Organocatalytic Atroposelective Cross‐Coupling of 1‐Azonaphthalenes and 2‐Naphthols

Atroposelective cross‐coupling is one of the most appealing routes to construct axially chiral binaphthyl molecules due to the modular and succinct nature. Although transition‐metal‐catalyzed cross‐couplings offer reliable synthetic means, alternative reaction modes that could be applied to broader substrate range without their pre‐functionalization is highly desirable. Herein we show that the application of chiral Brønsted acid catalyst as organocatalyst could accomplish cross‐coupling of 1‐azonaphthalenes and 2‐naphthols with high efficiency, exclusive C4‐selectivity as well as excellent enantioselectivity and functional group compatibility. The identification of acylimidazolinone auxiliary for azo activating group, effective remote catalyst control and arene resonance effect synergistically play key roles in the development of this method. The utility is further demonstrated by transformations of the products into other binaphthyl compounds with perfectly retained axial chirality. By judicious development of acylimidazolinone as activating group and the use of a chiral Brønsted acid (CBA) catalyst, the cross‐coupling of 1‐azonaphthalenes with 2‐naphthols was realized with high efficiency, exclusive C4‐selectivity and excellent enantioselectivity. The reaction tolerates various functional groups and stereoretentive conversions of products to other binaphthyl compounds were found viable.