Chiral bis-corrole 1 and 2 were prepared by reaction of (s)-2,2′-bis(bromomethyl)-1, 1′-binaphthyl and 10-(4-hydroxylphenyl)- 5,15-bis(pentafluorophenyl)corrole or 10-(3-hydroxylphenyl)-5,15-bis(pentafluorophenyl)corrole in DMF at 60 ℃ in the presence of anhydrous K2CO3 with an isolated yield -8%. Both 1 and 2 exhibit unsymmetrical induced circular dichroism (ICD) in the soret band with positive exciton chirality.
Polystyrene-supported hydroquinone (PS-HQ) is presented as an in situ polymeric cocatalyst to replace polystyrenesupported benzoquinone (PS-BQ) in the PdCl2-catalyzed acetalization of methyl acrylate with methanol in supercritical carbon dioxide (scCO2) under oxygen atmosphere. Due to deletion of H2O2 oxidation step, PS-HQ is more convenient and relatively inexpensive.
Zhao Yang WangHuan Feng JiangChao Rong QiYan Xia ShenShao Rong Yang
A new process for the Pd/Cu co-catalyzed homocoupling reaction of terminal alkynes was developed. The reaction was carried out in aqueous media with sodium percarbonate as both a clean oxidant and a base. Meanwhile, a palladium complex immobilized on a synthetic PS-PEG400-PPh2 resin was used as the catalyst, which may be recovered by simple filtration and reused for several times with high activity.
1 Introduction Nowadays, green chemistry has received increased attention. The use of water and scCO2 as a solvent or reagent is an important field for organic reactions and green chemistry both in laboratory and industry.
A novel and green method for the synthesis of dimethyl pyridine-3,5-dicarboxylate has been developed. It is PdCl2-catalyzed heterocyclotrimerization of methyl acrylate with urea in methanol/supercritical carbon dioxide. The target compound was obtained with a 75% isolated yield under the optimized con-ditions.
ZOU Bo,JIANG HuanFeng College of Chemistry,South China University of Technology,Guangzhou 510640,China
The reductive demetalation of manganese corroles was investigated in CH2Cl2/HCl (aqueous) solvent by using SnCl2 as reducing agent. It was found that the demetalation yields depend on the substituents of corrole macrocycle significantly. Electron- rich manganese corrole undergoes reductive demetalation more easily than electron-deficient ones. The isolated reductive demetalation yield of manganese 5,10,15-tris(phenyl)corrole in present system is moderate (46%). As for electron-deficient Mn(Ⅲ) 5,10,15-tris(pentafluorophenyl)corrole, the acid-induced demetalation in HOAc-HESO4 (V/V = 3:1) is preferable with an isolated yield of 67%.
Hai Yang LiuLing ChenFei YamHai Ying ZhanXiao YingXiang Li WangHuan Feng JiangChi Kwong Chang