The (5 + 1) annulation of ynone/cinnamates and related substrates with protected primary amines gives rise to isoquinolones, pyrrolidinones and pyrrolopiperazines in good to excellent yields under phosphine catalysis. The reaction is viable with chiral phosphines, although the selectivity is poor.

A phosphine‐catalyzed approach to pyrrolines has been developed that involves two mechanistically unlinked catalytic processes. The first involves the redox isomerization of amino crotonates to provide access to aliphatic tosyl imines, which then engage in a (3+2) annulation with various allenoates. The reaction shows generality, with 24 examples established, along with a low yielding and moderately enantioselective variant. Mechanistic studies indicate that the viability of the process is linked to the selection of catalysts with similar propensity to add to the two coupling partners.

Herein, we report an enantioselective catalytic annulation of electron-poor allenes with aminocrotonates. The reaction proceeds by the umpolung γ-amination of the allenoate and β-umpolung intramolecular conjugate addition. The reaction provides ready access to pyrrolidines using a homochiral phosphepine catalyst, which allows most products to form in good yields (55− 85%) with ≥95:5 er and ≥4:1 dr. An assisted tandem-catalytic variant is also viable, and mechanistic studies supporting the proposed reaction pathway are reported.