Visible-Light-Mediated Multicomponent Reaction for Secondary Amine Synthesis

2021 ◽  
Author(s):  
Qingmin Wang ◽  
Xiaochen Wang ◽  
Binbing Zhu ◽  
Jianyang Dong ◽  
hao tian ◽  
...  
Keyword(s):  
Natural Products ◽  
Visible Light ◽  
Small Molecule ◽  
Secondary Amine ◽  
Multicomponent Reaction ◽  
Functional Group ◽  
Secondary Amines ◽  
Biological Probes

The widespread presence of secondary amines in agrochemicals, pharmaceuticals, natural products, and small-molecule biological probes has inspired efforts to streamline the synthesis of molecules with this functional group. Herein, we...

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.

scholarly journals Visible light photoredox-catalyzed deoxygenation of alcohols

2014 ◽  
Vol 10 ◽  
pp. 2157-2165 ◽  
Author(s):  
Daniel Rackl ◽  
Viktor Kais ◽  
Peter Kreitmeier ◽  
Oliver Reiser
Keyword(s):  
Natural Products ◽  
Visible Light ◽  
Blue Light ◽  
Functional Group ◽  
Bond Cleavage ◽  
Environmentally Benign ◽  
Visible Light Photocatalysis ◽  
Water Mixture ◽  
Visible Light Photocatalyst ◽  
Single Bonds

Carbon–oxygen single bonds are ubiquitous in natural products whereas efficient methods for their reductive defunctionalization are rare. In this work an environmentally benign protocol for the activation of carbon–oxygen single bonds of alcohols towards a reductive bond cleavage under visible light photocatalysis was developed. Alcohols were activated as 3,5-bis(trifluoromethyl)-substituted benzoates and irradiation with blue light in the presence of [Ir(ppy)2(dtb-bpy)](PF6) as visible light photocatalyst and Hünig’s base as sacrificial electron donor in an acetonitrile/water mixture generally gave good to excellent yields of the desired defunctionalized compounds. Functional group tolerance is high but the protocol developed is limited to benzylic, α-carbonyl, and α-cyanoalcohols; with other alcohols a slow partial C–F bond reduction in the 3,5-bis(trifluoromethyl)benzoate moiety occurs.

Factors controlling nitrosamine formation during wastewater chlorination

2002 ◽  
Vol 2 (3) ◽  
pp. 191-198 ◽  
Author(s):  
W.A. Mitch ◽  
D.L. Sedlak
Keyword(s):  
Secondary Amine ◽  
Water Reuse ◽  
Potable Water ◽  
Functional Group ◽  
Reaction Scheme ◽  
Secondary Amines ◽  
Low Levels ◽  
Potent Carcinogen

Recent discoveries of the formation of low levels of the potent carcinogen N-nitrosodimethylamine (NDMA) during wastewater chlorination has caused concern where indirect potable water reuse is practiced. Experiments indicate that nitrosamine formation during chlorination of wastewater is consistent with a reaction scheme involving the slow formation of a hydrazine intermediate from a secondary amine and monochloramine, followed by its rapid oxidation to the corresponding N-nitrosamine. A survey of precursors indicates that secondary amines form their corresponding N-nitrosamines to the greatest extent. However, molecules containing the secondary amine as a functional group can also form the corresponding N-nitrosamine. NDMA is the predominant N-nitrosamine found in chlorinated wastewater. However, other nitrosamines are detected. These N-nitrosamines may be important if the summed risk posed by the exposure to all N-nitrosamines is considered.

scholarly journals Advances in the Asymmetric Total Synthesis of Natural Products Using Chiral Secondary Amine Catalyzed Reactions of α,β-Unsaturated Aldehydes

Molecules ◽  
2019 ◽  
Vol 24 (18) ◽  
pp. 3412 ◽  
Author(s):  
Zhonglei Wang
Keyword(s):  
Natural Products ◽  
Total Synthesis ◽  
Secondary Amine ◽  
Bioactive Molecules ◽  
Secondary Amines ◽  
Asymmetric Total Synthesis ◽  
Bioactive Natural Products ◽  
Unsaturated Aldehydes ◽  
Target Molecules ◽  
Catalyzed Reactions

