33265-69-9Relevant academic research and scientific papers
A new pathway to pyrrolo[1,2-a]quinoxalines via solvent-free one-pot strategy utilizing FeMoSe nanosheets as efficient recyclable synergistic catalyst
To, Tuong A.,Nguyen, Chuc T.,Tran, My H.P.,Huynh, Thai Q.,Nguyen, Tung T.,Le, Nhan T.H.,Nguyen, Anh D.,Tran, Phong D.,Phan, Nam T.S.
, p. 163 - 173 (2019)
FeMoSe nanocatalyst was synthesized using solvothermal approach from readily available precursors, namely Mo(CO)6, FeSO4 and Se, and characterized by spectroscopic and microscopic analyses. The FeMoSe material offered high catalytic
Elemental Sulfur Mediated Synthesis of Pyrrolo[1,2- a ]quinoxalines from 1-(2-Nitroaryl)pyrroles
Ho, Tuan H.,Phan, Nhu T. A.,Ho, Thuyen T. C.,Tran, Duyen L. M.,Nguyen, Tung T.,Phan, Nam T. S.
, p. 4117 - 4123 (2021/08/03)
Methods to afford pyrrolo[1,2- a ]quinoxalines often require the use of prefunctionalized aniline precursors, transition metals, and/or harsh conditions. Herein we describe a simple coupling of 1-(2-nitroaryl)pyrroles and arylacetic acids, in the presence of elemental sulfur, to furnish the fused heterocycles in good yields. The conditions are compatible with many functionalities including ester, nitrile, halogen, and nitro groups. Use of benzyl alcohols and picoline coupling reagents was also attempted.
Synthesis of 4-Aryl Pyrrolo[1,2-α]quinoxalines via Iron-Catalyzed Oxidative Coupling from an Unactivated Methyl Arene
Ahn, Jiwon,Lee, Seok Beom,Song, Injae,Chun, Simin,Oh, Dong-Chan,Hong, Suckchang
, p. 7390 - 7402 (2021/06/21)
Herein, we describe the direct synthesis of pyrrolo[1,2-α]quinoxaline via oxidative coupling between methyl arene and 1-(2-aminophenyl) pyrroles. Oxidation of the benzylic carbon of the methyl arene was achieved by di-t-butyl peroxide in the presence of an iron catalyst, followed by conversion to an activated aldehyde in situ. Oxygen played a crucial role in the oxidation process to accelerate benzaldehyde formation. Subsequent Pictet-Spengler-type annulation completed the quinoxaline structure. The protocol tolerated various kinds of functional groups and provided 22 4-aryl pyrrolo[1,2-α]quinoxalines when various methyl arene derivatives were used. The developed method proceeded in air, and all catalysts, reagents, and solvents were easily accessible.
Tin(ii) chloride dihydrate/choline chloride deep eutectic solvent: Redox properties in the fast synthesis of: N -arylacetamides and indolo(pyrrolo)[1,2- a] quinoxalines
Bejarano, Oscar Rodríguez,Ochoa-Puentes, Cristian,Pe?a-Solórzano, Diana,Trujillo, Sergio Alfonso
, p. 40552 - 40561 (2020/11/18)
In this contribution a physicochemical, IR and Raman characterization for the tin(ii) chloride dihydrate/choline chloride eutectic mixture is reported. The redox properties of this solvent were also studied by cyclic voltammetry finding that it can be successfully used as an electrochemical solvent for electrosynthesis and electroanalytical processes and does not require negative potentials as verified by the reduction of nitrobenzene. The potential use of this eutectic mixture as a redox solvent was further explored in obtaining aromatic amines and N-arylacetamides starting from a wide variety of nitroaromatic compounds. In addition, a fast synthetic strategy for the construction of a series of indolo(pyrrolo)[1,2-a]quinoxalines was developed by reacting 1-(2-nitrophenyl)-1H-indole(pyrrole) with aldehydes. This simple protocol offers a straightforward method for the construction of the target quinoxalines in short reaction times and high yields where the key step involves a tandem one-pot reductive cyclization-oxidation.
