Achieving conformational control over C–C, C–N and C–O bonds in biaryls, N,N′-diarylureas and diaryl ethers: advantages of a relay axis†
Mark S. Betson,Ann Bracegirdle,Jonathan Clayden,Madeleine Helliwell,Andrew Lund,Mark Pickworth,Timothy J. Snape,Christopher P. Worrall
Chemical Communications Pub Date : 12/18/2006 00:00:00 , DOI:10.1039/B614618J
Abstract

The orientation of Ar–C, Ar–N and Ar–O bonds in biaryls, N,N′-diarylureas and diaryl ethers (whose conformers are distinguishable by NMR) may be controlled with a selectivity up to >95 : 5 by an adjacent stereogenic centre; the selectivity may be greater when a second stereogenic axis is inserted between the controlling centre and the slowly rotating bond.

Graphical abstract: Achieving conformational control over C–C, C–N and C–O bonds in biaryls, N,N′-diarylureas and diaryl ethers: advantages of a relay axis