@article{SandSchmidt2021, author = {Sand, Patrick and Schmidt, Bernd}, title = {Ruthenium-catalyzed sulfoalkenylation of acetanilides and dual-use of the catalyst directing group}, series = {European journal of organic chemistry}, volume = {2021}, journal = {European journal of organic chemistry}, number = {40}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1434-193X}, doi = {10.1002/ejoc.202101216}, pages = {5497 -- 5506}, year = {2021}, abstract = {In contrast to vinylsulfonates and vinylsulfones, vinylsulfonamides are unreactive in Pd-catalyzed oxidative Heck-coupling reactions with acetanilides. This limitation has been resolved by using a C-H-activation protocol based on Ru-Cu-Ag-catalysis. Overall, the Ru-Cu-Ag-catalyzed conditions turned out to be more reliable and showed better reproducibility than the Pd-catalyzed C-H-activation. The coupling products thus obtained are functionalized styrenyl sulfones and -sulfonamides which can be used as starting materials for the synthesis of sulfonyl pyrroles and sulfonyl pyrrolo[2,3-c]quinolines.}, language = {en} } @article{BrietzkeKellingSchildeetal.2016, author = {Brietzke, Thomas Martin and Kelling, Alexandra and Schilde, Uwe and Mickler, Wulfhard and Holdt, Hans-J{\"u}rgen}, title = {Heterodinuclear Ruthenium(II) Complexes of the Bridging Ligand 1,6,7,12-Tetraazaperylene with Iron(II), Cobalt(II), Nickel(II), as well as Palladium(II) and Platinum(II)}, series = {Zeitschrift f{\~A}¼r anorganische und allgemeine Chemie}, volume = {642}, journal = {Zeitschrift f{\~A}¼r anorganische und allgemeine Chemie}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0044-2313}, doi = {10.1002/zaac.201500645}, pages = {8 -- 13}, year = {2016}, abstract = {The first heterodinuclear ruthenium(II) complexes of the 1,6,7,12-tetraazaperylene (tape) bridging ligand with iron(II), cobalt(II), and nickel(II) were synthesized and characterized. The metal coordination sphere in this complexes is filled by the tetradentate N,N-dimethyl-2,11-diaza[3.3](2,6)-pyridinophane (L-N4Me2) ligand, yielding complexes of the general formula [(L-N4Me2)Ru(mu-tape)M(L-N4Me2)](ClO4)(2)(PF6)(2) with M = Fe {[2](ClO4)(2)(PF6)(2)}, Co {[3](ClO4)(2)(PF6)(2)}, and Ni {[4](ClO4)(2)(PF6)(2)}. Furthermore, the heterodinuclear tape ruthenium(II) complexes with palladium(II)- and platinum(II)-dichloride [(bpy)(2)Ru(-tape)PdCl2](PF6)(2) {[5](PF6)(2)} and [(dmbpy)(2)Ru(-tape)PtCl2](PF6)(2) {[6](PF6)(2)}, respectively were also prepared. The molecular structures of the complex cations [2](4+) and [4](4+) were discussed on the basis of the X-ray structures of [2](ClO4)(4)MeCN and [4](ClO4)(4)MeCN. The electrochemical behavior and the UV/Vis absorption spectra of the heterodinuclear tape ruthenium(II) complexes were explored and compared with the data of the analogous mono- and homodinuclear ruthenium(II) complexes of the tape bridging ligand.}, language = {en} } @article{SchmidtHauke2014, author = {Schmidt, Bernd and Hauke, Sylvia}, title = {Metathesis-Based de novo synthesis of noviose}, series = {European journal of organic chemistry}, volume = {2014}, journal = {European journal of organic chemistry}, number = {9}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1434-193X}, doi = {10.1002/ejoc.201301615}, pages = {1951 -- 1960}, year = {2014}, abstract = {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.