Stefan Bienz - Academia.edu (original) (raw)
Papers by Stefan Bienz
Spektroskopische Methoden in der organischen Chemie, 2016
Spektroskopische Methoden in der organischen Chemie, 2016
Spektroskopische Methoden in der organischen Chemie, 2016
Spektroskopische Methoden in der organischen Chemie, 2016
Metabolites
Spider venoms are highly complex mixtures. Numerous spider venom metabolites are uniquely found i... more Spider venoms are highly complex mixtures. Numerous spider venom metabolites are uniquely found in spider venoms and are of interest concerning their potential use in pharmacology, agriculture, and cosmetics. A nontargeted ultra-high performance high-resolution electrospray tandem mass spectrometry (UHPLC-HR-ESI-MS/MS) approach offers a resource-saving way for the analysis of crude spider venom. However, the identification of known as well as the structure elucidation of unknown low molecular mass spider venom compounds based on their MS/MS spectra is challenging because (1) acylpolyamine toxins are exclusively found in spider and wasp venom, (2) reference MS/MS spectra are missing in established mass spectrometry databases, and (3) trivial names for the various toxin metabolites are used in an inconsistent way in literature. Therefore, we introduce the freely accessible MS website for low molecular mass spider venom metabolites, venoMS, containing structural information, MS/MS spec...
ChemInform
ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance t... more 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 Text” option. The original article is trackable via the “References” option.
Zeitschrift für Naturforschung B
2,2,N-Trimethyl-N-phenyl-2H-azirin-3-amine (1a) was prepared by successive treatment of 2,N-dimet... more 2,2,N-Trimethyl-N-phenyl-2H-azirin-3-amine (1a) was prepared by successive treatment of 2,N-dimethyl-N-phenylpropanamide (18) with phosgene, triethylamine, and sodium azide. Reaction of 1a in THF solution with boron trifluoride gave 2-amino-1,3,3-trimethyl-3H-indolium tetrafluoroborate (19) in high yield.T he latter reacted with acetic anhydride in pyridine to give a mixture of N-(2,3-dihydro-1,3,3-trimethylindol-2-yliden)acetamide (22) and 2,3-dihydro- 1,3,3-trimethylindol-2-one (21).On hydrolysis with aqueous HCl, 22 was converted to 21.T he molecular structures of 19 and 22 were established by X-ray crystal structure determination.
The Journal of Organic Chemistry
![Research paper thumbnail of Absolute Configuration of (S)-(+)-[(Benzyloxymethyl)(tert-butyl)methylsilyl] Methyl Ketone](https://attachments.academia-assets.com/69249225/thumbnails/1.jpg)
](Acta Crystallographica Section C Crystal Structure Communications
The absolute configuration of the title compound was confirmed by an X-ray crystal structure anal... more The absolute configuration of the title compound was confirmed by an X-ray crystal structure analysis of (R)-(+)-[(benzyloxymethyl)(tert-butyl)methylsilyl] methyl ketone 2,4,6-triisopropylphenylsulfonylhydrazone, C30H48N203SSi, reported herein. The asymmetric unit of the hydrazone contains two molecules which are linked by intermolecular hydrogen bonds.
Acta Crystallographica Section C Crystal Structure Communications
The title compound, N-{4-[(benzenesulfonyl)amino]butyl}benzenesulfonamide (C 16 H 20 N 2 O 4 S 2)... more The title compound, N-{4-[(benzenesulfonyl)amino]butyl}benzenesulfonamide (C 16 H 20 N 2 O 4 S 2), is useful in the synthesis of natural or unnatural polyamine derivatives. The molecule is centrosymmetric with a straight-chain alkane core and N-H•••O intermolecular hydrogen bonds link the molecules into an infinite two-dimensional network. Comment The title compound, (1), is of interest as a synthon for the synthesis of natural or unnatural polyamine derivatives. For example, it will be a useful reagent in our planned synthesis of polyamine spider toxins and analogues (Schäfer et al., 1994). The structure of (1) does not display any unusual geometrical features. The molecule is centrosymmetric and its alkane core has an essentially straight-chain conformation (Table 1). The N atoms are clearly pyramidal, as N1 deviates from the plane defined by S1, C2 and H1 by 0.31 (1) Å. This indicates that there is no delocalization of the lone pair of electrons on the N atom towards the sulfonyl group.
ChemInform
ABSTRACT The treatment of alkoxymethyl-substituted hydrosilanes with palladium on charcoal gave r... more ABSTRACT The treatment of alkoxymethyl-substituted hydrosilanes with palladium on charcoal gave rise to the corresponding alkyl silyl ethers by the migration of the silicon-bound hydrogen atom to the alpha-carbon atom and of the alkoxy group to the silicon center. Kinetic investigations revealed that two parallel reactions are involved in the rearrangement: an intramolecular reaction, following pseudo-first-order kinetics and showing an inverse kinetic deuterium isotope effect, is dominant in the initial phase of the transformation, and an intermolecular reaction becomes important in the later course of the transformation. The dominant reaction in the first phase of the transformation has to be classified as a dyotropic arrangement of type I, due to the intramolecular course and the reaction order, and it represents the first catalyzed example of a rearrangement of this type.
ChemInform
ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance t... more 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 Text” option. The original article is trackable via the “References” option.
ChemInform
ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance t... more 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 Text” option. The original article is trackable via the “References” option.
Spektroskopische Methoden in der organischen Chemie, 2016
Spektroskopische Methoden in der organischen Chemie, 2016
ChemInform, 2010
ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance t... more 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 Text” option. The original article is trackable via the “References” option.
