Catalyst-Free Annulation of Acylethynylpyrroles with 1-Pyrrolines: A Straightforward Access to Tetrahydrodipyrrolo[1,2-a:1?,2?-c]imidazoles

Acylethynylpyrroles undergo facile (rt, MeCN or MeOH, 24-72 h) catalyst-free annulation with 1-pyrrolines to afford acylmethylenetetrahydrodipyrrolo[1,2-a:1 ',2 '-c]imidazoles in up to 93% yield and 90% E-stereoselectivity of the olefin moiety.

Automated summary

This study reports a novel reaction method in which Acylethynylpyrroles undergo facile catalyst-free annulation with 1-pyrrolines to afford acylmethylenetetrahydrodipyrrolo[1,2-a:1 ',2 '-c]imidazoles. The reaction achieves high yields and E-stereoselectivity of the olefin moiety.