TY - JOUR A1 - Schmidt, Bernd A1 - Hauke, Sylvia T1 - Metathesis-Based de novo synthesis of noviose JF - European journal of organic chemistry N2 - The rare carbohydrate L-(+)-noviose was synthesized from enantiomerically pure L-lactate. The configuration at C-4 was established by diastereoselective nucleophilic addition to an in-situ-generated lactaldehyde. The resulting homoallylic alcohol was further transformed into a set of ring-closing metathesis (RCM) precursors. These compounds were converted into noviose in few steps using RCM and RCM-allylic-oxidation sequences. KW - Carbohydrates KW - Allylic oxidation KW - Oxygen heterocycles KW - Metathesis KW - Ruthenium Y1 - 2014 U6 - https://doi.org/10.1002/ejoc.201301615 SN - 1434-193X SN - 1099-0690 VL - 2014 IS - 9 SP - 1951 EP - 1960 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Schmidt, Bernd A1 - Hauke, Sylvia T1 - Olefin cross metathesis based de novo synthesis of a partially protected L-amicetose and a fully protected L-cinerulose derivative JF - Beilstein journal of organic chemistry N2 - Cross metathesis of a lactate derived allylic alcohol and acrolein is the entry point to a de novo synthesis of 4-benzoate protected L-amicetose and a cinerulose derivative protected at C5 and C1. KW - carbohydrates KW - de novo synthesis KW - lactate KW - metathesis KW - ruthenium Y1 - 2014 U6 - https://doi.org/10.3762/bjoc.10.102 SN - 1860-5397 VL - 10 SP - 1023 EP - 1031 PB - Beilstein-Institut zur Förderung der Chemischen Wissenschaften CY - Frankfurt, Main ER - TY - JOUR A1 - Schmidt, Bernd A1 - Hauke, Sylvia A1 - Muehlenberg, Nino T1 - Imino glycals via Ruthenium-catalyzed RCM and isomerization JF - Synthesis N2 - N-Allyl-N-homoallylamines were converted in one step into cyclic enamides via a ruthenium-catalyzed assisted tandem catalytic ring-closing metathesis-isomerization sequence. The sequence relies on the in situ transformation of a metathesis active Ru-carbene into an isomerization active Ru-hydride by addition of hydroxide as a chemical trigger. KW - heterocycles KW - isomerization KW - metathesis KW - ruthenium KW - tandem reaction Y1 - 2014 U6 - https://doi.org/10.1055/s-0033-1338615 SN - 0039-7881 SN - 1437-210X VL - 46 IS - 12 SP - 1648 EP - 1658 PB - Thieme CY - Stuttgart ER - TY - JOUR A1 - Kafka, Stanislav A1 - Hauke, Sylvia A1 - Salcinovic, Arjana A1 - Soidinsalo, Otto A1 - Urankar, Damijana A1 - Kosmrlj, Janez T1 - Copper(I)-Catalyzed [3+2] Cycloaddition of 3-Azidoquinoline-2,4(1H,3H)-diones with terminal alkynes JF - Molecules N2 - 3-Azidoquinoline-2,4(1H,3H)-diones 1, which are readily available from 4-hydroxyquinolin-2(1H)-ones 4 via 3-chloroquinoline-2,4(1H, 3H)-diones 5, afford, in copper(I)-catalyzed [3 + 2] cycloaddition reaction with terminal acetylenes, 1,4-disubstituted 1,2,3-triazoles 3 in moderate to excellent yields. The structures of compounds 3 were confirmed by (1)H and (13)C-NMR spectroscopy, combustion analyses and mass spectrometry. KW - cycloaddition KW - azides KW - quinoline-2,4(1H,3H)-diones KW - terminal alkynes KW - 1,2,3-triazoles Y1 - 2011 U6 - https://doi.org/10.3390/molecules16054070 SN - 1420-3049 VL - 16 IS - 5 SP - 4070 EP - 4081 PB - MDPI CY - Basel ER - TY - JOUR A1 - Schmidt, Bernd A1 - Hauke, Sylvia T1 - Cross metathesis of allyl alcohols how to suppress and how to promote double bond isomerization JF - Organic & biomolecular chemistry : an international journal of synthetic, physical and biomolecular organic chemistry N2 - Under standard conditions the cross metathesis of allyl alcohols and methyl acrylate is accompanied by the formation of