scholarly journals An Expedient Approach to Pyrazolo[3,4-b]pyridine-3-carboxamides via Palladium-Catalyzed Aminocarbonylation

Synthesis ◽  
2021 ◽  
Author(s):  
John J. Keating ◽  
Ryan M. Alam
Keyword(s):  
Functional Group ◽  
Ex Situ ◽  
Pharmacological Properties ◽  
Drug Molecules ◽  
Wide Range ◽  
Palladium Catalyzed ◽  
Privileged Scaffold ◽  
Synthetic Methodologies ◽  
Heterocyclic Moiety ◽  
Co Gas

AbstractPyrazolo[3,4-b]pyridine is a privileged scaffold found in many small drug molecules that possess a wide range of pharmacological properties. Efforts to further develop and exploit synthetic methodologies that permit the functionalization of this heterocyclic moiety warrant investigation. To this end, a series of novel 1,3-disubstituted pyrazolo[3,4-b]pyridine-3-carboxamide derivatives have been prepared by introducing the 3-carboxamide moiety using palladium-catalyzed aminocarbonylation methodology and employing CO gas generated ex situ using a two-chamber reactor (COware®). The functional group tolerance of this optimized aminocarbonylation protocol is highlighted through the synthesis of a range of diversely substituted C-3 carbox­amide pyrazolo[3,4-b]pyridines in excellent yields of up to 99%.

Advances in the Synthesis of Xanthenes: An Overview

2018 ◽  
Vol 15 (3) ◽  
pp. 341-369 ◽  
Author(s):  
Ankita Chaudhary ◽  
Jitender M. Khurana
Keyword(s):  
Heterogeneous Catalysts ◽  
Biological Activities ◽  
Reaction Times ◽  
Environmentally Benign ◽  
Central Nucleus ◽  
Diversity Oriented Synthesis ◽  
Wide Range ◽  
Privileged Scaffold ◽  
Synthetic Methodologies ◽  
Reaction Media

Background: Xanthene is pharmacologically important oxygen containing heterocyclic moeity exhibiting an array of potent biological activities like antibacterial, antiviral, antiinflammatory, antitumor, antioxidant, antiplasmodial etc. Other useful applications of these heterocycles are as fluorescent materials for the visualization of biomolecules and in laser technology. Objective: This review gives an insight of the literature available on the methods for the construction of xanthene nucleus. This review article can be reasonably encouraging for those involved in the synthesis of molecules exhibiting a wide range of biological activities involving xanthene as central nucleus and would provide them assistance in developing new eco-friendly, efficient and economical viable methods. Conclusion: Owing to diverse applications of xanthenes, various synthetic methodologies have been developed, whether to construct this privileged scaffold. Many of the reported methods involve the use of various harsh catalysts/reagents that are not environmentally benign, produce a large amount of waste and need longer reaction times. The sustainable and diversity oriented synthesis of xanthene scaffold which incorporates Green Chemistry tools like multicomponent reaction approach, heterogeneous catalysts, alternate reaction media such as water, ionic liquids, polyethylene glycol etc. has also been developed.

Cu-Catalyzed Allylation of Amines with Cyclopropyldiphenylsulfonium Trifluoromethanesulfonate

Synthesis ◽  
2022 ◽  
Author(s):  
Yu Ma ◽  
Ze-Yu Tian ◽  
Shuang-Yang Zheng ◽  
Cheng-Pan Zhang
Keyword(s):  
Aromatic Amines ◽  
Functional Group ◽  
Secondary Amines ◽  
Reaction Conditions ◽  
Drug Molecules ◽  
Wide Range ◽  
Catalyzed Reactions ◽  
Cyclic Compounds

Cyclopropyldiphenylsulfonium salt is a famous ylide precursor that was previously extensively employed in the preparation of cyclic compounds and has been successfully utilized as an efficient allylation reagent in this work. The Cu-catalyzed reactions of cyclopropyldiphenylsulfonium trifluoromethanesulfonate with amines in the presence of an appropriate ligand provided the N-allylated products in good yields. Aliphatic/aromatic amines and primary/secondary amines were all mildly converted under the reaction conditions. This protocol was also applicable to N-functionalization of drug molecules, supplying the corresponding N-allylated compounds in satisfactory yields. The reaction showed good functional group tolerance, a wide range of substrates, and excellent chemoselectivity, which offered an interesting method for the synthesis of N-allyl amines.

scholarly journals Palladium-Catalyzed Cross-Coupling of Gem-Bromofluoroalkenes with Alkylboronic Acids for the Synthesis of Alkylated Monofluoroalkenes

