One-Pot Construction of Indolo[2,3-<i>b</i>]quinoxalines through Ruthenium-Catalyzed <i>Ortho</i> C–H Bond Functionalization of 2-Arylquinoxalines with Sulfonyl Azides
N-substituted indolo[2,3-b]quinoxalines has been developed through a Ru(II)-catalyzed ortho C–H functionalization of 2-arylquinoxalines with sulfonyl azides and further oxidation with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone in one pot. This double C–N bond formation strategy provides a new efficient route for the preparation of a series of biologically relevant 6H-indolo[2,3-b]quinoxaline derivatives in
N-取代的吲哚并[2,3- b ]喹喔啉的合成是通过Ru(II)催化的2-芳基喹喔啉与磺酰叠氮化物的邻位C-H官能化并用2,3-二氯-5进一步氧化而开发的, 6-二氰基-1,4-苯醌一锅。这种双C-N键形成策略为制备一系列生物相关的6 H-吲哚[2,3- b ]喹喔啉衍生物提供了一条新的有效途径,产率高达94%,表明底物适用范围广泛。初步的机理研究表明,连续的 C-N 键形成是通过第一步中五元钌环中间体的形成和第二步中自由基机制的形成进行的。
Visible light promoted tandem dehydrogenation-deaminative cyclocondensation under aerobic conditions for the synthesis of 2-aryl benzimidazoles/quinoxalines from <i>ortho</i>-phenylenediamines and arylmethyl/ethyl amines
作者:Firdoos Ahmad Sofi、Rohit Sharma、Ravi Rawat、Asit K. Chakraborti、Prasad V. Bharatam
DOI:10.1039/d0nj03002c
日期:——
Visible light promoted dominosynthesis of 2-aryl benzimidazoles is reported through the reaction of ortho-phenylenediamines and arylmethyl amines underaerobicconditions. The methodology has wide substrate scope and tolerates a wide range of functional groups affording the products in high yields. The use of arylethyl amines instead of arylmethyl amines gives 2-aryl quinoxalines.
I<sub>2</sub> catalyzed tandem protocol for synthesis of quinoxalines via sp<sup>3</sup>, sp<sup>2</sup> and sp C–H functionalization
作者:Kamlesh S. Vadagaonkar、Hanuman P. Kalmode、Kaliyappan Murugan、Atul C. Chaskar
DOI:10.1039/c4ra08589b
日期:——
One-pot, atom-economic synthesis of quinoxalines has been achieved through generation of arylglyoxalfrom easily available ethylarenes, ethylenearenes and ethynearenes, and subsequent condensation with o-phenylenediamines. Catalytic I2 with TBHP as an oxidant in DMSO is the system of choice for this dominoreaction involving C–H functionalization/oxidative cyclization. This metal-free, mechanistically
One-Pot Protocol for the Synthesis of Imidazoles and Quinoxalines using<i>N</i>-Bromosuccinimide
作者:Sachin D. Pardeshi、Pratima A. Sathe、Kamlesh S. Vadagaonkar、Atul C. Chaskar
DOI:10.1002/adsc.201700900
日期:2017.12.11
N‐bromosuccinimide (NBS)‐mediated one‐pot, green, efficient and practical synthesis of substituted imidazoles and quinoxalines has been achieved by the reaction of styrenes with N‐arylbenzamidines and o‐phenylenediamines, respectively, in a water:1,4‐dioxane mixture. The reaction involves formation of an α‐bromo ketone as an intermediate in the presence of NBS and water, followed by condensation with
C-N Bond Formation Catalyzed by Ruthenium Nanoparticles Supported on N-Doped Carbon via Acceptorless Dehydrogenation to Secondary Amines, Imines, Benzimidazoles and Quinoxalines
作者:Bin Guo、Hong-Xi Li、Shi-Qi Zhang、David James Young、Jian-Ping Lang
DOI:10.1002/cctc.201801525
日期:2018.12.21
Ruthenium nanoparticles (NPs) supported on N‐doped carbon (Ru/N−C) were prepared by the pyrolysis of cis‐Ru(phen)2Cl2 loaded onto carbon powder (VULCAN XC72R) at 800 °C. Ru/N−C NPs (0.2 mol% Ru) selectively catalyzed either acceptorless dehydrogenation coupling (ADC) or auto‐transfer‐hydrogen (ATH) reactions of amines with alcohols to imines and secondary amines. Such selectivity could be controlled