Synthesis of a series of novel hexahydrochromenopyrrole analogues has been accomplished through an intramolecular 1,3-dipolar cycloaddition (1,3-DC reaction) of azomethine ylides, generated by the aldehyde induced decarboxylation of secondary amino acids. These compounds were screened for antibacterial and antifungal activities against six human pathogenic bacteria and three human pathogenic fu...

An efficient synthesis of a range of 1,2-benzisoxazoles using an improved 1,3-dipolar cycloaddition of nitrile oxides and benzyne is described. Key to the procedure is the in situ generation of the reactive nitrile oxide and benzyne reaction partners mediated by TBAF. Reactions are complete within 30 s, giving the target products in good to excellent yield.

The room temperature 1,3-dipolar cycloaddition reactions of the boron azide, Cy2BN3 with the electron-poor acetylenes RCO2C≡CCO2R, EtC≡CCOMe and HC≡CP(=O)Ph2 afforded new 1,2,3-triazoles. In the case of RCO2C≡CCO2R, a new macrocyclic product was isolated with loss of the R group.

It all clicks into place: A potent telomere-targeting small molecule has been identified by using the copper-free 1,3-dipolar cycloaddition of a series of alkyne and azide building blocks catalyzed by a non-Watson-Crick DNA secondary structure (see picture). This method rapidly identifies, otherwise unanticipated, potent small-molecule probes to selectively target a given RNA or DNA.

The 1,3-dipolar cycloaddition of azides and activated alkynes has been used for site-selective labeling of biomolecules in vitro and in vivo. While copper catalysis has been widely employed to activate terminal alkynes for [3 + 2] cycloaddition, this method, often termed "click chemistry", is currently incompatible with living systems because of the toxicity of the metal. We recently reported a...

The cycloaddition of azides to alkynes is one of the most important synthetic routes to 1H-[1,2,3]-triazoles. Here a novel regiospecific copper(I)-catalyzed 1,3-dipolar cycloaddition of terminal alkynes to azides on solid-phase is reported. Primary, secondary, and tertiary alkyl azides, aryl azides, and an azido sugar were used successfully in the copper(I)-catalyzed cycloaddition producing div...

The 1,3-dipolar cycloaddition of azomethine ylides bearing the biologically active 1,4-dihydropiridine ring to C(60) was investigated by means of quantum mechanical calculations at the semiempirical AM1 and DFT (B3LYP/6-31G) methods. The presence of two chiral centers and one chiral axis in the resulting fulleropyrrolidines leads to four possible [6,6] cycloaddition products. Formation of atrop...

A novel one-pot two step tandem reaction for the synthesis of indolizine-1-carbonitrile derivatives (5a-i) was identified. The route comprises 1,3-dipolar cycloaddition reaction of aromatic aldehyde derivatives (1a-i), malononitrile (2) and 1-(2-(4-bromophenyl)-2-oxoethyl)-2-chloropyridin-1-ium (4) under ultrasound irradiation at room temperature in the presence of triethylamine at acetonitrile...