Molecules ◽  
2020 ◽  
Vol 25 (23) ◽  
pp. 5532
Author(s):  
Laëtitia Chausset-Boissarie ◽  
Nicolas Cheval ◽  
Christian Rolando
Keyword(s):  
Organic Synthesis ◽  
Functional Group ◽  
Materials Science ◽  
Cross Coupling ◽  
High Yield ◽  
Efficient Synthesis ◽  
Mild Conditions ◽  
Wide Range ◽  
Palladium Catalyzed ◽  
Novel Strategy

Monofluoroalkenes are versatile fluorinated synthons in organic synthesis, medicinal chemistry and materials science. In light of the importance of alkyl-substituted monofluoroalkenes efficient synthesis of these moieties still represents a synthetic challenge. Herein, we described a mild and efficient methodology to obtain monofluoroalkenes through a stereospecific palladium-catalyzed alkylation of gem-bromofluoroalkenes with primary and strained secondary alkylboronic acids under mild conditions. This novel strategy gives access to a wide range of functionalized tri- and tetrasubstituted monofluoroalkenes in high yield, with good functional group tolerance, independently from the gem-bromofluoroalkenes geometry.

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.

scholarly journals Chiral Alkyl Amine Synthesis via Catalytic Enantioselective Hydroalkylation of Enamides

2020 ◽  
Author(s):  
Deyun Qian ◽  
Srikrishna Bera ◽  
Xile Hu
Keyword(s):  
Natural Products ◽  
Functional Group ◽  
Building Blocks ◽  
Alkyl Halides ◽  
Enantioselective Synthesis ◽  
Mild Conditions ◽  
Drug Molecules ◽  
Alkyl Amines ◽  
Wide Range ◽  
Synthetic Intermediates

Chiral alkyl amines are omnipresent as bio-active molecules and synthetic intermediates. Catalytic and enantioselective synthesis of alkyl amines from readily accessible precursors is challenging. Here we develop a nickel-catalyzed hydroalkylation method to assemble a wide range of chiral alkyl amines from enamides and alkyl halides in high regio- and enantioselectivity. The method works for both non-activated and activated alkyl halides, and is able to produce enantiomerically enriched amines with two minimally differentiated alpha-alkyl substituents. The mild conditions lead to high functional group tolerance, which is demonstrated in the post-product functionalization of many natural products and drug molecules, as well as the synthesis of chiral building blocks and key intermediates to bio-active compounds.

scholarly journals Chiral Alkyl Amine Synthesis via Catalytic Enantioselective Hydroalkylation of Enamides

2020 ◽  
Author(s):  
Deyun Qian ◽  
Srikrishna Bera ◽  
Xile Hu
Keyword(s):  
Natural Products ◽  
Functional Group ◽  
Building Blocks ◽  
Alkyl Halides ◽  
Enantioselective Synthesis ◽  
Mild Conditions ◽  
Drug Molecules ◽  
Alkyl Amines ◽  
Wide Range ◽  
Synthetic Intermediates

Chiral alkyl amines are omnipresent as bio-active molecules and synthetic intermediates. Catalytic and enantioselective synthesis of alkyl amines from readily accessible precursors is challenging. Here we develop a nickel-catalyzed hydroalkylation method to assemble a wide range of chiral alkyl amines from enamides and alkyl halides in high regio- and enantioselectivity. The method works for both non-activated and activated alkyl halides, and is able to produce enantiomerically enriched amines with two minimally differentiated alpha-alkyl substituents. The mild conditions lead to high functional group tolerance, which is demonstrated in the post-product functionalization of many natural products and drug molecules, as well as the synthesis of chiral building blocks and key intermediates to bio-active compounds.

Medicinal applications of coumarins bearing azetidinone and thiazolidinone moieties

2021 ◽  
Author(s):  
Siddappa A Patil ◽  
Shivaputra A Patil ◽  
Temilade Fariyike ◽  
Kostiantyn O Marichev ◽  
Hector Mario Heras Martinez ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
Biological Activities ◽  
Heterocyclic Ring ◽  
Pharmacological Properties ◽  
Structure Activity Relationships ◽  
Naturally Occurring ◽  
Structure Activity ◽  
Wide Range ◽  
Synthetic Routes ◽  
Synthetic Methodologies

