steven Bull | University of Bath (original) (raw)

Papers by steven Bull

Research paper thumbnail of ChemInform Abstract: Conjugate Additions of Organocuprates to a 3-Methylene-6-isopropyldiketopiperazine Acceptor for the Asymmetric Synthesis of Homochiral α-Amino Acids

Research paper thumbnail of Stereoselective conjugate addition of organocuprates to a dehydroalanine derived diketopiperazine

Journal of the Chemical Society, Perkin Transactions 1, 1998

An asymmetric synthesis of homochiral -amino acids has been developed which is based on the conju... more An asymmetric synthesis of homochiral -amino acids has been developed which is based on the conjugate addition of organocuprates to the dehydroalanine equivalent (3S)-N,NЈ-bis(p-methoxybenzyl)-3-isopropyl-6-methylenepiperazine-2,5-dione 6.

Research paper thumbnail of SuperQuat, (S)-4-benzyl-5,5-dimethyl-oxazolidin-2-one for the asymmetric synthesis of α-substituted-aldehydes

Tetrahedron: Asymmetry, 2000

2001 reduction, hydrogenation reduction, hydrogenation O 0220

Research paper thumbnail of A practical synthesis of enantiopure (S)-4-(4-hydroxybenzyl)-oxazolidin-2-one

Oxazole derivatives R 0220

Research paper thumbnail of Non-linear effects operate and dynamic ligand exchange occurs when chiral BINOL–boron Lewis acids are used for asymmetric catalysis

Non-linear effects reveal that the use of chiral BINOL-boron reagents for aza-Diels-Alder reactio... more Non-linear effects reveal that the use of chiral BINOL-boron reagents for aza-Diels-Alder reactions results in an enantioselective catalytic species containing at least 2 equiv. of BINOL. Dynamic ligand exchange and ligand accelerated catalysis occurs in these reactions, consistent with the formation of a cyclic borate ester of BINOL with enhanced Lewis acidity.

Research paper thumbnail of An efficient synthesis of semiplenamide C

Semiplenamides are anandamide-like fatty acid amide metabolites previously isolated from a marine... more Semiplenamides are anandamide-like fatty acid amide metabolites previously isolated from a marine cyanobacterium that display a range of biological activity. Novel syn-aldol/dehydration methodology has been developed for the stereoselective synthesis of the core (E)-α,β-unsaturated amide functionality of this class of natural product, and employed for the efficient synthesis of semiplenamide C.

Research paper thumbnail of An Efficient Asymmetric Synthesis of Cascarillic Acid

Synlett, 2006

... An Efficient Asymmetric Synthesis of Cascarillic Acid. Matt Cheeseman, Steven D. Bull*. ... 1... more ... An Efficient Asymmetric Synthesis of Cascarillic Acid. Matt Cheeseman, Steven D. Bull*. ... 12 anti-α-Alkyl-β-hydroxy-N-acyl-oxazolidin-2-ones normally exhibit J ( 2 ′ ,3 ′ ) coupling constants of ³7.0 Hz see: Evans DA, Tedrow JS, Shaw JT, Downey CW,J. Am. Chem. Soc. ...

Research paper thumbnail of 2-Halo-diketopiperazines as chiral glycine cation equivalents

Tetrahedron-asymmetry, 2004

A range of (2S,5S)-5-isopropyl-2-halo-N,N′-bis-(p-methoxybenzyl)-piperazine-3,6-diones 8 (Cl), 11... more A range of (2S,5S)-5-isopropyl-2-halo-N,N′-bis-(p-methoxybenzyl)-piperazine-3,6-diones 8 (Cl), 11, 12 (F) and 13 (Br) have been prepared, either via electrophilic halogenation of the corresponding lithiated diketopiperazine, or via transhalogenation from fluoro-11 and 12. The product distribution and stereoselectivity of additions of allyltrimethylsilane, sodium thiophenolate and a range of organomagnesium reagents to chloro 8 are reported. In the reactions with Grignard reagents the

Research paper thumbnail of Chiral Glycine Cation Equivalents: N-Acyliminium Species Derived from Diketopiperazines

Research paper thumbnail of A chiral relay auxiliary for the synthesis of homochiral α-amino acids

Journal of the Chemical Society, Perkin Transactions 1, 1998

" />. RSC Publishing Logo. ...

