OLIGOMERIZATION OF ALDEHYDES CATALYZED BY COBALT CARBONYL-COMPLEXES

The catalytic activity of Co-2(CO)(6)L-2 complexes (L = carbon monoxid e, phosphines) has been tested in the oligomerization of aldehydes und er the conditions adopted for hydroformylation of olefins. The influen ce of the type of substrate, phosphinic ligand and reaction temperatur e has been investigated. The products formed are beta-hydroxyaldehydes , alpha,beta-unsaturated aldehydes and beta-hydroxyesters, Very poor c atalytic activity was shown by cobalt complexes in the oligomerization of ketones. The role of cobalt carbonyI complexes in the aldehyde oli gomerization has been rationalized by a mechanism, in which acylcobalt intermediates are involved. (C) 1998 Elsevier Science B.V. All rights reserved.