Chirality is one of the most important attributes for its presence in a vast majority of bioactive natural products and pharmaceuticals. Asymmetric organocatalysis methods have emerged as a powerful methodology for the construction of highly enantioenriched structural skeletons of the target molecules. Due to their extensive application of organocatalysis in the total synthesis of bioactive molecules and some of them have been used in the industrial synthesis of drugs have attracted increasing interests from chemists. Among the chiral organocatalysts, chiral secondary amines (MacMillan’s catalyst and Jorgensen’s catalyst) have been especially considered attractive strategies because of their impressive efficiency. Herein, we outline advances in the asymmetric total synthesis of natural products and relevant drugs by using the strategy of chiral secondary amine catalyzed reactions of α,β-unsaturated aldehydes in the last eighteen years.

scholarly journals Visible light mediated photocatalytic [2 + 2] cycloaddition/ring-opening rearomatization cascade of electron-deficient azaarenes and vinylarenes

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Noelia Salaverri ◽  
Rubén Mas-Ballesté ◽  
Leyre Marzo ◽  
José Alemán
Keyword(s):  
Natural Products ◽  
Double Bond ◽  
Visible Light ◽  
Bioactive Compounds ◽  
Late Stage ◽  
Ring Opening ◽  
Functional Group ◽  
Theoretical Calculations ◽  
Double Bonds ◽  
Heterocyclic Derivatives

Abstract The broad presence of azaarene moieties in natural products has promoted the development of new functionalization reactions, giving access to larger libraries of bioactive compounds. The light promoted [2 + 2] photocycloaddition reaction to generate cyclobutanes has been extensively studied in photochemistry. In particular, De Mayo reported the [2 + 2] cycloaddition followed by retroaldol condensation between enols of 1,3-dicarbonyls and double bonds to synthesize 1,5-dicarbonyls. Herein, we describe the [2 + 2] photocycloaddition followed by a ring-opening rearomatization reaction between electron-deficient 2-methylene-azaarenes and double bonds, taking advantage of the ability of these heterocyclic derivatives to form the corresponding pseudo-enamine intermediate. The procedure shows a high functional group tolerance either on the double bond or the heteroarene side and allows the presence of different electron-withdrawing groups. In addition, the wide applicability of this reaction has been demonstrated through the late-stage derivatization of several natural products. Photochemical studies, together with theoretical calculations, support a mechanism involving the photosensitization of the pseudo-enamine intermediate.

Visible-Light Photocatalytic Ugi/Aza-Wittig Cascade Towards 2-aminomethyl-1,3,4-oxadiazole derivatives

Synthesis ◽  
2021 ◽  
Author(s):  
Camilla Russo ◽  
Rolando Cannalire ◽  
Paolo Luciano ◽  
Francesca Brunelli ◽  
Giancesare Tron ◽  
...  
Keyword(s):  
Amino Acids ◽  
Visible Light ◽  
Multicomponent Reaction ◽  
Late Stage ◽  
Functional Group ◽  
Synthetic Approach ◽  
Reaction Conditions ◽  
One Pot ◽  
Oxadiazole Derivatives ◽  
Visible Light Photocatalytic

A new visible light photocatalytic multicomponent reaction (MCR) involving N-alkyl-N-methylanilines, N-isocyanoiminotriphenyl phosphorane, and carboxylic acids leading to 1,3,4-oxadiazole derivatives is herein reported. The developed mild reaction conditions enable a broad substrate scope and a good functional group tolerance, as further highlighted in the late stage functionalization of amino acids and drugs. Additionally, a 2-step one-pot protocol for the obtention of non-symmetrical diacylhydrazines is also reported as an expeditious and green synthetic approach to such valuable scaffolds.

Azulene as an ingredient for visible-light- and stimuli-responsive photoswitches

2021 ◽  
Author(s):  
Andrey G. Lvov ◽  
Aleksei Bredihhin
Keyword(s):  
Visible Light ◽  
Functional Group ◽  
Unique Combination ◽  
Stimuli Responsive

The azulene molecule features an unique combination of optical, luminescent, and stimuli-responsive properties. This makes the azulene motif a promising functional group to be introduced in photoswitches. Recent challenges in...

scholarly journals Modern Synthetic Methods for the Stereoselective Construction of 1,3-Dienes

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 249
Author(s):  
Raquel G. Soengas ◽  
Humberto Rodríguez-Solla
Keyword(s):  
Organic Chemistry ◽  
Natural Products ◽  
Functional Group ◽  
Biological Activities ◽  
Synthetic Methods ◽  
Bond Forming ◽  
Drug Candidates ◽  
The Past ◽  
Wide Range

The 1,3-butadiene motif is widely found in many natural products and drug candidates with relevant biological activities. Moreover, dienes are important targets for synthetic chemists, due to their ability to give access to a wide range of functional group transformations, including a broad range of C-C bond-forming processes. Therefore, the stereoselective preparation of dienes have attracted much attention over the past decades, and the search for new synthetic protocols continues unabated. The aim of this review is to give an overview of the diverse methodologies that have emerged in the last decade, with a focus on the synthetic processes that meet the requirements of efficiency and sustainability of modern organic chemistry.

