Synthesis of quinoline/oxindole appended phenylvinyl-2,5-dihydrofuran derivatives via ring-closing enyne metathesis

A sequential synthetic process was developed to synthesize quinoline/oxindole appended phenylvinyl-2,5-dihydrofuran derivatives. The synthesis involved multiple steps, starting with the base-promoted nucleophilic addition of terminal alkynes to specific carbonyl compounds (11H-indeno[1,2-b]quinolin-11-one and isatin derivatives). The resulting propargyl alcohol derivatives were then subjected to O-allylation. Subsequently, the 1,6-enyne compounds obtained underwent ring-closing enyne metathesis using Grubb's II catalyst, resulting in the desired quinoline/oxindole appended phenylvinyl-2,5-dihydrofuran derivatives. The structures and relative stereochemistry of the synthesized compounds were confirmed by spectroscopic analysis and single-crystal XRD studies.