Ag-Catalyzed Asymmetric Interrupted Barton-Zard Reaction Enabling the Enantioselective Dearomatization of 2-and 3-Nitroindoles

We disclose a Ag-catalyzed asymmetric interrupted Barton-Zard reaction of alpha-aryl-substituted isocyanoacetates with 2- and 3-nitroindoles, which enables the dearomatization of nitroindoles and hence offers rapid access to an array of optically active tetrahydropyrrolo[3,4-b]indole derivatives bearing three contiguous stereogenic centers, including two tetrasubstituted chiral carbon atoms with pretty outcomes (up to 99% yield, 91:9 dr, and 96% ee). The synthetic potential of the protocol was showcased by the gram-scale reaction and versatile transformations of the product.

Automated summary

In this study, a novel Ag-catalyzed asymmetric reaction was developed to achieve the dearomatization of nitroindoles, leading to the synthesis of a variety of optically active tetrahydropyrrolo[3,4-b]indole derivatives with high yields and enantioselectivity. The synthetic potential of this protocol was demonstrated through gram-scale reactions and versatile transformations of the product.