Recent Advances on Small Molecule Medicinal Chemistry to Treat Human Diseases-Part III

2021 ◽  
Vol 21 (17) ◽  
pp. 1517-1518
Author(s):  
Dharmendra Kumar Yadav
Keyword(s):  
Natural Products ◽  
Drug Discovery ◽  
Small Molecule ◽  
Anticancer Agents ◽  
Medicinal Chemistry ◽  
Review Article ◽  
Human Diseases ◽  
Bioactive Metabolite ◽  
Metabolite Production ◽  
Life Threatening

The discovery and utilization of novel metabolites from natural sources are gaining momentum in the present era. The drug discovery programs have witnessed a remarkable shift from conventional medicines to exploiting natural products and their “value addition”, for treating lifethreatening diseases. The global outbreak of life-threatening diseases namely Ebola, SARS,including infections of the bloodstream (bacteremia), heart valves (endocarditis), lungs (pneumonia), and brain (meningitis) and AIDS calls for a more targeted approach to effectively combat the emerging diseases. In the present scenario, natural products and their extracts are being explored extensively for the treatment of various life threatening diseases. In this thematic issue, several review articles contributed by the scientist and researchers in the different areas of medicinal chemistry, synthetic chemistry, new emerging multi-drug targets were collected. This issue begins with a review article on the “Chemistry and Pharmacology of Natural Catechins from Camellia sinensis as anti-MRSA agents” by Gaur et al. and focuses on the spread of MRSA strains is of great concern because of limited treatment options for staphylococcal infections, since these strains are resistant to the entire class of β-lactam antibiotics. In addition, MRSA exhibits resistance to other classes of antimicrobial agents such as fluoroquinolones, cephalosporins, aminoglycosides, macrolide and even glycopeptides (vancomycin and teicoplanine), leading to the emergence of resistant strains such as glycopeptide intermediate (GISA) and resistant strain (GRSA) of S. aureus. In this review, chemical constituents responsible for the anti-MRSA activity of tea are explored [1]. The next article of this issue is a review article on the “Recent Advancements in the Synthesis and Chemistry of Benzofused Nitrogen- and Oxygen-based Bioactive Heterocycles” by Sharma et al. which focuses on medicinal importance of these bioactive benzo-fused heterocycles; special attention has been given to their synthesis as well as medicinal/pharmaceutical properties in detail [2]. “Trends in pharmaceutical design of Endophytes as anti-infective,” by Tiwari et al., is the third article in this issue. The review focused on the meta-analysis of bioactive metabolite production from endophytes, extensively discussing the bioprospection of natural products for pharmaceutical applications. In light of the emerging importance of endophytes as antiinfective agents, an exploration of the pharmaceutical design of novel chemical entities and analogues has enabled efficient and cost-effective drug discovery programs. However, bottlenecks in endophytic biology and research requires a better understanding of endophytic dynamics and mechanism of bioactive metabolite production towards a sustainable drug discovery program [3]. The last article of this issue is also research article on “Recent development of tetrahydro-quinoline/isoquinoline based compounds as anticancer agents” by Yadav et al. The article reported the synthesis of potent tetrahydroquinoline/isoquinoline molecules of the last 10 years with their anticancer properties in various cancer cell lines and stated their half-maximal inhibitory concentration (IC50). In addition, we also considered the discussion of molecular docking and structural activity relationship wherever provided to understand the possible mode of activity an target involved and structural features responsible for the better activity, so the reader can directly find detail for designing new anticancer agents. [4]. Finally I would like to thank all authors who contributed to this issue, titled “Recent advances on small molecule medicinal chemistry to treat human diseases”.

Asymmetric Hydrogenation of O-/N-Functional Group Substituted Arenes

2021 ◽  
Author(s):  
bingru shao ◽  
Lei Shi ◽  
Yong-Gui Zhou
Keyword(s):  
Natural Products ◽  
Functional Group ◽  
Asymmetric Hydrogenation ◽  
Biologically Active ◽  
Synthetic Methods

Asymmetric hydrogenation of aromatical compouds represents one of the most straightforward synthetic methods to construct important chiral cyclic skeletons that are often found in biologically active agents and natural products....

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