Synthesis of C3-Quaternary 2H-Pyrrolines by [3+2] Cycloaddition of Isocyanoacetates and 1,1-Disubstituted Alkenes

Under mild conditions, C3-quaternary 2H-pyrrolines can be convergently and efficiently assembled by Cu(II) and weak bases cocatalyzed [3+2] cycloaddition of 1,1-disubstituted alkenes and isocyanoacetates. Various functionalities can be tolerated, affording 2H-pyrrolines with up to two quaternary centers in a single step.