A transition-metal free synthesis of highly functionalized 2-hydroxy-2′-amino-1,1′-biaryls from N-arylhydroxylamines has been developed. This operationally simple and readily scalable approach relies on a cascade of reactions that initially generates transient N,O-diarylhydroxylamines, via direct O-arylation, which then undergo rapid [3,3]-sigmatropic rearrangement and subsequent rearomatization to
thionyl bromide is demonstrated in this work. Mild reaction conditions and broad scope of substrates ranging from heterocyclic structures to pharmaceutics-potential motifs are used in the reactions of this paper. Efficient bromination of ortho CH bonds of the aryhydroxylamines has been achieved. Ortho-bromoanilide products were obtained in good to excellent yields, and model scaled-up reactions of this
AbstractA metal‐ and oxidant‐free, practical and efficient method for the synthesis of highly versatile and synthetically useful ortho‐trifluoromethanesulfonylated anilines from arylhydroxylamines and trifluoromethanesulfinic chloride was developed. This rapid transformation proceeded smoothly with good yields and excellent ortho‐selectivity in the absence of any metals or ligands. Mechanistically, the reaction comprised a noncanonical O‐trifluoromethanesulfinylation of the arylhydroxylamine, and the subsequent [2,3]‐sigmatropic rearrangement to afford ortho‐trifluoromethanesulfonylated aniline derivatives. The practical application of this reaction was demonstrated by further conversion into a series of functional molecules under different reaction conditions.
231. The structure of naphthalene, hydrindene, and tetralin derivatives