Recyclable Tertiary Amine Modified Diarylprolinol Ether as Aminocatalyst for the Sequential Asymmetric Synthesis of Functionalized Cyclohexanes and Chromenes

The one‐pot, organocatalytic Hayashi sequential reaction (HSR) of β‐nitroacrylate, aldehyde, toluenethiol, and ethyl 2‐(diethoxyphosphoryl)acrylate allowed the synthesis of almost stereoisomerically pure, highly functionalized polysubstituted cyclohexanes with very high diastereo‐ and enantio‐selectivity (up to > 99 % ee). The one‐pot synthesis consists of the tertiary amine modified diarylprolinol silyl ether‐mediated asymmetric Michael reaction, a domino Michael reaction/Horner–Wadsworth–Emmons reaction, and a sulfa‐Michael reaction. In addition, we have also demonstrated an improved protocol for the domino oxa‐Michael/aldol reaction of salicyladehydes with α,β‐unsaturated aldehydes with recyclable tertiary amine‐modified diarylprolinol silyl ether 3d as an effective organocatalyst, which results in the formation of chiral chromenes with good enantioselectivities (up to 94 % ee). UV/Vis and CD spectroscopy provide a cross‐validation method to elucidate the slight difference between electron‐withdrawing 3d and diphenylprolinol silyl ether 3a, which can give indirect evidence for the enhancement of enantioselective induction with 3d in the above transformations. Modifying Jørgensen–Hayashi catalysts with the introduction of amino group on the diaryl prolinol silyl ether enhances their stereoselectivity in certain asymmetric transformations. The tertiary amine‐modified diarylprolinol silyl ether catalyzes the synthesis of highly functionalized polysubstituted cyclohexanes and chromenes with very high diastereo‐ and enantio‐selectivity (up to > 99 % ee).