In the present perspective the advances and real possibilities of 1,3-dipolar cycloadditions as key steps in the total synthesis of virus inhibitors are described. Azides, nitrones, and azomethine ylides are the most appropriate 1,3-dipoles for the synthesis of privileged structures with the highest biological responses against viruses.

The reaction of 1-alkynes with acyl azides in the presence of [Tpm(*,Br)Cu(NCMe)]BF(4) [Tpm(*,Br) = tris(3,5-dimethyl-4-bromopyrazolyl)methane] as the catalyst provides 2,5-oxazoles in moderate to high yields. This is a novel transformation of the CuAAC type that constitutes a significant variation of the commonly observed [3 + 2] cycloaddition reaction to yield 1,2,3-triazoles.

Efficient regioselective synthesis of nucleoside conjugates was achieved by cycloaddition reaction of azides and alkynes using sodium ascorbate/ CuSO4 system as a catalyst. These 16 novel thymidine analogues were obtained in excellent yields (75-100%), employing mild reaction conditions with a broad scope of structural modification. For the compounds tested, no specific antiviral effects could ...

Monodentate phosphoramidite ligands are used to accelerate the copper(i)-catalyzed 1,3-dipolar cycloaddition of azides and alkynes (CuAAC) rapidly yielding a wide variety of functionalized 1,4-disubstituted-1,2,3-triazoles; Cu(i) and Cu(ii) salts both function as the copper source in aqueous solution to provide excellent yields.

The reaction between trimethylsilyl azide and pentaphenylborole was recently shown to produce the corresponding 1,2-azaborine. Investigating this transformation theoretically suggests that the reaction proceeds via coordination of the azide to the borole, rearrangement to a bicyclic species, and conversion to a kinetically favoured eight-membered BN3C4 heterocycle or expulsion of N2 to furnish ...

We designed and synthesized All-in-One (AIO) reactive azide reagents for bioorthogonal reactions with highly efficient Cu(I) ligand moieties, an azido group, and functional tags for imaging or purification. The AIO reagents displayed fast and efficient click ligation and can be applied in a wide range of in vivo systems.

Matrix isolation infrared (IR) studies have been carried out on the vaporisation of the alkali-metal azides MN3 (M = Na, K, Rb and Cs). The results show that under high vacuum conditions, molecular KN3, RbN3 and CsN3 are present as stable high-temperature vapour species, together with variable amounts of nitrogen gas and the corresponding metal atoms. The characterisation of these molecular azi...