On the origin of copper(I) catalysts from copper(II) precursors in C-N and C-O cross-couplings.
Cu(II) precursors ligated to phenanthrolines are reduced in situ by alcohols or amines in the presence of a base (Cs(2)CO(3)) to generate Cu(I) species which are active catalysts in C-N and C-O cross-coupling reactions. The conversion Cu(II) --> Cu(I) has been evidenced and monitored by UV-vis and NMR spectroscopy.
Franc
Grégory
G
UMR CNRS-ENS-UPMC 8640, Ecole Normale Supérieure, Département de Chimie, 24 rue Lhomond, F-75231, Paris Cedex 5, France.
Jutand
Anny
A