Employing methenamine as a new supporting ligand, the copper-catalyzed coupling reactions of aryl bromides or aryl iodides with various phenols successfully proceeded in good yields under mild conditions. A series of ...Employing methenamine as a new supporting ligand, the copper-catalyzed coupling reactions of aryl bromides or aryl iodides with various phenols successfully proceeded in good yields under mild conditions. A series of diaryl ethers were obtained with excellent yields in the presence of K3PO4 and copper（l） salt.展开更多
A general, rapid and highly efficient method for the synthesis of diaryl ethers under the assistance of microwave irradiation was described. A series of diaryl ethers were prepared by direct coupling of phenols and ar...A general, rapid and highly efficient method for the synthesis of diaryl ethers under the assistance of microwave irradiation was described. A series of diaryl ethers were prepared by direct coupling of phenols and aryl halides in good to excellent yields in anhydrous DMF or NMP at 150 ℃ within 20 rain. The presence of water was found to have a significant impact on the Ullmann C-O coupling reaction between aryl halides and phenols under microwave irradiation.展开更多
A series of salicylaldimine ligands were designed to promote the copper-catalyzed Ullmann cross- coupling reaction. After a screening process, 2-（（2-isopropylphenylimino）methyl）phenol was found to serve as a good ...A series of salicylaldimine ligands were designed to promote the copper-catalyzed Ullmann cross- coupling reaction. After a screening process, 2-（（2-isopropylphenylimino）methyl）phenol was found to serve as a good supporting ligand for this reaction. Employing this Schiff-base ligand as a new supporting ligand, the copper-catalyzed coupling reactions of aryl bromides and aryl iodides with various phenols successfully proceeded in good yields under mild conditions. Various diaryl ethers were obtained with excellent yields in dioxane in the presence of K3P04 and a catalytic amount of copper（I） salt.展开更多
采用水热-尿素水解法制备了系列含Cu2+的类水滑石化合物Cu x Mg3-x Al1-LDHs,并考察了这些催化剂对苯酚和碘苯合成二苯醚反应的催化性能.利用X射线粉末衍射(XRD)、差热热重(TG-DTA)、H2程序升温还原(H2-TPR)和扫描电镜(SEM)等方法对催...采用水热-尿素水解法制备了系列含Cu2+的类水滑石化合物Cu x Mg3-x Al1-LDHs,并考察了这些催化剂对苯酚和碘苯合成二苯醚反应的催化性能.利用X射线粉末衍射(XRD)、差热热重(TG-DTA)、H2程序升温还原(H2-TPR)和扫描电镜(SEM)等方法对催化剂进行了表征.结果表明,Cu2+含量较低时,类水滑石催化剂具有较好的结晶度和热稳定性,随Cu2+含量的增加,层板间距加大,热稳定性也随之降低.催化活性测试结果表明,适量Cu2+的掺入可使催化剂的催化活性提高,其中催化剂Cu2Mg1Al1-LDHs具有较好的催化活性,在80℃条件下二苯醚收率达到55%.展开更多
Ullmann-type diaryl ether synthesis can be performed at 100 ℃ in good to excellent yields by aryl iodides as the substrates under the assistance of copper（Ⅱ） and 2,2＇-biimidazolyl.
文摘Employing methenamine as a new supporting ligand, the copper-catalyzed coupling reactions of aryl bromides or aryl iodides with various phenols successfully proceeded in good yields under mild conditions. A series of diaryl ethers were obtained with excellent yields in the presence of K3PO4 and copper（l） salt.
基金Project supported by the Guangdong Provincial Natural Science Foundation （No. 04009718）
文摘A general, rapid and highly efficient method for the synthesis of diaryl ethers under the assistance of microwave irradiation was described. A series of diaryl ethers were prepared by direct coupling of phenols and aryl halides in good to excellent yields in anhydrous DMF or NMP at 150 ℃ within 20 rain. The presence of water was found to have a significant impact on the Ullmann C-O coupling reaction between aryl halides and phenols under microwave irradiation.
基金the National Natural Science Foundation of ChinaKey Laboratory of Organic Synthesis of Jiangsu Province for the financial support(Nos.21201147,21302063,KJS1112)
文摘A series of salicylaldimine ligands were designed to promote the copper-catalyzed Ullmann cross- coupling reaction. After a screening process, 2-（（2-isopropylphenylimino）methyl）phenol was found to serve as a good supporting ligand for this reaction. Employing this Schiff-base ligand as a new supporting ligand, the copper-catalyzed coupling reactions of aryl bromides and aryl iodides with various phenols successfully proceeded in good yields under mild conditions. Various diaryl ethers were obtained with excellent yields in dioxane in the presence of K3P04 and a catalytic amount of copper（I） salt.
文摘采用水热-尿素水解法制备了系列含Cu2+的类水滑石化合物Cu x Mg3-x Al1-LDHs,并考察了这些催化剂对苯酚和碘苯合成二苯醚反应的催化性能.利用X射线粉末衍射(XRD)、差热热重(TG-DTA)、H2程序升温还原(H2-TPR)和扫描电镜(SEM)等方法对催化剂进行了表征.结果表明,Cu2+含量较低时,类水滑石催化剂具有较好的结晶度和热稳定性,随Cu2+含量的增加,层板间距加大,热稳定性也随之降低.催化活性测试结果表明,适量Cu2+的掺入可使催化剂的催化活性提高,其中催化剂Cu2Mg1Al1-LDHs具有较好的催化活性,在80℃条件下二苯醚收率达到55%.
文摘Ullmann-type diaryl ether synthesis can be performed at 100 ℃ in good to excellent yields by aryl iodides as the substrates under the assistance of copper（Ⅱ） and 2,2＇-biimidazolyl.
