Dearomatization of Electron-Deficient Nitrogen Heterocycles via Cobalt-Catalyzed Asymmetric Cyclopropanation

2016 ◽  
Vol 81 (8) ◽  
pp. 3070-3075 ◽  
Author(s):  
Amruta Joshi-Pangu ◽  
Ryan D. Cohen ◽  
Matthew T. Tudge ◽  
Yonggang Chen
Keyword(s):  
Nitrogen Heterocycles ◽  
Asymmetric Cyclopropanation

ChemInform Abstract: Dearomatization of Electron-Deficient Nitrogen Heterocycles via Cobalt-Catalyzed Asymmetric Cyclopropanation.

ChemInform ◽  
2016 ◽  
Vol 47 (34) ◽  
Author(s):  
Amruta Joshi-Pangu ◽  
Ryan D. Cohen ◽  
Matthew T. Tudge ◽  
Yonggang Chen
Keyword(s):  
Nitrogen Heterocycles ◽  
Asymmetric Cyclopropanation

Hydrogen Cyanide Polymers from the Impact of Comet P/Shoemaker-Levy 9 on Jupiter

1997 ◽  
Vol 161 ◽  
pp. 179-187
Author(s):  
Clifford N. Matthews ◽  
Rose A. Pesce-Rodriguez ◽  
Shirley A. Liebman
Keyword(s):  
Amino Acids ◽  
Solar System ◽  
Hydrogen Cyanide ◽  
Nitrogen Heterocycles ◽  
Laboratory Studies ◽  
Heterogeneous Solids ◽  
The Many ◽  
Comet Halley ◽  
The Impact ◽  
By Products

AbstractHydrogen cyanide polymers – heterogeneous solids ranging in color from yellow to orange to brown to black – may be among the organic macromolecules most readily formed within the Solar System. The non-volatile black crust of comet Halley, for example, as well as the extensive orangebrown streaks in the atmosphere of Jupiter, might consist largely of such polymers synthesized from HCN formed by photolysis of methane and ammonia, the color observed depending on the concentration of HCN involved. Laboratory studies of these ubiquitous compounds point to the presence of polyamidine structures synthesized directly from hydrogen cyanide. These would be converted by water to polypeptides which can be further hydrolyzed to α-amino acids. Black polymers and multimers with conjugated ladder structures derived from HCN could also be formed and might well be the source of the many nitrogen heterocycles, adenine included, observed after pyrolysis. The dark brown color arising from the impacts of comet P/Shoemaker-Levy 9 on Jupiter might therefore be mainly caused by the presence of HCN polymers, whether originally present, deposited by the impactor or synthesized directly from HCN. Spectroscopic detection of these predicted macromolecules and their hydrolytic and pyrolytic by-products would strengthen significantly the hypothesis that cyanide polymerization is a preferred pathway for prebiotic and extraterrestrial chemistry.

Evaluation of Antioxidant and Antitumor Activities of Some Prepared Nitrogen Heterocycles

2011 ◽  
Vol 3 (7) ◽  
pp. 106-110
Author(s):  
Mohamed Abd El-Moneim ◽  
◽  
Ibrahim M El-Deen ◽  
Wessam Abd El-Fattah
Keyword(s):  
Nitrogen Heterocycles ◽  
Antitumor Activities

General Cyclopropane Assembly via Enantioselective Redox-Active Carbene Transfer to Aliphatic Olefins

2018 ◽  
Author(s):  
Marc Montesinos-Magraner ◽  
Matteo Costantini ◽  
Rodrigo Ramirez-Contreras ◽  
Michael E. Muratore ◽  
Magnus J. Johansson ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Asymmetric Synthesis ◽  
Chemical Space ◽  
Synthetic Approach ◽  
Asymmetric Cyclopropanation ◽  
Redox Active ◽  
Wide Range ◽  
Leaving Group ◽  
Stereoelectronic Properties ◽  
Carbene Transfer

Asymmetric cyclopropane synthesis currently requires bespoke strategies, methods, substrates and reagents, even when targeting similar compounds. This limits the speed and chemical space available for discovery campaigns. Here we introduce a practical and versatile diazocompound, and we demonstrate its performance in the first unified asymmetric synthesis of functionalized cyclopropanes. We found that the redox-active leaving group in this reagent enhances the reactivity and selectivity of geminal carbene transfer. This effect enabled the asymmetric cyclopropanation of a wide range of olefins including unactivated aliphatic alkenes, enabling the 3-step total synthesis of (–)-dictyopterene A. This unified synthetic approach delivers high enantioselectivities that are independent of the stereoelectronic properties of the functional groups transferred. Our results demonstrate that orthogonally-differentiated diazocompounds are viable and advantageous equivalents of single-carbon chirons<i>.</i>

Polyeondensed nitrogen heterocycles. IV. Pyrazolo[1,5-d]-.s-triazolo[3,4-∫]-as-triazine

1973 ◽  
Vol 10 (1) ◽  
pp. 103-105 ◽  
Author(s):  
Enrico Ajello ◽  
Caterina Arnone
Keyword(s):  
Nitrogen Heterocycles

Synthesis of Lactams and Other Nitrogen Heterocycles by Intramolecular Cyclizations of Carbamates and Acyl Derivatives of Aminosulfones.

ChemInform ◽  
2003 ◽  
Vol 34 (34) ◽  
Author(s):  
Nora M. Hernandez ◽  
Melina J. Sedano ◽  
Hollie K. Jacobs ◽  
Aravamudan S. Gopalan
Keyword(s):  
Nitrogen Heterocycles ◽  
Intramolecular Cyclizations ◽  
Derivatives Of ◽  
Acyl Derivatives

Phenothiazine and amide-ornamented novel nitrogen heterocyclic hybrids: synthesis, biological and molecular docking studies

2020 ◽  
Vol 44 (10) ◽  
pp. 4049-4060
Author(s):  
Ramar Sivaramakarthikeyan ◽  
Ayyanar Karuppasamy ◽  
Shunmugam Iniyaval ◽  
Krishnaraj Padmavathy ◽  
Wei-Meng Lim ◽  
...  
Keyword(s):  
Molecular Docking ◽  
Nitrogen Heterocycles ◽  
Docking Studies ◽  
Spectral Techniques ◽  
Molecular Docking Studies ◽  
Nitrogen Heterocyclic

The synthesis of phenothiazine and amide-ornamented nitrogen heterocycles (25–34) has been accomplished utilizing a multi-step synthetic protocol and the structures have been established based on physical and spectral techniques.

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