TiCl4-Mediated Baylis-Hillman and aldol reactions were developed without th
e direct use of a Lewis base. These processes involve the conjugate additio
n of TiCl4 to alpha,beta-unsaturated substrates followed by carbonyl coupli
ng. Baylis-Hillman olefins were obtained when alpha,beta-unsaturated ketone
s were employed as the substrates, whereas beta-halogenated aldol products
were generated with an alpha,beta-unsaturated N-acyl benzoxalinone as the M
ichael-type acceptor. (C) 1999 Elsevier Science Ltd. All rights reserved.