N???????-Phthalimide as a Site-Protecting and Stereodirecting Group in Rhodium-Catalyzed C-H Functionalization with Donor/Acceptor Carbenes

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 Rh-2(S-2-Cl-5-BrTPCP)(4) as catalyst, whereas Rh-2(S-TPPTTL)(4) was the most effective catalyst for C-H functionalization at tertiary C-H bonds and for the desymmetrization of N-phthalimidocyclohexane.

Automated summary

The rhodium-catalyzed enantioselective C-H functionalization of unactivated C-H bonds by donor/acceptor carbene-induced C-H insertion can be extended to substrates containing nitrogen functionality. The rhodium-stabilized donor/acceptor carbenes are generated by rhodium-catalyzed decomposition of aryldiazoacetates. The phthalimido group is the optimal nitrogen protecting group. C-H functionalization at the most sterically accessible site can be achieved using Rh-2(S-2-Cl-5-BrTPCP)(4) as catalyst, while Rh-2(S-TPPTTL)(4) is the most effective catalyst for functionalization at tertiary C-H bonds and for the desymmetrization of N-phthalimidocyclohexane.