A copper-catalyzed three component reaction of aryl acetylene, sulfonyl azide and enaminone to form iminolactone via 6π electrocyclization

We developed a copper-catalyzed three component reaction of aryl acetylene, enaminone and sulfonyl azide to construct iminolactone via copper-catalyzed alkyne–azide cycloaddition (CuAAC), Michael addition of metalated ketenimine followed by elimination and 6π electrocyclization.

Copper(i)–Y zeolite catalyzed N-sulfonylketenimine mediated annulation of hydroxynaphthoquinones: syntheses of naphtho[2,1-b]furan-2,5-diones and benzo[de]chromene-2,6-diones

An efficient, one pot synthesis of novel naphtho[2,1-b]furan-2,5-diones and benzo[de]chromene-2,6-diones was reported using copper(i)–Y zeolite as catalyst.

Copper-catalyzed three-component cascade reaction of alkynes, sulfonyl azides and simple aldehydes/ketones

A copper-catalyzed dimethylzinc-promoted three-component cascade reaction of alkynes, sulfonyl azides, and simple aldehydes or ketones is described, which delivers polysubstituted olefins expeditiously in one pot under mild conditions.

A copper-catalyzed cascade reaction of o-bromoarylisothiocyanates with isocyanides leading to benzo[d]imidazo[5,1-b]thiazoles under ligand-free conditions

A copper-catalyzed method has been realized for the synthesis of benzo[d]imidazo[5,1-b]thiazoles via intermolecular [3 + 2] cycloaddition and intramolecular C–S bond formation.

Copper(I)-Y Zeolite-Catalyzed Regio- and Stereoselective [2 + 2 + 2] Cyclotrimerization Cascade: An Atom- and Step-Economical Synthesis of Pyrimido[1,6-a]quinoline

An elegant copper(I)-Y zeolite-catalyzed tandem process, involving ketenimine-based termolecular [2 + 2 + 2]/[NC + CC + NC] cycloaddition, using sulfonyl azide, alkyne, and quinoline, to prepare pyrimido[1,6-a]quinolines is reported. In this straightforward, highly atom- and step-economical protocol, copper(I) promotes for azide-alkyne [3 + 2] cycloaddition which is followed by ring-rearrangement/ketenimine formation/regio- and stereoselective [2 + 2 + 2] termolecular cycloaddition and dehydrogenation cascade to yield selectively the E-isomer of pyrimido[1,6-a]quinoline.

One-pot synthesis of hydrazono-sulfonamide adducts using Cu(BTC) MOF catalyst and their remarkable AIEE properties: unprecedented copper(ii)-catalyzed generation of ketenimine

One pot & simple operation; short reaction time; no column purification; very less catalyst loading; scalable.

Catalytic Isonitrile Insertions and Condensations Initiated by RNC-X Complexation

Isonitriles are delicately poised chemical entities capable of being coaxed to react as nucleophiles or electrophiles. Directing this tunable reactivity with metal and non-metal catalysts provides rapid access to a large array of complex nitrogenous structures ideally functionalized for medicinal applications. Isonitrile insertion into transition metal complexes has featured in numerous synthetic and mechanistic studies, leading to rapid deployment of isonitriles in numerous catalytic processes, including multicomponent reactions (MCR). Covering the literature from 1990-2014, the present review collates reaction types to highlight reactivity trends and allow catalyst comparison.

Cu(I)-catalyzed synthesis of dihydropyrimidin-4-ones toward the preparation of β- and β3-amino acid analogues

A copper(I)-catalyzed synthesis of substituted dihydropyrimidin-4-ones from propargyl amides via the formation of ketenimine intermediate has been successfully developed; the synthesis afforded good isolated yields (80-95%). The mild reaction conditions at room temperature allow the reaction to proceed to completion in a few hours without altering the stereochemistry. Further, by involving a variety of reactive nucleophiles, the obtained substituted dihydropyrimidin-4-ones were elegantly transformed into the corresponding β- and β(3)-amino acid analogues.

The copper(i)-catalyzed tandem reaction of o-alkynylphenyl isothiocyanates with isocyanides: a rapid synthesis of 5H-benzo[d]imidazo[5,1-b][1,3]thiazines

An efficient route to 5H-benzo[d]imidazo[5,1-b][1,3]thiazines has been developed using the copper(i)-catalyzed tandem reaction of o-alkynylphenyl isothiocyanates with isocyanides in THF with Cs₂CO₃ as base.