The research on 1,2,3-triazoles has been lively and ever-growing since its stimulation by the advent of click chemistry The attractiveness of 1H-1,2,3-triazoles and their derivatives originates from their unique combination of facile accessibility via click chemistry and truly diverse supramolecular interactions, which enabled myriads of applications in supramolecular and coordination chemistry The nitrogen-rich triazole features a highly polarized carbon atom allowing the complexation of anions by hydrogen and halogen bonding or, in the case of the triazolium salts, via charge-assisted hydrogen and halogen bonds On the other hand, the triazole offers several N-coordination modes including coordination via anionic and cationic nitrogen donors of triazolate and triazolium ions, respectively After CH-deprotonation of the triazole and the triazolium, powerful carbanionic and mesoionic carbene donors, respectively, are available The latter coordination mode even features non-innocent ligand behavior Moreover, these supramolecular interactions can be combined, eg, in ion-pair recognition, preorganization by intramolecular hydrogen bond donation and acceptance, and in bimetallic complexes Ultimately, by clicking two building blocks into place, the triazole emerges as a most versatile functional unit allowing very successful applications, eg, in anion recognition, catalysis, and photochemistry, thus going far beyond the original purpose of click chemistry It is the intention of this review to provide a detailed analysis of the various supramolecular interactions of triazoles in comparison to established functional units, which may serve as guidelines for further applications

Beyond click chemistry - supramolecular interactions of 1,2,3-triazoles.

Recent advances in catalysis in micellar media

Polynuclear halide complexes of Bi(III): From structural diversity to the new properties

Appropriately substituted 2-alkenylphenols undergo a mild formal [3C+2C] cycloaddition with alkynes when treated with a Rh(III) catalyst and an oxidant. The reaction, which involves the cleavage of the terminal C–H bond of the alkenyl moiety and the dearomatization of the phenol ring, provides a versatile and efficient approach to highly appealing spirocyclic skeletons and occurs with high selectivity.

http://pubs.acs.org/doi/pdf/10.1021/ja5034952

Rhodium(III)-catalyzed dearomatizing (3 + 2) annulation of 2-alkenylphenols and alkynes.

An organocatalytic azide–aldehyde [3+2] cycloaddition (organo-click) reaction of a variety of enolizable aldehydes is reported. The organo-click reaction is characterized by a high rate and regioselectivity, mild reaction conditions, easily available substrates with simple operation, and excellent yields with a broad spectrum of substrates. It constitutes an alternative to the previously known CuAAC, RuAAC, and IrAAC click reactions.

http://www.chtf.stuba.sk/~szolcsanyi/education/files/Chemia%20heterocyklickych%20zlucenin/Prednaska%203/Doplnkove%20studijne%20materialy/Triazoles/Regioselective%20Synthesis%20of%201,4-Disubstituted%201,2,3-Triazoles.pdf

An Organocatalytic Azide–Aldehyde [3+2] Cycloaddition: High‐Yielding Regioselective Synthesis of 1,4‐Disubstituted 1,2,3‐Triazoles

Organocatalytic 1,3-dipolar cycloaddition reactions of ketones and azides with water as a solvent

In the presence of Cu(OAc)2 the title compounds are obtained while K2S2O8 promotes the formation of furan derivatives.

Palladium‐Catalyzed [2+2+1] Oxidative Annulation of 4‐Hydroxycoumarins with Unactivated Internal Alkynes: Access to Spiro Cyclopentadiene‐Chroman‐2,4‐dione Complexes

We disclose herein an efficient enantioselective organocatalytic Michael reaction between α,β-unsaturated ketones and malonic acid half thioesters (MAHTs). The reactions are catalyzed by a primary amine to generate Michael addition products in good to excellent yields (62–87%) with high to excellent enantioselectivities (80–98%).

Tao Gao

Papers

Organocatalytic 1,3-dipolar cycloaddition reactions of ketones and azides with water as a solvent

Palladium‐Catalyzed [2+2+1] Oxidative Annulation of 4‐Hydroxycoumarins with Unactivated Internal Alkynes: Access to Spiro Cyclopentadiene‐Chroman‐2,4‐dione Complexes

A highly enantioselective Michael reaction between α,β-unsaturated ketones and malonic acid half-thioesters

General and Direct Synthesis of Indolizine-1-carbaldehydes by 1,3-Dipolar Cycloaddition of Phenylpropiolaldehyde with Pyridinium Ylides

Highly regioselective dipolar cycloadditions of nitrile oxides with α,β-acetylenic aldehydes