Mechanism of the cyclization reaction of the intermediate, 3-mercapto-4-methallylquinoline, in the thio-claisen rearrangement

1969 ◽  
Vol 10 (29) ◽  
pp. 2453-2456 ◽  
Author(s):  
Yosuo Makisumi ◽  
Akira Murabayashi
Keyword(s):  
Claisen Rearrangement ◽  
Cyclization Reaction

α-Alkoxyalkyl Triphenylphosphonium Salts: Synthesis and Reactions

2019 ◽  
Vol 23 (16) ◽  
pp. 1738-1755
Author(s):  
Humaira Y. Gondal ◽  
Zain M. Cheema ◽  
Abdul R. Raza ◽  
Ahmed Abbaskhan ◽  
M. I. Chaudhary
Keyword(s):  
Carbonyl Compounds ◽  
Claisen Rearrangement ◽  
Alder Reaction ◽  
Coupling Reactions ◽  
Phosphonium Salts ◽  
Organic Transformations ◽  
Enol Ethers ◽  
Wide Range ◽  
Synthetic Methodologies ◽  
Alkoxy Groups

Following numerous applications of Wittig reaction now functionalized phosphonium salts are gaining attention due to their characteristic properties and diverse reactivity. This review is focused on α-alkoxyalkyl triphenylphosphonium salts: an important class of functionalized phosphonium salts. Alkoxymethyltriphenylphosphonium salts are majorly employed in the carbon homologation of carbonyl compounds and preparation of enol ethers. Their methylene insertion strategy is extensively demonstrated in the total synthesis of a wide range of natural products and other important organic molecules. Similarly enol ethers prepared thereof are important precursors for different organic transformations like Diels-Alder reaction, Claisen rearrangement, Coupling reactions, Olefin metathesis and Nazarov cyclization. Reactivity of these α-alkoxyalkylphosphonium salts have also been studied in the nucleophilic substitution reactions. A distinctive application of this class of phosphonium salts was recently reported in the phenylation of carbonyl compounds under very mild conditions. Synthesis of structurally diverse alkoxymethyltriphenylphosphonium salts with variation in alkoxy groups as well as counter anions are reported in literature. Here we present a detailed account of different synthetic methodologies for the preparation of this unique class of quaternary phosphonium salts and their applications in organic synthesis.

Synthesis of Novel Bis-pyrazoles via Electrophilic Cyclization

2019 ◽  
Vol 16 (6) ◽  
pp. 511-516
Author(s):  
Adnan Cetin
Keyword(s):  
13C Nmr ◽  
Cyclization Reaction ◽  
Electrophilic Cyclization ◽  
Pyrazole Derivatives ◽  
Spectral Analyses ◽  
Mass Spectral ◽  
Palladium Catalyzed ◽  
Ft Ir ◽  
Reaction Compound

Efficient steps towards the synthesis of novel (phenyl)(1'-aryl-1,5,5'-triphenyl[3,3'-bi-1Hpyrazol]- 4-yl)methanones 4a-e were developed. The procedure starts from 1-(4-benzoyl-1,5-diphenyl- 1H-3-pyrazolyl)-3-phenyl-2-propyn-1-one (2) which was synthesized by a palladium catalyzed crosscoupling reaction. Compound 2 reacted with various hydrazines to give (E)-(phenyl)[1,5-diphenyl-3- [3-phenyl-1-(2-arylhydrazono)-2-propyn-1-yl]-1H-4-pyrazolyl]methanones E-3a-e. The bis-pyrazole derivatives 4a-e were synthesized from electrophilic cyclization reaction of α,β-acetylenic hydrazones E-3a-e and copper(I) iodide. All synthesized compounds were characterized by FT-IR, 1H, 13C NMR and Mass spectral analyses.

Total Synthesis of Icaritin via Microwave-assistance Claisen Rearrangement

2014 ◽  
Vol 11 (9) ◽  
pp. 677-681 ◽  
Author(s):  
Van-Son Nguyen ◽  
Ling Shi ◽  
Yue Li ◽  
Qiu-An Wang
Keyword(s):  
Total Synthesis ◽  
Claisen Rearrangement ◽  
Microwave Assistance

Quaternary Carbon Center Forming [3 + 2] Cyclization Reaction by Adjusting the Substituents of Substrates

2019 ◽  
Vol 84 (21) ◽  
pp. 13871-13880 ◽  
Author(s):  
Xie-Chao Yang ◽  
Jin-Yu Liu ◽  
Zhen Liu ◽  
Xiu-Qin Hu ◽  
Peng-Fei Xu
Keyword(s):  
Cyclization Reaction ◽  
Quaternary Carbon

The unique substitution-cyclization reaction cascade inspired highly selective H2Sn probe development

2020 ◽  
Vol 304 ◽  
pp. 127382 ◽  
Author(s):  
Li Fu ◽  
Chunfei Chen ◽  
Wenqiang Chen ◽  
Jun Huang ◽  
Junan Xiao ◽  
...  
Keyword(s):  
Cyclization Reaction

Copper-catalyzed alkynylation/annulation cascades of N-allyl ynamides: regioselective access to medium-sized N-heterocycles

2021 ◽  
Vol 8 (1) ◽  
pp. 18-24
Author(s):  
Xu-Heng Yang ◽  
Jian Huang ◽  
Fang Wang ◽  
Zhuoliang Liu ◽  
Yujiao Li ◽  
...  
Keyword(s):  
Claisen Rearrangement ◽  
Synthetic Strategy ◽  
Key Steps

A synthetic strategy based on sequential application of aza-Claisen rearrangement, C–H functionalization, C–N coupling and cyclization as key steps has been developed for the synthesis of 6-, 7-, 8-, and 9-membered rings N-heterocycles.

New Stereoselective Entry to Azaspirocyclic Nucleus of Halichlorine and Pinnaic Acids by Radical Translocation/Cyclization Reaction

2003 ◽  
Vol 5 (17) ◽  
pp. 3017-3020 ◽  
Author(s):  
Kiyosei Takasu ◽  
Hiroshi Ohsato ◽  
Masataka Ihara
Keyword(s):  
Cyclization Reaction
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