Mesoionic triazolylidene nickel complexes: synthesis, ligand lability, and catalytic C–C bond formation activity

Files in This Item:
File Description SizeFormat 
om-2014-00593s_ms_revised.pdf1.22 MBAdobe PDFDownload
Title: Mesoionic triazolylidene nickel complexes: synthesis, ligand lability, and catalytic C–C bond formation activity
Authors: Wei, Yingfei
Petronilho, Ana
Müller-Bunz, Helge
Albrecht, Martin
Permanent link: http://hdl.handle.net/10197/6826
Date: 28-Jul-2014
Abstract: A set of triazolylidene (trz) nickel(II) complexes [NiCpX(trz)] was synthesized by a direct metalation of the corresponding triazolium salt with nickelocene, NiCp2. While at short reaction times and in the presence of a coordinating anion X the mono-carbene complex is preferably formed, long reaction times induce the gradual transformation of [NiCpX(trz)] to the bis-carbene complexes [Ni(Cp)(trz)2]+. Kinetic analyses lend strong support to a consecutive pathway involving triazolylidene dissociation from [NiCpX(trz)] en route to the bis-carbene complex. Similar carbene transfer is observed in a solid-state reaction upon heating the complex [NiCpI(trz)] in vacuo, which induces disproportionation to [NiI2(trz)2] and NiCp2, confirming that the Ni–C(trz) bond is kinetically labile. The complexes [Ni(Cp)(trz)2]+ and [NiCpX(trz)] were both efficient catalyst precursors for Suzuki–Miyaura cross-coupling of aryl bromides and phenylboronic acid, with turnover frequencies exceeding 228 h–1. Complex degradation after short reaction times, identified in separate experiments, prohibits high turnover numbers, and for high conversions, repetitive additions of triazolylidene nickel complex and phenylboronic acid are necessary.
Funding Details: European Research Council
Type of material: Journal Article
Publisher: American Chemical Society
Copyright (published version): 2014 American Chemical Society
Keywords: Monocarbene complexes;Biscarbene complexes;Kinetic lability
DOI: 10.1021/om500593s
Language: en
Status of Item: Peer reviewed
Appears in Collections:Chemistry Research Collection

Show full item record

SCOPUSTM   
Citations 10

25
Last Week
0
Last month
checked on Jun 15, 2018

Download(s) 50

79
checked on May 25, 2018

Google ScholarTM

Check

Altmetric


This item is available under the Attribution-NonCommercial-NoDerivs 3.0 Ireland. No item may be reproduced for commercial purposes. For other possible restrictions on use please refer to the publisher's URL where this is made available, or to notes contained in the item itself. Other terms may apply.