Cooperative Catalytic System Research Articles

ChemInform Abstract: Iron Powder‐CuI Cooperative Catalytic System in Sonogashira Cross‐Coupling Reaction.

AbstractA cheaper cooperative catalytic system in Sonogashira cross‐coupling reactions of aryl‐, vinyl‐, alkyl‐substituted terminal alkynes with aryl iodides is presented.

Cooperative Copper(I) and Primary Amine Catalyzed Room‐Temperature Carbocyclization of Formyl Alkynes

AbstractAn efficient CuI/amine catalytic system is described for the carbocyclization of α‐disubstituted formylalkynes at room temperature. Merging aminocatalysis to the copper(I)‐catalyzed activation of alkynes led to clean carbocyclization of a wide range of functionalized substrates under mild conditions. This novel cooperative catalytic system allowed the formation of a variety of carbo‐ and heterocycles, including pyrrolidines, in good to excellent yields. Mechanistic aspects of this process are also discussed.

Iron Powder-CuI Cooperative Catalytic System in Sonogashira Cross-Coupling Reaction

Furthermore, besidessuch palladium based systems, several catalytic systemswhich are inexpensive and benign to the environment havebeen developed for both an academic viewpoint and a largescale industrial application. For example, many copper saltscombined with appropriate ligands have been used as analternative to palladium based systems for Sonogashiracross-coupling reaction.

NHC/Iron cooperative catalysis: aerobic oxidative esterification of aldehydes with phenols

An NHC/iron cooperative catalytic system mediates the aerobic oxidative esterification of aldehydes with phenols. The use of equimolar amounts of reactants led to good to excellent isolated yields of esters.

InCl3/CyNH2Cocatalyzed Carbocyclization Reaction: An Entry to α-Disubstitutedexo-Methylene Cyclopentanes

An efficient and cheap synthetic approach to functionalized exo-methylene cyclopentanes has been developed from α-disubstituted formyl-alkynes by merging amine catalysis with the indium activation of alkynes. We uncovered the crucial role of the amine cocatalyst and the development of a new cooperative catalytic system allowed the cyclization of a broad range of substrates. A mechanistic study was realized in order to rationalize the determining influence of the amine cocatalyst.

Cooperative Catalysis with Metal and Secondary Amine: Synthesis of 2-Substituted Quinolines via Addition/Cycloisomerization Cascade

A cooperative catalytic system, consisting of CuI and pyrrolidine, has been developed for an efficient synthesis of 2-substituted quinolines. A combination of both the catalysts is necessary; the use of either catalyst alone does not give the product.

Chiral Brønsted Acid Directed Iron‐Catalyzed Enantioselective Friedel–Crafts Alkylation of Indoles with β‐Aryl α′‐Hydroxy Enones

A cooperative catalytic system established by the combination of an iron salt and a chiral Brønsted acid has proven to be effective in the asymmetric Friedel-Crafts alkylation of indoles with beta-aryl alpha'-hydroxy enones. Good to excellent yields and enatioselectivities were observed for a variety of alpha'-hydroxy enones and indoles, particularly for the beta-aryl alpha'-hydroxy enones bearing an electron-withdrawing group at the para position of the phenyl ring (up to 90 % yield and 91 % ee). The proton of the chiral Brønsted acid, the Lewis acid activation site, as well as the inherent basic site for the hydrogen-bonding interaction of the Brønsted acid are responsible for the high catalytic activities and enantioselectivities of the title reaction. A possible reaction mechanism was proposed. The key catalytic species in the catalytic system, the phosphate salt of Fe(III), which was thought to be responsible for the high activity and good enantioselectivity, was then confirmed by ESIMS studies.

Direct Catalytic Asymmetric Aldol Reactions of Thioamides: Toward a Stereocontrolled Synthesis of 1,3-Polyols

A direct catalytic asymmetric aldol reaction of thioamides with a soft Lewis acid/hard Brønsted base cooperative catalytic system comprising (R,R)-Ph-BPE/[Cu(CH(3)CN)(4)]PF(6)/LiOAr is described. Highly chemoselective deprotonative activation of thioamides allows for a direct aldol reaction of alpha-nonbranched aliphatic aldehydes, which are susceptible to self-condensation. Facile reduction of the thioamide functionality and a catalyst-controlled second aldol reaction provides 1,3-diols in a highly stereoselective manner.

ChemInform Abstract: Facile and Selective Synthesis of Propargylic Amines and 1,6‐Diynes: One‐Pot Three‐Component Coupling Reactions of Alkynylsilanes, Aldehydes and Amines by a Cooperative Catalytic System Comprised of CuCl and Cu(OTf)2.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform Abstract: Facile and Efficient Synthesis of Polyfunctionalized Benzofurans: Three‐Component Coupling Reactions from an Alkynylsilane, an o‐Hydroxybenzaldehyde Derivative, and a Secondary Amine by a Cu(I)—Cu(II) Cooperative Catalytic System.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Facile and Selective Synthesis of Propargylic Amines and 1,6-Diynes: One-Pot Three-Component Coupling Reactions of Alkynylsilanes, Aldehydes and Amines by a Cooperative Catalytic System Comprised of CuCl and Cu(OTf)2

Described herein is a three-component coupling reaction of alkynylsilanes, aldehydes and amines by a cooperative catalytic system comprised of CuCl and Cu(OTf) 2 , leading to the production of a variety of propargyl amine derivatives. This catalytic system was successfully applied to the practical preparation of 1,6-diyne derivatives via twice-performed, domino-type coupling reactions.

Facile and efficient synthesis of polyfunctionalized benzofurans: three-component coupling reactions from an alkynylsilane, an o-hydroxybenzaldehyde derivative, and a secondary amine by a Cu(I)–Cu(II) cooperative catalytic system

The combination of 5 mol % Cu(OTf) 2 and CuCl in the presence of DMAP effectively catalyzed a three-component coupling reaction involving an alkynylsilane, an o-hydroxybenzaldehyde derivative, and a secondary amine. The reaction proceeded via intramolecular 5- exo- dig cyclization, resulting in direct synthesis of the corresponding benzofuran derivatives in moderate to excellent yields.

Cooperative Catalysis by General Acid and Base Bifunctionalized Mesoporous Silica Nanospheres

A team effort: Mesoporous silica nanosphere (MSN) materials bifunctionalized with a general acid group and a base group in various relative concentrations are described and shown to function as cooperative catalytic systems. The turnover numbers observed indicate that the acid groups can activate substrates in cooperation with the base groups to catalyze reactions that involve carbonyl activation (see picture).