Synthesis and Reactions of 2‐[1‐Methyl‐1‐(pyrrolidin‐2‐yl)ethyl]‐1 H ‐pyrrole and Some Derivatives with Aldehydes: Chiral Structures Combining a Secondary‐Amine Group with an 1 H ‐Pyrrole Moiety as Excellent H‐Bond Donor

The synthesis of compound 2 and its derivatives 6 and 8 combining a pyrrolidine ring with an 1 H ‐pyrrole unit is described ( Scheme 2 ). Their attempted usability as organocatalysts was not successful. Reacting these simple pyrrolidine derivatives with cinnamaldehyde led to the tricyclic products 3b, 9b , and 10b first ( Scheme 1, Fig. 2 ). The final, major products were the pyrrolo‐indolizidine tricycles 3a, 9a , and 10a obtained via the iminium ion reacting intramolecularly with the nucleophilic β ‐position of the 1 H ‐pyrrole moiety ( cf. Scheme 1 ).