Intramolecular cyclizations of α-lithioamine synthetic equivalents: Convenient syntheses of 3-, 5-, and 6-membered-ring heterocyclic nitrogen compounds and elaborations of 3-membered ring systems

Article abstract of DOI:10.1021/jo00081a002

A lithiation-intramolecular cyclization reaction of N-Boc chloroalkyl secondary amines is reported to provide the 2-aryl-substituted pyrrolidine and piperidines 6, 7, 9, and 11 and a series of 2-azabicyclo[3.1.0] derivatives 14-25, including cyclopropane derivatives of proline and of the indolizidine-pyrrolizidine alkaloid ring system. Lithiation-substitutions of N-Boc-N-ethylcyclopropylamine to give 27-29 and lithiation-silylations of N- Boc aziridines to give 31-33 also are reported.