DIASTEREOSELECTIVE SYNTHESIS OF 2,4-SUBSTITUTED TETRAHYDROQUINOLINES VIA Hf(OTf)(4)-CATALYZED SUBSTITUTION/CYCLIZATION OF 2-AMINOBENZYL ALCOHOLS WITH STYRENES

摘要

An efficient and convenient stereoselective synthetic approach to 2,4-substituted 1,2,3,4-tetrahydroquinoline has been developed. This catalytic procedure involves a sequential reaction of 2-aminobenzyl alcohol with styrenes in the presence of Hf(OTf)(4) catalyst followed by intramolecular cyclization of the resulting cation species to give a variety of cis-2,4-substituted tetrahydroquinolines in good yield and diastereoselectivity.