scholarly journals Directed Markovnikov Hydroarylation and Hydroalkenylation of Alkenes Under Nickel Catalysis

2021 ◽  
Author(s):  
Zi-Qi Li ◽  
Omar Apolinar ◽  
Ruohan Deng ◽  
Keary Engle
Keyword(s):  
Functional Groups ◽  
Product Yield ◽  
Computational Studies ◽  
Nickel Catalysis ◽  
Reaction Conditions ◽  
Full Account ◽  
Coordination Properties ◽  
Mild Conditions ◽  
Limiting Step ◽  
Shed Light

We report a full account of our research on nickel-catalyzed Markovnikov-selective hydroarylation and hydroalkenylation of non-conjugated alkenes, which has yielded a toolkit of methods that proceed under mild conditions with alkenyl sulfonamide, ketone, and amide substrates. Regioselectivity is controlled through catalyst coordination to the native Lewis basic functional groups contained within these substrates. To maximize product yield, reaction conditions were fine-tuned for each substrate class, reflecting the different coordination properties of the directing functionality. Detailed kinetic and computational studies shed light on the mechanism of this family of transformations, pointing to transmetalation as the turnover-limiting step.

scholarly journals Directed Markovnikov Hydroarylation and Hydroalkenylation of Alkenes Under Nickel Catalysis

2021 ◽  
Author(s):  
Zi-Qi Li ◽  
Omar Apolinar ◽  
Ruohan Deng ◽  
Keary Engle
Keyword(s):  
Functional Groups ◽  
Product Yield ◽  
Computational Studies ◽  
Nickel Catalysis ◽  
Reaction Conditions ◽  
Full Account ◽  
Coordination Properties ◽  
Mild Conditions ◽  
Limiting Step ◽  
Shed Light

We report a full account of our research on nickel-catalyzed Markovnikov-selective hydroarylation and hydroalkenylation of non-conjugated alkenes, which has yielded a toolkit of methods that proceed under mild conditions with alkenyl sulfonamide, ketone, and amide substrates. Regioselectivity is controlled through catalyst coordination to the native Lewis basic functional groups contained within these substrates. To maximize product yield, reaction conditions were fine-tuned for each substrate class, reflecting the different coordination properties of the directing functionality. Detailed kinetic and computational studies shed light on the mechanism of this family of transformations, pointing to transmetalation as the turnover-limiting step.

Borates as a Traceless Activation Group for Intermolecular Alkylarylation of Ethylene through Photoredox/Nickel Dual Catalysis

Synlett ◽  
2020 ◽  
Author(s):  
Shengqing Zhu ◽  
Lingling Chu ◽  
Xiaoliang Feng ◽  
Lei Guo
Keyword(s):  
Functional Groups ◽  
Aryl Halides ◽  
Nickel Catalysis ◽  
Mild Conditions ◽  
Dual Catalysis

AbstractA formal ethylene alkylarylation reaction with aryl halides and alkyl oxalates enabled by synergistic photoredox/nickel catalysis is reported. This protocol takes advantage of borates as a traceless activation group, achieving the formal ethylene difunctionalized products via a catalytic three-component 1,2-alkylarylation of vinyl borate followed by a base-assisted deborylation process. The mild conditions allow for excellent functional groups compatibility and broad substrate scope.

scholarly journals Directed Markovnikov Hydroarylation and Hydroalkenylation of Alkenes Under Nickel Catalysis

2021 ◽  
Author(s):  
Zi-Qi Li ◽  
Omar Apolinar ◽  
Ruohan Deng ◽  
Keary M. Engle
Keyword(s):  
Nickel Catalysis ◽  
Full Account ◽  
Mild Conditions

We report a full account of our research on nickel-catalyzed Markovnikov-selective hydroarylation and hydroalkenylation of non-conjugated alkenes, which has yielded a toolkit of methods that proceed under mild conditions with...

