K. Pitchumani, Abraham Joy, Nicolette Prevost and V. Ramamurthy
Depending on the number of Brønsted acid sites present, Ca Y can act either as a reagent and reduce stilbenes to 1,2-diarylethanes or act as a catalyst and isomerize cis-stilbenes to the more stable trans form; Lewis acid sites generated by the activation process yield radical cations from stilbenes but these do not yield any stable products.