Ortho-C-H addition of 2-substituted pyridines with alkenes and imines enabled by mono(phosphinoamido)-rare earth complexes

We here reported a special catalytic performance of mono(phosphinoamido)-ligated rare earth complexes in ortho-C-H functionalization of pyridines with nonpolar alkenes and polar imines. Upon treatment with one equiv. of borate reagent B(C6F5)(3) or [Ph3C][B(C6F5)(4)], complex NP1-Sc can act as an efficient catalyst for ortho-C-H alkylation of pyridines towards alkenes. In the presence of 1:1 mixed secondary amine of HN (SiMe3)(2) and HNBn2, complex NP2-Gd can catalyze ortho-C-H addition of pyridines towards imines, effectively. A wide range of substrates were subjected to the catalysis to render the one step synthesis of a variety of ortho-alkylated and ortho-aminoalkylated pyridine derivatives in good yields and an excellent regioselectivity and chemoselectivity.

Automated summary

In this study, a special catalytic performance of mono(phosphinoamido)-ligated rare earth complexes in ortho-C-H functionalization of pyridines with nonpolar alkenes and polar imines was reported. The complexes showed high efficiency in synthesizing a variety of ortho-alkylated and ortho-aminoalkylated pyridine derivatives with good yields and excellent regioselectivity and chemoselectivity.