N‐Bridgehead Heterocyclic Compounds Thenoly‐Substituted. Part 2. Azaindolizines.

Abstract

Ring closure reactionsRing closure reactions O 0130 N-Bridgehead Heterocyclic Compounds Thenoly-Substituted. Part 2. Azaindolizines. -Quaternary salts of diazines, such as (I) and (IV) react with activated acetylenic compounds (II) in the presence of an epoxide to give the corresponding anellated products (III) and (V), respectively. -(GEORGESCU, E. I.; GEORGESCU, F.; ROIBU, C.; IUHAS, P. C.; DRAGHICI, C. C.; CAPROIU, M. T.; Rev. Roum. Chim. 47 (2002) 8-9, 885-891; S.C. OLTCHIM Res. Cent., RO-1000 Ramnicu-Valcea, Rom.; Eng.) -M. Paetzel 36-038

A new approach for the synthesis of benzo[f]pyrrolo[1,2-a]-quinolines

“…1,2 In order to continue our work [3][4][5][6] on the synthesis of new N-bridgehead heterocyclic compounds with interesting chemical and biological properties, we extended our study to the synthesis of new benzo[f]pyrrolo[1,2-a]quinoline derivatives. It is well known that 1,3-dipolar cycloaddition reactions, conducted in a sequential manner, are efficient approaches for the synthesis of new interesting heterocyclic compounds.…”

New N-bridgehead heterocyclic compounds. II. Carbamoyl-substituted azaindolizines

“…In our previous works [7][8][9][10][11][12] many similar 1,3-dipolar cycloaddition reactions were described.…”

Pyrrolo[1,2-b]pyridazines. A revisit

“…One of the most useful methods for obtaining pyrrolopyridazine derivatives is the 1,3-dipolar cycloaddition between pyridazinium N-ylides and activated olefinic or acetylenic dipolarophiles. The synthesis of pyrrolo[1,2-b]pyridazines through 1,3-dipolar cycloadditions has been described in over 35 papers, using acetylenic, [68][69][70][71][72][73][74][75][76][77][78][79][80] olefinic, [80][81][82][83][84][85][86][87][88][89][90][91][92] as well as both acetylenic and olefinic dipolarophiles. [93][94][95][96][97][98][99][100][101][102][103] The advantages of the method consist of: a) the availability of the raw material, as pyridazinium salts are easily obtained from pyridazine or its derivatives and halogenated derivatives, and b) the pyridazinium N-ylide generation and the cycloaddition are performed "one-pot", and the cycloaddition does not require special reaction conditions.…”