Organocatalytic Asymmetric Synthesis of N,N-Bis(dihydrofuranyl)hydroxyamines: A Cascade Reaction Involving Friedel-Crafts Alkylation, Internal Redox Reaction, and Umpolung

Stereoselective syntheses of N,N-bis(dihydrofuranyl)-hydroxyamines from phenols and nitroolefins have been accomplished by means of cycle-specific catalysis with guanidine/bisthiourea organocatalyst and achiral base. Circumstantial evidence supports the idea that a nitroso intermediate participates in the dimerization, which involves internal redox reaction/umpolung.