Oxidative Cross-dehydrogenative Coupling Research Articles

CuII Complex of a 1,10‐Phenanthroline‐Based Pincer as an Efficient Catalyst for Oxidative Cross Dehydrogenative Coupling of Carboxylic Acids with Unactivated Alkanes

AbstractSynthesis of a well‐defined CuII complex 1 featuring a phenanthroline‐based tridentate scaffold, 2‐pyrazol‐(1,10‐phenanthroline) (L) and studies of its catalytic activity in the cross dehydrogenative coupling of acids with common alkanes to form allylic esters are reported. The complex 1 showed excellent catalytic activity in the oxidative cross dehydrogenative coupling of a wide variety of alkanes with acids to form the corresponding allylic esters in moderate to high yields. Several control experiments along with spectroscopic studies were carried out to characterize catalyst 1 and to explore the plausible mechanistic pathways.

N-Bromosuccinimide-Induced C-H Bond Functionalization: AnIntramolecular Cycloaromatization of Electron Withdrawing Group Substituted 1-Biphenyl-2-ylethanone for the Synthesis of 10-Phenanthrenol.

An NBS-induced intramolecular cycloaromatization for the synthesis of 10-phenanthrenols from electron-withdrawing group substituted 1-biphenyl-2-ylethanones is described. The in situ generated bromide was designed to act as an initiator for the radical C-H bond activation. An oxidative cross-dehydrogenative coupling reaction of a highly active C-H bond with an inert C-H bond readily occurs under mild conditions without the need for transition metals or strong oxidants.

Iodine-Catalyzed Oxidative Cross-Dehydrogenative Coupling of Quinoxalinones and Indoles: Synthesis of 3-(Indol-2-yl)quinoxalin-2-one under Mild and Ambient Conditions

A highly efficient iodine-catalyzed oxidative cross-dehydrogenative coupling reaction of quinoxalinones and indoles has been developed. Without the requirement of peroxide and acid, this reaction utilizes a catalytic amount of molecular iodine to facilitate the C–C bond formation under ambient air. This simple and easy-to-handle protocol represents an interesting synthetic alternative with a good scope and functional group compatibility.

Copper-catalyzed α-benzylation of BODIPYs via radical-triggered oxidative cross-coupling of two C-H bonds.

An oxidative cross-dehydrogenative coupling of BODIPYs with toluene and its derivatives has been developed, allowing for the facile synthesis of a broad range of structurally diverse α-benzylated BODIPYs. The method exhibits excellent chemoselectivity, affording exclusively α-benzylated BODIPYs in the presence of t-BuOOH and a catalytic amount of Cu(OAc)2. The direct use of readily available toluene and its derivatives as coupling partners avoids unproductive steps for preactivating the functional group installation, and is therefore attractive. Most of the resulting dyes are highly emissive in the solid state due to the introduction of bulky benzyl groups onto the BODIPY core.

Iron(ii)-catalyzed C-2 cyanomethylation of indoles and pyrroles via direct oxidative cross-dehydrogenative coupling with acetonitrile derivatives

A novel and efficient approach for the C(sp2)–H/C(sp3)–H oxidative coupling of indoles and pyrroles with acetonitrile derivatives was reported by using the Fe(ii) complex.

TBHP/n-Bu4PBr-Promoted Oxidative Cross-Dehydrogenative Coupling of Aryl Methanols: A Facile Synthesis of Symmetrical Carboxylic Anhydride Derivatives

A transition-metal-free oxidative cross-dehydrogenative coupling reaction has been developed for the preparation of symmetrical carboxylic anhydrides through self-coupling dual C–O bond formations of aryl methanols. In the presence of a catalytic amount of tetrabutylphosphonium bromide (TBPB) as transfer agent and aqueous tert-butyl hydroperoxide (TBHP) as oxidant and reactant, methylene groups of aryl methanols were efficiently oxidized to C=O and coupled with the peroxide oxygen from TBHP to form a diverse array of symmetrical carboxylic anhydride derivatives.

Cobalt-Catalyzed Cross-Dehydrogenative Coupling Reaction between Unactivated C(sp2)-H and C(sp3)-H Bonds.

Catalytic oxidative cross-dehydrogenative coupling between unactivated C(sp2)-H and C(sp3)-H bonds is achieved by the cobalt-catalyzed o-alkylation reaction of aromatic carboxamides containing (pyridin-2-yl)isopropyl amine (PIP-NH2) as a N,N-bidentate directing group. Many different C(sp3)-H bonds in alkanes, toluene derivatives and even in the α-position of ethers and thioethers can be used as coupling partners. This method has a broad substrate scope and the tolerance of various functional groups.

