[1,2-Benzenediolato(2−)-O,O′]oxotitanium. A Mild and Efficient Catalyst for the Michael Reaction of Ketene Silyl Acetals with α,β-Unsaturated Ketones

In the presence of a catalytic amount of [1,2-benzenediolato(2−)-O,O′]oxotitanium, ketene silyl acetals smoothly react with α,β-unsaturated ketones to afford the corresponding Michael adducts in high yields.