Synthesis of Spiropyrrolidines via Five-Component 1,3-Dipolar Cycloaddition of Azomethine Ylides and Olefinic Dipolarophiles Generated In Situ Simultaneously

An efficient and straightforward five-component cascade protocol has been developed to synthesize the highly substituted dispiroindenoquinoxaline pyrrolidine derivatives from ninhydrin, 1,2-phenylenediamine, sarcosine, 1,3-indanedione, and aldehydes via cascade reactions under mild conditions, in which 1,3-dipole azomethine ylide and the dipolarophile were simultaneously generated in situ. This novel method is complementary to the classical Huisgen cycloaddition in that it is well-suited to the preparation of dispiroindenoquinoxaline pyrrolidine derivatives.