Catalytic asymmetric allylation of ketones and a tandem asymmetric allylation/diastereoselective epoxidation of cyclic enones.

A simple procedure is reported for the catalytic asymmetric allylation of ketones, utilizing titanium tetraisopropoxide, BINOL, 2-propanol additive, and tetraallylstannane as allylating agent. A variety of ketone substrates, including acetophenone derivatives and alpha,beta-unsaturated cyclic enones, reacted to form tertiary homoallylic alcohols in good yields (67-99%) and with high levels of enantioselectivity (generally >80%). A novel one-pot enantioselective allylation/diastereoselective epoxidation has also been introduced.

Atropisomeric amides: Achiral ligands with chiral conformations.

A new class of achiral ligands with atropisomeric conformations has been coordinated to titanium(IV). The ligands are ortho-hydroxy benzamide derivatives which are deprotonated on reaction with titanium tetraisopropoxide to furnish Ti(L)(2)(O-iPr)(2) complexes (L=ortho-phenoxy benzamide). In these octahedral titanium compounds, the ortho-phenoxy benzamide ligands chelate to titanium, bonding through the phenoxide oxygen and the amide carbonyl oxygen.