scholarly journals Appel-reagent-mediated transformation of glycosyl hemiacetal derivatives into thioglycosides and glycosyl thiols

2013 ◽  
Vol 9 ◽  
pp. 974-982 ◽  
Author(s):  
Tamashree Ghosh ◽  
Abhishek Santra ◽  
Anup Kumar Misra
Keyword(s):  
Reaction Sequence ◽  
Reaction Conditions ◽  
One Pot ◽  
Carbon Tetrabromide

A series of glycosyl hemiacetal derivatives have been transformed into thioglycosides and glycosyl thiols in a one-pot two-step reaction sequence mediated by Appel reagent (carbon tetrabromide and triphenylphosphine). 1,2-trans-Thioglycosides and β-glycosyl thiol derivatives were stereoselectively formed by the reaction of the in situ generated glycosyl bromides with thiols and sodium carbonotrithioate. The reaction conditions are reasonably simple and yields were very good.

scholarly journals One-Pot Synthesis of Novel Multisubstituted 1-Alkoxyindoles

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1466
Author(s):  
Ye Eun Kim ◽  
Hyunsung Cho ◽  
Yoo Jin Lim ◽  
Chorong Kim ◽  
Sang Hyup Lee
Keyword(s):  
Alkyl Halide ◽  
The Novel ◽  
Reaction Conditions ◽  
One Pot ◽  
One Pot Synthesis ◽  
Consecutive Reactions ◽  
Intramolecular Condensation ◽  
Synthetic Sequence ◽  
Novel Target

Studies on a one-pot synthesis of novel multisubstituted 1-alkoxyindoles 1 and their mechanistic investigations are presented. The synthesis of 1 was successfully achieved through consecutive four step reactions from substrates 2. The substrates 2, prepared through a two-step synthetic sequence, underwent three consecutive reactions of nitro reduction, intramolecular condensation, and nucleophilic 1,5-addition to provide the intermediates, 1-hydroxyindoles 8, which then were alkylated in situ with alkyl halide to afford the novel target products 1. We optimized the reaction conditions for 1 focusing on the alkylation step, along with the consideration of formation of intermediates 8. The optimized condition was SnCl2·2H2O (3.3 eq) and alcohols (R1OH, 2.0 eq) for 1–2 h at 40 °C and then, base (10 eq) and alkyl halides (R2Y, 2.0 eq) for 1–4 h at 25–50 °C. Notably, all four step reactions were performed in one-pot to give 1 in good to modest yields. Furthermore, the mechanistic aspects were also discussed regarding the reaction pathways and the formation of side products. The significance lies in development of efficient one-pot reactions and in generation of new 1-alkoxyindoles.

scholarly journals A novel Pd-catalysed sequential carbonylation/cyclization approach toward bis- N -heterocycles: rationalization by electronic structure calculations

2018 ◽  
Vol 5 (9) ◽  
pp. 181140 ◽  
Author(s):  
Liliana Damas ◽  
Rui M. B. Carrilho ◽  
Sandra C. C. Nunes ◽  
Alberto A. C. C. Pais ◽  
László Kollár ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Electronic Structure Calculations ◽  
Reaction Conditions ◽  
One Pot ◽  
New Family ◽  
Synthetic Strategy ◽  
Heterocyclic Derivatives ◽  
Amine Groups ◽  
Structure Calculations

An unprecedented palladium-catalysed sequential aminocarbonylation/cyclization synthetic strategy, using carbon monoxide and structurally different aliphatic diamines as N -nucleophiles, gives access, in one pot, to a new family of indole-based N -heterocyclic derivatives (hydropyrazinones, benzodiazepinones and hydroquinoxalines). Optimization of the reaction conditions towards double carbonylation ( P CO = 30 bar, T = 80°C, iodoindole/diamine ratio = 1 : 1.5, toluene as solvent) allowed the target cyclic products, which are formed in situ via intramolecular cyclization of the ketocarboxamide intermediates, to be obtained through a nucleophilic addition/elimination reaction with the pendant terminal amine groups. The structure of the diamine nucleophile was revealed to affect the reaction's selectivity, with the best yields for the cyclic products being obtained in the presence of (1 S , 2S )-(+)-cyclohexane-1,2-diamine ( a ) as the nucleophile, using either 5- or 7-iodoindole as the substrate. The reaction's selectivity was rationalized based on electronic structure calculations, which explain the effect of the diamine structure on the predominant formation of the cyclic products.

