scholarly journals Direct access to multi-functionalized benzenes via [4 + 2] annulation of α-cyano-β-methylenones and α,β-unsaturated aldehydes

RSC Advances ◽  
2020 ◽  
Vol 10 (49) ◽  
pp. 29171-29174 ◽  
Author(s):  
Qianfa Jia ◽  
Yunfei Lan ◽  
Xin Ye ◽  
Yinhe Lin ◽  
Qiao Ren
Keyword(s):  
Direct Access ◽  
Reaction Conditions ◽  
Metal Free ◽  
Unsaturated Aldehydes ◽  
Wide Range ◽  
High Yields

An efficient [4 + 2] benzannulation of α-cyano-β-methylenones and α,β-unsaturated aldehydes was achieved under metal-free reaction conditions selectively delivering a wide range of polyfunctional benzenes in high yields respectively (up to 94% yield).

Metal-free [3+3] benzannulation of 1-indanylidene-malononitrile with Morita–Baylis–Hillman carbonates: direct access to functionalized fluorene and fluorenone derivatives

2020 ◽  
Vol 56 (13) ◽  
pp. 1948-1951 ◽  
Author(s):  
Ya-Sa Xie ◽  
Run-Feng Huang ◽  
Ran Li ◽  
Chuan-Bao Zhang ◽  
Ji-Ya Fu ◽  
...  
Keyword(s):  
Direct Access ◽  
Metal Free ◽  
Wide Range ◽  
High Yields

An efficient [3+3] benzannulation of Morita–Baylis–Hillman carbonates with 1-indanylidenemalononitrile was achieved selectively delivering a wide range of functional fluorene or fluorenone compounds in high yields (up to 86% yields).

p-Sulfonic acid calix[n]arene catalyzed synthesis of bioactive heterocycles: A review

2020 ◽  
Vol 24 ◽  
Author(s):  
Bubun Banerjee ◽  
Gurpreet Kaur ◽  
Navdeep Kaur
Keyword(s):  
Supramolecular Chemistry ◽  
Sulfonic Acid ◽  
Catalytic Efficiency ◽  
The Other ◽  
Reaction Conditions ◽  
Metal Free ◽  
Bioactive Scaffolds ◽  
Wide Range ◽  
Efficient Alternative ◽  
Bioactive Heterocycles

: Metal-free organocatalysts are becoming an important tool for the sustainable developments of various bioactive heterocycles. On the other hand, during last two decades, calix[n]arenes have been gaining considerable attention due to their wide range of applicability in the field of supramolecular chemistry. Recently, sulfonic acid functionalized calix[n] arenes are being employed as an efficient alternative catalyst for the synthesis of various bioactive scaffolds. In this review we have summarized the catalytic efficiency of p-sulfonic acid calix[n]arenes for the synthesis of diverse biologically promising scaffolds under various reaction conditions. There is no such review available in the literature showing the catalytic applicability of p-sulfonic acid calix[n]arenes. Therefore, we strongly believe that this review will surely attract those researchers who are interested about this fascinating organocatalyst.

Deuterated Aryl Alkyl Ethers Synthesis via Nucleophilic Etherification of Aryl Alkyl Ethers and Thioethers with Deuterated Alcohols

Synlett ◽  
2019 ◽  
Vol 30 (15) ◽  
pp. 1805-1809
Author(s):  
Shuai Li ◽  
Xia Wang ◽  
Xin-Ge Yang ◽  
Gui-Quan Yu ◽  
Xue-Qiang Wang
Keyword(s):  
Transition Metal ◽  
Nucleophilic Aromatic Substitution ◽  
Aromatic Substitution ◽  
Mechanistic Studies ◽  
Reaction Conditions ◽  
Metal Free ◽  
Wide Range ◽  
Alkyl Ethers

A transition-metal-free etherification protocol that is capable of synthesizing deuterated ethers is described. A wide range of aryl alkyl ethers and thioethers were suitable for this transformation owing to the mild reaction conditions. Besides, a series of sterically bulky deuterated alcohols were successfully incorporated into cyano-substituted arenes. The results of mechanistic studies suggested this reaction might take place via nucleophilic aromatic substitution pathway.

