Crystal structure and Hirshfeld surface analysis of (22 RS,23 SR,25 RS,26 SR)-23,25,5-trimethyl-21-(2,2,2-tri-fluoro-acet-yl)-5-aza-2(2,6)-piperidina-1,3(2,5)-di-furana-cyclo-hexa-phan-24-one.

The title compound, C20H21F3N2O4, features a main twelve-membered difuryl ring with which the furan rings make dihedral angles of 76.14 (5) and 33.81 (5)°. The dihedral angle between the furan rings is 42.55 (7)°. The six-membered nitro-gen heterocycle has a twist-boat conformation. In the crystal, pairs of mol-ecules are connected by inter-molecular C-H⋯O inter-actions, generating an R 2 2(14) ring motif. These pairs of mol-ecules form zigzag chains along the a-axis direction by means of C-H⋯F inter-actions. Furthermore, C-H⋯π and C-F⋯π inter-actions link the mol-ecules into chains along the b-axis direction, forming sheets parallel to the (001) plane. These sheets are also connected by van der Waals inter-actions.

Facile synthesis of pyrrolo[2,1-a]isoquinolines by domino reaction of 1-aroyl-3,4-dihydroisoquinolines with conjugated ketones, nitroalkenes and nitriles.

A convenient protocol for the synthesis of 5,6-dihydropyrrolo[2,1-a]isoquinolines with various electron-withdrawing substituents at C-2 atom is described. This approach is based on the two-component domino reaction of 1-aroyl-3,4-dihydroisoquinolines with α,ß-unsaturated ketones, nitroalkenes and acrylonitrile. Depending on the selected substrates, the reaction was performed in TFE under reflux or under microwave irradiation. Only for the two examples, a transition metal catalyst was used.