Torquoselective olefination with ynolates

We have developed the torquoselectivity-controlled olefination of carbonyl compounds with ynolates to afford tetrasubstituted alkenes. In the olefination of acylsilanes, α-oxy and α-aminoketones, and esters, the high selectivity and yield have been achieved under mild conditions. The E/Z selectivity is determined in the step of electrocyclic ring-opening of the β-lactone enolates (oxetenes) derived from cycloaddition of ynolates with carbonyl compounds. The theoretical calculations revealed that the several secondary orbital interactions are critical for the high torquoselectivity. The E/Z selectivity can be estimated by considerations of the electronic properties of the substituents of carbonyl compounds, wherein the electron-donating substituents would be trans to the carboxylate on the olefins and the electron accepting ones cis to it. This methodology is the novel olefination constructing multisubstituted olefins.