[reaction: see text] The construction of multivalent neoglycoconjugates is efficiently achieved by the regiospecific catalytic cycloaddition of alkynes and azides using the organic-soluble copper complexes (Ph(3)P)(3).CuBr and (EtO)(3)P.CuI. The simultaneous use of microwave irradiation shortened notably the reaction times.

The solvothermal in situ double cycloaddition reaction of 2-cyanopyrimidine, Cu(2)O and NaN(3) with aqueous ammonia additive generated a two dimensional copper(I) coordination polymer with 5-pyrimidyl-tetrazolate, 3,5-bispyrimidyl-1,2,4-triazolate and the cyano group as the ligands. This reaction can be tuned to yield two dimensional coordination polymers solely based on tetrazolate or 1,2,4-tr...

2-Pyrrolines can be generated by the PhP(2-catechyl) mediated coupling of alkene-tethered imines and acid chlorides. This reaction proceeds via phosphorus-containing 1,3-dipoles, which undergo cycloaddition with alkenes with high stereo- and regioselectivity. The modularity of this reaction can be used to assemble a range of polysubstituted pyrrolines in one pot transformations.

The combination of two or more unsaturated structural units to form cyclic organic compounds is commonly referred to as cycloaddition, and the combination of two unsaturated structural units that forms a six-membered ring is formally either a [5 + 1]-, [4 + 2]-, [2 + 2 + 2]-, or [3 + 3]-cycloaddition. Occurring as concerted or stepwise processes, cycloaddition reactions are among the most usefu...

A click reaction (copper-catalyzed azide-alkyne cycloaddition) catalyzed by "naked" copper ions (without ligands) generated in situ from a copper substrate by laser ablation in a high-voltage assisted laser desorption/ionization (HALDI) ion source is demonstrated.

Ugi adducts derived from aromatic aldehydes may be converted to pyrrolines via addition of Michael acceptors under microwave irradiation. The reaction may proceed via unusual formation of azomethine ylides followed by a [3+2] cycloaddition using Michael acceptors.

This Communication describes a highly efficient phosphine-catalyzed [2+3]-cycloaddition reaction using alpha-trimethylsilyl-substituted aryl allenones and electron deficient olefins; both good yields and good asymmetric induction were obtained.

A series of designer lipidated pseudopeptidic triazolophanes was synthesized using a copper-catalyzed azide-alkyne cycloaddition reaction. These 32-membered cyclophanes form sturdy vesicles and pot-like supramolecular structures, as demonstrated by ultramicroscopic studies.

Reaction of a zirconium imido and a hydrazinediido complex with bis(trimethylsilyl)sulfur diimide yielded the corresponding formal [2+2] cycloaddition products, the trisimidosulfito complex and the hydrazidobis(imido)sulfito complex containing an unprecedented SN(2)(N-N) unit.

A catalytic method to synthesize the highly strained cyclobutene was developed. The reaction was believed to proceed through a formal indium-catalyzed [2+2] cycloaddition between electron-deficient enynals and various alkynes.