Research paper thumbnail of ChemInform Abstract: The Asymmetric Synthesis of β-Haloaryl-β-Amino Acid Derivatives

Cheminform, 2000

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Research paper thumbnail of ChemInform Abstract: Stereoselective Conjugate Addition of Organocuprates to a Dehydroalanine Derived Diketopiperazine

Research paper thumbnail of The biosynthetic origin of diketopiperazines derived from D-proline

Journal of the Chemical Society, Perkin Transactions 1, 1998

RSC Publishing Logo. ...

Research paper thumbnail of Chemoselective debenzylation of N-benzyl tertiary amines with ceric ammonium nitrate

Journal of The Chemical Society-perkin Transactions 1, 2000

Treatment of a range of N-benzyl tertiary amines with aqueous ceric ammonium nitrate results in N... more Treatment of a range of N-benzyl tertiary amines with aqueous ceric ammonium nitrate results in N-debenzylation to afford the corresponding secondary amine. Chemoselective mono-N-debenzylation of N-benzyl tertiary amines is shown to occur in the presence of N-benzyl ...

Research paper thumbnail of ChemInform Abstract: Asymmetric Synthesis of β-Haloaryl β-Amino Acid Derivatives

…, 2002

3. ChemInform Abstract ChemInform is a weekly Abstracting Service, delivering concise information... more 3. ChemInform Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full ...

Research paper thumbnail of Sonoelectrochemical and sonochemical effects of cavitation: correlation with interfacial cavitation induced by 20 kHz ultrasound

Ultrasonics Sonochemistry, 2000

Sonoelectrochemical measurements at macro-electrodes under extreme conditions with a very short d... more Sonoelectrochemical measurements at macro-electrodes under extreme conditions with a very short distance between ultrasonic horn tip and electrode and different ultrasound intensity levels are shown to result in violent cavitation detected in form of current peaks superimposed on the average limiting current. Analysis of the current data obtained for the oxidation of ferrocene in dimethylformamide (0.1 M NBu 4 PF 6 ) at a 4 mm diameter Pt disc electrode and for the reduction of Ru(NH 3 )3+ 6 in aqueous 0.1 M KCl at a 6 mm diameter Pt disc electrode consistently indicate a change of the physicochemical nature of sonoelectrochemical processes under extreme conditions.

Research paper thumbnail of Electrochemically Driven Ion Insertion Processes across Liquid|Liquid Boundaries:  Neutral versus Ionic Redox Liquids

The Journal of Physical Chemistry B, 2001

Electrochemically induced redox processes of liquid or solid compounds accompanied by the simulta... more Electrochemically induced redox processes of liquid or solid compounds accompanied by the simultaneous transfer of ions from the adjacent electrolyte solution are of fundamental interest 1-4 and of importance for various potential applications, such as energy storage, 5 charge ...

Research paper thumbnail of Kinetic resolution strategies using non-enzymatic catalysts

Tetrahedron: Asymmetry, 2003

Research paper thumbnail of An efficient asymmetric synthesis of grenadamide

Tetrahedron Letters, 2005

The cyclopropane containing natural product grenadamide has been prepared in six steps using (R)-... more The cyclopropane containing natural product grenadamide has been prepared in six steps using (R)-5,5-dimethyl-oxazolidin-2-one as a chiral auxiliary for asymmetric synthesis. Key synthetic steps include the use of the b-hydroxyl group of a syn-aldol product as a ÔtemporaryÕ stereocentre to control the facial selectivity of a directed cyclopropanation reaction, as well as the use of phenylethylamine as a nucleophile for the direct aminolysis of an N-acyl-oxazolidin-2-one intermediate.

