik, Shanmugam,Gandhi, Thirumanavelan
supporting information
p. 5486 - 5489
(2017/11/06)
Synthesis of 2-Keto(hetero)aryl Benzox(thio)azoles through Base Promoted Cyclization of 2-Amino(thio)phenols with α,α-Dihaloketones
An interesting base-promoted protocol for the synthesis of 2-keto(hetero)aryl benzox(thi)azoles has been developed. Starting from commercially available 2-amino(thio)phenols and α,α-dihaloketones, moderate to good yields of the corresponding heterocycles can be achieved. Notably, only EtNH2 was required as the promoter here, and the reaction can be easily performed on a large scale.
Cobalt-Catalyzed Decarboxylative 2-Benzoylation of Oxazoles and Thiazoles with α-Oxocarboxylic Acids
Cobalt-catalyzed decarboxylative cross-coupling of oxazoles and thiazoles with α-oxocarboxylic acids was developed through an sp2 C-H bond functionalization process. This work represents the first example of cobalt-catalyzed decarboxylative C-H
A one-pot hypoiodite catalysed oxidative cycloetherification approach to benzoxazoles
A practical one-pot hypoiodite catalysed oxidative cyclization approach to synthesize α-ketobenzoxazole derivatives was successfully developed. This operationally simple protocol utilizes easily-accessible starting materials and has a broad substrate scope with excellent yields. This journal is the Partner Organisations 2014.
Nickel-catalyzed decarboxylative acylation of heteroarenes by sp 2 C-H functionalization
Nickel-catalyzed ligand-free decarboxylative cross-coupling of azole derivatives with α-oxoglyoxylic acids has been developed. This work represents the first example of decarboxylative cross-coupling reactions, in a C-H bond functionalization manner, thro
Palladium-catalyzed carbonylative C-H activation of heteroarenes
Not only carbonylation: The first carbonylative cross-coupling reactions towards ketones using C-H activation have been developed. Various heteroarenes, such as oxazoles, thiazoles, and imidazoles were used as coupling partners in this methodology. DBU =