A Practical Titanium-Catalyzed Synthesis of Bicyclic Cyclopentenones and Allylic Amines.
A practical titanium-catalyzed synthesis of bicyclic cyclopentenones and allylic amines is described. The process converts enyne substrates to iminocyclopentenes using 10 mol % of the air- and moisture-stable precatalyst Cp(2)TiCl(2) in the presence of n-BuLi and triethylsilyl cyanide. The resulting iminocyclopentenes can be hydrolyzed to cyclopentenones in good yields or reduced to allylic silylamines with Red-Al or DIBALH. Treatment of the crude silylamines with acetyl chloride allows isolation of allylic amides in excellent yields.
Hicks
Frederick A.
FA
Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139.
Berk
Scott C.
SC
Buchwald
Stephen L.
SL