scholarly journals Regioselective synthesis of benzonitriles via amino-catalyzed [3+3] benzannulation reaction

2020 ◽  
Vol 44 (9-10) ◽  
pp. 592-597
Author(s):  
Lin Jiang ◽  
Wen-Fei Jin ◽  
Liu-Dong Yu ◽  
Ming-Wei Yuan ◽  
Hong-Li Li ◽  
...  
Keyword(s):  
Environmentally Friendly ◽  
Regioselective Synthesis ◽  
Reaction Conditions ◽  
Unsaturated Aldehydes ◽  
High Yields ◽  
Environmentally Friendly Method

A straightforward synthesis of benzonitriles is achieved via amino-catalyzed [3+3] benzannulation of α,β-unsaturated aldehydes and 4-arylsulfonyl-2-butenenitriles. Using pyrrolidine as an organocatalyst via iminium activation, a series of substituted benzonitriles were obtained in good to high yields in a regioselective manner. This reaction can proceed smoothly under mild reaction conditions and without the aid of any metals, additional oxidants, or strong bases, thus making this an efficient and environmentally friendly method to access benzonitriles.

scholarly journals Tyrosine and Drug-like Late-stage Benzylic Functionalization via Photoredox Catalysis

2020 ◽  
Author(s):  
Tobias Brandhofer ◽  
Volker Derdau ◽  
María Mendez ◽  
Christoph Pöverlein ◽  
Olga Garcia Mancheno
Keyword(s):  
Natural Products ◽  
Visible Light ◽  
Late Stage ◽  
Medicinal Chemistry ◽  
Functional Group ◽  
Reaction Conditions ◽  
Site Selectivity ◽  
Wide Range ◽  
High Yields ◽  
Therapeutic Compounds

Abstract Visible light mediated late-stage functionalization is a rising field in synthetic and medicinal chemistry, allowing the fast and diversified modification of valuable, potentially therapeutic compounds such as peptides. However, there are relatively few mild methodologies for the C(sp3)-H functionalization of complex peptides. Herein, we report a visible light mediated photocatalytic protocol for the benzylic C-H modification of tyrosine and related C-H bonds. The embraced radical-cation/deprotonation strategy enables an incorporation of a wide range of valuable functional groups in high yields and chemoselectivity. The mild reaction conditions, site-selectivity and high functional group tolerance was highlighted by the functionalization of complex peptides, drugs and natural products, providing a promising synthetic platform in medicinal chemistry.

Metal-free Synthesis of N-Sulfonylformamidines via Skeletal Reconstruction of Sulfonyl Oximonitriles

2022 ◽  
Author(s):  
Feng Li ◽  
Ziyan Wu ◽  
Jingjing Wang ◽  
Siyuan Zhang ◽  
Jiaxin Yu ◽  
...  
Keyword(s):  
Secondary Amines ◽  
Domino Reaction ◽  
Reaction Conditions ◽  
Metal Free ◽  
High Yields ◽  
Skeletal Reconstruction

We firstly develop an unprecedented domino reaction of sulfonyl oximonitriles with secondary amines to streamline synthesis of N-sulfonylformamidines in decent to high yields under mild reaction conditions. In addition, the...

scholarly journals A Task-Specific Ionic-Liquid-Mediated Solvent-Free Protocol for Direct Access to Dimethyl Acetal Protected Benzimidazole 2-Carboxaldehydes

SynOpen ◽  
2020 ◽  
Vol 04 (04) ◽  
pp. 89-95
Author(s):  
Swapan Majumdar ◽  
Barnali Deb ◽  
Ankita Chakraborty ◽  
Jewel Hossain
Keyword(s):  
Ionic Liquid ◽  
Scale Up ◽  
Reaction Times ◽  
Dimethyl Acetal ◽  
Single Step ◽  
Direct Access ◽  
Imidazolium Ionic Liquid ◽  
Reaction Conditions ◽  
High Yields ◽  
Task Specific Ionic Liquid

