Synthesis of New Chiral Bidentate Isonitrile–Acyclic Diaminocarbene Palladium(II) Compounds and Their Catalytic Activity
journal contributionposted on 28.09.2015, 00:00 by Matthias Knorn, Eugen Lutsker, Oliver Reiser
Five new chiral bidentate isonitrile–diaminocarbene palladium(II) complexes (5a–5e) as well as the bis-diaminocarbene complex 6 were prepared by metal-mediated nucleophilic addition of amines to the corresponding bisisonitrile–palladium(II) compound 4. The new chelates were fully characterized by 1D and 2D NMR experiments, IR, and ESI-MS. In addition, the X-ray structure of 5a, 5c, and 6 could be analyzed, showing different sterical properties. We furthermore investigated the relationship between their structure and their catalytic activity. The mixed ligand complexes 5a and 5c showed high activity both in Suzuki–Miyaura cross-coupling and in intermolecular asymmetric allylic alkylation (AAA) reactions as well as moderate chiral induction in the AAA.