Enantioselective Dearomatization of Substituted Phenols via Organocatalyzed Electrophilic Amination

Highly efficient and stereoselective dearomatization of substituted phenols was achieved via chiral phosphoric acid-catalyzed electrophilic para-amination with commercially available azodicarboxylates. This protocol readily afforded a series of chiral 2,5-cyclohexadienones bearing 4-aza-quaternary stereocenters with excellent yields and enantioselectivities (≤99% yield and >99% ee). Easy scale-up of this reaction to a gram scale and diverse derivatizations of the chiral products into α-tertiary amines and α-tertiary heterocycles derivatives well demonstrated the potential of this method

Atroposelective Synthesis of Diarylamines via Organocatalyzed Electrophilic Amination

Axially chiral diarylamine atropisomers represent a distinct category characterized by two contiguous chiral C–N axes, which exhibit a significantly lower racemization barrier due to the concerted rotation of both C–N axes. In this work, we introduce an effective method for the atroposelective synthesis of axially chiral diarylamines through organocatalyzed asymmetric electrophilic amination with azodicarboxylates, which afforded a variety of acyclic secondary diarylamine atropisomers in good yields with high enantioselectivities. This method expands the scope of catalytic asymmetric synthesis beyond N-aryl quinoid-type atropisomers, enabling the catalytic atroposelective synthesis of chiral diarylamines without constraining one C–N axis through intramolecular hydrogen bonding. Both experimental and computational studies show a minimal contribution of intramolecular hydrogen bonding in stabilizing configurations of these atropisomers, which undergo racemization via the concerted rotation of both C–N axes

Atroposelective Synthesis of Diarylamines via Organocatalyzed Electrophilic Amination

Axially chiral diarylamine atropisomers represent a distinct category characterized by two contiguous chiral C–N axes, which exhibit a significantly lower racemization barrier due to the concerted rotation of both C–N axes. In this work, we introduce an effective method for the atroposelective synthesis of axially chiral diarylamines through organocatalyzed asymmetric electrophilic amination with azodicarboxylates, which afforded a variety of acyclic secondary diarylamine atropisomers in good yields with high enantioselectivities. This method expands the scope of catalytic asymmetric synthesis beyond N-aryl quinoid-type atropisomers, enabling the catalytic atroposelective synthesis of chiral diarylamines without constraining one C–N axis through intramolecular hydrogen bonding. Both experimental and computational studies show a minimal contribution of intramolecular hydrogen bonding in stabilizing configurations of these atropisomers, which undergo racemization via the concerted rotation of both C–N axes