Immobilizing Redox Enzyme on Amino Functional Group-Integrated Tailor-Made Polyester Textile: High Loading, Stability, and Application in a Bio-Fenton System

A metal- and catalyst-free photoinduced radical cascade hydroalkylation of 1,7-enynes has been disclosed. The process is triggered by a SET event involving a photoexcited electron-donor-aceptor complex between NHPI ester and Hantzsch ester, which decomposes to afford a tertiary radical that is readily trapped by the enyne. <a>The method provides an operationally simple, robust and step-economical approach to the construction of diversely functionalized dihydroquinolinones bearing quaternary-centers. A sequential one-pot hydroalkylation-isomerization approach is also allowed giving access to a family of quinolinones. A wide substrate scope and high functional group tolerance was observed in both approaches</a>.

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Dual Nickel/Palladium-Catalyzed Reductive Cross-Coupling Reactions Between Two Phenol Derivatives

10.26434/chemrxiv.12448970.v1 ◽

2020 ◽

Author(s):

Baojian Xiong ◽

Yue Li ◽

Yin Wei ◽

Søren Kramer ◽

Zhong Lian

Keyword(s):

Functional Group ◽

Low Cost ◽

Cross Coupling ◽

Coupling Reactions ◽

Phenol Derivatives ◽

Cross Coupling Reactions ◽

Palladium Catalyzed ◽

One Step ◽

Aryl Tosylates ◽

Low Sensitivity

Cross-coupling between substrates that can be easily derived from phenols is highly attractive due to the abundance and low cost of phenols. Here, we report a dual nickel/palladium-catalyzed reductive cross-coupling between aryl tosylates and aryl triflates; both substrates can be accessed in just one step from readily available phenols. The reaction has a broad functional group tolerance and substrate scope (>60 examples). Furthermore, it displays low sensitivity to steric effects demonstrated by the synthesis of a 2,2’disubstituted biaryl and a fully substituted aryl product. The widespread presence of phenols in natural products and pharmaceuticals allow for straightforward late-stage functionalization, illustrated with examples such as Ezetimibe and tyrosine. NMR spectroscopy and DFT calculations indicate that the nickel catalyst is responsible for activating the aryl triflate, while the palladium catalyst preferentially reacts with the aryl tosylate.

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Effects of Wet Chemical Oxidation on Surface Functionalization and Morphology of Highly Oriented Pyrolytic Graphite

10.26434/chemrxiv.12907604.v1 ◽

2020 ◽

Author(s):

Mikhail Trought ◽

Isobel Wentworth ◽

Timothy Leftwich ◽

Kathryn Perrine

Keyword(s):

Surface Functionalization ◽

Functional Group ◽

Pyrolytic Graphite ◽

Surface Oxidation ◽

Chemical Oxidation ◽

Synthesis Methods ◽

Acid Solutions ◽

Highly Oriented Pyrolytic Graphite ◽

Wet Chemical ◽

Surface Morphologies

The knowledge of chemical functionalization for area selective deposition (ASD) is crucial for designing the next generation heterogeneous catalysis. Surface functionalization by oxidation was studied on the surface of highly oriented pyrolytic graphite (HOPG). The HOPG surface was exposed to with various concentrations of two different acids (HCl and HNO3). We show that exposure of the HOPG surface to the acid solutions produce primarily the same -OH functional group and also significant differences the surface topography. Mechanisms are suggested to explain these strikingly different surface morphologies after surface oxidation. This knowledge can be used to for ASD synthesis methods for future graphene-based technologies.

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Catalytic Synthesis of Cyclic Guanidines via Hydrogen Atom Transfer and Radical-Polar Crossover

10.26434/chemrxiv.13318421.v1 ◽

2020 ◽

Author(s):

Shunya Ohuchi ◽

Hiroki Koyama ◽

Hiroki Shigehisa

Keyword(s):

Hydrogen Atom ◽

Functional Group ◽

Hydrogen Atom Transfer ◽

Catalytic Synthesis ◽

Membered Ring ◽

Biologically Active ◽

Atom Transfer ◽

Powerful Method ◽

Protective Groups ◽

The Common

A catalytic synthesis of cyclic guanidines, which are found in many biologically active compounds and natu-ral products, was developed, wherein transition-metal hydrogen atom transfer and radical-polar crossover were employed. This mild and functional-group tolerant process enabled the cyclization of alkenyl guanidines bearing common protective groups, such as Cbz and Boc. This powerful method not only provided the common 5- and 6-membered rings but also an unusual 7-membered ring. The derivatization of the products afforded various heterocycles. We also investigated the se-lective cyclization of mono-protected or hetero-protected (TFA and Boc) alkenyl guanidines and their further derivatiza-tions.

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Design, 22-step synthesis, and evaluation of highly potent D-ring modified and linker-equipped analogs of spongistatin 1

10.26434/chemrxiv.5773830.v1 ◽

2018 ◽

Author(s):

James Leighton ◽

Linda M. Suen ◽

Makeda A. Tekle-Smith ◽

Kevin S. Williamson ◽

Joshua R. Infantine ◽

...