Palladium-catalyzed one-pot cycloaddition reactions of thioureas with 3H-indol-3-ones generated in situ from 2-alkynyl arylazides: rapid and efficient access to imidazoloindolines

2020 ◽  
Vol 7 (21) ◽  
pp. 3480-3485
Author(s):  
Ping Li ◽  
Boyu Zhu ◽  
Yao Xu ◽  
Zhiqiang Zhou ◽  
Guiwen Hu ◽  
...  
Keyword(s):  
Cycloaddition Reactions ◽  
Reaction Conditions ◽  
One Pot ◽  
One Pot Synthesis ◽  
Efficient Access ◽  
Palladium Catalyzed

An efficient palladium-catalyzed one-pot synthesis of imidazoloindolines from 2-alkynyl arylazides under mild reaction conditions has been described.

Aminoxylation of Thioalkynes through Radical-Polar Crossover

Synlett ◽  
2019 ◽  
Vol 31 (06) ◽  
pp. 592-594
Author(s):  
Giovanni Di Mauro ◽  
Martina Drescher ◽  
Sara Tkaczyk ◽  
Nuno Maulide
Keyword(s):  
Bronsted Acid ◽  
Brønsted Acid ◽  
Reaction Conditions ◽  
One Pot ◽  
Brönsted Acid ◽  
Direct Formation

A one-pot procedure for the aminoxylation of thioalkynes for the direct formation of α-functionalized thioesters under mild reaction conditions is reported. A ketenethionium ion is the key intermediate, which is generated in situ by Brønsted acid mediated protonation and undergoes a radical-polar crossover.

scholarly journals One-Step Synthesis of Acylboron Compounds via Cu-Catalyzed Carbonylative Borylation of Alkyl Halides

2020 ◽  
Author(s):  
Cheng Li-Jie ◽  
Zhao Siling ◽  
Neal Mankad
Keyword(s):  
Alkyl Halides ◽  
Efficient Synthesis ◽  
Mechanistic Studies ◽  
Acyl Halide ◽  
Reaction Conditions ◽  
One Pot ◽  
One Step ◽  
High Yields ◽  
Tertiary Alkyl

A Cu-catalyzed carbonylative borylation of unactivated alkyl halides has been developed, enabling efficient synthesis of aliphatic potassium acyltrifluoroborates (KATs) in high yields by treating the in-situ formed tetracoordinated acylboron intermediates with aqueous KHF2. A variety of functional groups are tolerated under the mild reaction conditions, and primary, secondary and tertiary alkyl halides are all applicable. In addition, this method also provides facile access to N-methyliminodiacetyl (MIDA) acylboronates as well as α-methylated potassium acyltrifluoroborates in a one-pot manner. Mechanistic studies indicate a radical atom transfer carbonylation (ATC) mechanism to form acyl halide intermediates that are subsequently borylated by (NHC)CuBpin.<br>

Straightforward and Expeditious One-Pot Tandem Synthesis of 3,5-Diaryl-1,2,4-Selenadiazoles from Aryl Nitriles

Synthesis ◽  
2019 ◽  
Vol 51 (22) ◽  
pp. 4279-4283
Author(s):  
Sahar Majnooni ◽  
Zainab Almansaf ◽  
Miu Tsuji ◽  
Ahmad R. Khosropour ◽  
Hassan Zali-Boeini ◽  
...  
Keyword(s):  
Efficient Synthesis ◽  
Oxidative Dimerization ◽  
Reaction Conditions ◽  
One Pot ◽  
Aryl Nitriles ◽  
Dimerization Reaction ◽  
Tandem Synthesis ◽  
Operational Simplicity

A one-pot process for the efficient synthesis of 3,5-diaryl-1,2,4-selenadiazoles from aryl nitriles has been developed. This tandem transformation was performed in excellent yields (91–98%) via in situ selenoamidation and a subsequent oxidative dimerization reaction. This method features relatively mild reaction conditions, operational simplicity, straightforward separation of the products, and the utilization of inexpensive reagents.

