(CAAC)Pd(py) Catalysts Disproportionate to Pd(CAAC)2

Palladium complexes with one N-heterocyclic carbene (NHC) and a pyridine ancillary ligand are powerful cross-coupling precatalysts. Herein, we report such complexes with a cyclic (alkyl)­(amino)­carbene (CAAC) ligand replacing the NHC. We find that the alleged reduced form, (CAAC)­Pd­(py), dispropor...

Full description

Saved in:
Bibliographic Details
Published in:Organometallics 2023-07, Vol.42 (13), p.1567-1572
Main Authors: Marigo, Nicola, Morgenstern, Bernd, Biffis, Andrea, Munz, Dominik
Format: Article
Language:English
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Palladium complexes with one N-heterocyclic carbene (NHC) and a pyridine ancillary ligand are powerful cross-coupling precatalysts. Herein, we report such complexes with a cyclic (alkyl)­(amino)­carbene (CAAC) ligand replacing the NHC. We find that the alleged reduced form, (CAAC)­Pd­(py), disproportionates to the (CAAC)2Pd0 complex and palladium nanoparticles. This notwithstanding, they are potent catalysts in the Buchwald–Hartwig amination with aryl chlorides under mild conditions (60 °C). In the presence of dioxygen, these complexes catalyze the formation of diazenes from anilines. The catalytic activities of the NHC- and CAAC-supported palladium(0) and palladium­(II) complexes are similar in the cross-coupling reaction, yet the CAAC complexes are superior for diazene formation.
ISSN:0276-7333
1520-6041
DOI:10.1021/acs.organomet.3c00150