Selective activation of glycosyl donors utilising electrochemical techniques: a study of the thermodynamic oxidation potentials of a range of chalcoglycosides.
A series of six chalcoglycosides (phenyl-2,3,4,6-tetra-O-benzoyl-1-seleno-beta-D-glucopyranoside, phenyl-2,3,4,6-tetra-O-benzyl-1-seleno-beta-D-glucopyranoside, phenyl-2,3,4,6-tetra-O-benzyl-1-thio-beta-D-glucopyranoside, p-tolyl-2,3,4,6-O-benzoyl-1-thio-beta-D-glucopyranoside, p-tolyl-2,3,4,6-O-ben...
| Main Authors: | , , , , |
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| Format: | Journal article |
| Language: | English |
| Published: |
2004
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| _version_ | 1797103065518571520 |
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| author | France, R Rees, N Wadhawan, J Fairbanks, A Compton, R |
| author_facet | France, R Rees, N Wadhawan, J Fairbanks, A Compton, R |
| author_sort | France, R |
| collection | OXFORD |
| description | A series of six chalcoglycosides (phenyl-2,3,4,6-tetra-O-benzoyl-1-seleno-beta-D-glucopyranoside, phenyl-2,3,4,6-tetra-O-benzyl-1-seleno-beta-D-glucopyranoside, phenyl-2,3,4,6-tetra-O-benzyl-1-thio-beta-D-glucopyranoside, p-tolyl-2,3,4,6-O-benzoyl-1-thio-beta-D-glucopyranoside, p-tolyl-2,3,4,6-O-benzyl-1-thio-beta-D-glucopyranoside, and phenyl-2,3,4,6-O-benzyl-beta-D-glucopyranoside) are voltammetrically interrogated in dimethyl sulfoxide, so as to determine their formal (i.e. thermodynamic) redox potentials. The electrochemical oxidation of the chalcoglycoside is shown to follow an overall EC-type mechanism, in which the electro-generated cation radical undergoes an irreversible carbon-chalcogen bond rupture to produce the corresponding glycosyl cation, which may react further. The kinetics of the initial heterogeneous electron transfer process and subsequent irreversible homogeneous chemical degradation of the radical cation are reported, with values for the standard electrochemical rate constant k(0) in the order of 10(-2) cm s(-1) and the first order homogeneous rate constant, k(1), of the order of 10(3) s(-1). The formal oxidation potentials were found to vary according to the identity of the chalcogenide, such that OPh > SPh similar to STol > SePh. |
| first_indexed | 2024-03-07T06:14:46Z |
| format | Journal article |
| id | oxford-uuid:f0b3cdcd-3433-471d-a9dd-c15690781e8d |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T06:14:46Z |
| publishDate | 2004 |
| record_format | dspace |
| spelling | oxford-uuid:f0b3cdcd-3433-471d-a9dd-c15690781e8d2022-03-27T11:50:15ZSelective activation of glycosyl donors utilising electrochemical techniques: a study of the thermodynamic oxidation potentials of a range of chalcoglycosides.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:f0b3cdcd-3433-471d-a9dd-c15690781e8dEnglishSymplectic Elements at Oxford2004France, RRees, NWadhawan, JFairbanks, ACompton, RA series of six chalcoglycosides (phenyl-2,3,4,6-tetra-O-benzoyl-1-seleno-beta-D-glucopyranoside, phenyl-2,3,4,6-tetra-O-benzyl-1-seleno-beta-D-glucopyranoside, phenyl-2,3,4,6-tetra-O-benzyl-1-thio-beta-D-glucopyranoside, p-tolyl-2,3,4,6-O-benzoyl-1-thio-beta-D-glucopyranoside, p-tolyl-2,3,4,6-O-benzyl-1-thio-beta-D-glucopyranoside, and phenyl-2,3,4,6-O-benzyl-beta-D-glucopyranoside) are voltammetrically interrogated in dimethyl sulfoxide, so as to determine their formal (i.e. thermodynamic) redox potentials. The electrochemical oxidation of the chalcoglycoside is shown to follow an overall EC-type mechanism, in which the electro-generated cation radical undergoes an irreversible carbon-chalcogen bond rupture to produce the corresponding glycosyl cation, which may react further. The kinetics of the initial heterogeneous electron transfer process and subsequent irreversible homogeneous chemical degradation of the radical cation are reported, with values for the standard electrochemical rate constant k(0) in the order of 10(-2) cm s(-1) and the first order homogeneous rate constant, k(1), of the order of 10(3) s(-1). The formal oxidation potentials were found to vary according to the identity of the chalcogenide, such that OPh > SPh similar to STol > SePh. |
| spellingShingle | France, R Rees, N Wadhawan, J Fairbanks, A Compton, R Selective activation of glycosyl donors utilising electrochemical techniques: a study of the thermodynamic oxidation potentials of a range of chalcoglycosides. |
| title | Selective activation of glycosyl donors utilising electrochemical techniques: a study of the thermodynamic oxidation potentials of a range of chalcoglycosides. |
| title_full | Selective activation of glycosyl donors utilising electrochemical techniques: a study of the thermodynamic oxidation potentials of a range of chalcoglycosides. |
| title_fullStr | Selective activation of glycosyl donors utilising electrochemical techniques: a study of the thermodynamic oxidation potentials of a range of chalcoglycosides. |
| title_full_unstemmed | Selective activation of glycosyl donors utilising electrochemical techniques: a study of the thermodynamic oxidation potentials of a range of chalcoglycosides. |
| title_short | Selective activation of glycosyl donors utilising electrochemical techniques: a study of the thermodynamic oxidation potentials of a range of chalcoglycosides. |
| title_sort | selective activation of glycosyl donors utilising electrochemical techniques a study of the thermodynamic oxidation potentials of a range of chalcoglycosides |
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