Schneider, Jörg; Wolf, Dirk; Blaser, Dieter; Boese, Roland:

Stoichiometric homo-aldol coupling of acetone, cyclohexanone, and acetophenone by the [(h5-CpR)Co] (R = Me5, 1,2,4-tri-tert-butyl) moiety.

In: European Journal of Inorganic Chemistry, (2000) ; Nr. 4, S. 713-718
ISSN: 1434-1948
Zeitschriftenaufsatz / Fach: Chemie
Abstract:
Acetone, cyclohexanone, and acetophenone react with the toluene-bridged triple-decker complexes [{(h5-C5R)Co}2-m-(h4:h4-toluene)] (R = Me5 3; 1,2,4-t-Bu3 4) by toluene substitution and homo-aldol coupling of two ketone mols. to form the 1st oxadiene Co complexes. These reactions may involve a Csp3-H activation step of the ketones by 14 e- [(h5-C5R)Co] fragments generated from the triple-decker complexes 3 and 4. If no acidic protons are present in the position a to the carbonyl C position in the ketone, no Csp3-H activation occurs. In agreement with this, benzophenone does not react with complex 3.