Bicyclic Pyrrolidines for Medicinal Chemistry via [3 + 2]-Cycloaddition.

A general approach to bicyclic fused pyrrolidines via [3 + 2]-cycloaddition between nonstabilized azomethyne ylide and endocyclic electron-deficient alkenes was elaborated. "Push-pull" alkenes and CF-alkenes did not react with the azomethyne ylide under the previously reported conditions, and we developed a superior protocol (LiF, 140 °C, no solvent). Among obtained products were medchem-relevant bicyclic sulfones, monofluoro-, difluoro-, and trifluoromethyl-substituted pyrrolidines.

Cyclobutane-derived diamines: synthesis and molecular structure.

Cyclobutane diamines (i.e., cis- and trans-1,3-diaminocyclobutane, 6-amino-3-azaspiro[3.