Facile Synthesis of Azaarene-Substituted Hydroxycoumarins Possessing High Biological Activities via Three-Component C(sp(3))-H Functionalization

The molecular diversity scope of 4-hydroxycoumarin in the synthesis of heterocyclic compounds via multicomponent reactions

4-Hydroxycoumarins are some of the most versatile heterocyclic scaffolds and are frequently applied in the synthesis of various organic compounds. 4-Hydroxycoumarin-based compounds are important among heterocyclic structures due to their biological and pharmaceutical activities. In this study, we provide an overview on the recent applications of 4-hydroxycoumarin in multicomponent reactions for the synthesis of various heterocyclic compounds during the time period of 2015-2018.

Palladium-catalyzed three-component reaction for the synthesis of 3,3-disubstituted allylic alcohols with regio- and stereoselectivity

A novel three-component assembly of allenic alcohols, aryl iodides and 1,3-dicarbonyl compounds into 3,3-disubstituted allylic alcohols was promoted in the presence of a palladium source.

Organocatalytic C(sp3)-H Functionalization via Carbocation-Initiated Cascade [1,5]-Hydride Transfer/Cyclization: Synthesis of Dihydrodibenzo[b,e]azepines

Carbocation-initiated cascade [1,5]-hydride transfer/cyclization and dimerization reactions were developed to synthesize dihydrodibenzo[b,e]azepine and octahydrodipyrroloquinoline derivatives in high yields. These redox-neutral C(sp³)-H functionalization-involving cascade reactions feature transition-metal-free, high atom- and step-economy, and environmental friendliness with water as the sole byproduct.

Highly efficient one-pot tandem Friedlander annulation and chemo-selective Csp3–H functionalization under calcium catalysis

Highly efficient and regioselective Friedlander synthesis of 2-methyl-3-acyl quinolines and their chemoselective C_sp3–H functionalization is described for the first time using Ca(OTf)₂ as the sustainable catalyst under solvent free conditions with atom and step economy.

Palladium-catalyzed three-component tandem cyclization of buta-2,3-dien-1-ol, aryl iodides, and imines: an efficient protocol for the synthesis of oxazolidine derivatives

An efficient three-component tandem cyclization reaction for the synthesis of highly substituted oxazolidines was achieved through the Pd⁰-catalyzed cyclization of buta-2,3-dien-1-ol with aryl iodides and imines.

Palladium-catalyzed three-component tandem reaction of sulfonyl hydrazones, aryl iodides and allenes: highly stereoselective synthesis of (Z)-α-hydroxymethyl allylic sulfones

Sulfonyl hydrazones have been identified as an excellent sulfonyl anion surrogate in the tandem reaction with aryl iodides and allenes for the synthesis of functionalized (Z)-allylic sulfones.

Zinc-catalyzed chemoselective alkylation of α-keto amides with 2-alkylazaarenes

A zinc-catalyzed C(sp³)–H addition of 2-alkylazaarenes to α-keto amides to furnish azaarene incorporated α-hydroxy amides has been developed for the first time. Chemoselective alkylation of the keto functionality of the α-keto amides in the presence of isolated ketones is the key advantage of this Zn-catalyzed protocol.