Unified Synthesis of 1,2-Oxy-aminoarenes via a Bio-inspired Phenol-Amine Coupling

Summary 1,2-Aminophenols and their related nitrogen-containing heterocycles are ubiquitous in medicine, agriculture, and materials science. Here, we describe a bio-inspired and unified approach for their synthesis through a direct, catalytic aerobic coupling of phenols and amines. Key to the formation of the aromatic C–N bond is a facile condensation between the amine and an ortho -quinone, which triggers redox isomerization to an ortho -iminophenol before a series of downstream events. We discuss the factors that govern regioselectivity during aerobic ortho -oxygenation of the phenol and condensation of the amine, and we demonstrate synthetic utility by preparing a structurally diverse family of immunosuppressive heterocycles and the indole alkaloid cephalandole A. Our conditions involve a wide range of simple, un-activated substrates, occur at room temperature with an earth-abundant copper-catalyst and a commercially available diamine ligand, and produce water as the only stoichiometric by-product.

Cs2 CO3 -Catalyzed Aerobic Oxidative Cross-Dehydrogenative Coupling of Thiols with Phosphonates and Arenes.

An efficient Cs2 CO3 -catalyzed oxidative coupling of thiols with phosphonates and arenes that uses molecular oxygen as the oxidant is described. These reactions provide not only a novel alkali metal salt catalyzed aerobic oxidation, but also an efficient approach to thiophosphates and sulfenylarenes, which are ubiquitously found in pharmaceuticals and pesticides. The reaction proceeds under simple and mild reaction conditions, tolerates a wide range of functional groups, and is applicable to the late-stage synthesis and modification of bioactive molecules.

Direct vinylogous oxidative cross-dehydrogenative coupling of 4-nitroisoxazoles with N-aryl tetrahydroisoquinolines in water under air conditions

Using water as the solvent and air as the oxidant, a direct catalytic vinylogous cross-dehydrogenative coupling reaction was developed.

Electrochemically Oxidative α-C-H Functionalization of Ketones: A Cascade Synthesis of α-Amino Ketones Mediated by NH4I.

An efficient electrochemical protocol for the synthesis of α-amino ketones via the oxidative cross-dehydrogenative coupling of ketones and secondary amines has been developed. The electrochemistry performs in a simple undivided cell using NH4I as a redox catalyst and a cheap graphite plate as electrodes under constant current conditions. Gram-scale reaction demonstrates the practicality of the protocol. The reaction is proposed to procced through an initial α-iodination of ketone, followed by a nucleophilic substitution of amines.

ChemInform Abstract: A Metal‐Free Oxidative Cross‐Dehydrogenative Coupling of N‐Aryl Tetrahydroisoquinolines and 2‐Methylazaarenes Using a Recyclable Oxoammonium Salt as Oxidant in Aqueous Media.

ChemInformVolume 47, Issue 48 Preparative Organic Chemistry ChemInform Abstract: A Metal-Free Oxidative Cross-Dehydrogenative Coupling of N-Aryl Tetrahydroisoquinolines and 2-Methylazaarenes Using a Recyclable Oxoammonium Salt as Oxidant in Aqueous Media. Li Fang, Li Fang Key Lab. Green Pharm. Technol., Zhejiang Univ. Technol., Hangzhou 310014, Peop. Rep. ChinaSearch for more papers by this authorZhenhua Li, Zhenhua Li Key Lab. Green Pharm. Technol., Zhejiang Univ. Technol., Hangzhou 310014, Peop. Rep. ChinaSearch for more papers by this authorZhijiang Jiang, Zhijiang Jiang Key Lab. Green Pharm. Technol., Zhejiang Univ. Technol., Hangzhou 310014, Peop. Rep. ChinaSearch for more papers by this authorZhiyong Tan, Zhiyong Tan Key Lab. Green Pharm. Technol., Zhejiang Univ. Technol., Hangzhou 310014, Peop. Rep. ChinaSearch for more papers by this authorYuanyuan Xie, Yuanyuan Xie Key Lab. Green Pharm. Technol., Zhejiang Univ. Technol., Hangzhou 310014, Peop. Rep. ChinaSearch for more papers by this author Li Fang, Li Fang Key Lab. Green Pharm. Technol., Zhejiang Univ. Technol., Hangzhou 310014, Peop. Rep. ChinaSearch for more papers by this authorZhenhua Li, Zhenhua Li Key Lab. Green Pharm. Technol., Zhejiang Univ. Technol., Hangzhou 310014, Peop. Rep. ChinaSearch for more papers by this authorZhijiang Jiang, Zhijiang Jiang Key Lab. Green Pharm. Technol., Zhejiang Univ. Technol., Hangzhou 310014, Peop. Rep. ChinaSearch for more papers by this authorZhiyong Tan, Zhiyong Tan Key Lab. Green Pharm. Technol., Zhejiang Univ. Technol., Hangzhou 310014, Peop. Rep. ChinaSearch for more papers by this authorYuanyuan Xie, Yuanyuan Xie Key Lab. Green Pharm. Technol., Zhejiang Univ. Technol., Hangzhou 310014, Peop. Rep. ChinaSearch for more papers by this author First published: 10 November 2016 https://doi.org/10.1002/chin.201648052Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume47, Issue48November, 2016 RelatedInformation

