Conformation and stereodynamics of 2,2′-disubstituted N,N′-diaryl ureas
作者:Jonathan Clayden、Loïc Lemiègre、Mark Pickworth、Lyn Jones
DOI:10.1039/b802673d
日期:——
Except in the most hindered of cases, N,N'-diaryl N,N'-dimethyl ureas adopt a conformation with the two aryl rings disposed cis to one another. Variable temperature NMR studies reveal the rate at which the Ar-N bonds rotate as well as the conformational preference of ortho disubstituted ureas in which more than one cis orientation is possible. In general, a conformation in which the aryl rings lie