From Dimethylamine to Pyrrolidine: The Development of an Improved Nickel Pincer Complex for Cross-Coupling of Nonactivated Secondary Alkyl Halides

Replacement
of a dimethyl amino group of the amidobis­(amine) nickel­(II)
pincer complex (1), [(MeN2N)­Ni–Cl],
by a pyrrolidino group resulted in a new nickel­(II) pincer complex
(2), [(PyrNMeNN)­Ni–Cl].
Complex 2 is an efficient catalyst for Kumada and Suzuki–Miyaura
cross-coupling of nonactivated secondary alkyl halides, while complex 1 is largely inactive. The significant activity difference
is tentatively attributed to a minimal structural difference, which
leads to a more hemilabile ligand.