scholarly journals Screening of ligands for the Ullmann synthesis of electron-rich diaryl ethers

2012 ◽  
Vol 8 ◽  
pp. 1105-1111 ◽  
Author(s):  
Nicola Otto ◽  
Till Opatz
Keyword(s):  
Low Temperatures ◽  
Potassium Phosphate ◽  
Model System ◽  
Multidentate Ligands ◽  
Copper Iodide ◽  
Structural Class ◽  
Diaryl Ethers ◽  
Aryl Bromides ◽  
Diaryl Ether ◽  
Ether Synthesis

In the search for new ligands for the Ullmann diaryl ether synthesis, permitting the coupling of electron-rich aryl bromides at relatively low temperatures, 56 structurally diverse multidentate ligands were screened in a model system that uses copper iodide in acetonitrile with potassium phosphate as the base. The ligands differed largely in their performance, but no privileged structural class could be identified.

ChemInform Abstract: Diaryl Ether Synthesis in Supercritical Carbon Dioxide in Batch and Continuous Flow Modes.

ChemInform ◽  
2009 ◽  
Vol 40 (8) ◽  
Author(s):  
Jin-Kyun Lee ◽  
Matthew J. Fuchter ◽  
Rachel M. Williamson ◽  
Gary A. Leeke ◽  
Edward J. Bush ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Continuous Flow ◽  
Diaryl Ether ◽  
Ether Synthesis ◽  
Supercritical Carbon

A Monte Carlo simulation of steady state of 2D Ising model in temperature field

2016 ◽  
Vol 30 (04) ◽  
pp. 1650022 ◽  
Author(s):  
Zeshun Chen ◽  
Changming Xiao ◽  
Zhen Yao
Keyword(s):  
Monte Carlo ◽  
Temperature Field ◽  
Steady State ◽  
Ising Model ◽  
Low Temperatures ◽  
Ferromagnetic State ◽  
Model System ◽  
Local Magnetization ◽  
New Energy ◽  
High And Low Temperatures

Supposing the Ising model system is placed in a temperature field with constant high and low temperatures on both sides, then the system will shift to a non-equilibrium steady state with a certain temperature gradient. With the assistance of local temperature, the steady state of two-dimensional Ising model is studied via the avenue of Monte Carlo simulations in this paper. It is found that the local energy and magnetization are continuous, but there is a sharp decline in the magnetization strength when the temperature falls into the range of 2.2–2.4. The local magnetization [Formula: see text], when the temperature [Formula: see text]. It is the indication that the system is in the ferromagnetic state. However, when [Formula: see text], [Formula: see text], and then the ferromagnetic state turns into the paramagnetic state. Furthermore, a completely new and special state of Ising model system and the corresponding material is possible if the high and low temperatures of the temperature field are larger and smaller than the critical value of the system, respectively. According to this material, the magnetic driving machine, from which a new energy source can be obtained, is qualitatively discussed at the end of this paper.

tert-Butoxide mediated cascade desulfonylation/arylation/hydrolysis of cyclic sulfonyimines using diaryliodonium salts: synthesis of diaryl ether derivatives bearing a 2-aldehyde group

RSC Advances ◽  
2016 ◽  
Vol 6 (92) ◽  
pp. 89234-89237 ◽  
Author(s):  
Xiaofei Qian ◽  
Jianwei Han ◽  
Limin Wang
Keyword(s):  
Aldehyde Group ◽  
Diaryl Ethers ◽  
Diaryliodonium Salts ◽  
Diaryl Ether ◽  
Hydrolysis Of

Cascades of cyclic sulfonyimines mediated by tBuOK with diaryliodonium salts has been developed, giving the diaryl ethers in good yields.

A modular approach to the bisbenzylisoquinoline alkaloids tetrandrine and isotetrandrine

2020 ◽  
Vol 18 (16) ◽  
pp. 3047-3068 ◽  
Author(s):  
Ramona Schütz ◽  
Maximilian Meixner ◽  
Iris Antes ◽  
Franz Bracher
Keyword(s):  
Modular Approach ◽  
Diaryl Ether ◽  
Bisbenzylisoquinoline Alkaloids ◽  
Ether Synthesis

A modular short-step synthesis of the bisbenzylisoquinoline alkaloids tetrandrine and isotetrandrine was developed employing N-acyl-Pictet–Spengler reaction and Ullman diaryl ether synthesis as central steps.

scholarly journals Carbamate-directed benzylic lithiation for the diastereo- and enantioselective synthesis of diaryl ether atropisomers

2011 ◽  
Vol 7 ◽  
pp. 1327-1333 ◽  
Author(s):  
Abigail Page ◽  
Jonathan Clayden
Keyword(s):  
Diethyl Ether ◽  
Enantioselective Synthesis ◽  
Diaryl Ethers ◽  
Diaryl Ether ◽  
Enantioselective Deprotonation

Diaryl ethers carrying carbamoyloxymethyl groups may be desymmetrised enantio- and diastereoselectively by the use of the sec-BuLi–(−)-sparteine complex in diethyl ether. Enantioselective deprotonation of one of the two benzylic positions leads to atropisomeric products with ca. 80:20 e.r.; an electrophilic quench typically provides functionalised atropisomeric diastereoisomers in up to 97:3 d.r.

