Catalytic Sulfone Upgrading Reaction with Alcohols via Ru(II)

2019 ◽  
Author(s):  
Tomas Vojkovsky ◽  
Shubham Deolka ◽  
Saiyyna P. Stepanova ◽  
Michael C. Roy ◽  
Eugene Khaskin
Keyword(s):  
Functional Groups ◽  
Secondary Alcohol ◽  
Value Added ◽  
Catalytic Dehydrogenation ◽  
Reaction Conditions ◽  
Stoichiometric Amount ◽  
Reaction Proceeds ◽  
One Step ◽  
Value Added Products

<a>Sulfones and sulfonamides with an α-CH bond can be easily alkylated by aliphatic alcohols to add the carbon skeleton of the alcohol via a one-step, Ru(II) catalyzed redox neutral reaction. The reaction requires a sub-stoichiometric amount of base and produces only water as a byproduct. A number of pharmaceutically relevant functional groups such as piperidine, morpholine, etc. are well tolerated under the reaction conditions to give higher value-added products in one step from widely available substrates. The reaction proceeds through a sulfone carbanion addition to an in-situ generated aldehyde formed via catalytic dehydrogenation and subsequent catalyst mediated replacement of the secondary alcohol by hydrogen.</a>

Catalytic Sulfone Upgrading Reaction with Alcohols via Ru(II)

2019 ◽  
Author(s):  
Tomas Vojkovsky ◽  
Shubham Deolka ◽  
Saiyyna P. Stepanova ◽  
Michael C. Roy ◽  
Eugene Khaskin
Keyword(s):  
Functional Groups ◽  
Secondary Alcohol ◽  
Value Added ◽  
Catalytic Dehydrogenation ◽  
Reaction Conditions ◽  
Stoichiometric Amount ◽  
Reaction Proceeds ◽  
One Step ◽  
Value Added Products

<a>Sulfones and sulfonamides with an α-CH bond can be easily alkylated by aliphatic alcohols to add the carbon skeleton of the alcohol via a one-step, Ru(II) catalyzed redox neutral reaction. The reaction requires a sub-stoichiometric amount of base and produces only water as a byproduct. A number of pharmaceutically relevant functional groups such as piperidine, morpholine, etc. are well tolerated under the reaction conditions to give higher value-added products in one step from widely available substrates. The reaction proceeds through a sulfone carbanion addition to an in-situ generated aldehyde formed via catalytic dehydrogenation and subsequent catalyst mediated replacement of the secondary alcohol by hydrogen.</a>

scholarly journals Computational and experimental investigations of one-step conversion of poly(carbonate)s into value-added poly(aryl ether sulfone)s

2016 ◽  
Vol 113 (28) ◽  
pp. 7722-7726 ◽  
Author(s):  
Gavin O. Jones ◽  
Alexander Yuen ◽  
Rudy J. Wojtecki ◽  
James L. Hedrick ◽  
Jeannette M. García
Keyword(s):  
High Performance ◽  
Density Functional ◽  
Value Added ◽  
Single Step ◽  
Nucleophilic Attack ◽  
Experimental Investigations ◽  
Aryl Ether ◽  
One Step ◽  
Poly Carbonate

It is estimated that ∼2.7 million tons poly(carbonate)s (PCs) are produced annually worldwide. In 2008, retailers pulled products from store shelves after reports of bisphenol A (BPA) leaching from baby bottles, reusable drink bottles, and other retail products. Since PCs are not typically recycled, a need for the repurposing of the PC waste has arisen. We report the one-step synthesis of poly(aryl ether sulfone)s (PSUs) from the depolymerization of PCs and in situ polycondensation with bis(aryl fluorides) in the presence of carbonate salts. PSUs are high-performance engineering thermoplastics that are commonly used for reverse osmosis and water purification membranes, medical equipment, as well as high temperature applications. PSUs generated through this cascade approach were isolated in high purity and yield with the expected thermal properties and represent a procedure for direct conversion of one class of polymer to another in a single step. Computational investigations performed with density functional theory predict that the carbonate salt plays two important catalytic roles in this reaction: it decomposes the PCs by nucleophilic attack, and in the subsequent polyether formation process, it promotes the reaction of phenolate dimers formed in situ with the aryl fluorides present. We envision repurposing poly(BPA carbonate) for the production of value-added polymers.

