The quinoline motif is an integral part of a wide variety of bioactive classes of compounds. An increasingly popular entry into tetrahydroquinolines is represented by the T-reaction, i.e. a subtype of the transformations relying on the isomerization-cyclization sequence known as the tert.-amino-effect. The latter was shown to proceed via a most remarkable helical dipolar intermediate generated upon a hydrideshift from an alpha-amino-C-H in tert.-anilines to an unsaturated ortho-substituent, accomplishing C-C-bond formation from a nonactivated NCH-moiety. The tert.-amino-effect was first...