Direct catalytic asymmetric vinylogous conjugate addition of unsaturated butyrolactones to α,β-unsaturated thioamides

Soft Lewis acid/Brønsted base cooperative catalysts have enabled direct catalytic asymmetric vinylogous conjugate addition of α,β- and β,γ-unsaturated butyrolactones to α,β-unsaturated thioamides with perfect atom economy. When using α-angelica lactone and its derivatives as pronucleophiles, as little as 0.5 mol % catalyst loading was sufficient to complete the reaction necessary to construct consecutive tri- and tetrasubstituted stereogenic centers in a highly diastereo- and enantioselective fashion. Soft spot: Soft Lewis acid/Brønsted base cooperative catalysts have enabled the title reaction of α,β- and β,γ- unsaturated butyrolactones with perfect atom economy. When using α-angelica lactone and its derivatives as pronucleophiles, a 0.5 mol % catalyst loading was sufficient to complete the reaction to construct consecutive tri- and tetrasubstituted stereogenic centers in a highly diastereo- and enantioselective fashion.