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The selective synthesis of N2-sulfonyl and N2-H 1,2,3-triazoles via organocatalytic annulation of enaminone/enaminoester with sulfonyl azide has been realized. The unconventional selectivity providing N2-sulfoyl 1,2,3-triazoles takes place in pure water, wherein the hydrogen bond effect between water and the intermediate resulting from enamine-azide corporation accounts for the novel reaction selectivity. On the other hand, the reactions conducted in DMSO specifically afford N2-H 1,2,3-triazoles in the absence of such hydrogen bond effect.

The perfluoroalkylsulfonylation (CF3SO2, C2F5SO2 and CHF2SO2) in the enaminone C H bonds has been developed simply via the promotion of molecular iodine by using stable and cheap sodium perfluoroalkyl sulfinates as coupling partners. The stereoselective synthesis of E-configurated α-perfluoroalkylsulfonyl enaminones has been realized via unprecedented C H bond elaboration and C C double bond configuration inversion by free radical process.

Chromone and flavone are both central backbones of natural products and clinical medicines. Synthesis of diversely functionalized chromones and flavones constitutes significant research contents of the modern synthetic science because abundant molecular libraries of such types are crucial in providing candidate compounds for the discovery of new pharmaceuticals and functional materials. The direct C H bond activation or functionalization on these heterocyclic backbones provides highly powerful tools for the rapid accesses to densely functionalized chromone and flavone derivatives. Considering the importance of the functionalized chromone and flavone compounds as well as the notable advances in the synthesis of such products by direct C H activation or functionalization, we review herein the research advances in the C H bond activation and functionalization reactions of chromone and flavones, in hope of showing the current states and promise of the research domain.

The three-component synthesis of structurally unsymmetrical pyridines with polysubstituted structure has been realized via the catalytic system consisting of CuI and KHSO4. The employment of two different enaminones is the main factor allowing the successful [3+2+1] construction of the pyridine ring based on the formation of two C C and one C N bonds.

The domino reactions between enaminones and sulfonyl hydrazines enabling novel synthesis of pyrazoline have been achieved by employing water as reaction medium and acetic acid as cheap and green additive are reported. Two new C N and one new C N bonds have been constructed during the formation of these pyrazoline scaffolds. Unlike the conventional formation of pyrazoles in the organic solvent mediated reactions of enaminones and hydrazines, the present reactions providing pyrazolines disclose new transformation pattern of enaminones by employing water as medium.

The multicomponent reactions of o -, m , or p -iodophenols, arylboronic acids, and dichloromethane (DCM) have been designed for the synthesis of various bisaryloxy methanes via one-pot procedure consists of Williamson etherification and Suzuki coupling.

The synthesis of 1,3,4-trisubstituted pyrroles has been realized via the cascade reactions of phenylacetaldehydes and primary amines. It is the first time that this annulation involving the construction of one new C–C and two new C–N bonds has been successfully conducted under metal-free conditions.

The intramolecular C–N bond forming cross coupling reactions on the enaminones has been achieved for the synthesis of imidazole[1,2-a]pyridines via copper-catalyzed C(sp2)–H amination. This protocol provides a new route for the synthesis of 2-unsubstituted imidazole[1,2-a]pyridines via easily available starting materials.

An organocatalytic cascade reaction involving the incorporation of alkyl propiolates and primary amines has been realized for the facile synthesis of 1,4-dihydropyridines (1,4-DHPs) bearing a C4 acetate fragment. This method allows rapid and atom economical generation of N -aryl, N -alkyl, and NH 1,4-DHPs with moderate to excellent yields.

The one-pot reactions of acyl chlorides, Wittig reagents, and o-iodoanilines involving a copper-catalyzed C–C coupling have been realized to provide various indoles. The reactions proceed on the basis of the in situ generation of allenes to incorporate o-iodoanilines via tandem Michael addition, C–C coupling, and tautomerization to afford indoles. This direct one-pot protocol allows the synthesis of indoles with all easily available materials.

The tunable three-component reactions of enals, electron deficient alkynes, and primary amines have been achieved for selective synthesis of 1,4- and 1,2-dihydropyridines. The selectivity has been found to be in close relation to the property of the amine component.

The first multicomponent synthesis of tetrahydropyrimidinthiones has been realized via the four-component assembly of aromatic aldehyde, enaminone, aromatic amine, and thiourea. The reaction was performed at room temperature and the products were obtained in excellent diastereoselectivity.

A Mannich-type three-component reaction involving aldehydes, acetamide, and enolizable ketones or β-keto esters for the preparation of β-acetamido carbonyl compounds in the presence of TMSCl is described. This newly developed protocol is operationally convenient, widely applicable, and highly diastereoselective.

A new three-component reaction among o-phthalaldehyde, N-alkyl/aryl substituted urea, and an aromatic aldehyde has been developed at ambient condition, and a class of isoindolinones with novel C-3 substitution were conveniently synthesized. The general diastereomeric excess as high as over 99% of the products indicated the excellent stereoselectivity posed in this multicomponent reaction.

A simple and mild synthesis of a new family of cyclopeptide analogues cyclo[-Arg-Gly-Asp-Ψ(triazole)-Gly-Xaa-] that is obtained by cyclization with click chemistry was investigated. In addition, the method was also successfully expanded to the synthesis of their analogues of different ring sizes. The result supports the potential utility of click chemistry in the preparation of novel integrin domain-binding antagonists and other cyclopeptide analogues.

Copper-catalyzed oxidative coupling reactions of terminal alkynes have been performed at room temperature by using enaminone as effective ligand. Both symmetrical and unsymmetrical 1,3-diynes bearing various functional groups have been synthesized in moderate to excellent yields via homo- and cross-coupling reactions.