Chitosan-Cu Catalyzed Novel Ferrocenated Spiropyrrolidines: Green Synthesis, Single Crystal X-ray Diffraction, Hirshfeld Surface and Antibacterial Studies.

Chitosan-bounded copper (chitosan-Cu) was introduced for green synthesis of novel ferrocenated spiropyrrolidine hybrids, namely 3'-(4-.bromobenzoyl)-5'-(4-hydroxybenzyl)-4'-ferrocenylspiro[indoline-3,2'-pyrrolidin]-2-one and 3'-(4-bromobenzoyl)-4'-ferrocenylspiro[indoline-3,2'-pyrrolidin]-2-one, in good yield. A one-pot three-component 1,3-dipolar cycloaddition reaction was employed for the formation of spiropyrrolidines from 1-(4-bromophenyl)-ferrocene-prop-2-en-1-one and azomethine ylides, which were developed in situ from tyrosine, glycine, and isatin, respectively. Various spectroscopic methods were used to establish the structures of spiropyrrolidines, and a single crystal X-ray diffraction study of a spiropyrrolidine provided additional confirmation. The crystallographic study revealed that compound