Four-component strategy for selective synthesis of azepino[5,4,3-cd]indoles and pyrazolo[3,4-b]pyridines

Jiang, Bo; Ye, Qin; Fan, Wei; Wang, Shuliang; Tu, Shu‐Jiang; Li, Guigen

doi:10.1039/c4cc00740a

Cited by 54 publications

(23 citation statements)

References 38 publications

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“…Jiang et al. recently established, with the aid of microwave irradiation, novel chemoselective four‐component domino reactions of phenylglyoxals, anilines, and 7 , which produced either azepino[5,4,3‐ cd ]indole 11 or pyrazolo[3,4‐ b ]pyridine 12 in the presence of p ‐TsOH catalyst in DMF (Scheme ) . Thus, depending on the substituent in the phenyl ring of aniline, two different products were obtained.…”

Section: Aliphatic Axb3 Smentioning

confidence: 99%

Aldo‐X Bifunctional Building Blocks for the Synthesis of Heterocycles

Ravichandiran

Lai

2016

The Chemical Record

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Compounds containing oxygen, nitrogen, or sulfur atoms inside the rings are attracting much attention and interest due to their biological importance. In recent years, several methods for the synthesis of such molecules have been reported by using aldo-X bifunctional building blocks (AXB3 s) as substrates; these are a wide class of organic molecules that contain at least two reactive sites, among them, one aldehyde, acetal, or semiacetal group was involved. Because of the multiple reactivities, AXB3 s are widely used in the one-pot synthesis of biologically important heterocycles. This review summarizes the synthesis of important heterocycles by using AXB3 s as pivotal components in establishing multicomponent reactions, tandem reactions, and so forth. In many cases, the established reaction systems with AXB3 s were characterized by some green properties, such as easy access to the substrate, mild and environmentally benign conditions, and wide scope of the substrate.

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Section: Aliphatic Axb3 Smentioning

confidence: 99%

Aldo‐X Bifunctional Building Blocks for the Synthesis of Heterocycles

Ravichandiran

Lai

2016

The Chemical Record

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“…Under acidic conditions, reaction of arylglyoxal, aminopyrazole, and aromatic amines provide pyrrolopyridine and fused indoles (Scheme , Equation 2) . However, arylglyoxal and aminopyrazole derivatives in the presence of the acidic catalyst para ‐toluenesulfonic acid ( p TsA) in N , N ‐dimethylformamide (DMF) provide diverse interesting products dependent upon the type of substituents and the ratio of the substrates (Scheme , Equation 3) .…”

Section: Introductionmentioning

confidence: 99%

Multicomponent Reactions of Arylglyoxal, 4‐Hydroxycoumarin, and Cyclic 1,3‐C,N‐Binucleophiles: Binucleophile‐Directed Synthesis of Fused Five‐ and Six‐Membered N‐Heterocycles

et al. 2017

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The multicomponent reaction (MCR) of arylglyoxal, 4‐hydroxycoumarin, and various cyclic 1,3‐C,N‐binucleophiles in acetic acid under microwave conditions provides fused five‐ or six‐ membered N‐heterocycles depending on the ring size of the binucleophiles. 1,3‐C,N‐binucleophiles, such as amino‐pyrazole/oxazole, that have a five‐membered ring provide fused six‐membered dihydropyridines or pyridine derivatives, whereas aminouracil, cytosine, and 4/3‐aminocoumarines that have a six‐membered ring provide the corresponding five‐membered fused pyrroles. By using DFT calculations, the mechanism of the ring‐size‐dependent multicomponent cyclization reaction is explained. Cyclic 1,3‐C,N‐binucleophiles, such as aminopyrazole, aminooxazole, aminocoumarin, aminouracil, and cytosine, were explored in this MCR, and the corresponding fused pyrroles/dihydropyridines or pyridines were obtained in very good yields. The structures of the fused molecules were unambiguously confirmed by spectroscopic techniques and single‐crystal X‐ray analysis.

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“…14 In recent years, our laboratories have focused on the development of bicyclization cascades for multiple ring constructions. 15 Recently, we have reported a I 2 /O 2 -enabled cross-dehydrogenative coupling (CDC) between the preformed triethylammonium thiolates and simple arylhydrazines, allowing direct N-S bond-formation to access functionalized 1,2,3-thiadiazoles (Scheme 1a). 16 To continue this project, hydrazine hydrate was used as replacement for arylhydrazines to investigate its synthetic utilization.…”

Section: Introductionmentioning

confidence: 99%