Asymmetric Synthesis of Biaryl Atropisomers Using an Organocatalyst-Mediated Domino Reaction as the Key Step

A three-pot synthetic method that features the use of an organocatalyst as the key step was developed for the preparation of biaryl atropisomers. The first reaction is an asymmetric domino Michael–Henry reaction catalyzed by diphenylprolinol silyl ether to afford the substituted nitrocyclohexanecarbaldehyde with four stereogenic centers and one defined configuration of a stereogenic axis with excellent enantioselectivity. Removal of the central chirality from the domino products afforded biaryl atropisomers having axial chirality with excellent enantioselectivity.