Claus-Peter Reisinger

Application of palladacycles in Heck type reactions

Abstract 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.

Synthesis, structure and catalytic application of palladium(II) complexes bearing N-heterocyclic carbenes and phosphines ☆

Abstract A variety of mixed palladium(II) complexes bearing N-heterocyclic carbenes (NHCs) and triaryl- and trialkylphosphines [NHC(R2)]Pd(PR′3)I2 (R=Me, t-Bu, (R)-1-phenylethyl; R′=Ph, o-tolyl, cyclohexyl, t-Bu) have been prepared. Crystal structure details of trans-diiodo(1,3-di-tert-butylimidazolin-2-ylidene)(triphenylphosphino)palladium(II) are presented. The complexes were tested as catalysts in the Mizoroki–Heck, Suzuki–Miyaura and Stille reactions as well as in the dimerization of phenylacetylene. In catalytic studies of the Suzuki–Miyaura cross-coupling reaction, the performance of these novel complexes was compared to the results obtained by the corresponding bis(NHC) and bis(phosphine) complexes.

First palladium-catalyzed aminations of aryl chlorides☆

Abstract The palladium-catalyzed coupling reaction of aryl chlorides with various amines has been studied for the first time. Crucial for the success of this CN bond forming reaction is the use of potassium tert-butoxide as base. Turn over numbers up to 900 and yields up to 80% have been obtained.