@article{BudimanLorenzenLiuetal.2021, author = {Budiman, Yudha P. and Lorenzen, Sabine and Liu, Zhiqiang and Radius, Udo and Marder, Todd B.}, title = {Base-Free Pd-Catalyzed C-Cl Borylation of Fluorinated Aryl Chlorides}, series = {Chemistry - A European Journal}, volume = {27}, journal = {Chemistry - A European Journal}, number = {11}, doi = {10.1002/chem.202004648}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-225687}, pages = {3869 -- 3874}, year = {2021}, abstract = {Catalytic C-X borylation of aryl halides containing two ortho-fluorines has been found to be challenging, as most previous methods require stoichiometric amounts of base and the polyfluorinated aryl boronates suffer from protodeboronation, which is accelerated by ortho-fluorine substituents. Herein, we report that a combination of Pd(dba)2 (dba=dibenzylideneacetone) with SPhos (2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl) as a ligand is efficient to catalyze the C-Cl borylation of aryl chlorides containing two ortho-fluorine substituents. This method, conducted under base-free conditions, is compatible with the resulting di-ortho-fluorinated aryl boronate products which are sensitive to base.}, language = {en} } @article{HuangWuKrebsetal.2021, author = {Huang, Mingming and Wu, Zhu and Krebs, Johannes and Friedrich, Alexandra and Luo, Xiaoling and Westcott, Stephen A. and Radius, Udo and Marder, Todd B.}, title = {Ni-Catalyzed Borylation of Aryl Sulfoxides}, series = {Chemistry—A European Journal}, volume = {27}, journal = {Chemistry—A European Journal}, number = {31}, doi = {10.1002/chem.202100342}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-256778}, pages = {8149-8158}, year = {2021}, abstract = {A nickel/N-heterocyclic carbene (NHC) catalytic system has been developed for the borylation of aryl sulfoxides with B\(_{2}\)(neop)\(_{2}\) (neop=neopentyl glycolato). A wide range of aryl sulfoxides with different electronic and steric properties were converted into the corresponding arylboronic esters in good yields. The regioselective borylation of unsymmetric diaryl sulfoxides was also feasible leading to borylation of the sterically less encumbered aryl substituent. Competition experiments demonstrated that an electron-deficient aryl moiety reacts preferentially. The origin of the selectivity in the Ni-catalyzed borylation of electronically biased unsymmetrical diaryl sulfoxide lies in the oxidative addition step of the catalytic cycle, as oxidative addition of methoxyphenyl 4-(trifluoromethyl)phenyl sulfoxide to the Ni(0) complex occurs selectively to give the structurally characterized complex trans-[Ni(ICy)\(_{2}\)(4-CF\(_{3}\)-C\(_{6}\)H\(_{4}\)){(SO)-4-MeO-C\(_{6}\)H\(_{4}\)}] 4. For complex 5, the isomer trans-[Ni(ICy)\(_{2}\)(C\(_{6}\)H\(_{5}\))(OSC\(_{6}\)H\(_{5}\))] 5-I was structurally characterized in which the phenyl sulfinyl ligand is bound via the oxygen atom to nickel. In solution, the complex trans-[Ni(ICy)\(_{2}\)(C\(_{6}\)H\(_{5}\))(OSC\(_{6}\)H\(_{5}\))] 5-I is in equilibrium with the S-bonded isomer trans-[Ni(ICy)\(_{2}\)(C\(_{6}\)H\(_{5}\))(SOC\(_{6}\)H\(_{5}\))] 5, as shown by NMR spectroscopy. DFT calculations reveal that these isomers are separated by a mere 0.3 kJ/mol (M06/def2-TZVP-level of theory) and connected via a transition state trans-[Ni(ICy)\(_{2}\)(C\(_{6}\)H\(_{5}\))(η\(^{2}\)-{SO}-C\(_{6}\)H\(_{5}\))], which lies only 10.8 kcal/mol above 5.}, language = {en} } @phdthesis{Ming2021, author = {Ming, Wenbo}, title = {Synthesis of α‑Aminoboronates and PBP Pincer Palladium Boryl Complexes}, doi = {10.25972/OPUS-19832}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-198323}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2021}, abstract = {The first Borono-Strecker reaction has been developed to synthesize α-aminoboronates via a multicomponent reaction of readily available carbonyl compounds (aldehydes and ketones), amines and B2pin2. The preparation of α-amino cyclic boronates can be achieved via multicomponent coupling of salicylaldehydes, amines, and B2(OH)4. In addition, the diazaborole-based PBP pincer palladium chloride and the diazaborole-based PBP pincer palladium trifluoromethanesulfonate complexes were synthesized and fully characterized for the first time, and used as catalysts for Suzuki-Miyaura cross-coupling reactions.}, language = {en} }