A facile and efficient synthesis of highly functionalised 3,3′-dispiropyrrolidine- and 3,3′-dispiropyrrolizidine bisoxindoles via [3+2] cycloaddition

The [3+2] cycloaddition reaction of azomethine ylides with isomerised Morita-Baylis-Hillman adducts, both dipoles and dipolarophiles are derived from isatin, afforded highly functionalised 3,3′-dispiro pyrrolidine- and 3,3′-dispiropyrrolizidine bisoxindoles in high yields.