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1,3,4-Trisubstituted-1,2,3-Triazol-5-ylidene ‘Click’ Carbene Ligands: Synthesis, Catalysis and Self-Assembly

James D. Crowley A D , Ai-Lan Lee B D and Kelly J. Kilpin A C
+ Author Affiliations
- Author Affiliations

A Department of Chemistry, University of Otago, PO Box 56, Dunedin, New Zealand.

B School of Engineering and Physical Sciences, Chemistry – William H. Perkin Building, Heriot-Watt University, Edinburgh EH14 4AS, UK.

C Current address: Institut des Sciences et Ingénierie Chimique, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.

D Corresponding authors. Email: jcrowley@chemistry.otago.ac.nz, A.Lee@hw.ac.uk




James obtained his B.Sc. (Hons) (1998) and M.Sc. (2000) from Victoria University of Wellington and completed his PhD (2000–2005) at the University of Chicago under the direction of Prof. Brice Bosnich. In 2005 he moved to Prof. David Leigh's group at the University of Edinburgh, where he was awarded a British Ramsay Memorial Trust Fellowship (2006–2008), to carry out research on molecular machines. He started his independent career at the University of Otago in 2008 and was promoted to Senior Lecturer in 2011. His major research interests are in catalysis, self-assembly, molecular recognition and the development of molecular machines.



Ai-Lan hails from Malaysia and obtained her MSci(Hons) (2000) and Ph.D. (2004) from the University of Cambridge, working under the supervision of Prof. Steven V. Ley. She was subsequently awarded a Lindemann Trust Fellowship (2004–2005) to work at Boston College with Prof. Amir H. Hoveyda and Prof. Richard R. Schrock. In 2006, Ai-Lan was appointed as a fixed-term Lecturer at the University of Edinburgh, carrying out research with Prof. David A. Leigh. She has been in her present position as Lecturer at Heriot-Watt University since 2007 and her research interests include gold- and palladium-catalyzed reactions as well as the synthesis of mechanically interlocked architectures.



Kelly obtained her M.Sc. (2005) and Ph.D. (2009) degrees at the University of Waikato, under the supervision of Prof. Bill Henderson and Prof. Brian Nicholson in the field of organometallic gold chemistry. She then moved to the University of Otago to work as a postdoctoral fellow in the Crowley group (2009–2010) on 1,2,3-triazole chemistry. Kelly is currently funded by the New Zealand Science and Technology Postdoctoral Fellowship scheme to work on ruthenium anti-cancer drugs with Prof. Paul Dyson at the Ecole Polytechnique Fédérale de Lausanne (Switzerland).

Australian Journal of Chemistry 64(8) 1118-1132 https://doi.org/10.1071/CH11185
Submitted: 6 May 2011  Accepted: 4 June 2011   Published: 19 August 2011

Abstract

This review examines the use of the Cu(I)-catalyzed 1,3-cycloaddition of organic azides with terminal alkynes (the CuAAC ‘click’ reaction) for development of a novel family of abnormal/mesoionic N-heterocyclic carbenes and their corresponding metal complexes. These 1,3,4-trisubstituted-1,2,3-triazol-5-ylidenes have donor properties that are intermediate between the traditional Arduengo-type imidazol-2-ylidenes and more highly σ-donating abnormal carbenes, such as imidazol-4-ylidenes or pyrazolin-4-ylidenes. Metal complexes of the 1,3,4-trisubstituted-1,2,3-triazol-5-ylidenes have been used as catalysts for a variety of reactions including the CuAAC cycloaddition, Pd cross-couplings, and ring closing/ring opening metathesis. Additionally, ‘click’ carbene ligands have been used to generate self-assembled metallo-macrocycles and novel photosensitizers. The mild, modular CuAAC approach to these ligands should allow the rapid generation of libraries of 1,3,4-trisubstituted-1,2,3-triazol-5-ylidenes that can be further exploited to generate novel catalysts, metallo-pharmaceuticals and materials.


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