Lithium-Mediated Synthesis of Substituted Diarylmethylamines

Significance

A three-step urea synthesis, stereospecific rearrangement, and urea cleavage presents a novel way of synthesizing enantiomerically pure substituted diarylmethylamines. The key step is a lithium-mediated aryl transfer from one urea nitrogen to the benzylic carbon of the other urea nitrogen. This step proceeds with high levels of stereochemical retention, leading to ureas with high enantiomeric ratios. A variety of aryl groups containing substituents with different electronic or steric properties successfully undergo transfer. Cleavage of the urea by hydrolysis or reduction produces the corresponding diarylamines in good yields.