Benign by design. New catalysts for an environmentally conscious age

2001 ◽  
Vol 73 (7) ◽  
pp. 1087-1101 ◽  
Author(s):  
John Meurig Thomas ◽  
Robert Raja ◽  
Gopinathan Sankar ◽  
Robert G. Bell ◽  
Dewi W. Lewis
Keyword(s):  
Sustainable Development ◽  
Screening Methods ◽  
Reaction Conditions ◽  
Environmentally Conscious ◽  
Nanoparticle Catalysts ◽  
Fast Screening ◽  
Linear Alkanes ◽  
One Step ◽  
Acid Precursor

There is a pressing need for: (i) cleaner fuels (free of aromatics and of minimal sulfur content) or ones that convert chemical energy directly to electricity, silently and without production of noxious oxides and particulates; (ii) chemical, petrochemical, and pharmaceutical processes that may be conducted in a one-step, solvent-free manner, and that use air as the preferred oxidant; and (iii) industrial processes that minimize consumption of energy, production of waste or the use of corrosive, explosive, volatile and nonbiodegradable materials. All these needs and other desiderata, such as the in situ production and containment of aggressive and hazardous reagents, and the avoidance of use of ecologically harmful elements, may be achieved by designing the appropriate heterogeneous inorganic catalyst, which, ideally should be cheap, readily preparable, and fully characterizable, preferably under in situ reaction conditions. A range of nanoporous and nanoparticle catalysts, designed, synthesized, characterized, and tested by the authors and their colleagues, that meet most of the stringent demands of sustainable development and responsible (clean) technology is described. Specific examples that are highlighted include: (a) the production of adipic acid (precursor of polyamides and urethanes) without the use of concentrated nitric acid or the production of greenhouse gases such as nitrous oxide; (b) the production of caprolactam (precursor of nylon) without the use of oleum and hydroxylamine sulfate; and (c) the terminal oxyfunctionalization of linear alkanes in air. The topic of biocatalysis and sustainable development is also briefly discussed, and a cautionary note is sounded concerning fast screening methods for the discovery of new inorganic catalysts.

The AA* + B*B2 approach A simple and convenient synthetic strategy towards hyperbranched polyurea-urethanes

e-Polymers ◽  
2003 ◽  
Vol 3 (1) ◽  
Author(s):  
Bernd Bruchmann ◽  
Wolfgang Schrepp
Keyword(s):  
Functional Groups ◽  
Raw Materials ◽  
Protecting Groups ◽  
Isophorone Diisocyanate ◽  
Step Process ◽  
Synthetic Strategy ◽  
One Step

Abstract Synthesizing hyperbranched polyurethanes in a one step process using commercially available raw materials: these were the primary conditions for this work. By taking advantage of intramolecular reactivity differences of isocyanate groups in diisocyanates in combination with reactivity differences of OH and NH groups in alkanolamines, it is possible to generate in situ AB2 molecules by controlling reactions of specific functional groups towards each other. This AA* + B*B2 approach works without protecting groups and opens up a simple and versatile strategy towards hyperbranched aromatic as well as aliphatic polyureaurethanes. Preferential diisocyanates for this synthesis were 2,4-toluylene diisocyanate and isophorone diisocyanate, whereas diethanolamine and diisopropanolamine were used as isocyanate-reactive counterparts.

scholarly journals Catalytic β-Bromohydroxylation of Natural Terpenes: Useful Intermediates for the Synthesis of Terpenic Epoxides

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Saadia Oubaassine ◽  
Angela Köckritz ◽  
Reinhard Eckelt ◽  
Andreas Martin ◽  
Mustapha Ait Ali ◽  
...  
Keyword(s):  
Room Temperature ◽  
Reaction Conditions ◽  
Step Procedure ◽  
One Step

In a one-step procedure, various β-bromoalcohols were synthesized from natural terpenes in good to excellent yields. Using different catalysts, the reaction was carried out at room temperature, with H2O as nucleophile and N-bromosuccinimide as a bromine source under mild reaction conditions. The synthesized β-bromoalcohols were subsequently converted in situ to the corresponding epoxides in good yields.

A chiral Brønsted acid-catalyzed highly enantioselective Mannich-type reaction of α-diazo esters with in situ generated N-acyl ketimines

2018 ◽  
Vol 54 (28) ◽  
pp. 3516-3519 ◽  
Author(s):  
Rajshekhar A. Unhale ◽  
Milon M. Sadhu ◽  
Sumit K. Ray ◽  
Rayhan G. Biswas ◽  
Vinod K. Singh
Keyword(s):  
Phosphoric Acid ◽  
Reaction Conditions ◽  
Type Reaction ◽  
Chiral Phosphoric Acid ◽  
Brönsted Acid ◽  
Diazo Esters ◽  
Reaction Proceeds ◽  
Acid Catalyzed ◽  
Chiral Bronsted Acid

A chiral phosphoric acid-catalyzed asymmetric Mannich-type reaction of α-diazo esters with in situ generated N-acyl ketimines, derived from 3-aryl-3-hydroxyisoindolinones has been demonstrated. The reaction proceeds smoothly under mild reaction conditions.

