Clayden Jonathan, Turner Hazel, Helliwell Madeleine, Moir Elizabeth
School of Chemistry, University of Manchester, Manchester, UK.
J Org Chem. 2008 Jun 20;73(12):4415-23. doi: 10.1021/jo702706c. Epub 2008 Apr 10.
2,6-disubstituted N-aryl ureas rotate slowly about their Ar-N bonds and can exist as separable atropisomers. They also react remarkably diastereoselectively, with the urea axis controlling new stereogenic centers with high fidelity in a variety of nucleophilic and electrophilic addition reactions. The sense of diastereoselectivity in lateral lithiation-electrophilic quench reactions is electrophile-dependent and appears to be the result of stereospecific reaction with one of two interconvertible diastereoisomeric organolithiums.
