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.

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.

scholarly journals A Sustainable Improvement of ω-Bromoalkylphosphonates Synthesis to Access Novel KuQuinones

Organics ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 107-117
Author(s):  
Mattia Forchetta ◽  
Valeria Conte ◽  
Giulia Fiorani ◽  
Pierluca Galloni ◽  
Federica Sabuzi
Keyword(s):  
Metal Oxides ◽  
Phosphonic Acid ◽  
Organic Molecules ◽  
Building Blocks ◽  
Reaction Conditions ◽  
Phosphonic Acids ◽  
Sustainable Improvement ◽  
Phosphonate Esters ◽  
First Time ◽  
Complex Organic

Owing to the attractiveness of organic phosphonic acids and esters in the pharmacological field and in the functionalization of conductive metal-oxides, the research of effective synthetic protocols is pivotal. Among the others, ω-bromoalkylphosphonates are gaining particular attention because they are useful building blocks for the tailored functionalization of complex organic molecules. Hence, in this work, the optimization of Michaelis–Arbuzov reaction conditions for ω-bromoalkylphosphonates has been performed, to improve process sustainability while maintaining good yields. Synthesized ω-bromoalkylphosphonates have been successfully adopted for the synthesis of new KuQuinone phosphonate esters and, by hydrolysis, phosphonic acid KuQuinone derivatives have been obtained for the first time. Considering the high affinity with metal-oxides, KuQuinones bearing phosphonic acid terminal groups are promising candidates for biomedical and photo(electro)chemical applications.

scholarly journals A novel three-component reaction between isocyanides, alcohols or thiols and elemental sulfur: a mild, catalyst-free approach towards O-thiocarbamates and dithiocarbamates

2019 ◽  
Vol 15 ◽  
pp. 1523-1533 ◽  
Author(s):  
András György Németh ◽  
György Miklós Keserű ◽  
Péter Ábrányi-Balogh
Keyword(s):  
Elemental Sulfur ◽  
Building Blocks ◽  
Reaction Conditions ◽  
One Pot ◽  
Catalyst Free ◽  
Synthetic Procedure ◽  
Three Component Reaction ◽  
Wide Range ◽  
Organic Chemist ◽  
The One

A new multicomponent reaction has been developed between isocyanides, sulfur and alcohols or thiols under mild reaction conditions to afford O-thiocarbamates and dithiocarbamates in moderate to good yields. The one-pot reaction cascade involves the formation of an isothiocyanate intermediate, thus a catalyst-free synthesis of isothiocyanates, as valuable building blocks from isocyanides and sulfur is proposed, as well. The synthetic procedure suits the demand of a modern organic chemist, as it tolerates a wide range of functional groups, it is atom economic and easily scalable.

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.

Copper(II)-Promoted Oxidation/[3+2]Cycloaddition/Aromatization Cascade: Efficient Synthesis of Tetrasubstituted NH-Pyrrole from Chalcones and Iminodiacetates

Synlett ◽  
2019 ◽  
Vol 30 (12) ◽  
pp. 1442-1446 ◽  
Author(s):  
Zhang-qi Lin ◽  
Chao-dong Li ◽  
Zi-chun Zhou ◽  
Shuai Xue ◽  
Jian-rong Gao ◽  
...  
Keyword(s):  
Efficient Method ◽  
Cascade Reaction ◽  
Oxidative Cyclization ◽  
Efficient Synthesis ◽  
Reaction Conditions ◽  
Highly Efficient ◽  
Wide Range ◽  
Reaction Proceeds

A simple and highly efficient method for the preparation of tetrasubstituted NH-pyrrole from a wide range of chalcones and diethyl iminodiacetates via a Cu(OAc)2-promoted oxidation/[3+2]cycloaddition/aromatization cascade reaction has been developed. This reaction proceeds through dehydrogenations, deamination, and oxidative cyclization, affording the corresponding products in good to excellent yields. This convenient methodology for constructing tetrasubstituted NH-pyrroles has several advantages over existing methods, such as the use of easily accessible chalcones and readily available diethyl iminodiacetates, and mild reaction conditions. A wide range of substrates are tolerated.

