Synthesis of α-(aminoethyl)-α,β-enones via alkyne aza-Prins cyclization and their synthetic application to pyrrolidines

2021 ◽  
Vol 19 (13) ◽  
pp. 2959-2967
Author(s):  
Sho Amemiya ◽  
Shingo Okemoto ◽  
Akira Tsubouchi ◽  
Akio Saito
Keyword(s):  
Synthetic Method ◽  
Prins Cyclization ◽  
Synthetic Application

We developed the first synthetic method of conjugated enones via alkyne aza-Prins cyclization. The products could be converted into pyrrolidines by formal 5-endo-trig cyclization.

Direct Cyclization of Alkenyl Thioester via Transition Metal‐hydrogen Atom Transfer/radical‐polar Crossover Mechanism

2019 ◽  
Author(s):  
Shiori Date ◽  
Kensei Hamasaki ◽  
Karen Sunagawa ◽  
Hiroki Koyama ◽  
Chikayoshi Sebe ◽  
...  
Keyword(s):  
Natural Products ◽  
Hydrogen Atom ◽  
Transition Metal ◽  
Hydrogen Atom Transfer ◽  
Synthetic Method ◽  
Atom Transfer ◽  
Reaction Conditions ◽  
Hydride Hydrogen ◽  
Sulfur Heterocycles ◽  
One Step

<div>We report here a catalytic, Markovnikov selective, and scalable synthetic method for the synthesis of saturated sulfur heterocycles, which are found in the structures of pharmaceuticals and natural products, in one step from an alkenyl thioester. Unlike a potentially labile alkenyl thiol, an alkenyl thioester is stable and easy to prepare. The powerful Co catalysis via a cobalt hydride hydrogen atom transfer and radical-polar crossover mechanism enabled simultaneous cyclization and deprotection. The substrate scope was expanded by the extensive optimization of the reaction conditions and tuning of the thioester unit.</div>

Efficient CDI/CH3SO3H -Catalyzed, Microwave-Assisted Synthesis of 2-Substituted Benzothiazoles

2018 ◽  
Vol 16 (1) ◽  
pp. 34-39
Author(s):  
Yao-Wei Li ◽  
Pei-Ming Zhang ◽  
Rui Li ◽  
Yan Bai ◽  
Yu Yu ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Carboxylic Acids ◽  
1H Nmr ◽  
Good Yield ◽  
Microwave Assisted Synthesis ◽  
Synthetic Method ◽  
Benzothiazole Derivatives ◽  
Microwave Assisted ◽  
Highly Effective

CDI combined with CH3SO3H was found to be highly effective for the cyclization of 2-aminothiophenol derivatives with carboxylic acids under MW condition. Fourteen benzothiazole derivatives were synthesized in good yield and their structures were characterized by 1H-NMR, 13CNMR, IR and mass spectrometry. This simple, rapid synthetic method is believed to provide a useful process for the synthesis of 2-substituted benzothiazole compounds.

4-Hydroxy Pyridinium Triflate@SiO2 Nanoparticles as a Novel Efficient Catalyst for Fries Rearrangement of Aryl Esters with High Selectivity

2020 ◽  
Vol 17 (8) ◽  
pp. 654-660
Author(s):  
Shermineh Sadat Ghalehbandi ◽  
Dadkhoda Ghazanfari ◽  
Sayed Ali Ahmadi ◽  
Enayatollah Sheikhhosseini
Keyword(s):  
High Selectivity ◽  
Sio2 Nanoparticles ◽  
High Yield ◽  
Synthetic Method ◽  
Functionalized Silica ◽  
Efficient Catalyst ◽  
Fries Rearrangement ◽  
Free Condition ◽  
Solvent Free Condition ◽  
Work Up

Introduction: We developed a simple, fast and new method for the Fries rearrangement of aryl esters. Materials and Methods: 4-Hydroxy pyridinium triflate functionalized silica is a very efficient, reusable and economically available catalyst for the Fries rearrangement in solvent-free condition and under microwave irradiation. Results and Discussion: Also, a notable selectivity was observed in the presence of 4-hydroxy pyridinium triflate functionalized silica. Conclusion: Selectivity, shorter reaction time, high yield, and easy work-up are advantages of this synthetic method.

P-51: Preparation of (Y,Gd)BO[sub 3]:Eu[sup 3+] Phosphor with High Luminescent Efficiency by New Synthetic Method

2001 ◽  
Vol 32 (1) ◽  
pp. 742
Author(s):  
Dong-Kuk Kim ◽  
Seon-Mi Yoon ◽  
Cha-Joo Park ◽  
Song-Ho Byeon ◽  
Jung-Chul Park ◽  
...  
Keyword(s):  
Synthetic Method

Self-templated formation of hierarchically yolk-shell-structured ZnS/NC dodecahedra with superior lithium storage properties

Nanoscale ◽  
2021 ◽  
Author(s):  
Ping Wang ◽  
Aihua Yuan ◽  
Zhitao Wang ◽  
Xiao Ping Shen ◽  
Hantao Chen ◽  
...  
Keyword(s):  
Synthetic Method ◽  
Zeolitic Imidazolate Frameworks ◽  
Lithium Storage ◽  
Storage Properties

The hierarchical ZnS/NC dodecahedra are successfully constructed via a two-step synthetic method combining a sulfidation process and subsequent carbonization treatment, benefiting from the inherit merits of zeolitic imidazolate frameworks as...

scholarly journals Selective Synthesis of N-Acylnortropane Derivatives in Palladium-Catalysed Aminocarbonylation

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1813
Author(s):  
László Kollár ◽  
Ádám Erdélyi ◽  
Haroon Rasheed ◽  
Attila Takács
Keyword(s):  
Synthetic Method ◽  
Selective Synthesis ◽  
Varied Structure ◽  
Biological Importance ◽  
Aryl Iodides ◽  
Palladium Catalyzed ◽  
Derivatives Of

The aminocarbonylation of various alkenyl and (hetero)aryl iodides was carried out using tropane-based amines of biological importance, such as 8-azabicyclo[3.2.1]octan-3-one (nortropinone) and 3α-hydroxy-8-azabicyclo[3.2.1]octane (nortropine) as N-nucleophile. Using iodoalkenes, the two nucleophiles were selectively converted to the corresponding amide in the presence of Pd(OAc)2/2 PPh3 catalysts. In the presence of several iodo(hetero)arenes, the application of the bidentate Xantphos was necessary to produce the target compounds selectively. The new carboxamides of varied structure, formed in palladium-catalyzed aminocarbonylation reactions, were isolated and fully characterized. In this way, a novel synthetic method has been developed for the producing of N-acylnortropane derivatives of biological importance.

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