}, language = {en} } @article{SchmidtGeissler2011, author = {Schmidt, Bernd and Geissler, Diana}, title = {Olefin-Metathesis-Based Synthesis of Furans by an RCM/Deprotonation/Phosphorylation Sequence and Their Diels-Alder Reactions}, series = {European journal of organic chemistry}, journal = {European journal of organic chemistry}, number = {35}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1434-193X}, doi = {10.1002/ejoc.201101078}, pages = {7140 -- 7147}, year = {2011}, abstract = {Butenolides, obtained by ring-closing metathesis (RCM) of acrylates, undergo quantitative deprotonation with amide bases. Trapping of the resulting anions with electrophiles, for example, chlorophosphates, give furans. Subsequent DielsAlder reaction and acid-catalysed rearrangement of the resulting oxabicyclonorbornadienes give substituted benzenes.}, language = {en} } @article{BrietzkeMicklerKellingetal.2012, author = {Brietzke, Thomas Martin and Mickler, Wulfhard and Kelling, Alexandra and Schilde, Uwe and Kr{\"u}ger, Hans-Joerg and Holdt, Hans-J{\"u}rgen}, title = {Mono- and dinuclear Ruthenium(II)-1,6,7,12-Tetraazaperylene complexes of N,N '-Dimethyl-2,11-diaza[3.3](2,6)-pyridinophane}, series = {European journal of inorganic chemistry : a journal of ChemPubSoc Europe}, journal = {European journal of inorganic chemistry : a journal of ChemPubSoc Europe}, number = {29}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1434-1948}, doi = {10.1002/ejic.201200667}, pages = {4632 -- 4643}, year = {2012}, abstract = {Ruthenium(II) complexes [Ru(L-N4Me2)(dape)](PF6)2 {[1](PF6)2}, [Ru(L-N4Me2)(tape)](PF6)2 {[2](PF6)2}, and [{Ru(L-N4Me2)}2(mu-tape)](PF6)4 {[3](PF6)4} were synthesized in two reaction steps by first reacting [Ru(DMSO)4Cl2] with tetraazamacrocyclic ligand N,N'-dimethyl-2,11-diaza[3.3](2,6)-pyridinophane (L-N4Me2) in ethanol under microwave irradiation to the intermediate [Ru(L-N4Me2)Cl2], which was subsequently, without further isolation, reacted with 1,12-diazaperylene (dape) or 1,6,7,12-tetraazaperylene (tape). X-ray structures of [Ru(L-N4Me2)(dape)](PF6)2, [Ru(L-N4Me2)(tape)](PF6)2.acetone, and [{Ru(L-N4Me2)}2(mu-tape)](ClO4)4.MeCN were determined. The UV/Vis absorption spectra of [1](PF6)2, [2](PF6)2, and [3](PF6)4 in acetonitrile display intense low-energy dp(Ru)?p* (dape or tape) MLCT absorption bands centered at 579, 637, and 794 nm, respectively. Reversible metal oxidations for the bimetallic complex [{Ru(L-N4Me2)}2(mu-tape)]4+ ([3]4+) are detected at 1.69 and 1.28 V vs. SCE. The potential difference ?E = 410 mV and the intervalence-charge-transfer (IVCT) transition at 2472 nm indicate a high degree of electronic interaction between the two ruthenium ions mediated through the tape bridging ligand. All three complexes, [1]2+, [2]2+, and [3]4+, were characterized by UV/Vis spectroelectrochemistry. The monooxidized and monoreduced states, [1]3+, [2]3+, [3]5+, and [1]+, [2]+, [3]3+, are accessible by reversible one-electron oxidation and one-electron reduction processes, respectively, as documented by the observation of several stable isosbestic points in the spectral progressions. The second reduction in each complex and the second oxidation in [3]4+ prove to be irreversible in these spectroelectrochemical experiments. Monoreduced species [1]+, [2]+, and [3]3+ yield EPR signals indicating that the unpaired electron is mainly centered on the large surface ligands dape or tape.}, language = {en} }