scholarly journals Frontispiece: The Cysteine S-Alkylation Reaction as a Synthetic Method to Covalently Modify Peptide Sequences

2017 ◽  
Vol 23 (2) ◽  
Author(s):  
Enrica Calce ◽  
Stefania De Luca
Keyword(s):  
Alkylation Reaction ◽  
Synthetic Method

scholarly journals Synthesis of 1-(2-Methoxybenzyl)-1,10-phenanthrolin-1-ium Bromide from Gandapura Oil

2019 ◽  
Vol 8 (3) ◽  
pp. 239-244
Author(s):  
Muhammad Idham Darussalam Mardjan ◽  
◽  
Dhina Fitriastuti ◽  
Bambang Purwono ◽  
Jumina Jumina ◽  
...  
Keyword(s):  
Nucleophilic Substitution ◽  
Benzyl Alcohol ◽  
Substitution Reaction ◽  
Dimethyl Sulfate ◽  
Benzyl Bromide ◽  
Solvent Free ◽  
Alkylation Reaction ◽  
Synthetic Method ◽  
Free Condition ◽  
Solvent Free Condition

This study describes simple synthetic method to prepare 1-(2-methoxybenzyl)-1,10-phenanthrolin-1-ium bromide from gandapura oil. The salt were synthesized in four steps. Initially, commercial gandapura oil was directly subjected to the alkylation reaction under basic condition using dimethyl sulfate to give methyl 2-methxybenzoate in 86% yield. Next, the produced benzoate ester was reduced by LiAlH4 to produce 2-methoxybenzyl alcohol in 67% yield. The treatment of benzyl alcohol with phosphorus tribromide under solvent free condition produced the corresponding benzyl bromide (in 67% yield), which was directly introduced into bimolecular nucleophilic substitution reaction with 1,10-phenantroline monohydrate to finally give the desired product in 63% yield.

scholarly journals Tungsten-Catalyzed Direct N-Alkylation of Amines with Alcohols

2020 ◽  
Author(s):  
Xiao-Bing Lan ◽  
Zongren Ye ◽  
Weikang Li ◽  
Jiahao Liu ◽  
Ming Huang ◽  
...  
Keyword(s):  
Homogeneous Catalysis ◽  
Alkylation Reaction ◽  
Synthetic Method ◽  
Computational Studies ◽  
Primary Alcohols ◽  
Major Goal ◽  
Earth Abundant ◽  
Borrowing Hydrogen ◽  
Hydrogen Autotransfer

The implementation of earth-abundant metals mediated chemistry is a major goal in homogeneous catalysis. Borrowing hydrogen/hydrogen autotransfer (BH/HA) reaction, as a straightforward and sustainable synthetic method, has attracted considerable attention in the development of earth-abuandant metal catalysts. Herein, we report a tungsten-catalyzed <i>N</i>-alkylation reaction of amines with primary alcohols via BH/HA. This phosphine-free W(phen)(CO)<sub>4</sub> (phen=1,10-phenthroline) system was demonstrated as a practical and easily accessible <i>in-situ</i> catalysis for a broad range of amines and alcohols (up to 49 examples, including 16 previously undisclosed products). Notably, this tungsten system can tolerate numerous functional groups, especially the challenging substrates with sterically hindered substituents, or heteroatoms. Mechanistic insights based on experimental and computational studies are also provided.

scholarly journals Tungsten-Catalyzed Direct N-Alkylation of Amines with Alcohols

2020 ◽  
Author(s):  
Xiao-Bing Lan ◽  
Zongren Ye ◽  
Weikang Li ◽  
Jiahao Liu ◽  
Ming Huang ◽  
...  
Keyword(s):  
Homogeneous Catalysis ◽  
Alkylation Reaction ◽  
Synthetic Method ◽  
Computational Studies ◽  
Primary Alcohols ◽  
Major Goal ◽  
Earth Abundant ◽  
Borrowing Hydrogen ◽  
Hydrogen Autotransfer

The implementation of earth-abundant metals mediated chemistry is a major goal in homogeneous catalysis. Borrowing hydrogen/hydrogen autotransfer (BH/HA) reaction, as a straightforward and sustainable synthetic method, has attracted considerable attention in the development of earth-abuandant metal catalysts. Herein, we report a tungsten-catalyzed <i>N</i>-alkylation reaction of amines with primary alcohols via BH/HA. This phosphine-free W(phen)(CO)<sub>4</sub> (phen=1,10-phenthroline) system was demonstrated as a practical and easily accessible <i>in-situ</i> catalysis for a broad range of amines and alcohols (up to 49 examples, including 16 previously undisclosed products). Notably, this tungsten system can tolerate numerous functional groups, especially the challenging substrates with sterically hindered substituents, or heteroatoms. Mechanistic insights based on experimental and computational studies are also provided.

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.

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