Hayashi Catalyst Research Articles

Asymmetric organocatalytic Michael/α-alkylation reaction of α,β-unsaturated aldehyde with chloroacetophenone

Asymmetric organocatalytic Michael/α-alkylation reactions of α,β-unsaturated aldehydes with chloroacetophenones have been developed. The biologically useful cyclopropane motifs were synthesized with high yields and up to >99% ee, >30:1 dr through Jørgensen–Hayashi catalyst under mild conditions.

Superparamagnetic Nanoparticle‐Supported (S)‐Diphenyl‐ prolinol Trimethylsilyl Ether as a Recyclable Catalyst for Asymmetric Michael Addition in Water

AbstractA new superparamagnetic nanoparticle‐supported (S)‐diphenylprolinol trimethylsilyl ether (Jørgensen–Hayashi catalyst) was synthesized and applied for the asymmetric Michael addition of aldehydes to nitroalkenes in water, which gives products in moderate to good yields (up to 96%), good enantioselectivity (up to 90% ee) and diastereoselectivities (up to 99:1). The immobilized catalyst could be easily separated from the reaction by an external magnet and recycled for four times without significant loss of catalytic efficiency.