Abstract A mild, efficient, and practical catalytic system for the synthesis of highly privileged stilbene pharmacophores is reported. This system uses N-heterocyclic carbene palladium (II) Pyridine (NHC-Pd (II)-Py) complex to catalyze the formation of carbon-carbon bonds between olefin derivatives and various bromide. This simple, gentle and user-friendly method can offer a variety of stilbene products
作者:Qiang-Qiang Li、Zaher Shah、Jian-Ping Qu、Yan-Biao Kang
DOI:10.1021/acs.joc.7b02720
日期:2018.1.5
A base-promoted transition metal-free approach to substituted alkenes using alcohols under aerobic conditions using air as the inexpensive and clean oxidant is described. Aldehydes are relatively difficult to handle compared to corresponding alcohols due to their volatility and penchant to polymerize and autoxidize. Wittig ylides are easily oxidized to aldehydes and consequently form homo-olefination
Palladium(<scp>ii</scp>) ligated with a selenated (Se, C<sub>NHC</sub>, N<sup>−</sup>)-type pincer ligand: an efficient catalyst for Mizoroki–Heck and Suzuki–Miyaura coupling in water
respectively) at very low catalyst loading (0.2 mol%) and under mild reaction conditions in water. The complex (1) was also investigated for Suzuki-Miyaura coupling and found to be selectively efficient (yields up to 94%) for Suzuki-Miyaura coupling of aromatic bromides at 0.01 mol% of 1 in water. All coupling reactions were carried out in the green and economical solvent, water, which is highly desirable
Asymmetrically substituted distyrylbenzenes and their polar crystal structures
作者:Alain Collas、Roeland De Borger、Tatyana Amanova、Christophe M. L. Vande Velde、Jan K. Baeke、Roger Dommisse、Christian Van Alsenoy、Frank Blockhuys
DOI:10.1039/c0nj00732c
日期:——
The synthesis of twelve asymmetric donor–acceptor distyrylbenzene derivatives with either one nitrile group or one, two or three nitro groups as electron acceptors, and one, two or three methoxy groups as electron donors is reported. Peak potentials obtained from cyclic voltammetry were combined with experimental UV/Vis data and molecular dipole moments obtained from quantum chemical calculations, yielding insight into the influence of the positions of the substituents on the electronic structure and charge distribution of this as yet unexplored class of organic semiconductors. The supramolecular structures of five of these compounds have been studied using single-crystal X-ray diffraction to monitor the influence of the positions of donor and acceptor groups on the organisation of the molecules in the solid state, and three crystal structures have been identified in which the molecular dipoles do not organize themselves in a centrosymmetric lattice. Analysis of the dipoles in the unit cell yields further insight into the possible non-linear optical properties of these three polar structures.
Direct <i>trans</i>-Selective Ruthenium-Catalyzed Reduction of Alkynes in Two-Chamber Reactors and Continuous Flow
作者:Karoline T. Neumann、Sebastian Klimczyk、Mia N. Burhardt、Benny Bang-Andersen、Troels Skrydstrup、Anders T. Lindhardt
DOI:10.1021/acscatal.6b01045
日期:2016.7.1
efficient trans-selective hydrogenation of alkynes under lowhydrogenpressure and lowreaction temperatures is reported, applying a commercially available ruthenium hydride complex. The developed reaction conditions, which tolerate a variety of functional groups, are carried out in a two-chamber setup with ex situ generated hydrogen. The reaction setup is highly suitable for deuterium labeling. The trans-selective