Determining the Scope of the Lanthanoid-Mediated, Sequential Hydroamination/C—C Cyclization Reaction: Formation of Tricyclic and Tetracyclic Aromatic Nitrogen Heterocycles.

ChemInform ◽  
2004 ◽  
Vol 35 (15) ◽  
Author(s):  
Gary A. Molander ◽  
Shawn K. Pack
Keyword(s):  
Nitrogen Heterocycles ◽  
Cyclization Reaction ◽  
Reaction Formation

scholarly journals A Synthesis of 4-Chloro-2-(trichloromethyl)pyrimidines and Their Study in Nucleophilic Substitution

Synthesis ◽  
2018 ◽  
Vol 51 (02) ◽  
pp. 530-537 ◽  
Author(s):  
Moisés Romero-Ortega ◽  
Michelle Trujillo-Lagunas ◽  
Ignacio Medina-Mercado ◽  
Ivann Zaragoza-Galicia ◽  
Horacio Olivo
Keyword(s):  
Nucleophilic Substitution ◽  
Intramolecular Cyclization ◽  
Nitrogen Heterocycles ◽  
Cyclization Reaction ◽  
Substitution Reactions ◽  
Pyrimidine Derivatives ◽  
One Pot ◽  
Acyl Chlorides ◽  
Nucleophilic Substitution Reactions ◽  
One Pot Synthesis

A convenient two-step, one-pot synthesis of 4-chloro-2-(trichloromethyl)pyrimidines starting from 2-(trichloromethyl)-1,3-diazabutadienes is described. These nitrogen heterocycles were prepared by a sequential acylation/intramolecular cyclization reaction between 2-(trichloromethyl)-1,3-diazabutadienes and acyl chlorides in the presence of triethylamine followed by treatment with POCl3. This is the first report for the synthesis of this type of 4-chloro-2-(trichloromethyl)pyrimidine derivatives and serves as a source for a wide variety of other substituted pyrimidines by nucleophilic substitution reactions.

scholarly journals Restriction of the conrotatory motion in photo-induced 6π electrocyclic reaction: formation of the excited state of the closed-ring isomer in the cyclization

RSC Advances ◽  
2020 ◽  
Vol 10 (34) ◽  
pp. 20038-20045
Author(s):  
Tatsuhiro Nagasaka ◽  
Hikaru Sotome ◽  
Soichiro Morikawa ◽  
Lucas Martinez Uriarte ◽  
Michel Sliwa ◽  
...  
Keyword(s):  
Excited State ◽  
Molecular Geometry ◽  
Cyclization Reaction ◽  
Closed Ring ◽  
Electrocyclic Reaction ◽  
Reaction Formation

Restriction of the molecular geometry opens up a novel pathway in the cyclization reaction of a photochromic dithiazolylarylene derivative.

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.

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