Nigel P. Botting

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Organization: University of St Andrews

Department: School of Chemistry

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Chemicals
References

An improved procedure for the preparation of β-thiohydroximates for glucosinolate synthesis

Co-reporter:Susan E. Cobb, Kate F. Morgan, Nigel P. Botting

Tetrahedron Letters 2011 Volume 52(Issue 14) pp:1605-1607

Publication Date(Web):6 April 2011

DOI:10.1016/j.tetlet.2011.01.117

A novel and simple method is described for the synthesis of β-thiohydroximates from oximes and 2,3,4,6-tetra-O-acetyl-1-thio-β-d-glucopyranose, which are key intermediates in the synthesis of glucosinolates. The procedure involves the in situ formation of an oximyl chloride from the oxime, using inexpensive bleach, which is then reacted directly under basic conditions with the thioglucopyranose.

Iridium-catalyzed C–H activation/borylation/oxidation for the preparation of bis-protected phloroglucinol derivatives

Co-reporter:Laura J. Marshall, Karl M. Cable, Nigel P. Botting

Tetrahedron Letters 2010 Volume 51(Issue 20) pp:2690-2692

Publication Date(Web):19 May 2010

DOI:10.1016/j.tetlet.2010.03.049

The preparation of bis-protected phloroglucinol derivatives from a range of protected resorcinol substrates is presented. Functionalization was achieved via a two-step, one-pot iridium-catalyzed C–H activation/borylation/oxidation protocol. Our system gave high conversions to the arylboronic esters and good yields of the desired phenols following subsequent oxidation. A range of common protecting group categories was studied including alkyl, silyl, ether and ester.

A versatile synthesis of [2,3,4-13C3]isoflavones

Co-reporter:Nawaf Al-Maharik

Journal of Labelled Compounds and Radiopharmaceuticals 2010 Volume 53( Issue 3) pp:95-103

Publication Date(Web):

DOI:10.1002/jlcr.1732

Abstract

A flexible synthetic method is presented, which allows all the key isoflavones (daidzein, genistein, glycitein, formononetin and biochanin A) to be prepared in ¹³C-labelled form via the same route, involving the thallium(III)-mediated oxidative rearrangement of a key chalcone intermediate. This method results in the incorporation of ¹³C atoms at the 2, 3 and 4 positions of the isoflavone skeleton. We also report the first syntheses of ¹³C-labelled versions of the daidzein metabolites, equol and ODMA. Copyright © 2009 John Wiley & Sons, Ltd.

The first synthesis of [2-13C]phloroglucinol

Co-reporter:Laura J. Marshall;Karl M. Cable

Journal of Labelled Compounds and Radiopharmaceuticals 2010 Volume 53( Issue 10) pp:601-604

Publication Date(Web):

DOI:10.1002/jlcr.1788

Abstract

A fast and efficient synthesis of [2-¹³C]phloroglucinol in six steps from acyclic, non-aromatic precursors is presented, with regioselective placement of a ¹³C-atom in the aromatic ring. The ¹³C-label was introduced by reaction of [¹³C]methyl iodide with methyl 4-chloroformyl butyrate. Cyclization via an intramolecular Claisen condensation, followed by aromatization gave [2-¹³C]resorcinol. Following subsequent methylation of the hydroxyl groups, the third hydroxyl group was introduced using an iridium-catalysed C–H activation/borylation/oxidation procedure. Demethylation then yielded the desired [2-¹³C]phloroglucinol. Copyright © 2010 John Wiley & Sons, Ltd.

First synthesis of [1,3,5-13C3]gallic acid

Co-reporter:Laura J. Marshall, Karl M. Cable and Nigel P. Botting

Organic & Biomolecular Chemistry 2009 vol. 7(Issue 4) pp:785-788

Publication Date(Web):12 Jan 2009

DOI:10.1039/B813991A

An efficient and high-yielding synthesis for [1,3,5-13C3]gallic acid from non-aromatic precursors is presented. [3,5-13C2]4H-Pyran-4-one was first prepared from the reaction between triethyl orthoformate and [1,3-13C2]acetone. The third 13C-atom was introduced into the ring by reaction of the pyranone with diethyl [2-13C]malonate. The resulting ethyl 4-hydroxy-[1,3,5-13C3]benzoate was brominated in the 3- and 5-positions to give ethyl 3,5-dibromo-4-hydroxy-[1,3,5-13C3]benzoate. Subsequent hydrolysis of the ester and substitution of the bromine atoms with hydroxyl groups was achieved under basic conditions in a single step to yield the desired [1,3,5-13C3]gallic acid. The synthesis of [2,6-13C2]4H-pyran-4-one is also presented to demonstrate the potential of the methodology for the regioselective placement of 13C-atoms into benzene rings.

The synthesis of substituted phenols from pyranone precursors

Co-reporter:Laura J. Marshall, Karl M. Cable, Nigel P. Botting

Tetrahedron 2009 65(39) pp: 8165-8170

Publication Date(Web):

DOI:10.1016/j.tet.2009.07.083

The synthesis of novel hexa-13C-labelled glucosinolates from [13C6]-d-glucose

Co-reporter:Qingzhi Zhang, Tomas Lebl, Agnieszka Kulczynska, Nigel P. Botting

Tetrahedron 2009 65(25) pp: 4871-4876

Publication Date(Web):

DOI:10.1016/j.tet.2009.04.043

An Efficient Method for the Glycosylation of Isoflavones

Co-reporter:Nawaf Al-Maharik

European Journal of Organic Chemistry 2008 Volume 2008( Issue 33) pp:5622-5629

Publication Date(Web):

