scholarly journals Difluorocarbene enables to access 2-fluoroindoles from ortho-vinylanilines

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jianke Su ◽  
Xinyuan Hu ◽  
Hua Huang ◽  
Yu Guo ◽  
Qiuling Song
Keyword(s):  
Fluorine Atom ◽  
High Efficiency ◽  
Addition Reaction ◽  
Bond Cleavage ◽  
Therapeutic Agents ◽  
Bioactive Molecules ◽  
General Strategy ◽  
Michael Addition Reaction ◽  
Fundamental Properties ◽  
Synthetic Approaches

Abstract2-Fluoroindoles as an important structural scaffold are widely existing in many bioactive or therapeutic agents. Despite their potential usefulness, efficient constructions of 2-fluoroindole derivatives are very sparce. The development of straightforward synthetic approaches to access 2-fluoroindoles is highly desirable for studying their fundamental properties and applications. Herein, we report an efficient and general strategy for the construction of 2-fluoroindoles in which a wide variety of 2-fluoroindoles were accessed with high efficiency and chemoselectivity. Instead of starting from indole skeletons, our strategy constructs indole scaffolds alongside the incorporation of fluorine atom on C2 position in a formal [4+1] cyclization from readily accessible ortho-vinylanilines and difluorocarbene. In our protocol, commercially accessible halodifluoroalkylative reagents provide one carbon and one fluorine atom by cleaving one C-N tertiary bond and forming one C-N bond and one C-C double bond with ortho-vinylanilines. Downstream transformations on 2-fluoroindoles lead to various valuable bioactive molecules which demonstrated significant synthetic advantages over previous reports. And mechanistic studies suggest that the reaction undergoes a cascade difluorocarbene-trapping and intramolecular Michael addition reaction followed by Csp3-F bond cleavage.

Cupin Variants as Macromolecular Ligand Library for Stereoselective Michael Addition of Nitroalkanes

2019 ◽  
Author(s):  
Nobutaka Fujieda ◽  
Miho Yuasa ◽  
Yosuke Nishikawa ◽  
Genji Kurisu ◽  
Shinobu Itoh ◽  
...  
Keyword(s):  
Michael Addition ◽  
In Silico ◽  
Addition Reaction ◽  
Single Point ◽  
Point Mutations ◽  
Unsaturated Ketone ◽  
Michael Addition Reaction ◽  
Beta Barrel ◽  
Cupin Superfamily ◽  
Single Point Mutations

Cupin superfamily proteins (TM1459) work as a macromolecular ligand framework with a double-stranded beta-barrel structure ligating to a Cu ion through histidine side chains. Variegating the first coordination sphere of TM1459 revealed that H52A and H54A/H58A mutants effectively catalyzed the diastereo- and enantio-selective Michael addition reaction of nitroalkanes to an α,β-unsaturated ketone. Moreover, in silico substrate docking signified C106N and F104W single-point mutations, which inverted the diastereoselectivity of H52A and further improved the stereoselectivity of H54A/H58A, respectively.

Natural Compounds and Drug Discovery: Can Cnidarian Venom Play a Role?

2019 ◽  
Vol 19 (2) ◽  
pp. 114-118
Author(s):  
Gian Luigi Mariottini ◽  
Irwin Darren Grice
Keyword(s):  
Biological Activity ◽  
Marine Species ◽  
Natural Compounds ◽  
Therapeutic Agents ◽  
Industrial Applications ◽  
Bioactive Molecules ◽  
Sea Anemones ◽  
Therapeutic Approaches ◽  
Ongoing Research ◽  
Biological Compounds

Natural compounds extracted from organisms and microorganisms are an important resource for the development of drugs and bioactive molecules. Many such compounds have made valuable contributions in diverse fields such as human health, pharmaceutics and industrial applications. Presently, however, research on investigating natural compounds from marine organisms is scarce. This is somewhat surprising considering that the marine environment makes a major contribution to Earth's ecosystems and consequently possesses a vast storehouse of diverse marine species. Interestingly, of the marine bioactive natural compounds identified to date, many are venoms, coming from Cnidarians (jellyfish, sea anemones, corals). Cnidarians are therefore particularly interesting marine species, producing important biological compounds that warrant further investigation for their development as possible therapeutic agents. From an experimental aspect, this review aims to emphasize and update the current scientific knowledge reported on selected biological activity (antiinflammatory, antimicrobial, antitumoral, anticoagulant, along with several less studied effects) of Cnidarian venoms/extracts, highlighting potential aspects for ongoing research towards their utilization in human therapeutic approaches.