Radical Metal-Free Borylation of Aryl Iodides

Synthesis ◽  
2017 ◽  
Vol 49 (21) ◽  
pp. 4759-4768 ◽  
Author(s):  
Sandra Pinet ◽  
Mathieu Pucheault ◽  
Virginie Liautard ◽  
Mégane Debiais
Keyword(s):  
Steric Hindrance ◽  
Radical Mechanism ◽  
Electronic Effects ◽  
Simple Metal ◽  
Reaction Conditions ◽  
Metal Free ◽  
Aryl Iodides ◽  
Reaction Proceeds ◽  
Electronic Effects Of Substituents

A simple metal-free borylation of aryl iodides mediated by a fluoride sp2–sp3 diboron adduct is described. The reaction conditions are compatible with various functional groups. Electronic effects of substituents do not affect the borylation while steric hindrance does. The reaction proceeds via a radical mechanism in which pyridine serves to stabilize the boryl radicals, generated in situ.

scholarly journals Selective Nitration of Chlorobenzene by NO2 in the Alkali Zeolite NaZSM-5

2013 ◽  
Vol 2013 ◽  
pp. 1-5
Author(s):  
Scott J. Kirkby
Keyword(s):  
Gas Phase ◽  
Room Temperature ◽  
Temperature Dependent ◽  
Reaction Conditions ◽  
Cation Site ◽  
Zeolite Lattice ◽  
Reaction Proceeds ◽  
Ft Ir ◽  
Electron Donation

Chlorobenzene was reacted with NO2, in the initially acid-free zeolite NaZSM-5, to yield para-chloronitrobenzene exclusively. The precursors were loaded sequentially into self-supporting pellets of the zeolite, contained within a stainless steel cell, from the gas phase. The reaction proceeds spontaneously at room temperature. It is, however, very temperature dependent and effectively ceases at zero degrees Celsius. The reaction was monitored in situ using FT-IR. The active nitrating agent is formed from the partial electron donation by the NO2 to the Na+ cations present in the zeolite lattice. Under the reaction conditions, chlorobenzene is not readily mobile through the pore system; thus, only the molecules adsorbed near a cation site react to form para-chloronitrobenzene.

scholarly journals One-Step Synthesis of Acylboron Compounds via Cu-Catalyzed Carbonylative Borylation of Alkyl Halides

2020 ◽  
Author(s):  
Cheng Li-Jie ◽  
Zhao Siling ◽  
Neal Mankad
Keyword(s):  
Alkyl Halides ◽  
Efficient Synthesis ◽  
Mechanistic Studies ◽  
Acyl Halide ◽  
Reaction Conditions ◽  
One Pot ◽  
One Step ◽  
High Yields ◽  
Tertiary Alkyl

A Cu-catalyzed carbonylative borylation of unactivated alkyl halides has been developed, enabling efficient synthesis of aliphatic potassium acyltrifluoroborates (KATs) in high yields by treating the in-situ formed tetracoordinated acylboron intermediates with aqueous KHF2. A variety of functional groups are tolerated under the mild reaction conditions, and primary, secondary and tertiary alkyl halides are all applicable. In addition, this method also provides facile access to N-methyliminodiacetyl (MIDA) acylboronates as well as α-methylated potassium acyltrifluoroborates in a one-pot manner. Mechanistic studies indicate a radical atom transfer carbonylation (ATC) mechanism to form acyl halide intermediates that are subsequently borylated by (NHC)CuBpin.<br>

scholarly journals Development of ‘Lignin-First’ Approaches for the Valorization of Lignocellulosic Biomass

Molecules ◽  
2020 ◽  
Vol 25 (12) ◽  
pp. 2815 ◽  
Author(s):  
Tamás I. Korányi ◽  
Bálint Fridrich ◽  
Antonio Pineda ◽  
Katalin Barta
Keyword(s):  
Lignocellulosic Biomass ◽  
Structural Modification ◽  
Complex Structure ◽  
Value Added ◽  
Original Structure ◽  
Reaction Conditions ◽  
The Past ◽  
Pulp Paper ◽  
New Strategy ◽  
Value Added Products

Currently, valorization of lignocellulosic biomass almost exclusively focuses on the production of pulp, paper, and bioethanol from its holocellulose constituent, while the remaining lignin part that comprises the highest carbon content, is burned and treated as waste. Lignin has a complex structure built up from propylphenolic subunits; therefore, its valorization to value-added products (aromatics, phenolics, biogasoline, etc.) is highly desirable. However, during the pulping processes, the original structure of native lignin changes to technical lignin. Due to this extensive structural modification, involving the cleavage of the β-O-4 moieties and the formation of recalcitrant C-C bonds, its catalytic depolymerization requires harsh reaction conditions. In order to apply mild conditions and to gain fewer and uniform products, a new strategy has emerged in the past few years, named ‘lignin-first’ or ‘reductive catalytic fractionation’ (RCF). This signifies lignin disassembly prior to carbohydrate valorization. The aim of the present work is to follow historically, year-by-year, the development of ‘lignin-first’ approach. A compact summary of reached achievements, future perspectives and remaining challenges is also given at the end of the review.

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