AbstractA robust and straightforward protocol has been developed for the synthesis of a diverse array of dimethyl acetal protected benz­imidazole-2-carboxaldehydes by reacting various 2-amino aniline derivatives with methyl 4,4-dimethoxy-3-oxobutanoate using the task-specific­ imidazolium ionic liquid (HBIm·TFA) as a promoter for N-C/C-N annulation processes. The present protocol offers several advantages over existing protocols, such as single-step process, short reaction times, very mild reaction conditions, high yields, ease of purification, recovery and reusability of the catalyst, and scale-up of the reaction.

scholarly journals Design, Synthesis, and In Vitro Evaluation of Benzofuro[3,2-c]Quinoline Derivatives as Potential Antileukemia Agents

Molecules ◽  
2020 ◽  
Vol 25 (1) ◽  
pp. 203 ◽  
Author(s):  
Ying Lin ◽  
Dong Xing ◽  
Wen-Biao Wu ◽  
Gao-Ya Xu ◽  
Li-Fang Yu ◽  
...  
Keyword(s):  
Intramolecular Cyclization ◽  
Biological Evaluation ◽  
Quinoline Derivatives ◽  
Reaction Conditions ◽  
Design Synthesis ◽  
In Vitro Evaluation ◽  
Metal Free ◽  
Sequential Transformation ◽  
High Yields

Herein, we design and synthesize an array of benzofuro[3,2-c]quinolines starting from 3-(2-methoxyphenyl)quinolin-4(1H)ones via a sequential chlorination/demethylation, intramolecular cyclization pathway. This sequential transformation was efficient, conducted under metal-free and mild reaction conditions, and yielded corresponding benzofuro[3,2-c]quinolines in high yields. In vitro biological evaluation indicated that such type of compounds showed excellent antileukemia activity and selectivity, and therefore may offer a promising hit compound for developing antileukemia compounds.

scholarly journals Metal-Free Photoredox Phosphonation of C–N and C–X Bonds in Aqueous Solvent Mixtures

2021 ◽  
Author(s):  
Lei Pan ◽  
Alexandra Kelley ◽  
Maria Victoria Cooke ◽  
Macy Deckert ◽  
Sébastien Laulhé
Keyword(s):  
Building Blocks ◽  
Solvent Mixture ◽  
Solvent Mixtures ◽  
Environmental Footprint ◽  
Reaction Conditions ◽  
Metal Free ◽  
Aqueous Solvent ◽  
Wide Range ◽  
Reaction Proceeds ◽  
Phosphonate Esters

Aryl phosphonate esters are valuable moieties for the pharmaceutical and agrochemical industries. Accessing such compounds from affordable and abundant phosphite reagents and a wide range of aromatic building blocks under metal-free, visible light-induced reaction conditions would represent a desirable technology. Herein, we present an efficient and mild methodology for the synthesis of aromatic phosphonate esters in good to excellent yields using DBU and phenothiazine as a photoredox catalyst. The reaction exhibits wide functional group compatibility enabling the transformation in presence of ketone, amide, ester, amine, and alcohol moieties. Importantly, the reaction proceeds using a green solvent mixture primarily composed of water, thus lowering the environmental footprint of this transformation compared to current methods.

Iodide-Catalyzed Carbonylation–Benzylation of Benzyl Chlorides with Potassium Aryltrifluoroborates under Ambient Pressure of Carbon Monoxide

Synlett ◽  
2017 ◽  
Vol 29 (03) ◽  
pp. 369-374 ◽  
Author(s):  
Wei Han ◽  
Junjie Chen ◽  
Fengli Jin ◽  
Xiaorong Yuan
Keyword(s):  
Carbon Monoxide ◽  
Ambient Pressure ◽  
The Novel ◽  
Metal Free ◽  
Benzyl Chlorides ◽  
Wide Range ◽  
Palladium Catalyzed ◽  
Novel Method ◽  
High Yields ◽  
Co Gas

Tetra-N-butylammonium iodide (TBAI) catalyzed carbonylation–benzylation of unactivated benzyl chlorides with potassium aryltrifluoroborates using CO gas has been developed. This reaction is transition-metal free, is carried out under ambient pressure, and provides a wide range of 1,2,3-triarylpropan-1-one derivatives in high yields. The novel method represents a significant improvement over the traditional palladium-catalyzed carbonylation.

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