两种新型层状铜杂化材料,即噻吩-2,5-二膦酸铜 [Cu2(H2O)2(O3P–C4H2S–PO3)] (Pnma; a = 7.525 A, b = 18.292 A, c = 7.520 A)并且合成了 3-氟苯基膦酸铜 Cu(H2O)PO3–C6H4F (P21/c; a = 14.305 A, b = 7.550 A, c = 7.479 A, β = 92.32°)。这些化合物属于大型同源 Cu(H2O)PO3R/[Cu2(H2O)2(O3P–R–PO3)] 系列,其结构由孤立的二聚锥体 Cu2O6(H2O)2 单元的存在决定。结合铜阳离子的 Jahn-Teller 效应讨论了 Cu/H2O 摩尔比为 1 在稳定这种结构中的作用。对这两种化合物的多晶样品磁性行为的研究揭示了铜离子之间的反铁磁耦合。
Oxidative Phosphonylation of Aromatics with Ammonium Cerium(IV) Nitrate Arylphosphonates 5 and 6 can be prepared in good yields in a one-step synthesis starting from arenes with tri- or diethylphosphites and cerium ammonium nitrate (CAN) as oxidant. The selectivity of the oxidative phosphonylation is relatively low; the reactive species is a phosphite radical cation.
A “green” variation of the Hirao reaction: the P–C coupling of diethyl phosphite, alkyl phenyl-<i>H</i>-phosphinates and secondary phosphine oxides with bromoarenes using a P-ligand-free Pd(OAc)<sub>2</sub> catalyst under microwave and solvent-free conditions
作者:György Keglevich、Erzsébet Jablonkai、László B. Balázs
DOI:10.1039/c4ra03292f
日期:——
The P–C coupling of diethyl phosphite, alkyl phenyl-H-phosphinates, diphenylphosphine oxide and dialkylphosphine oxides with bromoarenes may be performed in the presence of a P-ligand-free Pd(OAc)2 catalyst and triethylamine undermicrowave-assisted (MW) and, in almost all cases, solvent-free conditions to afford diethyl arylphosphonates, alkyl diphenylphosphinates, aryldiphenylphosphine oxides and
NiCl2-catalyzed P–C coupling reaction of arylhalides and various > P(O)H-compounds under MW conditions without directly added P-ligands. The reactivity of a few aryl derivatives in the Pd(OAc)2-catalyzed Hirao reaction was also studied. An induction period was observed in the reaction of bromobenzene and diphenylphosphine oxide. Finally, the less known copper(I)-promoted P–C coupling reactions were investigated
anodic oxidation proceeds either via phosphiniumradicalcations, which then attack the arenes electrophilically, or via arene radicalcations, which add the trialkylphosphite as nucleophile. Aryl phosphonates are also obtained in good yield by chemical oxidation with peroxodisulfate/AgNO3 in acetonitrile/water or glacial acetic acid. The diethylphosphinium radicalcation, formed from diethylphosphite by