Enantioselective Palladium-Catalyzed [3C + 2C] and [4C + 3C] Intramolecular Cycloadditions of Alkylidenecyclopropanes

Palladium-catalyzed [3C + 2C + 2C] cycloaddition of enynylidenecyclopropanes: efficient construction of fused 5-7-5 tricyclic systems.

We report a Pd-catalyzed intramolecular [3C + 2C + 2C] cycloaddition between alkylidenecyclopropanes, alkynes and alkenes. The method provides synthetically relevant 5-7-5 tricyclic structures, with good chemoselectivity and complete diastereoselectivity.

Regulation of poliovirus 3C protease by the 2C polypeptide.

Poliovirus-encoded nonstructural polypeptide 2C is a multifunctional protein that plays an important role in viral RNA replication. 2C interacts with both intracellular membranes and virus-specific RNAs and has ATPase and GTPase activities. Extensive computer analysis of the 2C sequence revealed that in addition to the known ATPase-, GTPase-, membrane-, and RNA-binding domains it also contains ...

Rh(II)-catalyzed cycloadditions of 1-tosyl 1,2,3-triazoles with 2H-azirines: switchable reactivity of Rh-azavinylcarbene as [2C]- or aza-[3C]-synthon.

The Rh(II)-catalyzed formal [3+2] and [3+3] cycloadditions of 1-tosyl 1,2,3-triazoles with 2H-azirines have been developed, which enable the efficient synthesis of polysubstituted 3-aminopyrroles and 1,2-dihydropyrazines, respectively. The reported [3+2] cycloaddition represents the first application of 1-sulfonyl 1,2,3-triazole as a [2C]-component in relevant cycloaddition reactions.

Enantioselective copper-catalyzed 1,3-dipolar cycloadditions.

Nickel-Catalyzed Intramolecular [3 + 2 + 2] Cycloadditions of Alkylidenecyclopropanes. A Straightforward Entry to Fused 6,7,5-Tricyclic Systems

A highly diastereo- and chemoselective intramolecular nickel-catalyzed cycloaddition of alkene- and alkyne-tethered alkynylidenecyclopropanes is reported. The method constitutes the first fully intramolecular [3 + 2 + 2] alkylidenecyclopropropane cycloaddition occurring via a proximal cleavage of the cyclopropane and makes it possible to build relevant 6,7,5-tricyclic frameworks in a single-pot...