A clean and simple method for deprotection of phosphines from borane complexes

2018 ◽  
Vol 90 (1) ◽  
pp. 49-62 ◽  
Author(s):  
Oleg M. Demchuk ◽  
Radomir Jasinski ◽  
Dorota Strzelecka ◽  
Kamil Dziuba ◽  
Karolina Kula ◽  
...  
Keyword(s):  
Functional Groups ◽  
Phosphorus Atom ◽  
Kinetic Data ◽  
Reaction Conditions ◽  
Simple Method ◽  
Mild Conditions ◽  
Excellent Yield ◽  
Tertiary Phosphines ◽  
Quantumchemical Calculations ◽  
First Time

AbstractSimple, efficient, clean, and stereospecific protocols of protection of phosphorus atom with borane and deprotection from the borane complexes of the tertiary phosphines in mild conditions are reported. The proposed protection/deprotection reactions tolerate a range of functional groups and lead to pure products with excellent yield with no need for application of chromatographic or crystallisation purification procedures. For the first time mechanisms of the reactions of phosphine protection and deprotection have been studied based on experimental kinetic data as well as quantumchemical calculations, which allows designing reaction conditions suitable for a given substrate.

Radical Capture at Ni(II) Complexes: C-C, C-N, and C-O Bond Formation

2019 ◽  
Author(s):  
Abolghasem (Gus) Bakhoda ◽  
Stefan Wiese ◽  
Christine Greene ◽  
Bryan C. Figula ◽  
Jeffery A. Bertke ◽  
...  
Keyword(s):  
Functional Groups ◽  
Bond Formation ◽  
Dft Studies ◽  
Bond Forming ◽  
Aryl Amines ◽  
Shed Light ◽  
Competing Pathways

<p>The dinuclear b-diketiminato Ni<sup>II</sup><i>tert</i>-butoxide {[Me<sub>3</sub>NN]Ni}<sub>2</sub>(<i>μ</i>-O<i><sup>t</sup></i>Bu)<sub>2 </sub>(<b>2</b>), synthesized from [Me<sub>3</sub>NN]Ni(2,4-lutidine) (<b>1</b>) and di-<i>tert</i>-butylperoxide, is a versatile precursor for the synthesis of a series of Ni<sup>II</sup>complexes [Me<sub>3</sub>NN]Ni-FG to illustrate C-C, C-N, and C-O bond formation at Ni<sup>II </sup>via radicals. {[Me<sub>3</sub>NN]Ni}<sub>2</sub>(<i>μ</i>-O<i><sup>t</sup></i>Bu)<sub>2 </sub>reacts with nitromethane, alkyl and aryl amines, acetophenone, benzamide, ammonia and phenols to deliver corresponding mono- or dinuclear [Me<sub>3</sub>NN]Ni-FG species (FG = O<sub>2</sub>NCH<sub>2</sub>, R-NH, ArNH, PhC(O)NH, PhC(O)CH<sub>2</sub>, NH<sub>2</sub>and OAr). Many of these Ni<sup>II </sup>complexes are capable of capturing the benzylic radical PhCH(•)CH<sub>3 </sub>to deliver corresponding PhCH(FG)CH<sub>3 </sub>products featuring C-C, C-N or C-O bonds. DFT studies shed light on the mechanism of these transformations and suggest two competing pathways that depend on the nature of the functional groups. These radical capture reactions at [Ni<sup>II</sup>]-FG complexes outline key C-C, C-N, and C-O bond forming steps and suggest new families of nickel radical relay catalysts.</p>

Chemical reduction of chlorpyrifos driven by flavin mononucleotide functionalized titanium (IV) dioxide

2020 ◽  
Vol 5 (11) ◽  
Author(s):  
Stephanie Santos Díaz ◽  
Hazim Al-Zubaidi ◽  
Amir C. Ross-Obare ◽  
Sherine O. Obare
Keyword(s):  
Functional Groups ◽  
Organic Contaminants ◽  
Chemical Reduction ◽  
Flavin Mononucleotide ◽  
Reaction Conditions ◽  
Organophosphate Compounds ◽  
Biological Molecule ◽  
Highly Active ◽  
New Directions ◽  
Detrimental Impact

AbstractFor many decades, organohalide and organophosphate compounds have shown significant detrimental impact on the environment. Consequently, strategies for their remediation continue to be an area of emerging need. The reduction of the chlorpyrifos pesticide, a molecule that bears both organohalide and organophosphate functional groups, is an important area of investigation due to it toxic nature. In this report, we demonstrate the effectiveness of the biological molecule, flavin mononucleotide (FMN) toward chemically reducing chlorpyrifos. The FMN was found to be highly active when anchored to nanocrystalline TiO2 surfaces. The results show new directions toward the remediation of organic contaminants under mild reaction conditions.

