Metathesis Reaction of Diazo Compounds and para-Quinone Methides for C-C Double Bond Formation: Synthesis of Tetrasubstituted Alkenes and Quinolinones.

The para-quinone methides (p-QMs) are activated by Lewis acid and then attacked by diazo compounds. The following rearrangement leads to nitrogen gas extrusion and C-C double bond formation to constitute a metathesis reaction process. Therefore, the diazoester is transformed into tetrasubstituted alkenes, whereas the diazo-oxindole delivers the quinolinone products. Furthermore, the 13C-labeling experiments were also conducted to elucidate a possible mechanism.