A general synthesis of diaryl ethers via coupling of aryl halides with substituted phenoxytrimethylsilane in the presence of TBAF is described. The protocol is simple and mild, and gives good to excellent yields.
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
Seven diaryl ethers were synthesized with potassium fluoride coated alumina as a strong base and the addition of catalytic amount of PTC. The yield of diaryl ethers with addition of PTC was much higher than that witho...Seven diaryl ethers were synthesized with potassium fluoride coated alumina as a strong base and the addition of catalytic amount of PTC. The yield of diaryl ethers with addition of PTC was much higher than that without PTC.A discussion of the catalysis mechanism was given in this paper.展开更多
The efficient construction of axially chiral diaryl ethers(ACDEs)is an important,emerging but challenging task in organic synthesis.Existing success based on desymmetrization was limited to acyclic substrates and mono...The efficient construction of axially chiral diaryl ethers(ACDEs)is an important,emerging but challenging task in organic synthesis.Existing success based on desymmetrization was limited to acyclic substrates and mono-modification of only one of the four substituents with low modularity.Here we developed the first enantioselective approach that allows concomitant modification of two substituents across both aryl rings,thus permitting flexible diversification of such ACDE structures.A mild copper-catalyzed approach based on ring-opening of cyclic diaryl iodonium salts was achieved,leading to excellent efficiency and enantioselectivity as well as good regioselectivity under mild conditions.Mechanistic studies revealed that ring-opening by the copper catalyst is rate-determining and enantio-determining.The highly enantioenriched ACDE products can serve as effective chiral catalysts for asymmetric synthesis.展开更多
The reductive cross-coupling between C(aryl)—O and Si—Cl bonds is of much importance as a valuable strategy for the construction of C(aryl)—Si bonds but has remained a great challenge.Herein,we report a reductive c...The reductive cross-coupling between C(aryl)—O and Si—Cl bonds is of much importance as a valuable strategy for the construction of C(aryl)—Si bonds but has remained a great challenge.Herein,we report a reductive cross-coupling of diaryl ethers and chlorosilanes via strong electrophilic C(aryl)—O and Si—Cl bonds cleavage by iron catalysis,which constitutes an efficient protocol for the synthesis of a range of functionalized arylsilanes.The combination of low cost FeCl2 as the precatalyst and iPrMgCl as the reductant shows high activity in the successive cleavage of unactivated C(aryl)—O bonds of diaryl ethers and strong electrophilic Si—Cl bonds of chlorosilanes,allowing their cross-coupling in a reductive fashion.The low-valent iron species generated in situ by reduction of FeCl2 with iPrMgCl was proposed,which prefers to initially cleavage the C(aryl)—O bond of diaryl ethers with the chelation help of an o-amide auxiliary.展开更多
Nanoparticle Fe304 encapsulated CuO, as a heterogeneous catalyst, is a facile system for the synthesis of diaryl ethers by the cross-coupling reaction of various substituted aryl halides with various substituted pheno...Nanoparticle Fe304 encapsulated CuO, as a heterogeneous catalyst, is a facile system for the synthesis of diaryl ethers by the cross-coupling reaction of various substituted aryl halides with various substituted phenols, which avoids using any type of expensive ligand and can be recovered from the reaction mixture by using a simple magnet. Moreover, this catalyst can be reused three times with high catalytic activity.展开更多
文摘A general synthesis of diaryl ethers via coupling of aryl halides with substituted phenoxytrimethylsilane in the presence of TBAF is described. The protocol is simple and mild, and gives good to excellent yields.
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Seven diaryl ethers were synthesized with potassium fluoride coated alumina as a strong base and the addition of catalytic amount of PTC. The yield of diaryl ethers with addition of PTC was much higher than that without PTC.A discussion of the catalysis mechanism was given in this paper.
基金supported by the National Natural Science Foundation of China(22201023,22271242)the Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology(BM2012110)the Changzhou Sci&Tech Program(CZ20240027)。
文摘The efficient construction of axially chiral diaryl ethers(ACDEs)is an important,emerging but challenging task in organic synthesis.Existing success based on desymmetrization was limited to acyclic substrates and mono-modification of only one of the four substituents with low modularity.Here we developed the first enantioselective approach that allows concomitant modification of two substituents across both aryl rings,thus permitting flexible diversification of such ACDE structures.A mild copper-catalyzed approach based on ring-opening of cyclic diaryl iodonium salts was achieved,leading to excellent efficiency and enantioselectivity as well as good regioselectivity under mild conditions.Mechanistic studies revealed that ring-opening by the copper catalyst is rate-determining and enantio-determining.The highly enantioenriched ACDE products can serve as effective chiral catalysts for asymmetric synthesis.
基金financial support from the National Natural Science Foundation of China(21901206)Postdoctoral Science Foundation of China(2022M712589)+2 种基金General key R&D Projects in Shaanxi Province(2023-YBGY-321)Natural Science Foundation of Chongqing(CSTB2022NSCQ-MSX0826)Fundamental Research Funds for the Central Universities and the Haihe Laboratory of Sustainable Chemical Transformation.
文摘The reductive cross-coupling between C(aryl)—O and Si—Cl bonds is of much importance as a valuable strategy for the construction of C(aryl)—Si bonds but has remained a great challenge.Herein,we report a reductive cross-coupling of diaryl ethers and chlorosilanes via strong electrophilic C(aryl)—O and Si—Cl bonds cleavage by iron catalysis,which constitutes an efficient protocol for the synthesis of a range of functionalized arylsilanes.The combination of low cost FeCl2 as the precatalyst and iPrMgCl as the reductant shows high activity in the successive cleavage of unactivated C(aryl)—O bonds of diaryl ethers and strong electrophilic Si—Cl bonds of chlorosilanes,allowing their cross-coupling in a reductive fashion.The low-valent iron species generated in situ by reduction of FeCl2 with iPrMgCl was proposed,which prefers to initially cleavage the C(aryl)—O bond of diaryl ethers with the chelation help of an o-amide auxiliary.
基金Supported by the National Natural Science Foundation of China(201102087)Key Technologies R&D Program of He'nan Scientific and Technological Committee(112102210477)Funding Scheme for Young Teachers in Colleges and Universities in Henan Province(2011GGJS-157)~~
基金supported by the Natural Science Foundation of Gansu Province,China(No.1014RJZA022)Postgraduate Tutor Fund of Gansu Province Education Department(No.1101ZTC103)
文摘Nanoparticle Fe304 encapsulated CuO, as a heterogeneous catalyst, is a facile system for the synthesis of diaryl ethers by the cross-coupling reaction of various substituted aryl halides with various substituted phenols, which avoids using any type of expensive ligand and can be recovered from the reaction mixture by using a simple magnet. Moreover, this catalyst can be reused three times with high catalytic activity.