In-Situ Synthesis of Active Pharmaceutical Ingredients Which Content Pyrazole Skeleton

2020 ◽  
Vol 17 (10) ◽  
pp. 743-748
Author(s):  
Sultan Pathan ◽  
Anil Repale ◽  
Girdhar Pal
Keyword(s):  
Aldol Condensation ◽  
Active Pharmaceutical Ingredients ◽  
Reaction Sequence ◽  
One Pot ◽  
Pharmaceutical Ingredients ◽  
One Pot Synthesis ◽  
Inflammatory Drugs ◽  
Anti Inflammatory ◽  
Work Up

Celecoxib containing pyrazole derivatives were synthesized by path aldol condensation of substituted ketone with trifluoroethyl acetate subsequently by cyclization of the formed chalcones with 4-methanesulfonylphenylhydrazine. Here, a one-pot synthesis of celecoxib and substituted analogues have been reported which are nonsteroidal anti-inflammatory drugs for their cyclooxygenase (COX) inhibition, anti-inflammatory activity and ulcerogenic liability. In order to intermediate work-up, a continuous one-pot synthesis has been developed, performing the entire reaction sequence that results in a shorter time with good yield.

One-Pot Synthesis of 2-Substituted Benzoxazoles Directly from Carboxylic Acids

2008 ◽  
Vol 61 (11) ◽  
pp. 881 ◽  
Author(s):  
Dinesh Kumar ◽  
Santosh Rudrawar ◽  
Asit K. Chakraborti
Keyword(s):  
Carboxylic Acids ◽  
Methanesulfonic Acid ◽  
Acid Chlorides ◽  
Double Bonds ◽  
Reaction Conditions ◽  
One Pot ◽  
Effective Catalyst ◽  
One Pot Synthesis ◽  
Highly Effective

Methanesulfonic acid has been found to be a highly effective catalyst for a convenient and one-pot synthesis of 2-substituted benzoxazoles by the reaction of 2-aminophenol with acid chlorides, generated in situ from carboxylic acids. Aryl, heteroaryl, and arylalkyl carboxylic acids provided excellent yields of the corresponding benzoxazoles. The reaction conditions were compatible with various substituents such as chloro, bromo, nitro, methoxy, cyclopentyloxy, phenoxy, thiophenoxy, and conjugated double bonds. Benzoxazole formation was found to be general with respect to substituted 2-aminophenols.

scholarly journals Multicomponent versus domino reactions: One-pot free-radical synthesis of β-amino-ethers and β-amino-alcohols

2015 ◽  
Vol 11 ◽  
pp. 66-73 ◽  
Author(s):  
Bianca Rossi ◽  
Nadia Pastori ◽  
Simona Prosperini ◽  
Carlo Punta
Keyword(s):  
Free Radical ◽  
Cyclic Ether ◽  
Radical Addition ◽  
Domino Reaction ◽  
Alcohol Molecule ◽  
Secondary Products ◽  
Reaction Conditions ◽  
One Pot ◽  
Mild Conditions

Following an optimized multicomponent procedure, an aryl amine, a ketone, and a cyclic ether or an alcohol molecule are assembled in a one-pot synthesis by nucleophilic radical addition of ketyl radicals to ketimines generated in situ. The reaction occurs under mild conditions by mediation of the TiCl4/Zn/t-BuOOH system, leading to the formation of quaternary β-amino-ethers and -alcohols. The new reaction conditions guarantee good selectivity by preventing the formation of secondary products. The secondary products are possibly derived from a competitive domino reaction, which involves further oxidation of the ketyl radicals.

2-Phenyl-2,3-dihydrobenzo[d]thiazole: A Mild, Efficient, and Highly Active in situ Generated Chemoselective Reducing Agent for the One-Pot Synthesis of 5-Monoalkylbarbiturates in Water

Synlett ◽  
2017 ◽  
Vol 29 (04) ◽  
pp. 477-482 ◽  
Author(s):  
Dibakar Deka ◽  
Subarna Kalita
Keyword(s):  
Reducing Agent ◽  
High Yield ◽  
Purification Process ◽  
Reaction Conditions ◽  
One Pot ◽  
One Pot Synthesis ◽  
Highly Active ◽  
The One ◽  
Operational Simplicity

A metal- and catalyst-free reductive alkylation protocol for the one-pot synthesis of 5-monoalkylbarbiturates from barbituric acids and aldehydes using the in situ generated chemoselective reducing agent 2-phenyl-2,3-dihydrobenzo[d]thiazole from 2-aminothiophenol and benzaldehyde is described. The notable advantages of the protocol are operational simplicity, mild reaction conditions, high yield, short reaction time, and simple workup and purification process which make it highly attractive.

Sign in / Sign up

Export Citation Format

Share Document