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Papers by Rainer Kalkofen

Research paper thumbnail of CCDC 240544: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Research paper thumbnail of CCDC 266415: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Research paper thumbnail of CCDC 219961: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Research paper thumbnail of CCDC 219962: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Research paper thumbnail of Sustainable Solvents for Polychloroprene-Based Contact Adhesives

ADHESION ADHESIVES&SEALANTS, May 1, 2023

Research paper thumbnail of Enantio- and Diastereoselective Synthesis of Highly Substituted Acylcyclopropanes from Homoaldol Products by Stereospecific Homoallylic Cyclization

European Journal of Organic Chemistry, Nov 1, 2005

Catalytic enantioselective synthesis of 1hydroxy-2,3-bisboronate esters through multicomponent bo... more Catalytic enantioselective synthesis of 1hydroxy-2,3-bisboronate esters through multicomponent borylation/1,2-addition is reported. Catalyst and substrates are readily available, form both a C-B and CC bond, and generate up to three contiguous stereocenters. The reaction is tolerant of aryl, vinyl, and alkyl aldehydes and ketones in up to 95% yield, >20:1 dr, and 97:3 er. Intramolecular additions to aldehydes and ketones result in stereodivergent processes. The hydroxy bis(boronate) ester products are amenable to siteselective chemical elaboration.

Research paper thumbnail of Synthesis of Stereohomogeneous Cyclopropanecarbaldehydes and Cyclopropyl Ketones by Cycloalkylation of 4-Hydroxy-1-alkenyl Carbamates

Angewandte Chemie, Dec 10, 2004

Research paper thumbnail of Hoch enantiomerenangereicherte Keton-Homoenolat-Reagentien durch (−)-Spartein-vermittelteγ-Deprotonierung von achiralen 1-Alkenylcarbamaten

Angewandte Chemie, Mar 5, 2004

Research paper thumbnail of Polychloropren-basierte Kontaktklebstoffe mit nachhaltigen Lösemitteln

Adhäsion Kleben & Dichten, Feb 1, 2023

Research paper thumbnail of Highly Enantiomerically Enriched Ketone Homoenolate Reagents Prepared by (-)-Sparteine-Mediated γ-Deprotonation of Achiral 1-Alkenyl Carbamates

Research paper thumbnail of First Example of an Enantiospecific sp<sup>3</sup>-sp<sup>2</sup> Stille Coupling of a Chiral Allylstannane with Aryl Halides

Synlett, Aug 1, 2006

A chiral allylic stannane, easily accessible via an enantiotopos differentiating deprotonation of... more A chiral allylic stannane, easily accessible via an enantiotopos differentiating deprotonation of a 1-phenyl-1-alkenyl-carbamate, is coupled with different aryl halides. In this enantiospecific Stille reaction a η 3 -bound palladium species is assumed to eliminate either to an arylated 1-alkenyl carbamate or, after migration of the carbamoyloxy group, to a 2-alkenyl carbamate.

Research paper thumbnail of Synthese von stereohomogenen Cyclopropancarbaldehyden und Cyclopropylketonen durch Cycloalkylierung von 4-Hydroxy-1-alkenylcarbamaten

Angewandte Chemie, Dec 10, 2004

Research paper thumbnail of Sustainable Solvents for Polychloroprene-Based Contact Adhesives

adhesion ADHESIVES + SEALANTS

Research paper thumbnail of Polychloropren-basierte Kontaktklebstoffe mit nachhaltigen Lösemitteln

adhäsion KLEBEN & DICHTEN

Research paper thumbnail of Vulkanisierbare zusammensetzungen auf basis von epoxygruppen-haltigen ethylen-vinylacetat-copolymerisaten

Die Erfindung betrifft vulkanisierbare Zusammensetzungen enthaltend (a) mindestens ein Epoxygrupp... more Die Erfindung betrifft vulkanisierbare Zusammensetzungen enthaltend (a) mindestens ein Epoxygruppen-haltiges Ethylen-Vinylacetat-Copolymerisat mit einem Vinylacetatgehalt von mindestens 20 Gew.-%, bevorzugt mindestens 30 Gew.-%, besonders bevorzugt mindestens 40 Gew.-% bezogen auf das Epoxygruppen-haltige Ethylen-Vinylacetat-Copolymerisat und (b) mindestens einen carboxylierten Nitrilkautschuk.