Radical Metal-Free Borylation of Aryl Iodides

Synthesis ◽  
2017 ◽  
Vol 49 (21) ◽  
pp. 4759-4768 ◽  
Author(s):  
Sandra Pinet ◽  
Mathieu Pucheault ◽  
Virginie Liautard ◽  
Mégane Debiais
Keyword(s):  
Steric Hindrance ◽  
Radical Mechanism ◽  
Electronic Effects ◽  
Simple Metal ◽  
Reaction Conditions ◽  
Metal Free ◽  
Aryl Iodides ◽  
Reaction Proceeds ◽  
Electronic Effects Of Substituents

A simple metal-free borylation of aryl iodides mediated by a fluoride sp2–sp3 diboron adduct is described. The reaction conditions are compatible with various functional groups. Electronic effects of substituents do not affect the borylation while steric hindrance does. The reaction proceeds via a radical mechanism in which pyridine serves to stabilize the boryl radicals, generated in situ.

Metal-Free Halogenation of N-Substituted Enaminoesters and Enaminones: A Facile Access to Functionalized α,α-Dihaloimines

Synthesis ◽  
2020 ◽  
Vol 52 (08) ◽  
pp. 1301-1314 ◽  
Author(s):  
Changfu Qiu ◽  
Heshui Yu ◽  
Chuanjiang Qiu ◽  
Fangyi Li ◽  
Tongchuan Suo ◽  
...  
Keyword(s):  
Transition Metals ◽  
Building Blocks ◽  
Synthetic Method ◽  
Safe Operation ◽  
Reaction Conditions ◽  
Metal Free ◽  
Synthetic Utility ◽  
General Method

An efficient and general method for the synthesis of functionalized α,α-dihaloimines via halogenation of N-substituted enaminoesters and enaminones is described. This reaction, in which both α,α-dihaloimines and mixed α,α-dihaloimines could be achieved in good to excellent yields, is believed to proceed via an α-monohalogenated enamine intermediate. This synthetic method features no use of transition metals, readily accessible substrates, mild reaction conditions, simple and safe operation, and gram scale synthesis. Furthermore, the synthetic utility of the products was demonstrated by their efficient transformations to further useful nitrogen-containing heterocycles and building blocks.

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).

scholarly journals Direct C–H Alpha Arylation of Enones with ArI(O2CR)2 Reagents

2019 ◽  
Author(s):  
Felipe Cesar Sousa e Silva ◽  
Nguyen T Van ◽  
Sarah Wengryniuk
Keyword(s):  
Claisen Rearrangement ◽  
Bond Formation ◽  
Hypervalent Iodine ◽  
Enol Ethers ◽  
Silyl Enol Ethers ◽  
Metal Free ◽  
Wide Range ◽  
Reaction Proceeds ◽  
Mechanistic Investigations

Herein, we report the metal-free direct C–H arylation of enones mediated by hypervalent iodine reagents. The reaction proceeds via a reductive iodonium Claisen rearrangement of <i>in situ </i>b-pyridinium silyl enol ethers. The aryl groups are derived from ArI(O<sub>2</sub>CCF<sub>3</sub>)<sub>2</sub> reagents, which are readily accessed from the parent iodoarenes. It is tolerant of a wide range of substitution patterns and the incorporated arenes maintain the valuable iodine functional handle. Mechanistic investigations implicate arylation via an umpoled “enolonium” species and that the presence of a b-pyridinium moiety is critical for desired C–C bond formation.

scholarly journals Viscometric investigations and molecular interactions of some derivatives of 5-Substituted indole dihydropyrimidines in mixed organic solvents

2018 ◽  
Vol 35 (2) ◽  
pp. 23
Author(s):  
L. C. Heda ◽  
Rashmi Sharma ◽  
S. R. Mosalpuri ◽  
Pramod B. Chaudhari
Keyword(s):  
Organic Solvents ◽  
Molecular Interactions ◽  
Change Point ◽  
Solvent Mixture ◽  
Solvent Mixtures ◽  
Chemical Behavior ◽  
Viscosity Measurements ◽  
Aqueous Solvent ◽  
Benzene Concentration ◽  
Derivatives Of

Colloid chemical behavior of indole dihydropyrimidines in non-aqueous solvent mixture benzene-methanol of varying composition has been investigated by viscometric measurements at 303K± 0.1. The viscosity of the system increases with the increase in concentration. The Trend Change Point (TCP) values have been determined by intersection of two straightlines, which are found to be dependent on the composition of solvent  mixtures. The study confirms that the nature of synthesized compounds agglomerate formed below and above 50% benzene concentration is quite different. The viscometric data have been analyzed in terms of Einstein, Vand, Moulik and Jones-Dole equations. These well known equations have been successfully applied to explain the results of viscosity measurements and the viscometric parameters show that the behavior of compound changes in the proximity of 50% benzene concentration.

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