Triazene-Activated Donor–Acceptor Cyclopropanes: Ring-Opening and (3 + 2) Annulation Reactions

Cyclization and annulation reactions of nitrogen-substituted cyclopropanes and cyclobutanes.

Cyclization and annulation reactions initiated by ring-opening of small rings, especially cyclopropanes and cyclobutanes are now well-established in synthetic chemistry. Nevertheless, the potential of aminocyclopropanes and cyclobutanes, an important subclass for the synthesis of nitrogen-rich building blocks, has remained unexploited for a long time, despite important pioneering results. In th...

Domino ring-opening/recyclization reactions of doubly activated cyclopropanes as a strategy for the synthesis of furoquinoline derivatives.

Catalytic asymmetric [3 + 3] annulation of cyclopropanes with mercaptoacetaldehyde.

A highly diastereo- and enantioselective [3 + 3] annulation of donor-acceptor cyclopropanes with mercaptoacetaldehyde has been developed. In the presence of a N,N'-dioxide-Sc(iii) complex as the catalyst, a number of aromatic substituted cyclopropyl ketones reacted with mercaptoacetaldehyde smoothly, providing the corresponding chiral tetrahydrothiopyranols in moderate yields with excellent ee ...

A mild procedure for the Lewis acid-catalyzed ring-opening of activated cyclopropanes with amine nucleophiles.

The Lewis acid-catalyzed ring-opening of methyl 1-nitrocyclopropanecarboxylates with amine nucleophiles is described. The reaction proceeds at room temperature and with complete preservation of the enantiomeric purity from the electrophilic center of the cyclopropane to the acyclic product. The methodology was applied in an enantioselective synthesis of the dual serotonin/norepinephrine reuptak...

Ring Opening of Donor–Acceptor Cyclopropanes with N-Nucleo- philes

Abstract Ring opening of donor–acceptor cyclopropanes with various N-nucleophiles provides a simple approach to 1,3-functionalized compounds that are useful building blocks in organic synthesis, especially in assembling various N-heterocycles, including natural products. In this review, ring-opening reactions of donor–acceptor cyclopropanes with amines, amides, hydrazines, N-heterocycles, nitri...