A Palladium-Catalyzed Vinylcyclopropane (3 + 2) Cycloaddition Approach to the Melodinus Alkaloids

Abstract

A palladium-catalyzed (3 + 2) cycloaddition of a vinylcyclopropane and a β-nitrostyrene are employed to rapidly assemble the cyclopentane core of the Melodinus alkaloids. The ABCD ring system of the natural product family is prepared in six steps from commercially available materials.

Synthetic Applications and Methodological Developments of Donor−Acceptor Cyclopropanes and Related Compounds

“…[30,31] Although they possess no known biological activity, these compounds attracted our interest due to their structural complexity, specifically the highly congested cyclopentane (C) ring.…”

Highly functionalized donor–acceptor cyclopropanes applied toward the synthesis of the Melodinus alkaloids

“…33 We were able to synthesize monovinylcyclopropane 63 from dimethylmalonate ( 64 ) and dibromide 65 via a known procedure. 34 The subseuqent palladium-catalyzed (3 + 2) cycloaddition of cyclopropane 63 and nitrostyrene 47 proceeded smoothly.…”

Enantioselective Cycloadditions of Vinyl Cyclopropanes and Nitroolefins for Functionally and Optically Enriched Nitrocyclopentanes

“…In this context, Goldberg and Stoltz reported a palladium-catalyzed diastereoselective (3+2) cycloaddition of vinyl cyclopro-panes and b-2-dinitrostyrenes (Scheme 1). [12] After that, the Shi and Trost groups reported chiral-palladium-catalyzed enantioselective (3+2)-cycloadditions of vinyl cyclopropanes and electron-deficient alkenes. [13] Nitroolefins are versatile dipolarophiles in (3+2)-cycloadditions that provide valuable nitrogencontaining products, [14] which can be easily converted into medicinally and synthetically important compounds via the Nef reaction, reduction, and other transformations.…”