Visible-Light-Promoted Direct Amination of Phenols via Oxidative Cross-Dehydrogenative Coupling Reaction.

A transition-metal-free approach was disclosed for intermolecular aryl C-N bonds formation between phenols and cyclic anilines via cross-dehydrogenative coupling (CDC) amination that was mediated by visible light, wherein K2S2O8 served as an external oxidant. The salient features of this protocol include circumventing the requirement for prefunctionalized starting materials and achieving single regioselectivity of amination adducts at room temperature.

Transition-Metal-Free Acylation of Quinolines and Isoquinolines with Arylmethanols via Oxidative Cross-Dehydrogenative Coupling Reactions

An efficient acylation of quinolines and isoquinolines is described by use of arylmethanols as the acylating agents through a C–C bond formation via an oxidative cross-dehydrogenative coupling (CDC) strategy. This C-aroylation reaction was carried out by use of K2S2O8 as oxidant and methyltrioctylammonium chloride (Aliquat 336) as a transfer agent in MeCN at 80 °C under transition-metal-free conditions.

ChemInform Abstract: An Economical Synthesis of Substituted Quinoline‐2‐Carboxylates Through the Potassium Persulfate‐Mediated Cross‐Dehydrogenative Coupling of N‐Aryl Glycine Derivatives with Olefins.

A practical and economical K2S2O8-mediated oxidative cross-dehydrogenative coupling of N-aryl glycine derivatives with olefins has been established, affording structurally diverse quinoline-2-carboxylates in good to high efficiency. The low cost, negligible toxicity, and ease of handling of K2S2O8 combined with the absence of hazardous byproducts and the easy workup consisting of simple filtration are attractive based on economic and environmental factors.

ChemInform Abstract: TBHP/TFA Mediated Oxidative Cross‐Dehydrogenative Coupling of N‐Heterocycles with Aldehydes.

An effective and metal-free oxidative cross-dehydrogenative coupling (CDC) of N-heterocycles with diverse aldehydes has been established in the presence of TBHP/TFA. The scope with respect to aldehyde and N-heterocycle components is broad, allowing facile synthesis of a broad range of structurally diverse C1-acyl substituted heterocycles in good efficiency.

An economical synthesis of substituted quinoline-2-carboxylates through the potassium persulfate-mediated cross-dehydrogenative coupling of N-aryl glycine derivatives with olefins.

A practical and economical K2S2O8-mediated oxidative cross-dehydrogenative coupling of N-aryl glycine derivatives with olefins has been established, affording structurally diverse quinoline-2-carboxylates in good to high efficiency. The low cost, negligible toxicity, and ease of handling of K2S2O8 combined with the absence of hazardous byproducts and the easy workup consisting of simple filtration are attractive based on economic and environmental factors.

Transition metal-free cross-dehydrogenative coupling acylation of coumarins by the K2S2O8/Aliquat 336 catalytic system: a versatile strategy towards 4-aroylcoumarin derivatives

A new and efficient transition metal-free oxidative cross-dehydrogenative coupling (CDC) reaction is described for the preparation of 4-aroylcoumarin derivatives.

Benzylation of heterocyclic N-oxides via direct oxidative cross-dehydrogenative coupling with toluene derivatives

A novel cross-dehydrogenative coupling (CDC) of heterocyclic N-oxides with toluene derivatives has been disclosed.

Oxidative Cross-Dehydrogenative Coupling of N-Heterocycles with Aldehydes

Oxidative Cross-Dehydrogenative Coupling of N-Heterocycles with Aldehydes