3-dipolar cycloaddition

Synthesis of polysubstituted spiropyrrolidines using 2-acetylfuran, 2-acetylthiophene, and 2-acetylpyrrole

 A series of novel spirooxindoles have been synthesized through three-component 1,3-dipolar cycloaddition of azomethine ylides generated in situ by the decarboxylative condensation of isatin and sarcosine with the dipolarophile 3-phenyl-1-(heteroaryl -2-yl)prop-2-en-1- one, synthesized by the Knoevenagel reaction using 2-acetylfuran, 2-acetylpyrrole, 2-acetylthiophene and substituted benzaldehydes. These compounds are used for the first time as dipolarophiles.

Stereochemical Aspects of Reaction of 1,3-dipolar Cycloaddition in a Row of Conjugated Enones

The reaction of 1,3-dipolar cycloaddition of conjugated aryl(hetaryl) methylideneacetones, which containing various peripheral substituents, with azomethine ylides was carried out. It was established that the interaction is not chemoselective and proceeds with the participation of two non-equivalent reaction centers of dipolarophile with high diastereoselectivity. The products of cycloaddition were a mixture of structural isomers endo-cycloaddition. Monoenone transform to spyropyrrolidines with high endo-stereoselectivity.