EPSRC Reference: |
GR/R73263/01 |
Title: |
Selective Oxidation Processes of Alkenes and Alcohols through AMine Catalysis and Beyond |
Principal Investigator: |
Aggarwal, Professor VK |
Other Investigators: |
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Researcher Co-Investigators: |
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Project Partners: |
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Department: |
Chemistry |
Organisation: |
University of Bristol |
Scheme: |
Standard Research (Pre-FEC) |
Starts: |
01 April 2002 |
Ends: |
31 December 2005 |
Value (£): |
264,043
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EPSRC Research Topic Classifications: |
Chemical Synthetic Methodology |
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EPSRC Industrial Sector Classifications: |
Chemicals |
No relevance to Underpinning Sectors |
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Related Grants: |
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Panel History: |
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Summary on Grant Application Form |
During our investigations on iminium salt-mediated epoxidations, we discovered that amines themselves were capable of catalysing the epoxidation of alkenes. We now wish to confirm the mechanism of the process, synthesise a range of chiral amines to improve the enantioselectivity and investigate the regioselectivity in mono-epoxidation of polyolefins and diastereoselectivity of chiral alkenes. From the proposed mechanism (which involves amine radical cations as the true catalysts and amine radical cation-alkene complexes) it is anticipated that the latter two process should occur with high selectivity and in particular we expect complementary stereocontrol to that which is available using current methods. We have also discovered that amines are capable of catalysing the oxidation of alcohols into aldehydes and ketones and so with the range of chiral amines from above we will seek selective catalysts for (i) oxidation of meso diols, (ii) kinetic resolution of secondary alcohols and (iii) regioselective monooxidation of polyols. There are few methods for carrying out (i) and (iii) at present. We have also discovered that epoxidations can also be catalysed by nitrosamines/hv. This will be investigated further, in particular with alternative oxidants which generate less waste including H202. Alternative methods for generating amine radical cations (photolysis of thione carbamates, photolysis with triplet sensitizers, and electrochemical methods) which are also compatible with epoxidation using oxidants including H202will also be investigated as they should lead to even more environmentally benign processes. These alternative methods for aminium formation will be applied to asymmetric Dials Alder and cyclopropanation reactions. Finally, we will investigate the possibility of developing new processes based on the epoxidation reaction we have discovered. In particular we will investigate amine radical cation catalysed aziridination and episulfide formation from alkenes and amine/sulfide nucleophiles bearing good leaving groups. This latter process would be unique as it uses stable, non-toxic intermediates to prepare highly reactive aziridines and episulfides.
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Key Findings |
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Potential use in non-academic contexts |
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Impacts |
Description |
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Summary |
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Date Materialised |
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Sectors submitted by the Researcher |
This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk
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Project URL: |
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Further Information: |
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Organisation Website: |
http://www.bris.ac.uk |