Spektroskopische Methoden in der organischen Chemie, 2016
Spektroskopische Methoden in der organischen Chemie, 2016
Spektroskopische Methoden in der organischen Chemie, 2016
Spektroskopische Methoden in der organischen Chemie, 2016
Spektroskopische Methoden in der organischen Chemie, 2016
Metabolites
Spider venoms are highly complex mixtures. Numerous spider venom metabolites are uniquely found i... more Spider venoms are highly complex mixtures. Numerous spider venom metabolites are uniquely found in spider venoms and are of interest concerning their potential use in pharmacology, agriculture, and cosmetics. A nontargeted ultra-high performance high-resolution electrospray tandem mass spectrometry (UHPLC-HR-ESI-MS/MS) approach offers a resource-saving way for the analysis of crude spider venom. However, the identification of known as well as the structure elucidation of unknown low molecular mass spider venom compounds based on their MS/MS spectra is challenging because (1) acylpolyamine toxins are exclusively found in spider and wasp venom, (2) reference MS/MS spectra are missing in established mass spectrometry databases, and (3) trivial names for the various toxin metabolites are used in an inconsistent way in literature. Therefore, we introduce the freely accessible MS website for low molecular mass spider venom metabolites, venoMS, containing structural information, MS/MS spec...
ChemInform
ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance t... more 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 Text” option. The original article is trackable via the “References” option.
Zeitschrift für Naturforschung B
2,2,N-Trimethyl-N-phenyl-2H-azirin-3-amine (1a) was prepared by successive treatment of 2,N-dimet... more 2,2,N-Trimethyl-N-phenyl-2H-azirin-3-amine (1a) was prepared by successive treatment of 2,N-dimethyl-N-phenylpropanamide (18) with phosgene, triethylamine, and sodium azide. Reaction of 1a in THF solution with boron trifluoride gave 2-amino-1,3,3-trimethyl-3H-indolium tetrafluoroborate (19) in high yield.T he latter reacted with acetic anhydride in pyridine to give a mixture of N-(2,3-dihydro-1,3,3-trimethylindol-2-yliden)acetamide (22) and 2,3-dihydro- 1,3,3-trimethylindol-2-one (21).On hydrolysis with aqueous HCl, 22 was converted to 21.T he molecular structures of 19 and 22 were established by X-ray crystal structure determination.
The Journal of Organic Chemistry
Acta Crystallographica Section C Crystal Structure Communications
The absolute configuration of the title compound was confirmed by an X-ray crystal structure anal... more The absolute configuration of the title compound was confirmed by an X-ray crystal structure analysis of (R)-(+)-[(benzyloxymethyl)(tert-butyl)methylsilyl] methyl ketone 2,4,6-triisopropylphenylsulfonylhydrazone, C30H48N203SSi, reported herein. The asymmetric unit of the hydrazone contains two molecules which are linked by intermolecular hydrogen bonds.
Acta Crystallographica Section C Crystal Structure Communications
The title compound, N-{4-[(benzenesulfonyl)amino]butyl}benzenesulfonamide (C 16 H 20 N 2 O 4 S 2)... more The title compound, N-{4-[(benzenesulfonyl)amino]butyl}benzenesulfonamide (C 16 H 20 N 2 O 4 S 2), is useful in the synthesis of natural or unnatural polyamine derivatives. The molecule is centrosymmetric with a straight-chain alkane core and N-H•••O intermolecular hydrogen bonds link the molecules into an infinite two-dimensional network. Comment The title compound, (1), is of interest as a synthon for the synthesis of natural or unnatural polyamine derivatives. For example, it will be a useful reagent in our planned synthesis of polyamine spider toxins and analogues (Schäfer et al., 1994). The structure of (1) does not display any unusual geometrical features. The molecule is centrosymmetric and its alkane core has an essentially straight-chain conformation (Table 1). The N atoms are clearly pyramidal, as N1 deviates from the plane defined by S1, C2 and H1 by 0.31 (1) Å. This indicates that there is no delocalization of the lone pair of electrons on the N atom towards the sulfonyl group.
ChemInform
ABSTRACT The treatment of alkoxymethyl-substituted hydrosilanes with palladium on charcoal gave r... more ABSTRACT The treatment of alkoxymethyl-substituted hydrosilanes with palladium on charcoal gave rise to the corresponding alkyl silyl ethers by the migration of the silicon-bound hydrogen atom to the alpha-carbon atom and of the alkoxy group to the silicon center. Kinetic investigations revealed that two parallel reactions are involved in the rearrangement: an intramolecular reaction, following pseudo-first-order kinetics and showing an inverse kinetic deuterium isotope effect, is dominant in the initial phase of the transformation, and an intermolecular reaction becomes important in the later course of the transformation. The dominant reaction in the first phase of the transformation has to be classified as a dyotropic arrangement of type I, due to the intramolecular course and the reaction order, and it represents the first catalyzed example of a rearrangement of this type.
ChemInform
ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance t... more 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 Text” option. The original article is trackable via the “References” option.
ChemInform
ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance t... more 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 Text” option. The original article is trackable via the “References” option.
Spektroskopische Methoden in der organischen Chemie, 2016
Spektroskopische Methoden in der organischen Chemie, 2016
ChemInform, 2010
ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance t... more 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 Text” option. The original article is trackable via the “References” option.
Spektroskopische Methoden in der organischen Chemie, 2016