Enantioselective Wacker-type cyclization of 2-alkenyl-1,3-diketones promoted by Pd-SPRIX catalyst.

An enantioselective intramolecular Wacker-type cyclization of 2-alkenyl-1,3-diketones catalyzed by a Pd(II)−SPRIX complex was developed. The reaction proceeded in a 6-endo-trig mode to give the desired chromene derivatives with moderate to good enantioselectivity. Isomerization of C−C double bonds via a π-allyl Pd intermediate was involved as the key step.