Polyfunctionalized Biaryls Accessed By A One-Pot Nucleophilic Aromatic Substitution And Sigmatropic Rearrangement Reaction Cascade Under Mild Conditions

A practical synthetic method has been developed for polyfunctionalized biaryls based on a facile one-pot nucleophilic aromatic substitution (SNAr) reaction and [5,5]- or [3,3]-sigmatropic rearrangement reaction cascade. Under mild basic conditions, N-arylhydroxylamines reacted with o-activated fluoro (het)arenes to form N,O-diarylhydroxylamine intermediates which underwent spontaneously selective [5,5]sigmatropic rearrangement reaction to produce diverse functionalized 4-amino-4'-hydroxy-1,1'-biaryls. A sequential SNAr reaction and [3,3]-sigmatropic rearrangement took place between N-arylhydroxylamines and 2-fluoropyridine derivatives or 4-fluorobenzonitrile to afford functionalized 2-amino-2'-hydroxy-1,1'-biaryls. As invaluable and unique building blocks, the resulting biaryls were applied in the straightforward synthesis of N-2,O-2-coronarene, carbazole, aza- and diaza carbazole derivatives. (C) 2021 Elsevier Ltd. All rights reserved.