Palladium-Catalyzed Oxidative Double CH Functionalization/Carbonylation for the Synthesis of Xanthones
作者:Hua Zhang、Renyi Shi、Pei Gan、Chao Liu、Anxing Ding、Qiuyi Wang、Aiwen Lei
DOI:10.1002/anie.201201050
日期:2012.5.21
Two at once: Xanthones with different functional groups were obtained with CO (balloon) in the presence of a simple catalytic system that consists of Pd(OAc)2, K2S2O8, and trifluoroacetic acid (see scheme). Preliminary mechanism studies reveal that the second CHfunctionalization might be the rate‐determining step.
一次两个:在简单的催化体系(由Pd(OAc)2,K 2 S 2 O 8和三氟乙酸组成)的存在下,用CO(气球)获得具有不同官能团的氧杂蒽。初步的机理研究表明,第二个CH功能化可能是决定速率的步骤。
Palladium N-Heterocyclic Carbene
Catalysts for Synthesis of Diaryl Ethers
Novel functionalized 1,3-dialkylimidazolinium (LH) salts as precursors for N-heterocycliccarbenes (NHCs) have been prepared and successfully applied in the palladium-catalyzed synthesis of diaryl ethers and arylation ofbenzaldehydes. An efficient catalyst system was prepared in situ from Pd(OAc) 2 , 1,3-dialkylimidazolinium bromides (LHBr), and NaH.
<i>N</i>,<i>N</i>-Dimethyl Glycine-Promoted Ullmann Coupling Reaction of Phenols and Aryl Halides
作者:Dawei Ma、Qian Cai
DOI:10.1021/ol0350947
日期:2003.10.1
[reaction: see text] Ullmann-type diaryl ether synthesis can be performed at 90 degrees C using either aryl iodides or aryl bromides as the substrates under the assistance of N,N-dimethylglycine.
A simple and highly efficient Rh/C catalyzed route for the cleavage of the CâO bond of aromatic ether at 80 °C in the presence of 0.5 MPa of H2 in the scCO2âwater medium is reported; CO2 pressure and water play a key role under the tested conditions.
Cu(phen) complexes were observed in the copper(i)-catalyzed C–O coupling reaction using K2CO3 as the base and phen as the ligand under the catalytic reaction conditions by in situ electrospray ionization mass spectrometry (ESI-MS) and EPR analysis.