Research paper thumbnail of Evm-granulat als einbettungsmaterial für solarmodule, deren herstellungsverfahren, eine klebefolie sowie ein solarmodul und dessen herstellungsverfahren und herstellungsvorrichtung

Die Erfindung betrifft Granulate aus α-Olefin-Vinylacetat-Copolymeren mit einem Vinylacetat-Gehal... more Die Erfindung betrifft Granulate aus α-Olefin-Vinylacetat-Copolymeren mit einem Vinylacetat-Gehalt von > 40 Gew.-%, bezogen auf das Gesamtgewicht des α-Olefin-Vinylacetat-Copolymeren als Einbettungsmaterial fur Solarmodule, wobei die Granulate als Zuschlagstoffe mindestens ein UV-Aktivator und mindestens ein Silan-Kopplungsreagenz aufweisen, deren Verwendung fur die Folienherstellung von Solarmodulen.

Research paper thumbnail of Total Synthesis of (−)-Lasonolide A

Journal of the American Chemical Society, 2016

The lasonolides are novel polyketides that have displayed remarkable biological activity in vitro... more The lasonolides are novel polyketides that have displayed remarkable biological activity in vitro against a variety of cancer cell lines. Herein we describe our first generation approach to the formal synthesis of lasonolide A. The key findings from these studies ultimately allowed us to go on and complete a total synthesis of lasonolide A. The convergent approach unites two highly complex fragments utilizing a Ru-catalyzed alkene-alkyne coupling. This type of coupling typically generates branched products, however through a detailed investigation we are now able to demonstrate that subtle structural changes to the substrates can alter the selectivity to favor the formation of the linear product. The synthesis of the fragments features a number of atom economical transformations which are highlighted by the discovery of an engineered enzyme to perform a dynamic kinetic reduction of a β-ketoester to establish the absolute stereochemistry of the southern tetrahydropyran ring with high levels of enantioselectivity.

Research paper thumbnail of Uv curable flame retardant compounds, a uv curing method thereof, and the use thereof

Research paper thumbnail of First Example of an Enantiospecific sp 3 -sp 2 Stille Coupling of a Chiral Allylstannane with Aryl Halides

Synlett, 2006

A chiral allylic stannane, easily accessible via an enantiotopos differentiating deprotonation of... more A chiral allylic stannane, easily accessible via an enantiotopos differentiating deprotonation of a 1-phenyl-1-alkenyl-carbamate, is coupled with different aryl halides. In this enantiospecific Stille reaction a η 3 -bound palladium species is assumed to eliminate either to an arylated 1-alkenyl carbamate or, after migration of the carbamoyloxy group, to a 2-alkenyl carbamate.

Research paper thumbnail of Synthese von stereohomogenen Cyclopropancarbaldehyden und Cyclopropylketonen durch Cycloalkylierung von 4-Hydroxy-1-alkenylcarbamaten

Research paper thumbnail of CCDC 240544: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Research paper thumbnail of CCDC 266415: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Research paper thumbnail of CCDC 219961: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Research paper thumbnail of CCDC 219962: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Research paper thumbnail of Sustainable Solvents for Polychloroprene-Based Contact Adhesives

ADHESION ADHESIVES&SEALANTS, May 1, 2023

Research paper thumbnail of Enantio- and Diastereoselective Synthesis of Highly Substituted Acylcyclopropanes from Homoaldol Products by Stereospecific Homoallylic Cyclization

European Journal of Organic Chemistry, Nov 1, 2005

Catalytic enantioselective synthesis of 1hydroxy-2,3-bisboronate esters through multicomponent bo... more Catalytic enantioselective synthesis of 1hydroxy-2,3-bisboronate esters through multicomponent borylation/1,2-addition is reported. Catalyst and substrates are readily available, form both a C-B and CC bond, and generate up to three contiguous stereocenters. The reaction is tolerant of aryl, vinyl, and alkyl aldehydes and ketones in up to 95% yield, >20:1 dr, and 97:3 er. Intramolecular additions to aldehydes and ketones result in stereodivergent processes. The hydroxy bis(boronate) ester products are amenable to siteselective chemical elaboration.

Research paper thumbnail of Synthesis of Stereohomogeneous Cyclopropanecarbaldehydes and Cyclopropyl Ketones by Cycloalkylation of 4-Hydroxy-1-alkenyl Carbamates

Angewandte Chemie, Dec 10, 2004

Research paper thumbnail of Hoch enantiomerenangereicherte Keton-Homoenolat-Reagentien durch (−)-Spartein-vermittelteγ-Deprotonierung von achiralen 1-Alkenylcarbamaten

Angewandte Chemie, Mar 5, 2004

Research paper thumbnail of Polychloropren-basierte Kontaktklebstoffe mit nachhaltigen Lösemitteln

Adhäsion Kleben & Dichten, Feb 1, 2023

Research paper thumbnail of Highly Enantiomerically Enriched Ketone Homoenolate Reagents Prepared by (-)-Sparteine-Mediated γ-Deprotonation of Achiral 1-Alkenyl Carbamates

Research paper thumbnail of First Example of an Enantiospecific sp<sup>3</sup>-sp<sup>2</sup> Stille Coupling of a Chiral Allylstannane with Aryl Halides

Synlett, Aug 1, 2006

A chiral allylic stannane, easily accessible via an enantiotopos differentiating deprotonation of... more A chiral allylic stannane, easily accessible via an enantiotopos differentiating deprotonation of a 1-phenyl-1-alkenyl-carbamate, is coupled with different aryl halides. In this enantiospecific Stille reaction a η 3 -bound palladium species is assumed to eliminate either to an arylated 1-alkenyl carbamate or, after migration of the carbamoyloxy group, to a 2-alkenyl carbamate.

