Nickel-Catalyzed Borylation of Aryl- and Benzyltrimethylammonium Salts via C-N Bond Cleavage.

By developing a mild Ni-catalyzed system, a method for direct borylation of sp(2) and sp(3) C-N bonds has been established. The key to this hightly efficient C-N bond borylative cleavage depends on the appropriate choice of the nickel catalyst Ni(COD)2, ICy·HCl as a ligand, and the use of 2-ethoxyethanol as the cosolvent. This transformation shows good functional group compatibility and can serve as a powerful synthetic tool for gram-scale synthesis and late-stage C-N borylation of complex compounds.

Iodoarene-Catalyzed Stereospecific Intramolecular sp(3) C-H Amination: Reaction Development and Mechanistic Insights.

A new strategy is reported for intramolecular sp(3) C-H amination under mild reaction conditions using iodoarene as catalyst and m-CPBA as oxidant. This C-H functionalization involving iodine(III) reagents generated in situ occurs readily at sterically hindered tertiary C-H bonds. DFT (M06-2X) calculations show that the preferred pathway involves an iodonium cation intermediate and proceeds via an energetically concerted transition state, through hydride transfer followed by the spontaneous C-N bond formation.