Amine-Responsive Disassembly of Au I -Cu I Double Salts for Oxidative Carbonylation

Angew Chem Int Ed Engl. 2020 Jan 27;59(5):2080-2084. doi: 10.1002/anie.201914089. Epub 2019 Dec 10.

Abstract

A sensitive amine-responsive disassembly of self-assembled AuI -CuI double salts was observed and its utilization for the synergistic catalysis was enlightened. Investigation of the disassembly of [Au(NHC)2 ][CuI2 ] revealed the contribution of Cu-assisted ligand exchange of N-heterocyclic carbene (NHC) by amine in [Au(NHC)2 ]+ and the capacity of [CuI2 ]- on the oxidative step. By integrating the implicative information coded in the responsive behavior and inherent catalytic functions of d10 metal complexes, a catalyst for the oxidative carbonylation of amines was developed. The advantages of this method were clearly reflected on mild reaction conditions and the significantly expanded scope (51 examples); both primary and steric secondary amines can be employed as substrates. The cooperative reactivity from Au and Cu centers, as an indispensable prerequisite for the excellent catalytic performance, was validated in the synthesis of (un)symmetric ureas and carbamates.

Keywords: carbamates; double salts; oxidative carbonylation; synergistic catalysis; urea.