Research paper thumbnail of Rearrangements and racemisation during the synthesis of l-serine derived oxazolidin-2-ones

Tetrahedron, 2002

The propensity for N-Boc-4-hydroxymethyl-oxazolidin-2-ones to undergo rapid O-O and N-O carbonyl ... more The propensity for N-Boc-4-hydroxymethyl-oxazolidin-2-ones to undergo rapid O-O and N-O carbonyl transfer makes these L-serine derived chiral auxiliaries unsuitable for attachment to polymers. q

Research paper thumbnail of ChemInform Abstract: Conjugate Additions of Organocuprates to a 3-Methylene-6-isopropyldiketopiperazine Acceptor for the Asymmetric Synthesis of Homochiral α-Amino Acids

Research paper thumbnail of Stereoselective conjugate addition of organocuprates to a dehydroalanine derived diketopiperazine

Journal of the Chemical Society, Perkin Transactions 1, 1998

An asymmetric synthesis of homochiral -amino acids has been developed which is based on the conju... more An asymmetric synthesis of homochiral -amino acids has been developed which is based on the conjugate addition of organocuprates to the dehydroalanine equivalent (3S)-N,NЈ-bis(p-methoxybenzyl)-3-isopropyl-6-methylenepiperazine-2,5-dione 6.

Research paper thumbnail of SuperQuat, (S)-4-benzyl-5,5-dimethyl-oxazolidin-2-one for the asymmetric synthesis of α-substituted-aldehydes

Tetrahedron: Asymmetry, 2000

2001 reduction, hydrogenation reduction, hydrogenation O 0220

Research paper thumbnail of A practical synthesis of enantiopure (S)-4-(4-hydroxybenzyl)-oxazolidin-2-one

Oxazole derivatives R 0220

Research paper thumbnail of Non-linear effects operate and dynamic ligand exchange occurs when chiral BINOL–boron Lewis acids are used for asymmetric catalysis

Non-linear effects reveal that the use of chiral BINOL-boron reagents for aza-Diels-Alder reactio... more Non-linear effects reveal that the use of chiral BINOL-boron reagents for aza-Diels-Alder reactions results in an enantioselective catalytic species containing at least 2 equiv. of BINOL. Dynamic ligand exchange and ligand accelerated catalysis occurs in these reactions, consistent with the formation of a cyclic borate ester of BINOL with enhanced Lewis acidity.

Research paper thumbnail of An efficient synthesis of semiplenamide C

Semiplenamides are anandamide-like fatty acid amide metabolites previously isolated from a marine... more Semiplenamides are anandamide-like fatty acid amide metabolites previously isolated from a marine cyanobacterium that display a range of biological activity. Novel syn-aldol/dehydration methodology has been developed for the stereoselective synthesis of the core (E)-α,β-unsaturated amide functionality of this class of natural product, and employed for the efficient synthesis of semiplenamide C.

Research paper thumbnail of An Efficient Asymmetric Synthesis of Cascarillic Acid

Synlett, 2006

... An Efficient Asymmetric Synthesis of Cascarillic Acid. Matt Cheeseman, Steven D. Bull*. ... 1... more ... An Efficient Asymmetric Synthesis of Cascarillic Acid. Matt Cheeseman, Steven D. Bull*. ... 12 anti-α-Alkyl-β-hydroxy-N-acyl-oxazolidin-2-ones normally exhibit J ( 2 ′ ,3 ′ ) coupling constants of ³7.0 Hz see: Evans DA, Tedrow JS, Shaw JT, Downey CW,J. Am. Chem. Soc. ...

Research paper thumbnail of 2-Halo-diketopiperazines as chiral glycine cation equivalents

Tetrahedron-asymmetry, 2004

A range of (2S,5S)-5-isopropyl-2-halo-N,N′-bis-(p-methoxybenzyl)-piperazine-3,6-diones 8 (Cl), 11... more A range of (2S,5S)-5-isopropyl-2-halo-N,N′-bis-(p-methoxybenzyl)-piperazine-3,6-diones 8 (Cl), 11, 12 (F) and 13 (Br) have been prepared, either via electrophilic halogenation of the corresponding lithiated diketopiperazine, or via transhalogenation from fluoro-11 and 12. The product distribution and stereoselectivity of additions of allyltrimethylsilane, sodium thiophenolate and a range of organomagnesium reagents to chloro 8 are reported. In the reactions with Grignard reagents the

Research paper thumbnail of Chiral Glycine Cation Equivalents: N-Acyliminium Species Derived from Diketopiperazines

Research paper thumbnail of A chiral relay auxiliary for the synthesis of homochiral α-amino acids

Journal of the Chemical Society, Perkin Transactions 1, 1998

" />. RSC Publishing Logo. ...

