A general metal free approach to α-ketoamides via oxidative amidation–diketonization of terminal alkynes

A metal free catalytic system employing TMSOTf/I₂/DMSO for the oxidative amidation–diketonization of terminal alkynes, in order to produce a wide variety of α-ketoamides, has been developed.

Metal-free in situ sp3, sp2, and sp C–H functionalization and oxidative cross coupling with benzamidines hydrochloride: a promising approach for the synthesis of α-ketoimides

A new metal-free tandem protocol for the synthesis of α-ketoimides via sp³, sp², and sp C–H functionalization followed by oxidative cross coupling with benzamidines hydrochloride using catalytic iodine with TBHP in DMSO has been developed.

The syntheses of α-ketoamides vianBu4NI-catalyzed multiple sp3C–H bond oxidation of ethylarenes and sequential coupling with dialkylformamides

The ⁿBu₄NI-catalyzed sequential C–O and C–N bond formation via multiple sp³C–H bond activation of ethylarenes, using N,N-dialkylformamide as the amino source, provided α-ketoamides with moderate yields.

Copper-catalyzed aerobic oxidative C-H and C-C functionalization of 1-[2-(arylamino)aryl]ethanones leading to acridone derivatives

Efficient copper-catalyzed aerobic oxidative C-H and C-C functionalization of 1-[2-(arylamino)aryl]ethanones leading to acridones has been developed. The procedure involves cleavage of aromatic C-H and acetyl C-C bonds with intramolecular formation of a diarylketone bond. The protocol uses inexpensive Cu(O2CCF3)2 as catalyst, pyridine as additive, and economical and environmentally friendly oxygen as the oxidant, and the corresponding acridones with various functional groups were obtained in moderate to good yields.

CuI/BF3·Et2O cocatalyzed aerobic dehydrogenative reactions of ketones with benzylamines: facile synthesis of substituted imidazoles

A novel CuI/BF(3)·Et(2)O/O(2)-mediated reaction utilizing ketones and benzylamines for the construction of substituted imidazoles in one step under mild conditions has been demonstrated. This protocol involved the removal of eight hydrogen atoms, the functionalization of four C(sp(3))-H bonds and three new C-N bond formations.

Amidation of aldehydes and alcohols through α-iminonitriles and a sequential oxidative three-component Strecker reaction/thio-Michael addition/alumina-promoted hydrolysis process to access β-mercaptoamides from aldehydes, amines, and thiols

Mild and general alumina-promoted hydrolysis conditions for converting α-iminonitriles into carboxamides have been developed. In combination with the oxidative three-component Strecker reaction, the one-pot direct amidation of aldehydes and alcohols is reported. Subsequently, an Yb(OTf)(3)-catalyzed Michael addition of thiols to α,β-unsaturated α-iminonitriles is reported for the synthesis of β-mercapto-α-iminonitriles. The successful integration of an oxidative Strecker reaction, thio-Michael addition, and neutral-alumina-promoted hydrolysis of β-mercapto-α-iminonitriles into a three-component one-pot process allowed us to develop the direct conversion of amines, aldehydes, and thiols into β-mercaptoamides. All of these procedures were applicable to aromatic and aliphatic amines and aldehydes.

Copper-catalyzed oxidative cyclization of enynes for the synthesis of 4-carbonyl-quinolines with O2

A novel copper-catalyzed oxidative cyclization of enynes and in situ formed enynes leading to 4-carbonyl-quinolines by using dioxygen as an oxygen source has been developed.

Recent advances in copper-catalyzed dehydrogenative functionalization via a single electron transfer (SET) process

Copper salts have been developed as versatile catalysts for oxidative coupling reactions in organic synthesis. During these processes, Cu-catalysts are often proposed to serve as a one-electron oxidant to promote the single-electron transfer process. Recently, the transition-metal catalyzed direct dehydrogenative transformation has attracted considerable attention. This tutorial review summarizes the recent advances in the copper-catalyzed dehydrogenative functionalization via a single electron transfer (SET) process achieving C-C, C-N, C-O, C-halogen atoms, C-P, and N-N bond formation.