Application of palladacycles in Heck type reactions

In the last 3 years, there have been tremendous developments in palladium catalytic systems for Heck type reactions. One of the successful approaches towards activation of less reactive substrates like aryl chlorides involves the use of palladacycles 1, 2 and 3 as catalyst precursors. This article describes the principles of these systems with an emphasis on our own work and features the ongoing literature discussion about possible mechanisms involving Pd(0)/Pd(II) or Pd(II)/Pd(IV) catalytic cycles for this class of catalyst. (C) 1999 Elsevier Science S.A. All rights reserved.