Synthesis of substituted pyrrolidines by sequential radical cyclization and N-acyliminium ion reactions

Article abstract of DOI:10.1016/S0040-4039(99)01971-1

Readily available N-acyl-2-pyrrolines are converted into functionalized α-alkoxy-β-iodopyrrolidines by N-iodosuccinimide promoted alcohol addition to the enamine group. These compounds are readily cyclized using a sodium cyanoborohydride-catalytic tributylstannane system affording functionalized pyrrolidines in good yields. The cyclized products undergo N-acyliminium ion reactions, such as BF₃·OEt₂ mediated addition of allyltrimethylsilane.