An efficient catalyst system for diaryl ether synthesis from aryl chlorides

2005 ◽  
Vol 46 (18) ◽  
pp. 3237-3240 ◽  
Author(s):  
Surendra Harkal ◽  
Kamal Kumar ◽  
Dirk Michalik ◽  
Alexander Zapf ◽  
Ralf Jackstell ◽  
...  
Keyword(s):  
Catalyst System ◽  
Efficient Catalyst ◽  
Aryl Chlorides ◽  
Diaryl Ether ◽  
Ether Synthesis

Syntheses, Structural Studies, and Copper Iodide Complexes of Macrocycles Derived from Williamson Ether Syntheses Involving 2,9-Bis(4-hydroxyphenyl)-1,10-phenanthroline, α,ω-Dibromides, and Resorcinol or 2,7-Dihydroxynaphthalene

2017 ◽  
Vol 70 (4) ◽  
pp. 373 ◽  
Author(s):  
Zuzana Baranová ◽  
Hashem Amini ◽  
Madhav Neupane ◽  
Sydney C. Garrett ◽  
Andreas Ehnbom ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Terminal Alkynes ◽  
Structural Studies ◽  
Copper Iodide ◽  
Functional Theory ◽  
Nitrogen Donor ◽  
Void Volumes ◽  
Ether Synthesis

1,3-Bis(6-bromohexyloxy)benzene, 2,7-bis(6-bromohexyloxy)naphthalene, 1,3-bis(4-bromomethylbenzyloxy)benzene, and 1,3-bis(3-bromomethylbenzyloxy)benzene were prepared via Williamson ether synthesis using resorcinol or 2,7-dihydroxynaphthalene and 1,6-dibromohexane, 1,4-bis(bromomethyl)benzene, or 1,3-bis(bromomethyl)benzene (21–47 % yield). These dibromides were condensed with 2,9-bis(4-hydroxyphenyl)-1,10-phenanthroline in the presence of K2CO3 to give the corresponding 31- to 35-membered macrocycles (3a–d, 22–63 % yield). When 3a–d were treated with CuI, mononuclear 1 : 1 complexes formed, in which the CuI chelates to the nitrogen donor atoms of the phenanthroline moiety (4a–d, 40–80 % yield). The crystal structures of 3a–c and 4a–c were determined and analyzed using density functional theory calculations and in the context of rotaxanes that could be formed by treatment of 4a–d with terminal alkynes (e.g. macrocycle dimensions, void volumes). The copper and iodide atoms in 4a–c significantly protrude from the least-squares plane of the phenanthroline moiety (0.46–0.63 Å and 1.65–2.07 Å).

scholarly journals Visible-light photoredox-catalyzed C–O bond cleavage of diaryl ethers by acridinium photocatalysts at room temperature

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Fang-Fang Tan ◽  
Xiao-Ya He ◽  
Wan-Fa Tian ◽  
Yang Li
Keyword(s):  
Carboxylic Acid ◽  
Visible Light ◽  
Room Temperature ◽  
Acid Catalysis ◽  
Bond Cleavage ◽  
Diphenyl Ether ◽  
One Pot ◽  
Diaryl Ethers ◽  
Diaryl Ether ◽  
High Bond

AbstractCleavage of C–O bonds in lignin can afford the renewable aryl sources for fine chemicals. However, the high bond energies of these C–O bonds, especially the 4-O-5-type diaryl ether C–O bonds (~314 kJ/mol) make the cleavage very challenging. Here, we report visible-light photoredox-catalyzed C–O bond cleavage of diaryl ethers by an acidolysis with an aryl carboxylic acid and a following one-pot hydrolysis. Two molecules of phenols are obtained from one molecule of diaryl ether at room temperature. The aryl carboxylic acid used for the acidolysis can be recovered. The key to success of the acidolysis is merging visible-light photoredox catalysis using an acridinium photocatalyst and Lewis acid catalysis using Cu(TMHD)2. Preliminary mechanistic studies indicate that the catalytic cycle occurs via a rare selective electrophilic attack of the generated aryl carboxylic radical on the electron-rich aryl ring of the diphenyl ether. This transformation is applied to a gram-scale reaction and the model of 4-O-5 lignin linkages.

Sign in / Sign up

Export Citation Format

Share Document