X-Ray, Molecular Diffusion, and NOESY NMR Studies of Chiral, Tetranuclear Cu(I) Catalysts Based on Monodentate Thiol Analogues of TADDOL.
The new, stable, chiral thiol-TADDOL Cu(I) catalysts 1 (X=OH, OMe, NMe(2)) reveal an unexpected monodentate complexation mode, both in solution and in the solid state. For the first time, the aggregation state of organocopper complexes has been determined by NMR diffusion measurements. NOESY NMR data on model isocyanide Cu complexes reveal a different conformation of the TADDOL moiety as a function of the second potential donor group. TADDOL=alpha,alpha,alpha',alpha'-tetraaryl-2,2-dimethyl-1,3-dioxolane-4,5-dimethanol.
Pichota
A
Laboratorium für Organische Chemie der Eidgenössischen Technischen Hochschule, ETH-Zentrum Universitätstrasse 16, 8092 Zürich (Switzerland).
Pregosin
PS
Valentini
M
Wörle
M
Seebach
D