ketones, resulting from uncontrolled and undesired double bond isomerization. By conducting the CM in the presence of phenol, the catalyst loading and the reaction time required for quantiative conversion can be reduced, and isomerization can be suppressed. On the other hand, consecutive isomerization can be deliberately promoted by evaporating excess methyl acrylate after completing cross metathesis and by adding a base or silane as chemical triggers. Y1 - 2013 U6 - https://doi.org/10.1039/c3ob40167g SN - 1477-0520 VL - 11 IS - 25 SP - 4194 EP - 4206 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Schmidt, Bernd A1 - Krehl, Stefan A1 - Hauke, Sylvia T1 - Assisted tandem catalytic cross metathesis-oxidation in one flask from styrenes to 1,2-Diketones and further to quinoxalines JF - The journal of organic chemistry N2 - 1,2-Diketones were synthesized from styrenes by combining a cross metathesis and a Ru-catalyzed alkene oxidation to an assisted tandem catalytic sequence. The synthesis relies on the use of just one metathesis precatalyst, which was in situ converted to the oxidation catalyst by addition of an alkyl hydroperoxide as a chemical trigger and oxidant. The one-flask sequence can be extended beyond 1,2-diketones to quinoxalines, by condensation of the oxidation products with ortho-phenylenediamine. Y1 - 2013 U6 - https://doi.org/10.1021/jo4005684 SN - 0022-3263 VL - 78 IS - 11 SP - 5427 EP - 5435 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Schmidt, Bernd A1 - Hauke, Sylvia T1 - Cross metathesis of allyl alcohols: how to suppress and how to promote double bond isomerization N2 - Under standard conditions the cross metathesis of allyl alcohols and methyl acrylate is accompanied by the formation of ketones, resulting from uncontrolled and undesired double bond isomerization. By conducting the CM in the presence of phenol, the catalyst loading and the reaction time required for quantiative conversion can be reduced, and isomerization can be suppressed. On the other hand, consecutive isomerization can be deliberately promoted by evaporating excess methyl acrylate after completing cross metathesis and by adding a base or silane as chemical triggers. Y1 - 2014 UR - http://pubs.rsc.org/en/content/articlepdf/2013/ob/c3ob40167g U6 - https://doi.org/10.1039/c3ob40167g SN - 1477-0520 ER - TY - THES A1 - Hauke, Sylvia T1 - De novo Synthese von L-6-Desoxyzuckern via Ruthenium-Katalysierter Olefinmetathese Y1 - 2013 CY - Potsdam ER - TY - GEN A1 - Schmidt, Bernd A1 - Hauke, Sylvia T1 - Cross metathesis of allyl alcohols BT - how to suppress and how to promote double bond isomerization N2 - Under standard conditions the cross metathesis of allyl alcohols and methyl acrylate is accompanied by the formation of ketones, resulting from uncontrolled and undesired double bond isomerization. By conducting the CM in the presence of phenol, the catalyst loading and the reaction time required for quantiative conversion can be reduced, and isomerization can be suppressed. On the other hand, consecutive isomerization can be deliberately promoted by evaporating excess methyl acrylate after completing cross metathesis and by adding a base or silane as chemical triggers. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 241 KW - ring-closing metathesis KW - de-novo synthesis KW - catalyzed redox isomerization KW - carbohydrate-based oxepines KW - diels-alder reaction KW - olefin-metathesis KW - in-situ KW - ruthenium carbene KW - alkynol cycloisomerization KW - carbonyl-compounds Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-95037 SP - 4194 EP - 4206 ER -