Enantioselective Intermolecular C-H Functionalization of Allylic and Benzylic sp(3) C-H Bonds Using N-Sulfonyl-1,2,3-triazoles.

The enantioselective intermolecular sp(3) C-H functionalization at the allylic and benzylic positions was achieved using rhodium-catalyzed reactions with 4-phenyl-N-(methanesulfonyl)-1,2,3-triazole. The optimum dirhodium tetracarboxylate catalyst for these reactions was Rh2(S-NTTL)4. The rhodium-bound α-imino carbene intermediates preferentially reacted with tertiary over primary C-H bonds in good yields and moderate levels of enantioselectivity (66-82% ee).

Pyridine-based dicarbene ligand: synthesis and structure of a bis-2-pyridylidene palladium complex.

We herein report the synthesis of a bis-2-pyridylidene palladium(II) complex as an isoelectronic structure of the well-known 2,2'-bipyridine complexes. One-pot or stepwise C-Cl oxidative addition followed by base-mediated C-H palladation of the chlorobipyridine dication to palladium(0) yielded the bis-2-pyridylidene palladium(II) carbonate smoothly.