DOI:10.1002/ejoc.200800803

Abstract

The isoflavone phytoestrogens are still of current interest for their positive and negative health benefits. However, there are still many unanswered questions regarding their absorption, metabolism and bioavailability. Studies in this area require access to samples of both the isoflavone 7-O-glucosides, the form found in plants and the 7-O-glucuronides, which are important mammaliam metabolites. A new efficient, high-yielding glycosylation procedure is described for isoflavones, which employs 2,2,2-trifluoro-N-(p-methoxyphenyl)acetamidates as the glycosyl donors. This methodology was used to prepare the 7-O-glycosides of the three main isoflavones, daidzein, genistein and glycitein. The isoflavones were protected with hexanoyl groups which improved their solubility in organic solvents and improved the efficiency of the reaction. The same methodology was then adapted for the synthesis of the analogous 7-O-glucuronides. The new synthesis will provide access to large quantities of these compounds for further biological studies. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)

The synthesis of isotopically labelled glucosinolates for analysis and metabolic studies

Co-reporter:Nigel P. Botting;John J. Morrison;Avril A. B. Robertson

Journal of Labelled Compounds and Radiopharmaceuticals 2007 Volume 50(Issue 5‐6) pp:260-263

Publication Date(Web):30 JUL 2007

DOI:10.1002/jlcr.1225

Glucosinolates are dietary natural products with important cancer chemoprevention properties. The syntheses of a number of stable isotopically labelled (²H, ¹³C) glucosinolates, and their desulfo-analogues, are described. These compounds are used as internal standards for analysis and for metabolic studies. Copyright © 2007 John Wiley & Sons, Ltd.

The synthesis of [3,4,1′-13C3]genistein

Co-reporter:Mark F. Oldfield;Lirong Chen

Journal of Labelled Compounds and Radiopharmaceuticals 2007 Volume 50(Issue 14) pp:1266-1271

Publication Date(Web):4 OCT 2007

DOI:10.1002/jlcr.1460

A facile synthesis is described for [3,4,1′-¹³C₃]genistein for use as an internal standard in isoflavone analysis by mass spectrometric methods. Ethyl 4-hydroxy[1-¹³C]benzoate was first prepared from the reaction of diethyl [2-¹³C]malonate and 4H-pyran-4-one. Two further ¹³C atoms were incorporated using potassium [¹³C]cyanide as the source to give 4′-benzyloxy-[1,2,1′-¹³C₃]phenylacetonitrile. [3,4,1′-¹³C₃]Genistein was then constructed through coupling of the isotopically labelled phenylacetonitrile with phloroglucinol under Hoesch conditions, followed by formylation and cyclization. Copyright © 2007 John Wiley & Sons, Ltd.

The synthesis of glucosinolates deuterium labelled in the glucose fragment

Co-reporter:Avril A. B. Robertson

Journal of Labelled Compounds and Radiopharmaceuticals 2006 Volume 49(Issue 13) pp:1201-1211

Publication Date(Web):14 NOV 2006

DOI:10.1002/jlcr.1141

A facile synthesis is described for 2,3,4,6-tetra-O-acetyl-thio-β-D-[1-²H,6-²H₂]glucopyranose, which has been used to make an isotopically labelled desulphoglucosinolate, [1′-²H,6′-²H₂]desulfogluconasturtiin. This isotopically labelled building block can be employed to make any glucosinolate or desulfoglucosinolate for use as internal standards for MS based analytical methods. Copyright © 2006 John Wiley & Sons, Ltd.

The synthesis of [phenyl-2H5]gluconasturtiin and its metabolites for metabolic studies

Co-reporter:John J. Morrison

Journal of Labelled Compounds and Radiopharmaceuticals 2005 Volume 48(Issue 12) pp:897-907

Publication Date(Web):22 SEP 2005

DOI:10.1002/jlcr.1004

The synthesis of a deuterium labelled glucosinolate, [²H₅]gluconasturtiin, is described starting from [²H₅]bromobenzene. The potential metabolites of the glucosinolate, namely the [phenyl-²H₅]phenethyl isothiocyanate, nitrile, thiocyanate, amine and the mercapturic acid conjugate of phenethyl isothiocyanate are also described. This series of compounds has been prepared for use in feeding studies to examine the mammalian metabolism of gluconasturtiin and search for new biomarkers of exposure. Copyright © 2005 John Wiley & Sons, Ltd.

The synthesis of multiply 13C-labelled plant and mammalian lignans as internal standards for LC-MS and GC-MS analysis

Co-reporter:Nigel P. Botting;Tara Fryatt

Journal of Labelled Compounds and Radiopharmaceuticals 2005 Volume 48(Issue 13) pp:951-969

Publication Date(Web):12 OCT 2005

DOI:10.1002/jlcr.1007

The syntheses of multiply ¹³C-labelled derivatives of the two mammalian lignans, enterolactone and enterodiol, and two of their plant lignan precursors, secoisolariciresinol and matairesinol, are described. Three ¹³C atoms were incorporated into each lignan using potassium [¹³C]cyanide as the source for all of the ¹³C atoms. The compounds were prepared for use as internal standards in the LC-MS and GC-MS analysis of lignans. Copyright © 2005 John Wiley & Sons, Ltd.

First synthesis of [1,3,5-13C3]gallic acid

Co-reporter:Laura J. Marshall, Karl M. Cable and Nigel P. Botting

Organic & Biomolecular Chemistry 2009 - vol. 7(Issue 4) pp:NaN788-788

Publication Date(Web):2009/01/12

DOI:10.1039/B813991A