Studies on the titanium-catalyzed cyclopropanation of nitriles.
The Ti-mediated reaction of Grignard reagents with nitriles was investigated with sub-stoichiometric amounts of titanium isopropoxide. Cyanoesters were converted to spirocyclopropanelactams in good yields using as low as 0.05 eq of Ti(O(i)Pr)4. Under similar conditions, cyanocarbonates led to spirocyclopropane oxazolidinones and/or aminocyclopropylcarbinols. A very short synthesis of the naturally occurring aminocyclopropanecarboxylic acid illustrates the usefulness of this methodology.
Laroche
Christophe
C
UMR 6519--Réactions Sélectives et Applications, CNRS-Université de Reims Champagne-Ardenne, BP 1039, 51687 REIMS Cedex 2, France.
Harakat
Dominique
D
Bertus
Philippe
P
Szymoniak
Jan
J