Abstract: This experimental protocol combines the classical Wittig reaction with state-of-the-art visible-light photoredox catalysis. Using tert-butoxycarbonyl proline, benzaldehyde, and vinyltriphenylphosphonium bromide as substrates with 1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyanobenzene (4CzIPN) as the photosensitizer, the method achieves selective synthesis of E- and Z-alkene stereoisomers via a visible-light-induced radical-polar crossover mechanism. The experimental workflow encompasses visible-light-mediated synthesis, Schlenk techniques, NMR spectroscopic analysis, thin-layer chromatography, automated flash column chromatography purification, and mechanistic studies. Rooted in fundamental theoretical principles, this work translates cutting-edge techniques, methodologies, and green chemistry concepts into practical teaching applications, aiming to enhance students' integrated scientific research capabilities.

Key words: Wittig reaction, Visible light photoredox catalysis, Radical-polar crossover reaction, Olefins