A Regioselective Multicomponent Approach for the Synthesis of Novel 2‐Acetyl‐4‐phenylquinoline Designed Monospiro‐Pyrrolidine and Thiapyrrolizidine Hybrids

A convenient approach for the synthesis of 2‐acetyl‐4‐phenylquinoline designed monospiro‐pyrrolidine/thiapyrrolizidine hybrids has been achieved via a 1,3‐dipolar cycloaddition reaction of various azomethine ylides derived from isatin/acenaphthylene‐1,2‐dione/ninhydrin, ortho ‐phenylenediamine and sarcosine/ L ‐4‐thiazolidinecarboxylic acid with 2‐acetyl‐4‐phenylquinoline chalcone derivatives as dipolarophile. The regio‐ and stereochemistry of formation of the cycloadducts were determined by proton, carbon and 2D NMR and HR‐MS techniques. Additionally, the formation of products based on the secondary orbital interaction mechanism and intrinsic reaction coordinate calculation (HOMO and LUMO) on the proposed TS structure was unambiguously confirmed by the density functional theory using the B3LYP/6‐311G(d,p) levels of theory.