Sequential N-acylamide methylenation-enamide ring-closing metathesis:: a synthetic entry to 1,4-dihydroquinolines

A new synthetic entry to the 1,4-dihydroquinoline nucleus is reported. The procedure involves the dimethyltitanocene methylenation of N-(alkoxycarbonyl)amides derived from 2-allylanilines, followed by ring-closing metathesis of the resulting enamides. (c) 2005 Elsevier Ltd. All rights reserved.