Brønsted acid-catalyzed, enantioselective synthesis of 1,4-dihydroquinoline-3-carboxylates via in situ generated ortho-quinone methide imines

Abstract

A straightforward, catalytic, enantioselective approach toward the synthesis of a broad range of 1,4-dihydroquinoline-3-carboxylates is described. Under phosphoric acid catalysis in situ-generated ortho-quinone methide imines reacted with β-keto esters to form the nitrogen heterocycles with good yields and enantioselectivities in just one synthetic step under ambient reactions conditions.