Matthew McGrath - Academia.edu (original) (raw)
Papers by Matthew McGrath
Beilstein Journal of Organic Chemistry, 2007
Background Chiral base desymmetrisation of dimethyl sulfoximines could provide a general route to... more Background Chiral base desymmetrisation of dimethyl sulfoximines could provide a general route to chiral, enantioenriched dialkyl sulfoximines with potential for use in asymmetric catalysis. Results Asymmetric deprotonation of N-trialkylsilyl dimethyl sulfoximines with either enantiomer of lithium N,N-bis(1-phenylethyl)amide in the presence of lithium chloride affords enantioenriched sulfoximines on electrophilic trapping. Ketones, ketimines, trialkylsilyl chlorides and activated alkyl halides may be used as electrophiles in the reaction. Furthermore, a modified Horner-Emmons methodology was investigated. Conclusion Simple chiral lithium amides afford products with enantiomeric excesses of up to 70%, illustrating that chiral base desymmetrisation of dimethyl sulfoximines is possible.
Synthesis, 2006
... We are particularly grateful to Susannah Coote for some characterisation data. References. 1 ... more ... We are particularly grateful to Susannah Coote for some characterisation data. References. 1 Hoppe D, Hintze F, Tebben P,Angew. Chem., Int. Ed. Engl. 1990, 29: 1422. For reviews, see: 2a Hoppe D, Hense T,Angew. Chem., Int. Ed. Engl. 1997, 36: 2282. ...
Synthesis, 2011
Abstract Enantiomerically enriched forms of a sulfoximine-based myristic acid analogue are prepar... more Abstract Enantiomerically enriched forms of a sulfoximine-based myristic acid analogue are prepared using either an asymmetric desymmetrization with a chiral base, or an enantioselective oxidation procedure as key steps. Additionally, a variety of 2-oxa-2-alkyl ...
Organic & Biomolecular Chemistry, 2006
... Cédric Genet, Matthew J. McGrath and Peter O'Brien*. Department of Chemistry, University... more ... Cédric Genet, Matthew J. McGrath and Peter O'Brien*. Department of Chemistry, University of York, Heslington, York, UK YO10 5DD. E-mail: paob1@york.ac.uk; Fax: +44 1904 432165; Tel: +44 1904 432535. ... for lithiation of phosphine boranes24,25 and by Wilkinson et al. ...
The Journal of Organic Chemistry, 2003
European Journal of Organic Chemistry, 2011
The preparation of optically pure (–)-3-[(2R)-2-methoxy-2-phenylethoxy] phenol from resorcinol mo... more The preparation of optically pure (–)-3-[(2R)-2-methoxy-2-phenylethoxy] phenol from resorcinol monobenzoate and its conversion into diastereoisomeric tetraalkoxyresorcin [4] arenes together with proof of the absolute configurations of the products is reported. The ...
Chirality, 2003
Examination of the chemistry of a number of Australian insect species provided examples of unusua... more Examination of the chemistry of a number of Australian insect species provided examples of unusual structures and encouraged determinations of their absolute stereochemistry by stereocontrolled syntheses and chromatographic comparisons.
Australian Journal of Entomology, 2008
Cuticular hydrocarbon components in beetles of six Australian melolonthines whose larvae damage s... more Cuticular hydrocarbon components in beetles of six Australian melolonthines whose larvae damage sugarcane, Antitrogus parvulus (Britton), A. consanguineus (Blackburn), Lepidiota negatoria (Blackburn), L. picticollis (Lea), L. noxia (Britton) and Dermolepida alborhirtum (Arrow), are identified and compared. These species demonstrate species-specific cuticular hydrocarbon profiles with a number of unprecedented structures. Major components have been identified as polymethylated hydrocarbons, 3-methyl substituted n-alkanes, 9,10-allenes and the corresponding C9 alkenes. The similarity of these compounds shows some correlation with the phylogeny of the beetles, but two polymethylated C22 hydrocarbons are unique to A. parvulus. One C25 allene is shown to have a potential role in mate recognition in A. consanguineus.