Imidazole-based Cu(i)-catalyzed click polymerization of diazides and diynes under mild conditions

2021 ◽  
Author(s):  
Baixue Li ◽  
Jia Wang ◽  
Anjun Qin ◽  
Ben Zhong Tang
Keyword(s):  
Reaction Conditions ◽  
Mild Conditions ◽  
Click Polymerization

An efficient imidazole-based Cu(i)-catalyzed azide–alkyne click polymerization under mild reaction conditions was developed.

scholarly journals Continuous-Flow Processes for the Production of Floxacin Intermediates: Efficient C–C Bond Formation through a Rapid and Strong Activation of Carboxylic Acids

2020 ◽  
Vol 02 (03) ◽  
pp. e128-e132
Author(s):  
Shao-Zheng Guo ◽  
Zhi-Qun Yu ◽  
Wei-Ke Su
Keyword(s):  
Reaction Time ◽  
Continuous Flow ◽  
Flow System ◽  
Bond Formation ◽  
Product Yield ◽  
Raw Material ◽  
Material Consumption ◽  
Tank Reactor ◽  
Mild Conditions ◽  
Flow Processes

AbstractThe development of highly efficient C–C bond formation methods for the synthesis of ethyl 2-(2,4-dichloro-5-fluorobenzoyl)-3-(dimethylamino)acrylate 1 in continuous flow processes has been described, which is based on the concept of rapid and efficient activation of carboxylic acid. 2,4-Dichloro-5-fluorobenzoic acid is rapidly converted into highly reactive 2,4-dichloro-5-fluorobenzoyl chloride by treating with inexpensive and less-toxic solid bis(trichloromethyl)carbonate. And then it rapidly reacts with ethyl 3-(dimethylamino)acrylate to afford the desired 1. This process can be performed under mild conditions. Compared with the traditional tank reactor process, less raw material consumption, higher product yield, less reaction time, higher operation safety ensured by more the environmentally friendly procedure, and process continuity are achieved in the continuous-flow system.

scholarly journals Design of bifunctional quaternary phosphonium salt catalysts for CO2 fixation reaction with epoxides under mild conditions

2016 ◽  
Vol 18 (17) ◽  
pp. 4611-4615 ◽  
Author(s):  
Shiyao Liu ◽  
Naoki Suematsu ◽  
Keiji Maruoka ◽  
Seiji Shirakawa
Keyword(s):  
Co2 Fixation ◽  
Phosphonium Salt ◽  
Cyclic Carbonates ◽  
Efficient Synthesis ◽  
Reaction Conditions ◽  
Mild Conditions ◽  
Phosphonium Iodide ◽  
Fixation Reaction ◽  
Quaternary Phosphonium Salt

An efficient synthesis of cyclic carbonates from epoxides and CO2 under mild reaction conditions was achieved via the use of a designed bifunctional quaternary phosphonium iodide catalyst.

scholarly journals Conformation Study of Dual Stimuli-Responsive Core-Shell Diblock Polymer Brushes

Polymers ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1084
Author(s):  
Kaimin Chen ◽  
Lan Cao ◽  
Ying Zhang ◽  
Kai Li ◽  
Xue Qin ◽  
...  
Keyword(s):  
Polymer Brushes ◽  
Core Shell ◽  
Stimuli Responsive ◽  
Research Topics ◽  
Design And Synthesis ◽  
Mild Conditions ◽  
The Core ◽  
Responsive Polymer ◽  
Stimuli Responsive Polymer ◽  
Shed Light

Stimuli-responsive nanoparticles are among the most popular research topics. In this study, two types of core-shell (polystyrene with a photoiniferter (PSV) as the core and diblock as the shell) polymer brushes (PSV@PNIPA-b-PAA and PSV@PAA-b-PNIPA) were designed and prepared using surface-initiated photoiniferter-mediated polymerization (SI-PIMP). Moreover, their pH- and temperature-stimuli responses were explored by dynamic light scattering (DLS) and turbidimeter under various conditions. The results showed that the conformational change was determined on the basis of the competition among electrostatic repulsion, hydrophobic interaction, hydrogen bonding, and steric hindrance, which was also confirmed by protein adsorption experiments. These results are not only helpful for the design and synthesis of stimuli-responsive polymer brushes but also shed light on controlled protein immobilization under mild conditions.

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