F. Faigl et M. Schlosser, N-PHENYLPYRROLE - A KINETIC, THOUGH NOT THERMODYNAMIC PREFERENCE FOR DILITHIATION, Tetrahedron, 49(45), 1993, pp. 10271-10278
Under appropriate conditions the clean preparation of either the alpha
-monolithiated or the o,alpha-dilithiated derivative of N-phenylpyrrol
e is possible. In the latter case, the first deprotonation occurs at t
he alpha-position. Dimetalation is kinetically but not thermodynamical
ly favored.