6266-10-0Relevant articles and documents
Hemoglobin: A New Biocatalyst for the Synthesis of 2-substituted Benzoxazoles via Oxidative Cyclization
Li, Fengxi,Li, Zhengqiang,Tang, Xuyong,Cao, Xinyu,Wang, Chunyu,Li, Jialin,Wang, Lei
, p. 1192 - 1195 (2019/02/07)
Efficient and mild synthesis of a series of 2-substituted benzoxazoles via oxidative cyclization catalyzed by hemoglobins reported here for the first time. Satisfactory yields (84 %–97 %) and mild reaction conditions make this method highly viable for practical applications.
Oxidative NHC Catalysis for the Generation of Imidoyl Azoliums: Synthesis of Benzoxazoles
Patra, Atanu,James, Anjima,Das, Tamal Kanti,Biju, Akkattu T.
, p. 14820 - 14826 (2019/01/03)
N-Heterocyclic carbene (NHC)-catalyzed intramolecular cyclization of aldimines generated from 2-amino phenols and aromatic aldehydes leading to the synthesis of 2-arylbenzoxazoles under mild conditions is presented. The reaction proceeds via the generation of the aza-Breslow intermediates from imines and NHC, which under oxidative conditions form the key imidoyl azoliums and a subsequent intramolecular cyclization furnishes the product. The reaction tolerates a broad range of functional groups, and the products are formed in generally good yields.
OMS-2/H2O2/Dimethyl Carbonate: An Environmentally-Friendly Heterogeneous Catalytic System for the Oxidative Synthesis of Benzoxazoles at Room Temperature
Meng, Xu,Wang, Yuanguang,Chen, Baohua,Chen, Gexin,Jing, Zhenqiang,Zhao, Peiqing
supporting information, p. 2018 - 2024 (2017/12/26)
A manganese octahedral molecular sieve (OMS-2) was found to be an efficient and recyclable heterogeneous catalyst for the oxidative synthesis of benzoxazoles in the gram-scale from phenolic imines at room temperature. H2O2 and biobased reagent dimethyl carbonate (DMC) were successfully employed as the environmentally friendly oxidant and solvent, respectively, in an OMS-2-catalysted redox reaction for the first time. Benzoxazoles could also be obtained from N-substituted 2-aminophenols via Cu(OH)x/OMS-2-catalyzed sequential oxidative transformation at elevated temperatures.
Synthesis and biological activities of 2-aminophenol-based Schiff bases and their structure-activity relationship
Aslam, Muhammad,Anis, Itrat,Mehmood, Rashad,Iqbal, Lubna,Iqbal, Samina,Khan, Inamullah,Chishti, Muhammad Salman,Perveen, Shagufta
, p. 109 - 115 (2016/01/25)
Six Schiff bases 8-13 were synthesized by condensation of 2-aminophenol (1) with various chloro- and nitro-benzaldehydes (2-7), characterized, and evaluated for antioxidant, antibacterial, lipoxygenase, and urease inhibitory potentials. All Schiff bases e
Comparison of chelating ability of NO-, NS-, ONS-, and ONO-type Schiff base derivatives and their stability constants of Bis-complexes with copper(II)
Atabey, Hasan,Findik, Esra,Sari, Hayati,Ceylan, Mustafa
, p. 109 - 120 (2014/02/14)
The present study includes important findings relating to the number of donor atoms, species of ligands, and stabilities of complexes. Stabilities of complexes between Cu(II) ion and NO-, NS-, ONS-, and ONO-type Schiff bases were compared. Acid-base properties of the Schiff bases were explained at 25 ± 0.1 ° C and ionic strength (I) of 0.1 M supported by NaCl. The Hyperquad computer program was used for calculation of dissociation and stability constants. The overall stability constants of their Cu(II) complexes were calculated and the various formed complexes between the Schiff bases with Cu(II) ion formulated as CuL2, CuHL2, CuH2L 2, and CuH-1L2(Cu (OH) L2). The complexes of ONS- and ONO-type tridentate ligands were more stable than those of NO- and NS-type bidentate ligands. TUeBITAK.
Microwave-assisted synthesis of substituted dibenzo[b,f][1,4]thiazepines, dibenzo[b,f][1,4]oxazepines, benzothiazoles, and benzimidazoles
Lin, Yu-Chin,Li, Ni-Ching,Cherng, Yie-Jia
, p. 808 - 814 (2014/06/10)
A highly efficient synthesis for possessing 7-membered rings with two heteroatoms is described, using efficient microwave-assisted one-pot method to synthesize (substituted) dibenzo[b,f][1,4]thiazepines [1] and dibenzo[b,f][1,4]oxazepines [2] in high yields (up to 99%) by cyclocondensations of o-aminothiophenol or o-aminophenol with o-halobenzaldehydes, o-fluoroacetophenone, and o-fluorobenzophenone. In the absence of base, o-aminothiophenol reacted with o-halobenzaldehydes to afford benzothiazoles.
Niobium-catalyzed highly enantioselective aza-diels-alder reactions
Jur?ík, Václav,Arai, Kenzo,Salter, Matthew M.,Yamashita, Yasuhiro,Kobayashi, Shu
supporting information; experimental part, p. 647 - 651 (2009/04/21)
Niobium-based chiral Lewis acid was found to be highly effective catalyst for aza-Diels-Alder reactions of imines with Danishefsky's dienes. The reactions proceed in high yield with high enantioselectivity for both aromatic and aliphatic imines. The developed methodology was applied to total synthesis of (+)-anabasine.
A simple, convenient and effective method for the synthesis of dibenz(b,f) 1,4-oxazepines(cr); a new generation riot control agent and its analogues
Gutch,Acharya
, p. 393 - 396 (2008/09/19)
A new synthetic route has been developed for the synthesis of seven membered heterocyclic ring dibenz (b, f) 1,4-oxazepine (CR) starting with condensation of o-aminophenol and o-chlorobenzaldehyde followed by salt formation and cyclisation in DMSO at 120°C. The method has been extended for the preparation of other substituted dibenzoxazepines.
