Amendment in Titanium(IV) Chloride and Chalcogenide-Promoted Baylis–Hillman Reaction of Aldehydes with α,β-Unsaturated Ketones

The Baylis–Hillman reaction can be drastically affected by the reaction temperature and Lewis base. When the reaction was carried out at <−20°C using methyl sulfide as a Lewis base in the presence of titanium(IV) chloride, the chlorinated compound 1 was obtained as the major product. However, if the reaction was carried out at room temperature (10°C) in the presence of titanium(IV) chloride, the elimination compound 3 was formed as a major product.