Vicinal All-Carbon Quaternary Stereocenter Construction with Trifluoromethyl Groups via Organocatalytic Asymmetric Cascade Michael/Michael Reaction.

A thiourea organocatalyst efficiently promoted the asymmetric cascade Michael/Michael reactions between isatin-derived trifluoromethylacrylate and α-alkylidene succinimide, resulting in high yields of spirooxindole derivatives. These compounds exhibit vicinal all-carbon quaternary stereocenters and bear a trifluoromethyl group, with excellent enantioselectivities reaching up to 99 % ee. This work represents the first successful organocatalyst application for the direct construction of vicinal all-carbon quaternary stereocenters, featuring a trifluoromethyl group.

Asymmetric Henry Reaction of Trifluoromethyl Enones with Nitromethane Using a N,N-Dibenzyl Diaminomethylenemalononitrile Organocatalyst.

A novel N,N-dibenzyl diaminomethylenemalononitrile organocatalyst efficiently promoted asymmetric Henry reactions of trifluoromethyl enones with nitromethane, affording corresponding highly functionalized products in high yields with excellent enantioselectivities (up to 90% ee). This study is the first to report the successful example of the asymmetric 1,2-additions of nitromethane to trifluoromethyl enones.

Diaminomethylenemalononitrile as a Chiral Single Hydrogen Bond Catalyst: Application to Enantioselective Conjugate Addition of α-Branched Aldehydes.

An improved diaminomethylenemalononitrile organocatalyst, bearing a N,N-disubstituted structure, promoted enantioselective conjugate addition reaction of α-branched aldehydes with vinyl sulfone, affording adducts with excellent enantioselectivities (up to 96% ee). Mechanistic studies revealed that the diaminomethylenemalononitrile motif holds the vinyl sulfone substrate using a single hydrogen bond accompanied by multiple weak interactions, including electrostatic C-H⋅⋅⋅O interactions.