Catalytic Hydrogenations of Organic and Inorganic C=O Bonds

Lead Research Organisation: Imperial College London
Department Name: Dept of Chemistry

Abstract

New trialkylstannylium [R3Sn]+ triflates, triflimides, and tetra(fluoroaryl)borates will be synthesised using well-established organotin synthetic chemistry, which allows access to tin hydrides (simple inorganic reductions) and other counterions (salt metathesis). Reactions under catalytic direct hydrogenation conditions (H2, elevated T), with organic carbonyls, esters, and amides will be monitored primarily with 1H and 119Sn NMR. The same tin catalysts will be used for CO reduction, which will also utilise co-catalytic simple transition metal carbonyls [e.g. Fe(CO)5, Co2(CO)8] and will be carried out at 4-150 bar of syngas (CO+H2) 100-200 degrees C; this will be monitored by in situ GC-MS/IR analysis of gas aliquots (collaboration Christopher Tighe, Chem Eng) alongside 1H and 13C NMR spectroscopy of products mixtures.

Publications

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publication icon
Cooper RT (2017) Hydrogen activation using a novel tribenzyltin Lewis acid. in Philosophical transactions. Series A, Mathematical, physical, and engineering sciences

Studentship Projects

Project Reference Relationship Related To Start End Student Name
EP/N509486/1 01/10/2016 31/03/2022
1805095 Studentship EP/N509486/1 01/10/2016 30/09/2019 Joshua Sapsford
 
Description New stannylium Lewis acids for 'frustrated Lewis pair' methodologies have been found to be moisture tolerant under harsh conditions (strong Lewis bases + high temperatures). These Lewis acids will catalyse direct reductive aminations of carbonyls, using solvents, reagents and dihydrogen used as supplied without further purification.

The mechanism of hydrogen activation using these stannylium Lewis acids has been investigated. The transition state is ternary, and the different reactivities observed with different bases has been rationalised.
Exploitation Route I have made significant progress in understanding the mechansim of FLP reactivity with tin Lewis acids. Others will be able to use this information to design more effective stannylium catalysts. This is what I will be working on until the end of my PhD.
Sectors Chemicals

URL http://www.ashleyresearchgroup.org.uk/