The enantiomeric excesses for compounds 2c and 2d given in are incorrect. The ee should be 60% fo... more The enantiomeric excesses for compounds 2c and 2d given in are incorrect. The ee should be 60% for the experiment described in , entry 2 for 2c and 55-63% for the experiment described for 2d. Repeated experiments using chiral lithium amide 5 and 2c under optimal conditions gave 2c in 82% yield and 68% ee in one trial and in 58% yield and 55% ee in another. Reexamination of the HPLC traces of the products makes this evident in the case of 2c and was confirmed by comparison with new HPLC measurements under different separation conditions (Agilent 1200 instrument, Chiralcel OD-H, 1.0 mL.min -1 , 98:2 heptane:i-PrOH, t R1 20.7 min, t R2 23.4 min, 210 nm) whereas the ee of 2d was re-determined under different separation conditions on an alternative instrument (Agilent 1200 instrument, Chiralcel OD-H, 1.0 mL.min -1 , 97:3 heptane:i-PrOH, t R1 21.4 min, t R2 25.2 min, 210 nm) to provide a more accurate result arising from better peak resolution. Efficient separation of 2d appears to depend to some extent on the solvent used for the sample.
Brown allylation methodology has been employed to provide seven of the eight possible isomers of ... more Brown allylation methodology has been employed to provide seven of the eight possible isomers of the (ZE)(EZ) spiroacetal system representing the CD ring fragment (C17–C28) of spongistatin 1. The stereochemistry of the isomers follows from high–field NMR examinations which furnish insights into the trends in the NMR data for these ketal structures.
![Research paper thumbnail of Mannich andO-Alkylation Reactions of Tetraalkoxyresorcin[4]arenes – The Use of Some Products in Ligand-Assisted Reactions](https://attachments.academia-assets.com/49563414/thumbnails/1.jpg)
](European Journal of Organic Chemistry, 2006
Tetrahedron Letters, 2003
Intermediates involved in the conversion of 3-alkyl-3,4-dihydro-2H-1,3-benz[e]oxazines into 2-N,N... more Intermediates involved in the conversion of 3-alkyl-3,4-dihydro-2H-1,3-benz[e]oxazines into 2-N,N-dialkylaminomethylphenol derivatives, using morpholine and other high boiling secondary amines, have been identified and characterised. Additional experiments have established the involvement of o-quinone methide intermediates in the retro-Mannich reactions. Axially chiral resorcinarenes have been prepared by utilising the exchange reactions.
Cheminform, 2003
For Abstract see ChemInform Abstract in Full Text.
Journal of Organic Chemistry, 2004
Three new (+)-sparteine-like diamines were prepared from (-)-cytisine and evaluated as sparteine ... more Three new (+)-sparteine-like diamines were prepared from (-)-cytisine and evaluated as sparteine surrogates in the alpha-lithiation rearrangement of cyclooctene oxide and the palladium(II)/diamine catalyzed oxidative kinetic resolution of 1-indanol. The new diamines exhibited opposite enantioselectivity to that observed with (-)-sparteine but increasing the steric hindrance of the N-alkyl group beyond N-Et had a detrimental effect on enantioselectivity. The optimal N-Me diamine was evaluated with much success in five other (-)-sparteine-mediated processes involving different metals (lithium, magnesium, and copper) and different types of reaction mechanisms.
Journal of The American Chemical Society, 2005
A novel ligand exchange approach to catalytic asymmetric deprotonation-electrophilic trapping has... more A novel ligand exchange approach to catalytic asymmetric deprotonation-electrophilic trapping has been developed that uses 1.3 equiv of s-BuLi, 0.06-0.2 equiv of chiral diamine ((-)-sparteine or a (+)-sparteine surrogate), and 1.2 equiv of achiral bispidine. The methodology is illustrated with a range of examples and gives access to either enantiomer of useful chiral products in good yields using substoichiometric amounts of chiral diamines.
