Synthesis, structure and stereodynamics of atropisomeric -chloroamides

Atropisomeric N -chloroamides were efficiently accessed by electrophilic halogenation of ortho -substituted secondary anilides. The stereodynamics of atropisomerism in these novel scaffolds was interrogated by detailed experimental and computational studies, revealing that racemization is correlated with amide isomerization. The stereoelectronic nature of the amide was shown to significantly influence racemization rates, with potentially important implications for other C-N atropisomeric scaffolds. Novel atropisomeric N -chloroamides were prepared by efficient halogenation reactions and shown to racemize via a pathway involving geared bond rotation.