Direct Synthesis of Pyrrolo[1,2-α]quinoxalines via Iron-Catalyzed Transfer Hydrogenation between 1-(2-Nitrophenyl)pyrroles and Alcohols
Chun, Simin,Ahn, Jiwon,Putta, Ramachandra Reddy,Lee, Seok Beom,Oh, Dong-Chan,Hong, Suckchang
, p. 15314 - 15324 (2020/11/13)
Herein, we describe novel iron-catalyzed transfer hydrogenation between alcohols and 1-(2-nitrophenyl)pyrroles for the synthesis of pyrrolo[1,2-α]quinoxalines. The tricarbonyl (η4-cyclopentadienone) iron complex catalyzed the oxidation of alcohols and the reduction of nitroarenes, and the corresponding aldehydes and aniline were generated in situ. The resulting Pictet-Spengler-type annulation/oxidation completed the quinoxaline structure formation. The protocol tolerated various kinds of functional groups and provided 29 samples of 4-substituted pyrrolo[1,2-α]quinoxalines. The developed method was also applied for the synthesis of additional polyheterocycles.
Unexpected activated carbon-catalyzed pyrrolo[1,2-a]quinoxalines synthesis in water
Sun, Qi,Liu, Liyan,Yang, Yu,Zha, Zhenggen,Wang, Zhiyong
supporting information, p. 1379 - 1382 (2019/05/04)
An interesting and recyclable activated carbon/water catalytic system for efficient synthesis of pyrrolo[1,2-a]quinoxaline derivatives was developed. The intramolecular C–N and C–C bond can be easily constructed in water under mild condition. This reaction features a broad substrate scope, a good tolerance to water and air, metal-free, additive-free and redox reagent-free.
A highly divergent Pictet-Spengler approach for pyrrolo[1,2-a]quinoxalines from aryl amine using 1,2-dinitrobenzene as an oxidant
Pardeshi, Sachin D.,Patil, Bhausaheb N.,Patil, Prashant,Chaskar, Atul C.
supporting information, (2019/11/11)
A convenient Pictet-Splengler approach for the synthesis of substituted pyrrolo[1,2-a]quinoxalines from aryl amine and 1-(2-aminoaryl)-pyrrole has been developed. This is the first domino protocol involving formation of benzaldehyde as an intermediate from benzyl amines and benzyl alcohols using 1,2-DNB as an oxidant, followed by its endo cyclization with 1-(2-aminophenyl)-pyrrole to furnish the pyrrolo[1,2-a]quinoxalines. Notably, this procedure exhibits good functional group tolerance as well as good to moderate yield of pyrrolo[1,2-a]quinoxaline.
Metal-Free Synthesis of Pyrrolo[1,2- a ]quinoxalines Mediated by TEMPO Oxoammonium Salts
Huo, Heng-Rui,Tang, Xiang-Ying,Gong, Yue-Fa
, p. 2727 - 2740 (2018/06/20)
We herein describe a novel TEMPO oxoammonium salt initiated Pictet-Spengler reaction of imines, generated in situ from carbonyl compounds and pyrrole- or indole-containing substrates, to afford 4,5-dihydropyrrolo[1,2- a ]quinoxalines or 5,6-dihydroindolo[1,2- a ]quina-oxalines in good to excellent yields. Moreover, a one-pot synthesis of a biologically important quinoxaline is achieved via a cyclization-dehydrogenation process using one equivalent of the oxoammonium salt.
Molecular iodine-catalysed oxidative CO-C(alkyl) bond cleavage of aryl/heteroaryl alkyl ketones: an efficient strategy to access fused polyheterocycles
Mani, Geeta Sai,Rao, Ayanampudi Venkata Subba,Tangella, Yellaiah,Sunkari, Satish,Sultana, Faria,Namballa, Hari Krishna,Shankaraiah, Nagula,Kamal, Ahmed
, p. 15820 - 15829 (2018/10/04)
An efficient molecular iodine-catalysed one-pot strategy has been accomplished for the construction of various fused heterocycles such as pyridoimidazoles, pyrrolo[1,2-a]quinoxalines and imidazobenzothiazoles under metal and oxidant free conditions. Gratifyingly, this method allows the sequential formation of C-N and C-C bonds with concomitant CO-C(alkyl) bond cleavage. The key features of this protocol are a broad substrate scope, operational simplicity, good to moderate yields and metal-free conditions, which make this protocol convenient for the generation of a library of fused polyheterocycles.
Iridium-catalyzed Asymmetric Hydrogenation of Polycyclic Pyrrolo/Indolo[1,2-a]quinoxalines and Phenanthridines
Hu, Shu-Bo,Zhai, Xiao-Yong,Shen, Hong-Qiang,Zhou, Yong-Gui
supporting information, p. 1334 - 1339 (2018/02/06)
Owing to the dehydrogenative rearomatization of hydrogenation product and poisoning effect of nitrogen atom, asymmetric hydrogenation of polycyclic nitrogen-containing heteroaromatics is still a great challenge. Herein, through in situ protection of hydro
