Dynamic thermodynamic resolution: solvent effects, mechanism, and an asymmetric 3,4,5-substituted benzazepine synthesis.

[reaction: see text] The resolution in the lithiation-substitution sequence from 1 to 4-11 in MTBE is shown to be under thermodynamic control in contrast to the previous report of kinetic control in diethyl ether. Diastereomeric equilibration of a soluble complex is shown to be controlling and an asymmetric synthesis of a 3,4,5-substituted benzazepine is reported.