Research

Catalysis

Chemical processing is a prolific field in South Africa’s National Research and Development Strategy and catalysis is central to the chemical industry, being fundamental to the production of value-added materials. With feedstocks such as alkanes and alkenes readily available, there is a need for the design and synthesis of new, more efficient and selective catalysts which will allow for conversion into more useful products and add value to hydrocarbon products. South Africa is also one the largest suppliers of Platinum Group Metals world-wide and there is a drive to find useful, value-added applications for these metals.

However, with the depletion of available PGM resources and the added expense of these metals, PGM recovery and sustainability remains a key issue for researchers. Over the past few years, our group has been involved in immobilising catalysts on polymeric/dendritic supports and in biphasic media. This not only combines the advantages of homogeneous and heterogeneous catalysis but allows for ease of separation of the reaction product from rreaction mixtures, facilitating recycling of the catalysts to avoid environmental toxicity and makes purification of products easier. The multinuclear catalysts may also display enhanced activity over mononuclear analogues. Applications of this work have been extended to various organic transformation reactions, in particular, hydroformylation and carbon-carbon coupling reactions.

 

 

Selected Publications

Diteboho S. Ramarou, Banothile C.E. Makhubela and Gregory S. Smith*

Synthesis of Rh(I) alkylated-PTA complexes as catalyst precursors in the aqueous-biphasic hydroformylation of 1-octene

Journal of Organometallic Chemistry, 2018, 870, 23-31


Maxime Dauchy, Michel Ferreira, Jerome Leblond, Herve Bricout, Sebastien Tilloy, Gregory Smith and Eric Monflier*

New water-soluble Schiff-base ligands based on ß-cyclodextrin for aqueous biphasic hydroformylation reaction

Pure and Applied Chemistry, 2018, 90, 845-855


Munsaf Ali, Avinash K. Srivastava, Shepherd Siangwata, Gregory S. Smith and, Raj K. Joshi*

Photo induced alkyne hydration reactions mediated by a water soluble, reusable Rhodium(I) catalyst

Catalysis Communications, 2018, 115, 78-81


Cody Williams, Michel Ferreira, Eric Monflier, Selwyn F. Mapolie and Gregory S. Smith*

Synthesis and hydroformylation evaluation of Fréchet-type organometallic dendrons with N,O-salicylaldimine Rh(I) complexes at the focal point

Dalton Transactions, 2018, 47, 9418-9429


Preshendren Govender, Siyabonga Ngubane, Bruno Therrien and Gregory S. Smith*

Monometallic and mixed-valence bimetallic Rh(I/III) complexes: Synthesis, structure, electrochemistry and application in 1-octene hydroformylation

Journal of Organometallic Chemistry, 2017, 848, 281-287


Shepherd Siangwata, Sisaenkosi Chulu, Clive L. Oliver and Gregory S. Smith*

Rhodium-catalysed hydroformylation of 1-octene using aryl and ferrocenyl Schiff base-derived ligands

Applied Organometallic Chemistry, 2017, 31, e3593


Danielle Aucamp, Tim Witteler, Fabian Dielmann, Shepherd Siangwata, David C. Liles, Gregory S. Smith and Daniela I. Bezuidenhout*

A triarylated 1,2,3-triazol-5-ylidene ligand with a redox active ferrocenyl substituent for rhodium(I)-catalysed hydroformylation of 1-octene

European Journal of Inorganic Chemistry, 2017, 1227-1236


Shepherd Siangwata, Nadia Baartzes, Banothile C.E. Makhubela and Gregory S. Smith

Synthesis, characterization and reactivity of water-soluble ferrocenylimine-Rh(I) complexes as aqueous-biphasic hydroformylation catalyst precursors

Journal of Organometallic Chemistry, 2015, 796, 26-32


Leah C. Matsinha, Jincheng Mao, Selwyn F. Mapolie and Gregory S. Smith

Water-Soluble Palladium(II) Sulfhonated Thiosemicarbazone Complexes: Facile Synthesis and Preliminary Catalytic Studies in the Suzuki-Miyaura Cross-Coupling Reaction in Water

European Journal of Inorganic Chemistry, 2015, 4088-4094


Latisa Maqeda, Banothile C.E. Makhubela and Gregory S. Smith

Synthesis, characterization and evaluation of fluorocarbon-containing rhodium(I) complexes for biphasic hydroformylation reactions

Polyhedron, 2015, 91, 128-135


Leah C. Matsinha, Selwyn F. Mapolie and Gregory S. Smith

Recoverable and Recyclable Water-Soluble Sulphonated Salicylaldimine Rh(I) Complexes for 1-Octene Hydroformylation in Aqueous Biphasic Media

Dalton Transactions, 2015, 44, 1240-1248  (Open Access)


Linhua Lu, Prinessa Chellan, Gregory Smith*, Xiang Zhang, Hong yan and Jincheng Mao*

Thiosemicarbazone salicylaldiminato palladium(II)-catalysed alkynylation couplings between arylboronic acids and alkynes or alkynyl carboxylic acids

Tetrahedron, 2014, 70, 5980-5985


Leah C. Matsinha, Peter Malatji, Alan T. Hutton, Gerhard A. Venter, Selwyn F. Mapolie and Gregory S. Smith

Water-Soluble Half-Sandwich Ru-Arene complexes: Synthesis, Structure, Electrochemistry, DFT Studies, and Aqueous Phase Hydroformylation of 1-Octene

European Journal of Inorganic Chemistry, 2013, 4318-4328


Hong yan, Prinessa Chellan, Tingyi Li, Jincheng Mao, Kelly Chibale and Gregory Smith

Cyclometallated Pd(II) thiosemicarbazone complexes: new catalyst precursors for Suzuki-coupling reactions

Tetrahedron Letters, 2013, 54, 154-157


Emma B. Hager, Banothile C.E. Makhubela and Gregory S. Smith*

Aqueous-phase Hydroformylation of 1-octene using hydrophilic sulfonate salicylaldimine dendrimers

Dalton Transactions, 2012, 41, 13927-13935


Banothile C.E. Makhubela, Anwar M. Jardine, Gunnar Westman and Gregory S. Smith

Hydroformylation of 1-octene using low-generation Rh(I) Metallodendritic Catalysts based on a Tris-2-(2-pyridyliminoehtyl)amine scaffold

Dalton Transactions, 2012, 41, 10715-10723


Banothile C.E. Makhubela, Anwar Jardine and Gregory S. Smith

Rh(I) Complexes Supported on a Biopolymer as Recyclable and Selective Hydroformylation Catalysts

Green Chemistry, 2012, 14, 338-347


Banothile C.E. Makhubela, Anwar Jardine and Gregory S. Smith.

Pd Nanosized Particles Supported on Chitosan and 6-Deoxy-6-Amino Chitosan as Recyclable Catalysts for Suzuki-Miyaura and Heck Cross-coupling Reactions.

Applied Catalysis A: General, 2011, 393, 231-241


Guanlei Xie, Prinessa Chellan, Jincheng Mao, Kelly Chibale and Gregory S. Smith

Thiosemicarbazone Salicylaldiminato-Palladium(II)-Catalyzed Mizoroki-Heck Reactions

Advanced Synthesis and Catalysis, 2010, 352, 1641-1647

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