Synthesis of 3-phosphorylated 2-aza-1,3-dienes from imines derived from bisphosphonates

An Efficient Synthesis of Achiral and Chiral Cyclic Dehydro‐α‐Amino Acid Derivatives Through Nucleophilic Addition of Amines to β,γ‐Unsaturatedα‐Keto Esters

“…[20] In our case the combined effect of an electron-withdrawing group in the 2-position and a phenyl terminal substituent seems to activate the intramolecular 6π-azaelectrocyclization reaction with the process favoring the electrocyclization of 2-azatrienes [21] and 3-azatrienes. [22] In conclusion, we have described herein an easy and efficient synthesis of 3-amino-1,5-dihydro-2H-pyrrol-2-ones either through double nucleophilic addition of amines to β,γ-unsaturated α-keto esters or by the three-component reaction of ethyl pyruvate, aldehydes and amines.…”

A Novel Procedure to Synthesize 3‐Chloro‐1‐(4a,10b‐diazaphenanthrene‐2‐yl)‐4‐phenyl Azetidin‐2‐ones and Exploration of Their Anti‐Inflammatory Activity

“…The development of efficient and mild methods of synthesis of heterocyclic compounds represents a thrust area of intense research and development of these compounds . In this context, nitrogen‐containing heterocycles are among the most useful and widely demonstrated categories .…”

Pseudopericyclic 1,5- versus Pericyclic 1,4- and 1,6-Electrocyclization in Electron-Poor 4-Aryl-2-azabuta-1,3-dienes: Indole Synthesis from 2H-Azirines and Diazo Compounds

“…Thus, 4-unsubstituted azadiene derived from 3-phenyl-2H-azirine and dimethyl diazomalonate 2a is thermally stable, whereas its 4-phenylsubstituted analogue is extremely unstable compound rapidly cyclizing to 2,3-dihydroazete 5a (Scheme 1). 9 Assuming that accumulation of aryl substituents at C 4 of 2-azadiene promotes the 1,4-cyclization we tried to synthesize 3,3-diphenylsubstituted 2,3-dihydroazete from 2,2,3-triphenyl-2H-azirine 1a and dimethyl diazomalonate 2a under Rh 2 (OAc) 4 -catalysis. Initially, the reaction was carried out by slow addition of 2a to a mixture of 1a and Rh 2 (OAc) 4 in 1,2-dichloroethane (DCE) at 84°C (method B).…”

“…9 Assuming that accumulation of aryl substituents at C 4 of 2-azadiene promotes the 1,4-cyclization we tried to synthesize 3,3-diphenylsubstituted 2,3-dihydroazete from 2,2,3-triphenyl-2H-azirine 1a and dimethyl diazomalonate 2a under Rh 2 (OAc) 4 -catalysis. Initially, the reaction was carried out by slow addition of 2a to a mixture of 1a and Rh 2 (OAc) 4 in 1,2-dichloroethane (DCE) at 84°C (method B). Unexpectedly a mixture of azadiene 3a and indole 6a in 12:1 ratio was obtained in 93% overall yield.…”

“…Compound 4b. (4) 4 (3 mg, 0.007 mmol) was added in one portion. The mixture was stirred under reflux until evolution of nitrogen had ceased (8 min).…”