7-Aryl-1,3,5-cycloheptatrienes react intermolecularly with methylenecyclopropanes in a triple gold(I)-catalyzed reaction to form cyclopentenes. The same formal (4+1) cycloaddition occurs with cyclobutenes. Other precursors of gold(I) carbenes can also be used as the C1 component of the cycloaddition.

Nickel(0) catalyzed [4+2] cycloaddition of electron-deficient dienes to alkynes and subsequent aromatization gave highly substituted arenes. This formal inverse electron-demand Diels-Alder cycloaddition is attributed to the formation of a seven-membered nickelacycle from a diene and an alkyne.

Total synthesis of ceratopicanol (1) was achieved with a tandem cycloaddition reaction of allenyl diazo compound 6 via a trimethylenemethane (TMM) diyl intermediate. The TMM diyl mediated [2+3] cycloaddition reaction furnished the consecutive quaternary carbon centers and showed an unusual diastereoselectivity.

In this protocol, we report a novel approach for the synthesis of a new class of heterocyclic 1H-1,2,3-triazole-modified peptidomimetic compounds. The process consists of an Ugi four-component condensation reaction of amines, an isocyanide, an aldehyde and acids followed by a Huisgen 1,3-dipolar cycloaddition reaction with an azide group in the presence of a catalytic amount of CuSO4</...

For the first time [3 + 2] 1,3-cycloaddition of an ionized carbonyl ylide has been observed in gas phase ion-molecule reactions of CH2OCH2 (1) with several carbonyl compounds. The reaction, which competes with electrophilic addition that leads to net CH2 transfer, occurs across the CdO double bond of acetaldehyde and several acyclic ketones yielding ionized 4,4-dialkyl-1,3-dioxolanes as unstabl...

Cycloaddition reactions are among the most powerful methods for the synthesis of complex compounds. In particular, the development and application of the 1,3-dipolar cycloaddition, an important member of this reaction class, has grown immensely due to its powerful ability to efficiently build various five-membered heterocycles. Azomethine ylides are commonly used as dipoles for the synthesis of...

An efficient one-pot three-component procedure for the synthesis of new chiral spiro-oxindolopyrrolizidines with highly regio-, diastereo-, and enantioselective from 1,3-dipolar cycloaddition of azomethine ylides and optically pure active cinamoyl oxazolidinone are described. The process occurs at room temperature in aqueous ethanol as green solvent and in the absence of any bidentate chelating...

The [3+2] cycloaddition between various nitriles and sodium azide proceeds smoothly in the presence of zeolite and sulfated Zircona as effective catalyst and in the water and DMF/MeOH, to give the corresponding arylaminotetrazoles in good to high yields. The reaction most probably precedes through the in situ formation of a catalyst azide species, followed by a successive [3+2] cycloaddition wi...

The [3+2] cycloaddition between various nitriles and sodium azide proceeds smoothly in the presence of zeolite and sulfated Zircona as effective catalyst and in the water and DMF/MeOH, to give the corresponding arylaminotetrazoles in good to high yields. The reaction most probably precedes through the in situ formation of a catalyst azide species, followed by a successive [3+2] cycloaddition wi...

Fifteen novel β-lactams bearing the N-ethyl tert-butyl carbamate group 5a-o and fifteen N-(2-aminoethyl) β-lactams 6a-o were synthesized by the ketene-imine [2+2] cycloaddition reaction (Staudinger ). The cycloaddition reaction was found to be totally diastereoselective leading exclusively to the formation of the cis-β-lactam derivatives. These newly synthesized β-lactams were evaluated for the...