Copper-Catalyzed Coupling of Oxime Acetates with Isothiocyanates: A Strategy for 2‑Aminothiazoles

A new strategy for 2-aminothiazoles is developed via the copper-catalyzed coupling of oxime acetates with isothiocyanates. Various 4-substituted and 4,5-disubstituted 2-aminothiazoles were formed smoothly under mild reaction conditions. This process involved copper-catalyzed N–O bond cleavage, activation of vinyl sp² C–H bonds, and C–S/C–N bond formations. It is noteworthy that the oxime acetates were used not only as a substrate but also as a single oxidant

Palladium-Catalyzed Tandem Annulation: A Strategy To Construct 2,3-Difunctionalized Benzofuran Derivatives in Ionic Liquids

An efficient and ecofriendly method for the construction of 2,3-difunctionalized benzofuran derivatives in moderate to good yields from readily available 2-alkynylphenols has been developed. This tandem annulation process, featuring one pot, three steps, good functional group tolerance, and high atom economy, makes this transformation efficient and practical. Moreover, this protocol is scalable, illustrating its potential applications in synthetic and pharmaceutical chemistry

Regioselective C–H Bond Alkynylation of Carbonyl Compounds through Ir(III) Catalysis

Selective C–H bond alkynylation toward modular access to material and pharmaceutical molecules is of great desire in modern organic synthesis. Reported herein is Ir­(III)-catalyzed regioselective C–H alkynylation of ketones and esters, which is generally applicable for the rapid construction of molecular complexity. This protocol provides a complementary process for conventional alkyne synthesis. Further functionalization of carbonyl-derived material molecules and pharmaceuticals demonstrates the potential synthetic utility of this methodology

Access to Thiazole via Copper-Catalyzed [3+1+1]-Type Condensation Reaction under Redox-Neutral Conditions

A new strategy for thiazoles via copper-catalyzed [3+1+1]-type condensation reaction from oximes, anhydrides and potassiumthiocyanate (KSCN) is developed herein. The transformation has good functional group tolerance and various thiazoles were formed smoothly in good to excellent yields under mild reaction conditions. This process involves copper-catalyzed N–O/C–S bond cleavages, activation of vinyl sp² C–H bond, and C–S/C–N bond formations which are under redox-neutral conditions as well as operational simplicity

Direct Assembly of 4‑Substituted Quinolines with Vinyl Azides as a Dual Synthon via CC and C–N Bond Cleavage

An unprecedented Zn-promoted selective cleavage of vinyl azides for the synthesis of 4-substituted quinolines is developed. In this conversion, vinyl azides function as a dual synthon via CC and C–N bond cleavage with two CC bonds and one CN bond formation in a one-step manner. The reaction is appreciated for its readily accessible substrates, high step economy, mild conditions, and use of air as the sole oxidant

Copper-Catalyzed Cyanation of <i>N</i>‑Tosylhydrazones with Thiocyanate Salt as the “CN” Source

A novel protocol for the synthesis of α-aryl nitriles has been successfully achieved via a copper-catalyzed cyanation of <i>N</i>-tosylhydrazones employing thiocyanate as the source of cyanide. The features of this method include a convenient operation, readily available substrates, low-toxicity thiocyanate salts, and a broad substrate scope

In Situ Activation of Azaarenes and Terminal Alkynes to Construct Bridged Polycyclic Compounds Containing Isoquinolinones

A copper-catalyzed [4+2] cyclization reaction of isoquinolines and alkynes is developed for the one-step construction of isoquinolinone derivatives with multisubstituted bridging rings. The unique feature of this three-component tandem cyclization reaction is the functionalization of the C1, N2, C3, and C4 positions of 3-haloisoquinolines via the construction of new C–N, CO, and C–C bonds. This dearomatization strategy for the synthesis of structurally complex isoquinolinone-bridged cyclic compounds offers good chemoselectivity, broad functional group compatibility, greenness, and high step economy