Research paper thumbnail of Synthese von stereohomogenen Cyclopropancarbaldehyden und Cyclopropylketonen durch Cycloalkylierung von 4-Hydroxy-1-alkenylcarbamaten

Angewandte Chemie, Dec 10, 2004

Research paper thumbnail of Sustainable Solvents for Polychloroprene-Based Contact Adhesives

adhesion ADHESIVES + SEALANTS

Research paper thumbnail of Polychloropren-basierte Kontaktklebstoffe mit nachhaltigen Lösemitteln

adhäsion KLEBEN & DICHTEN

Research paper thumbnail of Vulkanisierbare zusammensetzungen auf basis von epoxygruppen-haltigen ethylen-vinylacetat-copolymerisaten

Die Erfindung betrifft vulkanisierbare Zusammensetzungen enthaltend (a) mindestens ein Epoxygrupp... more Die Erfindung betrifft vulkanisierbare Zusammensetzungen enthaltend (a) mindestens ein Epoxygruppen-haltiges Ethylen-Vinylacetat-Copolymerisat mit einem Vinylacetatgehalt von mindestens 20 Gew.-%, bevorzugt mindestens 30 Gew.-%, besonders bevorzugt mindestens 40 Gew.-% bezogen auf das Epoxygruppen-haltige Ethylen-Vinylacetat-Copolymerisat und (b) mindestens einen carboxylierten Nitrilkautschuk.

Research paper thumbnail of Evm-granulat als einbettungsmaterial für solarmodule, deren herstellungsverfahren, eine klebefolie sowie ein solarmodul und dessen herstellungsverfahren und herstellungsvorrichtung

Die Erfindung betrifft Granulate aus α-Olefin-Vinylacetat-Copolymeren mit einem Vinylacetat-Gehal... more Die Erfindung betrifft Granulate aus α-Olefin-Vinylacetat-Copolymeren mit einem Vinylacetat-Gehalt von > 40 Gew.-%, bezogen auf das Gesamtgewicht des α-Olefin-Vinylacetat-Copolymeren als Einbettungsmaterial fur Solarmodule, wobei die Granulate als Zuschlagstoffe mindestens ein UV-Aktivator und mindestens ein Silan-Kopplungsreagenz aufweisen, deren Verwendung fur die Folienherstellung von Solarmodulen.

Research paper thumbnail of Total Synthesis of (−)-Lasonolide A

Journal of the American Chemical Society, 2016

The lasonolides are novel polyketides that have displayed remarkable biological activity in vitro... more The lasonolides are novel polyketides that have displayed remarkable biological activity in vitro against a variety of cancer cell lines. Herein we describe our first generation approach to the formal synthesis of lasonolide A. The key findings from these studies ultimately allowed us to go on and complete a total synthesis of lasonolide A. The convergent approach unites two highly complex fragments utilizing a Ru-catalyzed alkene-alkyne coupling. This type of coupling typically generates branched products, however through a detailed investigation we are now able to demonstrate that subtle structural changes to the substrates can alter the selectivity to favor the formation of the linear product. The synthesis of the fragments features a number of atom economical transformations which are highlighted by the discovery of an engineered enzyme to perform a dynamic kinetic reduction of a β-ketoester to establish the absolute stereochemistry of the southern tetrahydropyran ring with high levels of enantioselectivity.

Research paper thumbnail of Uv curable flame retardant compounds, a uv curing method thereof, and the use thereof

Research paper thumbnail of First Example of an Enantiospecific sp 3 -sp 2 Stille Coupling of a Chiral Allylstannane with Aryl Halides

Synlett, 2006

A chiral allylic stannane, easily accessible via an enantiotopos differentiating deprotonation of... more A chiral allylic stannane, easily accessible via an enantiotopos differentiating deprotonation of a 1-phenyl-1-alkenyl-carbamate, is coupled with different aryl halides. In this enantiospecific Stille reaction a η 3 -bound palladium species is assumed to eliminate either to an arylated 1-alkenyl carbamate or, after migration of the carbamoyloxy group, to a 2-alkenyl carbamate.

Research paper thumbnail of Synthese von stereohomogenen Cyclopropancarbaldehyden und Cyclopropylketonen durch Cycloalkylierung von 4-Hydroxy-1-alkenylcarbamaten