Beilstein Journal of Organic Chemistry, 2007
Background Chiral base desymmetrisation of dimethyl sulfoximines could provide a general route to... more Background Chiral base desymmetrisation of dimethyl sulfoximines could provide a general route to chiral, enantioenriched dialkyl sulfoximines with potential for use in asymmetric catalysis. Results Asymmetric deprotonation of N-trialkylsilyl dimethyl sulfoximines with either enantiomer of lithium N,N-bis(1-phenylethyl)amide in the presence of lithium chloride affords enantioenriched sulfoximines on electrophilic trapping. Ketones, ketimines, trialkylsilyl chlorides and activated alkyl halides may be used as electrophiles in the reaction. Furthermore, a modified Horner-Emmons methodology was investigated. Conclusion Simple chiral lithium amides afford products with enantiomeric excesses of up to 70%, illustrating that chiral base desymmetrisation of dimethyl sulfoximines is possible.
Synthesis, 2006
... We are particularly grateful to Susannah Coote for some characterisation data. References. 1 ... more ... We are particularly grateful to Susannah Coote for some characterisation data. References. 1 Hoppe D, Hintze F, Tebben P,Angew. Chem., Int. Ed. Engl. 1990, 29: 1422. For reviews, see: 2a Hoppe D, Hense T,Angew. Chem., Int. Ed. Engl. 1997, 36: 2282. ...
Synthesis, 2011
Abstract Enantiomerically enriched forms of a sulfoximine-based myristic acid analogue are prepar... more Abstract Enantiomerically enriched forms of a sulfoximine-based myristic acid analogue are prepared using either an asymmetric desymmetrization with a chiral base, or an enantioselective oxidation procedure as key steps. Additionally, a variety of 2-oxa-2-alkyl ...
Organic & Biomolecular Chemistry, 2006
... Cédric Genet, Matthew J. McGrath and Peter O'Brien*. Department of Chemistry, University... more ... Cédric Genet, Matthew J. McGrath and Peter O'Brien*. Department of Chemistry, University of York, Heslington, York, UK YO10 5DD. E-mail: paob1@york.ac.uk; Fax: +44 1904 432165; Tel: +44 1904 432535. ... for lithiation of phosphine boranes24,25 and by Wilkinson et al. ...
The Journal of Organic Chemistry, 2003
European Journal of Organic Chemistry, 2011
The preparation of optically pure (–)-3-[(2R)-2-methoxy-2-phenylethoxy] phenol from resorcinol mo... more The preparation of optically pure (–)-3-[(2R)-2-methoxy-2-phenylethoxy] phenol from resorcinol monobenzoate and its conversion into diastereoisomeric tetraalkoxyresorcin [4] arenes together with proof of the absolute configurations of the products is reported. The ...
Chirality, 2003
Examination of the chemistry of a number of Australian insect species provided examples of unusua... more Examination of the chemistry of a number of Australian insect species provided examples of unusual structures and encouraged determinations of their absolute stereochemistry by stereocontrolled syntheses and chromatographic comparisons.
Australian Journal of Entomology, 2008
Cuticular hydrocarbon components in beetles of six Australian melolonthines whose larvae damage s... more Cuticular hydrocarbon components in beetles of six Australian melolonthines whose larvae damage sugarcane, Antitrogus parvulus (Britton), A. consanguineus (Blackburn), Lepidiota negatoria (Blackburn), L. picticollis (Lea), L. noxia (Britton) and Dermolepida alborhirtum (Arrow), are identified and compared. These species demonstrate species-specific cuticular hydrocarbon profiles with a number of unprecedented structures. Major components have been identified as polymethylated hydrocarbons, 3-methyl substituted n-alkanes, 9,10-allenes and the corresponding C9 alkenes. The similarity of these compounds shows some correlation with the phylogeny of the beetles, but two polymethylated C22 hydrocarbons are unique to A. parvulus. One C25 allene is shown to have a potential role in mate recognition in A. consanguineus.