Research paper thumbnail of ChemInform Abstract: The Asymmetric Synthesis of β-Haloaryl-β-Amino Acid Derivatives

Cheminform, 2000

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Research paper thumbnail of ChemInform Abstract: Stereoselective Conjugate Addition of Organocuprates to a Dehydroalanine Derived Diketopiperazine

Research paper thumbnail of The biosynthetic origin of diketopiperazines derived from D-proline

Journal of the Chemical Society, Perkin Transactions 1, 1998

RSC Publishing Logo. ...

Research paper thumbnail of Chemoselective debenzylation of N-benzyl tertiary amines with ceric ammonium nitrate

Journal of The Chemical Society-perkin Transactions 1, 2000

Treatment of a range of N-benzyl tertiary amines with aqueous ceric ammonium nitrate results in N... more Treatment of a range of N-benzyl tertiary amines with aqueous ceric ammonium nitrate results in N-debenzylation to afford the corresponding secondary amine. Chemoselective mono-N-debenzylation of N-benzyl tertiary amines is shown to occur in the presence of N-benzyl ...

Research paper thumbnail of ChemInform Abstract: Asymmetric Synthesis of β-Haloaryl β-Amino Acid Derivatives

…, 2002

3. ChemInform Abstract ChemInform is a weekly Abstracting Service, delivering concise information... more 3. ChemInform Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full ...

Research paper thumbnail of Sonoelectrochemical and sonochemical effects of cavitation: correlation with interfacial cavitation induced by 20 kHz ultrasound

Ultrasonics Sonochemistry, 2000

Sonoelectrochemical measurements at macro-electrodes under extreme conditions with a very short d... more Sonoelectrochemical measurements at macro-electrodes under extreme conditions with a very short distance between ultrasonic horn tip and electrode and different ultrasound intensity levels are shown to result in violent cavitation detected in form of current peaks superimposed on the average limiting current. Analysis of the current data obtained for the oxidation of ferrocene in dimethylformamide (0.1 M NBu 4 PF 6 ) at a 4 mm diameter Pt disc electrode and for the reduction of Ru(NH 3 )3+ 6 in aqueous 0.1 M KCl at a 6 mm diameter Pt disc electrode consistently indicate a change of the physicochemical nature of sonoelectrochemical processes under extreme conditions.

Research paper thumbnail of Electrochemically Driven Ion Insertion Processes across Liquid|Liquid Boundaries:  Neutral versus Ionic Redox Liquids

The Journal of Physical Chemistry B, 2001

Electrochemically induced redox processes of liquid or solid compounds accompanied by the simulta... more Electrochemically induced redox processes of liquid or solid compounds accompanied by the simultaneous transfer of ions from the adjacent electrolyte solution are of fundamental interest 1-4 and of importance for various potential applications, such as energy storage, 5 charge ...

Research paper thumbnail of Kinetic resolution strategies using non-enzymatic catalysts

Tetrahedron: Asymmetry, 2003

Research paper thumbnail of An efficient asymmetric synthesis of grenadamide

Tetrahedron Letters, 2005

The cyclopropane containing natural product grenadamide has been prepared in six steps using (R)-... more The cyclopropane containing natural product grenadamide has been prepared in six steps using (R)-5,5-dimethyl-oxazolidin-2-one as a chiral auxiliary for asymmetric synthesis. Key synthetic steps include the use of the b-hydroxyl group of a syn-aldol product as a ÔtemporaryÕ stereocentre to control the facial selectivity of a directed cyclopropanation reaction, as well as the use of phenylethylamine as a nucleophile for the direct aminolysis of an N-acyl-oxazolidin-2-one intermediate.

Research paper thumbnail of Rearrangements and racemisation during the synthesis of l-serine derived oxazolidin-2-ones

Tetrahedron, 2002

The propensity for N-Boc-4-hydroxymethyl-oxazolidin-2-ones to undergo rapid O-O and N-O carbonyl ... more The propensity for N-Boc-4-hydroxymethyl-oxazolidin-2-ones to undergo rapid O-O and N-O carbonyl transfer makes these L-serine derived chiral auxiliaries unsuitable for attachment to polymers. q