Fa. Hicks et al., PRACTICAL TITANIUM-CATALYZED SYNTHESIS OF BICYCLIC CYCLOPENTENONES AND ALLYLIC AMINES, Journal of organic chemistry, 61(8), 1996, pp. 2713-2718
A practical titanium-catalyzed synthesis of bicyclic cyclopentenones a
nd allylic amines is described. The process converts enyne substrates
to iminocyclopentenes using 10 mol% of the air- and moisture-stable pr
ecatalyst Cp(2)TiCl(2) in the presence of n-BuLi and triethylsilyl cya
nide. The resulting iminocyclopentenes can be hydrolyzed to cyclopente
nones 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.