Top Organomet Chem (2016) 59: 103–138
DOI: 10.1007/3418_2015_148
# Springer International Publishing Switzerland 2015
Published online: 17 October 2015
Alkyne Activation Using Bimetallic Catalysts
Michael J. Page, D. Barney Walker, and Barbara A. Messerle
Abstract Bimetallic catalysts are capable of activating alkynes to undergo a
diverse array of reactions. The unique electronic structure of alkynes enables
them to coordinate to two metals in a variety of different arrangements. A number
of well-characterised bimetallic complexes have been discovered that utilise the
versatile coordination modes of alkynes to enhance the rate of a bimetallic
catalysed process. Yet, for many other bimetallic catalyst systems, which have
achieved incredible improvements to a reactions rate and selectivity, the mechanism of alkyne activation remains unknown. This chapter summarises the many
different approaches that bimetallic catalysts may be utilised to achieve cooperative
activation of the alkyne triple bond.
Keywords Alkyne activation Á Bimetallic Á Catalysis Á Catalyst Á Cooperativity
Contents
1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
2 Cyclotrimerisation, Dimerisation and Nucleophilic Substitution . . . . . . . . . . . . . . . . . . . . . . . . . 107
2.1 Cyclotrimerisation of Alkynes . . . . . . .. . . . . . . . . . . . . .. . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . 107
2.2 Dimerisation of Alkynes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
2.3 Nucleophilic Substitution of Propargylic Alcohols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
3 Cycloaddition with Azides, Alkynes, Alkenes and Allenes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
3.1 Azide–Alkyne Cycloaddition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
3.2 Cycloaddition of Alkynes with Alkynes, Alkenes and Allenes . . . . . . . . . . . . . . . . . . . . . 115
M.J. Page and D.B. Walker
School of Chemistry, The University of New South Wales, Sydney 2052, Australia
B.A. Messerle (*)
School of Chemistry, The University of New South Wales, Sydney 2052, Australia
Department of Chemistry and Biomolecular Sciences, Macquarie University, North Ryde
2109, Australia
e-mail: barbara.messerle@mq.edu.au
DOI: 10.1007/3418_2015_148
# Springer International Publishing Switzerland 2015
Published online: 17 October 2015
Alkyne Activation Using Bimetallic Catalysts
Michael J. Page, D. Barney Walker, and Barbara A. Messerle
Abstract Bimetallic catalysts are capable of activating alkynes to undergo a
diverse array of reactions. The unique electronic structure of alkynes enables
them to coordinate to two metals in a variety of different arrangements. A number
of well-characterised bimetallic complexes have been discovered that utilise the
versatile coordination modes of alkynes to enhance the rate of a bimetallic
catalysed process. Yet, for many other bimetallic catalyst systems, which have
achieved incredible improvements to a reactions rate and selectivity, the mechanism of alkyne activation remains unknown. This chapter summarises the many
different approaches that bimetallic catalysts may be utilised to achieve cooperative
activation of the alkyne triple bond.
Keywords Alkyne activation Á Bimetallic Á Catalysis Á Catalyst Á Cooperativity
Contents
1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
2 Cyclotrimerisation, Dimerisation and Nucleophilic Substitution . . . . . . . . . . . . . . . . . . . . . . . . . 107
2.1 Cyclotrimerisation of Alkynes . . . . . . .. . . . . . . . . . . . . .. . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . 107
2.2 Dimerisation of Alkynes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
2.3 Nucleophilic Substitution of Propargylic Alcohols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
3 Cycloaddition with Azides, Alkynes, Alkenes and Allenes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
3.1 Azide–Alkyne Cycloaddition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
3.2 Cycloaddition of Alkynes with Alkynes, Alkenes and Allenes . . . . . . . . . . . . . . . . . . . . . 115
M.J. Page and D.B. Walker
School of Chemistry, The University of New South Wales, Sydney 2052, Australia
B.A. Messerle (*)
School of Chemistry, The University of New South Wales, Sydney 2052, Australia
Department of Chemistry and Biomolecular Sciences, Macquarie University, North Ryde
2109, Australia
e-mail: barbara.messerle@mq.edu.au