Divergent titanium-mediated allylations with modulation by nickel or palladium

Palladium and nickel are used in conjunction with titanocene(III) complexes to perform selective allylations of carbonyl compounds and alkenes, respectively. Pd/Ti-catalyzed allylation of ketones proceeds diastereoselectively under mild conditions, whereas Ni/Ti-promoted cyclizations provide polyalkyl-substituted carbo- and heterocycles with excellent control over regio- and stereoselectivity.