Extended Dötz-Like Cyclization Reactions Towards the Synthesis of Eight-Membered Ring-Containing Polycycles: Scope and Theoretical Studies

2007 ◽  
Vol 13 (27) ◽  
pp. 7682-7700 ◽  
Author(s):  
José Barluenga ◽  
Martín Fañanás-Mastral ◽  
M. Angel Palomero ◽  
Fernando Aznar ◽  
Carlos Valdés
Keyword(s):  
Membered Ring ◽  
Theoretical Studies ◽  
Cyclization Reactions

scholarly journals Cascade cyclization reactions of alkylidenecyclopropanes for the construction of polycyclic lactams and lactones by visible light photoredox catalysis

2020 ◽  
Vol 7 (2) ◽  
pp. 374-379 ◽  
Author(s):  
Mintao Chen ◽  
Yin Wei ◽  
Min Shi
Keyword(s):  
Visible Light ◽  
Membered Ring ◽  
Visible Light Photocatalysis ◽  
Photoredox Catalysis ◽  
Cyclization Reactions ◽  
Cascade Cyclization

A facile method for the synthesis of seven- and eight-membered ring-containing polycyclic lactams and lactones by visible light photocatalysis has been developed.

Cyclization of Ph2Si(NHNHMe)2. II. Reactions with methyl iodide, HCl, and Ph2SiCl2, and thermolysis

1994 ◽  
Vol 72 (8) ◽  
pp. 1759-1763 ◽  
Author(s):  
Jiliang He ◽  
John F. Harrod
Keyword(s):  
Methyl Iodide ◽  
Membered Ring ◽  
Cyclization Reactions

The reaction of Ph2Si(NHNHMe)2 (1) with MeI results in a mixture of two six-membered ring isomers, 1,2,4,5-tetraaza-1,4-dimethyl-3,3,6,6-tetraphenyl-3,6-disilacyclohexane (2), 45%, and 1,2,4,5-tetraaza-1,5-dimethyl-3,3,6,6-tetraphenyl-3,6-disilacyclohexane (3), 40%. The reaction of 1 with HCl or Ph2SiCl2 proceeds in a similar fashion. The thermolysis of 1 is studied from 25–600 °C. In the range of 250–300 °C, about 50% of 1 is converted into 2,3, and 1,2,4-triaza-1-methyl-4-methylamino-3,3,5,5-tetraphenyl-3,5-disilacyclopentane, 8. Possible pathways for the formation of 2,3, and 8 in these cyclization reactions are discussed.

Construction of Versatile N-Heterocycles from in situ Generated 1,2-Diaza-1,3-dienes

2019 ◽  
Vol 23 (2) ◽  
pp. 164-187 ◽  
Author(s):  
Zhangpei Chen ◽  
Lingxin Meng ◽  
Zhiqiang Ding ◽  
Jianshe Hu
Keyword(s):  
Natural Products ◽  
Heterocyclic Compounds ◽  
Materials Science ◽  
Membered Ring ◽  
Research Interest ◽  
Cyclization Reactions ◽  
Bioactive Natural Products ◽  
Synthetic Drugs ◽  
Nitrogen Containing Compounds

N-Heterocyclic architectures are omnipresent in many bioactive natural products, synthetic drugs, and materials science, thus have evoked a vast research interest of academic, as well as industrial chemists. Recently, several efficient methods have been developed for the preparation of various nitrogen-containing compounds with in situ generated 1,2-diaza-1,3-dienes from the easily available precursors including α -haloketohydrazones, α-hydroxyl ketohydrazones, thiadiazole dioxides or their analogues, and other simple hydrazones. These methods are considered powerful tools in the synthesis of five-, six- and seven-membered ring heterocyclic compounds with good to excellent levels of conversions and selectivities. This review mainly summarizes recent advances on the chemistry of construction of versatile N-heterocycles from in situ generated 1,2-diaza-1,3- dienes and presents an extensive summary of the application scopes and limitations of the corresponding cyclization reactions. Moreover, enantioselective approaches are also covered.

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