Dual H-bond activation of NHC–Au(i)–Cl complexes with amide functionalized side-arms assisted by H-bond donor substrates or acid additives

Otto Seppänen,Santeri Aikonen,Carla Alamillo-Ferrer,Jordi Burés,Mikko Muuronen,Juho Helaja

doi:10.1039/d0cc05999d

Abstract

Novel approach with amide-tethered H-bond donor NHC ligands enabled Au(i)-catalysis via H-bonding. The plain NHC-Au(i)-Cl complex catalysed conversions of terminal N-propynamides to oxazolines, and enyne cycloisomerization with an acid additive, in DCM at RT. DFT calculations enlightened the function of the side-arm in the activation.

Highlights

Otto Seppanen, ‡a Santeri Aikonen, ‡a Mikko Muuronen,§a Carla Alamillo-Ferrer,b Jordi Bures b and Juho Helaja *a
DFT calculations enlightened the function of the sidearm in the activation
The precipitating AgCl residues are non-innocent in gold-catalysis[4] and multiple roles have been assigned for the counter ions.[5,6]

Summary

Introduction

Otto Seppanen, ‡a Santeri Aikonen, ‡a Mikko Muuronen,§a Carla Alamillo-Ferrer,b Jordi Bures b and Juho Helaja *a. The performance of catalysts 1a–2b was better than what has been reported for other NHC or P ligands in homogeneous gold-catalytic conversion with weakly or non-coordinative counter ions (Table S1, ESI†).

Results

Conclusion