scholarly journals Kinetic resolution of indolines by asymmetric hydroxylamine formation

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Gang Wang ◽  
Ran Lu ◽  
Chuangchuang He ◽  
Lei Liu
Keyword(s):  
Hydrogen Peroxide ◽  
Chemical Synthesis ◽  
Late Stage ◽  
Kinetic Resolution ◽  
High Efficiency ◽  
Bond Formation ◽  
Bioactive Molecules ◽  
Environmentally Benign ◽  
Secondary Amines

AbstractCatalytic kinetic resolution of amines represents a longstanding challenge in chemical synthesis. Here, we described a kinetic resolution of secondary amines through oxygenation to produce enantiopure hydroxylamines involving N–O bond formation. The economic and practical titanium-catalyzed asymmetric oxygenation with environmentally benign hydrogen peroxide as oxidant is applicable to a range of racemic indolines with multiple stereocenters and diverse substituent patterns in high efficiency with efficient chemoselectivity and enantio-discrimination. Late-stage asymmetric oxygenation of bioactive molecules that are otherwise difficult to synthesize was also explored.

Tandem Alkylation/Michael Addition Reaction of Dithiocarbamic Acids with Alkyl γ-Bromocrotonates: Access to Functionalized 1,3-Thiazolidine-2-thiones

Synthesis ◽  
2021 ◽  
Author(s):  
Azim Ziyaei Halimehjani ◽  
Petr Beier ◽  
Maryam Khalili Foumeshi ◽  
Ali Alaei ◽  
Blanka Klepetářová
Keyword(s):  
Amino Acids ◽  
Carbon Disulfide ◽  
Multicomponent Reaction ◽  
Michael Addition ◽  
Addition Reaction ◽  
Primary Amines ◽  
Oxidation Reactions ◽  
Michael Addition Reaction ◽  
Synthetic Utility ◽  
Reaction Proceeds

AbstractThiazolidine-2-thiones were prepared via a novel multicomponent reaction of primary amines (amino acids), carbon disulfide, and γ-bromocrotonates. The reaction proceeds via a domino alkylation/intramolecular Michael addition to provide the corresponding thiazolidine-2-thiones in high to excellent yields. By using diamines in this protocol, bis(thiazolidine-2-thiones) derivatives were synthesized. The synthetic utility of the adducts was demonstrated by hydrolysis, amidation, and oxidation reactions.

Bisphosphine catalyzed sequential [3 + 2] cycloaddition and Michael addition of ynones with benzylidenepyrazolones via dual α′,α′-C(sp3)–H bifunctionalization to construct cyclopentanone-fused spiro-pyrazolones

2018 ◽  
Vol 16 (48) ◽  
pp. 9461-9471 ◽  
Author(s):  
Jiayong Zhang ◽  
Zhiwei Miao
Keyword(s):  
Michael Addition ◽  
Addition Reaction ◽  
Michael Addition Reaction

A sequential [3 + 2] cycloaddition and Michael addition reaction of ynones with benzylidenepyrazolones afforded cyclopentanone-fused spiro-pyrazolones catalyzed by DPPB via dual α′,α′-C(sp3)–H bifunctionalization.

scholarly journals Bile Acid Conjugates with Anticancer Activity: Most Recent Research

Molecules ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 25
Author(s):  
Maria Luisa Navacchia ◽  
Elena Marchesi ◽  
Daniela Perrone
Keyword(s):  
Bile Acid ◽  
Cancer Therapy ◽  
Anticancer Activity ◽  
Bile Acids ◽  
Treatment Modality ◽  
Biological Properties ◽  
Therapeutic Agents ◽  
Bioactive Molecules ◽  
Hybrid Functional ◽  
Hybrid Molecules

The advantages of a treatment modality that combines two or more therapeutic agents in cancer therapy encourages the study of hybrid functional compounds for pharmacological applications. In light of this, we reviewed recent works on hybrid molecules based on bile acids. Due to their biological properties, as well as their different chemical/biochemical reactive moieties, bile acids can be considered very interesting starting molecules for conjugation with natural or synthetic bioactive molecules.

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