Keyword(s):

Targeted Delivery ◽

Functional Group ◽

Human Cancer ◽

Natural Sources ◽

Spongistatin 1 ◽

Human Cancer Cell Lines ◽

Drug Conjugates ◽

Attractive Candidate ◽

Complex Fragment ◽

Antibody Drug

With an average GI50 value against the NCI panel of 60 human cancer cell lines of 0.12 nM, spongistatin 1 is among the most potent anti-proliferative agents ever discovered rendering it an attractive candidate for development as a payload for antibody-drug conjugates and other targeted delivery approaches. It is unavailable from natural sources and its size and complex stereostructure render chemical synthesis highly time- and resource-intensive, however, and its development requires more efficient and step-economical synthetic access. Using novel and uniquely enabling direct complex fragment coupling alkallyl- and crotylsilylation reactions, we have developed a 22-step synthesis of a rationally designed D-ring modified analog of spongistatin 1 that is equipotent with the natural product, and have used that synthesis to establish that the C(15) acetate may be replaced with a linker functional group-bearing ester with only minimal reductions in potency.<br><div><br></div>

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Fabrication of Conductive Textile via Chemical Oxidative Polymerization of Aniline on Polyester Cloth

10.26434/chemrxiv.6154757.v1 ◽

2018 ◽

Author(s):

alireza razaghi

Keyword(s):

Acidic Solution ◽

Oxidative Polymerization ◽

Morphological Structure ◽

Infrared Spectrometry ◽

Aniline Monomer ◽

Polyester Textile ◽

Conductive Polyaniline ◽

Conductive Textile ◽

Polymerization Conditions ◽

Aniline Polymerization

In this research aniline polymerization conditions were optimized in presence of pre-treated polyester textile to achieve as high electrical conductivity as 100 S/Cm. Alkaline activation of the polyester textile was followed by immersion in to aqueous acidic solution of aniline monomer. Then the oxidant solution was used to initiate the polymerization. Finally, the prepared product was washed and dried prior to ant test. Functional groups were studied by Fourie-transformed infrared spectrometry (FTIR) from the surface of the polyaniline coated textile. Also, morphological structure of synthesized conductive polyaniline was studied by scanning electron microscopy (SEM). The synthesized cloth was used in a closed circuit in order to light up alight emitting diode to emphasis the conductivity of the textile and fibres that synthesised by this method.

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Fabrication of Conductive Textile via Chemical Oxidative Polymerization of Aniline on Polyester Cloth

10.26434/chemrxiv.6154757 ◽

2018 ◽

Author(s):

alireza razaghi

Keyword(s):

Acidic Solution ◽

Oxidative Polymerization ◽

Morphological Structure ◽

Infrared Spectrometry ◽

Aniline Monomer ◽

Polyester Textile ◽

Conductive Polyaniline ◽

Conductive Textile ◽

Polymerization Conditions ◽

Aniline Polymerization

In this research aniline polymerization conditions were optimized in presence of pre-treated polyester textile to achieve as high electrical conductivity as 100 S/Cm. Alkaline activation of the polyester textile was followed by immersion in to aqueous acidic solution of aniline monomer. Then the oxidant solution was used to initiate the polymerization. Finally, the prepared product was washed and dried prior to ant test. Functional groups were studied by Fourie-transformed infrared spectrometry (FTIR) from the surface of the polyaniline coated textile. Also, morphological structure of synthesized conductive polyaniline was studied by scanning electron microscopy (SEM). The synthesized cloth was used in a closed circuit in order to light up alight emitting diode to emphasis the conductivity of the textile and fibres that synthesised by this method.

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Catalytic Enantioselective Benzylation Directly from Aryl Acetic Acids

10.26434/chemrxiv.7119887.v1 ◽

2018 ◽

Author(s):

Patrick Moon ◽

Zhongyu Wie ◽

Rylan Lundgren

Keyword(s):

Functional Group ◽

Terminal Event ◽

Radical Intermediates ◽

Carbon Carbon Bond ◽

Or Groups ◽

Reaction Proceeds ◽

Wide Availability ◽

Metal Catalyzed ◽

The Stability ◽

Acetic Acids

The stability and wide availability of carboxylic acids make them valuable reagents in chemical synthesis. Most transition metal catalyzed processes using carboxylic acid substrates are initiated by a decarboxylation event that generates reactive carbanion or radical intermediates. Developing enantioselective methodologies relying on these principles can be challenging, as highly reactive species tend to react indiscriminately without selectivity. Furthermore, anionic or radical intermediates generated from decarboxylation can be incompatible with protic and electrophilic functionality, or groups that undergo trapping with radicals. We demonstrate that metal-catalyzed enantioselective benzylation reactions of allylic electrophiles can occur directly from aryl acetic acids. The reaction proceeds via a pathway in which decarboxylation is the terminal event, occurring after stereoselective carbon–carbon bond formation. The mechanistic features of the process enable enantioselective benzylation without the generation of a highly basic nucleophile. Thus, the process has broad functional group compatibility that would not be possible employing established protocols.<br>

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