Coumarins (2 H-chromen-2-ones), also known as benzopyran-2-ones, are a family of naturally occurring heterocyclic ring systems that contain a lactone moiety. Coumarins exhibit a wide range of well-studied pharmacological properties. Over the last few decades, as a result of advances in diverse oriented synthetic routes, physicochemical properties and numerous biological activities, coumarins have become globally studied molecules from various synthetic and medicinal chemists. Recently, several bioactive coumarins bearing azetidinone and thiazolidinone moieties have been found to display a range of therapeutic characteristics, including antimicrobial, anticancer, antidiabetic and anti-inflammatory properties. This review offers a brief description of the synthetic methodologies, known bioactivity and structure–activity relationships of coumarins bearing azetidinones and thiazolidinones.

scholarly journals Smart Nanoparticles for Drug Delivery Application: Development of Versatile Nanocarrier Platforms in Biotechnology and Nanomedicine

2019 ◽  
Vol 2019 ◽  
pp. 1-26 ◽  
Author(s):  
Domenico Lombardo ◽  
Mikhail A. Kiselev ◽  
Maria Teresa Caccamo
Keyword(s):  
Drug Delivery ◽  
Drug Delivery Systems ◽  
Polymeric Micelles ◽  
Mesoporous Silica Nanoparticles ◽  
Complex Environment ◽  
Application Development ◽  
Drug Molecules ◽  
Wide Range ◽  
Critical Issues ◽  
Synthetic Methodologies

The study of nanostructured drug delivery systems allows the development of novel platforms for the efficient transport and controlled release of drug molecules in the harsh microenvironment of diseased tissues of living systems, thus offering a wide range of functional nanoplatforms for smart application in biotechnology and nanomedicine. This article highlights recent advances of smart nanocarriers composed of organic (including polymeric micelles and vesicles, liposomes, dendrimers, and hydrogels) and inorganic (including quantum dots, gold and mesoporous silica nanoparticles) materials. Despite the remarkable developments of recent synthetic methodologies, most of all nanocarriers’ action is associated with a number of unwanted side effects that diminish their efficient use in biotechnology and nanomedicine applications. This highlights some critical issues in the design and engineering of nanocarrier systems for biotechnology applications, arising from the complex environment and multiform interactions established within the specific biological media.

Ligand-Enabled γ-C(sp3)–H Olefination of Free Carboxylic Acids

2020 ◽  
Author(s):  
Kiron Kumar Ghosh ◽  
Alexander Uttry ◽  
Francesca Ghiringhelli ◽  
Arup Mondal ◽  
Manuel van Gemmeren
Keyword(s):  
Reaction Mechanism ◽  
Carboxylic Acids ◽  
Michael Addition ◽  
Kinetic Studies ◽  
Wide Range ◽  
Palladium Catalyzed

We report the ligand enabled C(sp3)–H activation/olefination of free carboxylic acids in the γ-position. Through an intramolecular Michael-addition, δ-lactones are obtained as products. Two distinct ligand classes are identified that enable the challenging palladium-catalyzed activation of free carboxylic acids in the γ-position. The developed protocol features a wide range of acid substrates and olefin reaction partners and is shown to be applicable on a preparatively useful scale. Insights into the underlying reaction mechanism obtained through kinetic studies are reported.<br>

Stereospecific, Palladium-catalyzed C(sp3)–H Alkenylation and Alkynylation of a Proline Derivative Enabled by 8-Aminoquinoline as a Directing Group

2020 ◽  
Author(s):  
Aleksandra Balliu ◽  
Aaltje Roelofje Femmigje Strijker ◽  
Michael Oschmann ◽  
Monireh Pourghasemi Lati ◽  
Oscar Verho
Keyword(s):  
Carboxylic Acid ◽  
Building Blocks ◽  
Wide Range ◽  
Palladium Catalyzed ◽  
Directing Group ◽  
High Yields ◽  
Vinyl Iodides ◽  
Initial Results

<p>In this preprint, we present our initial results concerning a stereospecific Pd-catalyzed protocol for the C3 alkenylation and alkynylation of a proline derivative carrying the well utilized 8‑aminoquinoline directing group. Efficient C–H alkenylation was achieved with a wide range of vinyl iodides bearing different aliphatic, aromatic and heteroaromatic substituents, to furnish the corresponding C3 alkenylated products in good to high yields. In addition, we were able show that this protocol can also be used to install an alkynyl group into the pyrrolidine scaffold, when a TIPS-protected alkynyl bromide was used as the reaction partner. Furthermore, two different methods for the removal of the 8-aminoquinoline auxiliary are reported, which can enable access to both <i>cis</i>- and <i>trans</i>-configured carboxylic acid building blocks from the C–H alkenylation products.</p>

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