The rhodium-catalyzed enantioselective C–H functionalization
of unactivated C–H bonds by means of donor/acceptor carbene-induced
C–H insertion was extended to substrates containing nitrogen
functionality. The rhodium-stabilized donor/acceptor carbenes were
generated by rhodium-catalyzed decomposition of aryldiazoacetates.
The phthalimido group was the optimum nitrogen protecting group. C–H
functionalization at the most sterically accessible methylene site
was achieved using Rh2(S-2-Cl-5-BrTPCP)4as catalyst, whereas Rh2(S-TPPTTL)4was the most effective catalyst for C–H functionalization
at tertiary C–H bonds and for the desymmetrization ofN-phthalimidocyclohexane.