Hypervalent iodine(iii)-promoted N-incorporation into N-aryl vinylogous carbamates to quinoxaline diesters: access to 1,4,5,8-tetraazaphenanthrene

2016 ◽  
Vol 14 (17) ◽  
pp. 4018-4022 ◽  
Author(s):  
A. Sagar ◽  
Shinde Vidaycharan ◽  
Anand H. Shinde ◽  
Duddu S. Sharada

An oxidative N-incorporation strategy for synthesis of quinoxaline diesters under metal-free and mild reaction conditions is described via the formation of two C(sp2)–N bonds utilizing NaN3 as the cheap N-atom source.

Synlett ◽  
2017 ◽  
Vol 28 (19) ◽  
pp. 2525-2538 ◽  
Author(s):  
James Bull ◽  
Renzo Luisi ◽  
Leonardo Degennaro

Sulfoximines are emerging as valuable new isosteres for use in medicinal chemistry, with the potential to modulate physicochemical properties. Recent developments in synthetic strategies have made the unprotected ‘free’ NH-sulfoximine group more readily available, facilitating further study. This account reviews approaches to NH-sulfoximines, with a focus on our contribution to the field. Starting from the development of catalytic strategies involving transition metals, more sustainable metal-free processes have been discovered. In particular, the use of hypervalent iodine reagents to mediate NH-transfer to sulfoxides is described, along with an assessment of the substrate scope. Furthermore, a one-pot strategy to convert sulfides directly into NH-sulfoximines is discussed, with N- and O-transfer occurring under the reaction conditions. Mechanistic evidence for the new procedures is included as well as relevant synthetic applications that further exemplify the potential of these approaches.1 Introduction2 Strategies to Form NH-Sulfoximines Involving Transition-Metal Catalysts3 Metal-Free Strategies to Prepare NH-Sulfoximines4 Mechanistic Evidence for the Direct Synthesis of NH-Sulfoximines from Sulfoxides and Sulfides5 Further Applications6 Conclusion


RSC Advances ◽  
2016 ◽  
Vol 6 (90) ◽  
pp. 87134-87141 ◽  
Author(s):  
Chao Yang ◽  
Guanyun Cheng ◽  
Baofu Huang ◽  
Fengtian Xue ◽  
Chao Jiang

A metal-free method for regioselective construction of 2-acetoxy indolin-3-ones from N-substituted indoles using PhI(OAc)2 was developed under mild reaction conditions.


Synlett ◽  
2019 ◽  
Vol 30 (13) ◽  
pp. 1573-1579 ◽  
Author(s):  
Divakar Reddy Indukuri ◽  
Gal Reddy Potuganti ◽  
Manjula Alla

A facile, rapid, metal-free regioselective halogenation and thiocyanation of imidazo[1,2-a]pyridine/pyrimidine heterocycles has been achieved under solvent-free reaction conditions. Halogenations and thiocyanation of the heterocycles could be accomplished by simple grinding of reactants and hypervalent iodine reagents with the corresponding alkali metal or ammonium salts. The method has been extrapolated to a cleaner synthesis of brominated imidazo[1,2-a]pyridine/pyrimidine derivatives, starting from the corresponding heterocyclic amines and substituted α-bromoketones, utilising HBr generated in situ as the source of bromine.


Author(s):  
Arumugavel Murugan ◽  
Venkata Nagarjuna Babu ◽  
Nagaraj Sabarinathan ◽  
Sharada Duddu. S

Here we report a visible-light-promoted metal-free regioselective C3-H trifluoromehtylation reaction that proceeds via radical mechanism and which supported by control experiments. The combination of photoredox catalysis and hypervalent iodine reagent provides a practical approach for the present trifluoromethylation reaction and synthesis of a library of trifluoromethylated indazoles.


2020 ◽  
Vol 24 ◽  
Author(s):  
Bubun Banerjee ◽  
Gurpreet Kaur ◽  
Navdeep Kaur

: Metal-free organocatalysts are becoming an important tool for the sustainable developments of various bioactive heterocycles. On the other hand, during last two decades, calix[n]arenes have been gaining considerable attention due to their wide range of applicability in the field of supramolecular chemistry. Recently, sulfonic acid functionalized calix[n] arenes are being employed as an efficient alternative catalyst for the synthesis of various bioactive scaffolds. In this review we have summarized the catalytic efficiency of p-sulfonic acid calix[n]arenes for the synthesis of diverse biologically promising scaffolds under various reaction conditions. There is no such review available in the literature showing the catalytic applicability of p-sulfonic acid calix[n]arenes. Therefore, we strongly believe that this review will surely attract those researchers who are interested about this fascinating organocatalyst.


Author(s):  
Ayesha Jalil ◽  
Yaxin O Yang ◽  
Zhendong Chen ◽  
Rongxuan Jia ◽  
Tianhao Bi ◽  
...  

: Hypervalent iodine reagents are a class of non-metallic oxidants have been widely used in the construction of several sorts of bond formations. This surging interest in hypervalent iodine reagents is essentially due to their very useful oxidizing properties, combined with their benign environmental character and commercial availability from the past few decades ago. Furthermore, these hypervalent iodine reagents have been used in the construction of many significant building blocks and privileged scaffolds of bioactive natural products. The purpose of writing this review article is to explore all the transformations in which carbon-oxygen bond formation occurred by using hypervalent iodine reagents under metal-free conditions


Synthesis ◽  
2020 ◽  
Author(s):  
Peter Ehlers ◽  
Peter Langer ◽  
Marian Blanco Ponce ◽  
Silvio Parpart ◽  
Alexander Villinger ◽  
...  

AbstractA concise and modular synthesis of pyrrolo[1,2-a][1,6]- and [1,8]naphthyridines by a one-pot two-step reaction consisting of electrophilic acylation followed by an alkyne-carbonyl-metathesis reaction as the final cyclization step is reported. This developed synthetic methodology allows the facile synthesis of these heterocyclic core structures in mainly high overall yields under metal-free conditions. Reaction conditions are carefully optimized and display a novel supplement to access these tricyclic heterocyclic compounds.


2015 ◽  
Vol 39 (2) ◽  
pp. 805-809 ◽  
Author(s):  
Nagireddy Veera Reddy ◽  
Pailla Santhosh Kumar ◽  
Peddi Sudhir Reddy ◽  
Mannepalli Lakshmi Kantam ◽  
Kallu Rajender Reddy

A direct transformation of N-aryl formamides to the corresponding phenylurea derivatives via the formation of isocyanate intermediates is achieved in good yields using hypervalent iodine reagents as external oxidants.


Synthesis ◽  
2019 ◽  
Vol 52 (01) ◽  
pp. 69-74
Author(s):  
Yuan-Zhao Ji ◽  
Hui-Jing Li ◽  
Ying Liu ◽  
Yan-Chao Wu

It has been reported previously that treatment of aryl­ketone-derived arylsulfonylhydrazones with NXS/(nBu)4NX affords exclusively vinyl halides. In contrast, we have found that treatment of aryl­aldehyde-derived arylsulfonylhydrazones with N-chlorosuccinimide in the presence of potassium hydroxide affords 1,2,4,5-tetrazine derivatives in good to excellent yields. The present reactions are carried out under metal-free and mild reaction conditions.


Sign in / Sign up

Export Citation Format

Share Document