Asymmetric transfer hydrogenation of acetophenone derivatives using 2-benzyl-tethered ruthenium (II)/TsDPEN complexes bearing η6-(p-OR) (R = H, iPr, Bn, Ph) ligands
作者:Richard C. Knighton、Vijyesh K. Vyas、Luke H. Mailey、Bhalchandra M. Bhanage、Martin Wills
DOI:10.1016/j.jorganchem.2018.08.020
日期:2018.11
4′-OR (R = H, iPr, Bn, Ph) substituted ruthenium (II) biphenyl TsDPEN complexes are described; the complexes are accessed via an operationally simple and reliable two-step ligand synthesis followed by ligation to the ruthenium (II) centre. We report the preliminary asymmetric transfer hydrogenation (ATH) results on a range of primarily acetophenone derivatives with these new complexes using FA/TEA (5:2)
Catalytic Oxidative Cyclization of 2′-Arylbenzaldehyde Oxime Ethers under Photoinduced Electron Transfer Conditions
作者:Julie L. Hofstra、Brittany R. Grassbaugh、Quan M. Tran、Nicholas R. Armada、H. J. Peter de Lijser
DOI:10.1021/jo502324z
日期:2015.1.2
sequence is initiated by an electron transfer step followed by nucleophilicattack of the aryl ring onto the nitrogen of the oxime ether. A concave downward Hammett plot is presumably the result of a change in charge distribution in the radical cation species with strongly electron-donating substituents that yields a less electrophilic nitrogenatom and a decreased amount of cyclized product. The reaction
Direct Excitation of Aldehyde to Activate the C(
<i>sp</i>
<sup>
<i>2</i>
</sup>
)−H Bond by Cobaloxime Catalysis toward Fluorenones Synthesis with Hydrogen Evolution
highly reactive photoexcited triplet state of aromatic aldehyde intermediates is intercepted by the catalyst in the ground state, thus leading to the synthesis of a series of fluorenones, xanthones and thioxanthones in good to excellent yields without any external oxidants and with hydrogen as the byproduct.
已经成功开发了通过钴肟催化直接激发醛以激活其 C ( sp 2 )-H 键。在照射下,芳香醛中间体的高反应性光激发三重态被基态催化剂拦截,从而导致在没有任何外部氧化剂和氢作为副产品。