文摘
In the presence of (鈭?-sparteine or a (+)-sparteine surrogate, organolithiums add to N-alkenyl-N鈥?arylureas to give benzylic organolithiums in an enantioselective manner. Under the influence of DMPU, these organolithiums undergo rearrangement with migration of the N鈥?aryl ring from N to C, leading to the urea derivatives of enantiomerically enriched amines bearing tertiary substituents. Basic hydrolysis returns the functionalized amine, providing a new synthetic route to compounds with quaternary stereogenic centers bearing nitrogen.