The enantiomeric excesses for compounds 2c and 2d given in are incorrect. The ee should be 60% fo... more The enantiomeric excesses for compounds 2c and 2d given in are incorrect. The ee should be 60% for the experiment described in , entry 2 for 2c and 55-63% for the experiment described for 2d. Repeated experiments using chiral lithium amide 5 and 2c under optimal conditions gave 2c in 82% yield and 68% ee in one trial and in 58% yield and 55% ee in another. Reexamination of the HPLC traces of the products makes this evident in the case of 2c and was confirmed by comparison with new HPLC measurements under different separation conditions (Agilent 1200 instrument, Chiralcel OD-H, 1.0 mL.min -1 , 98:2 heptane:i-PrOH, t R1 20.7 min, t R2 23.4 min, 210 nm) whereas the ee of 2d was re-determined under different separation conditions on an alternative instrument (Agilent 1200 instrument, Chiralcel OD-H, 1.0 mL.min -1 , 97:3 heptane:i-PrOH, t R1 21.4 min, t R2 25.2 min, 210 nm) to provide a more accurate result arising from better peak resolution. Efficient separation of 2d appears to depend to some extent on the solvent used for the sample.
Brown allylation methodology has been employed to provide seven of the eight possible isomers of ... more Brown allylation methodology has been employed to provide seven of the eight possible isomers of the (ZE)(EZ) spiroacetal system representing the CD ring fragment (C17–C28) of spongistatin 1. The stereochemistry of the isomers follows from high–field NMR examinations which furnish insights into the trends in the NMR data for these ketal structures.
European Journal of Organic Chemistry, 2006
Tetrahedron Letters, 2003
Intermediates involved in the conversion of 3-alkyl-3,4-dihydro-2H-1,3-benz[e]oxazines into 2-N,N... more Intermediates involved in the conversion of 3-alkyl-3,4-dihydro-2H-1,3-benz[e]oxazines into 2-N,N-dialkylaminomethylphenol derivatives, using morpholine and other high boiling secondary amines, have been identified and characterised. Additional experiments have established the involvement of o-quinone methide intermediates in the retro-Mannich reactions. Axially chiral resorcinarenes have been prepared by utilising the exchange reactions.
Cheminform, 2003
For Abstract see ChemInform Abstract in Full Text.
Journal of Organic Chemistry, 2004
Three new (+)-sparteine-like diamines were prepared from (-)-cytisine and evaluated as sparteine ... more Three new (+)-sparteine-like diamines were prepared from (-)-cytisine and evaluated as sparteine surrogates in the alpha-lithiation rearrangement of cyclooctene oxide and the palladium(II)/diamine catalyzed oxidative kinetic resolution of 1-indanol. The new diamines exhibited opposite enantioselectivity to that observed with (-)-sparteine but increasing the steric hindrance of the N-alkyl group beyond N-Et had a detrimental effect on enantioselectivity. The optimal N-Me diamine was evaluated with much success in five other (-)-sparteine-mediated processes involving different metals (lithium, magnesium, and copper) and different types of reaction mechanisms.
Journal of The American Chemical Society, 2005
A novel ligand exchange approach to catalytic asymmetric deprotonation-electrophilic trapping has... more A novel ligand exchange approach to catalytic asymmetric deprotonation-electrophilic trapping has been developed that uses 1.3 equiv of s-BuLi, 0.06-0.2 equiv of chiral diamine ((-)-sparteine or a (+)-sparteine surrogate), and 1.2 equiv of achiral bispidine. The methodology is illustrated with a range of examples and gives access to either enantiomer of useful chiral products in good yields using substoichiometric amounts of chiral diamines.