19814-71-2Relevant articles and documents
Palladium-Catalyzed Formal Cross-Coupling of Diaryl Ethers with Amines: Slicing the 4-O-5 Linkage in Lignin Models
Zeng, Huiying,Cao, Dawei,Qiu, Zihang,Li, Chao-Jun
supporting information, p. 3752 - 3757 (2018/03/13)
Lignin is the second most abundant organic matter on Earth, and is an underutilized renewable source for valuable aromatic chemicals. For future sustainable production of aromatic compounds, it is highly desirable to convert lignin into value-added platform chemicals instead of using fossil-based resources. Lignins are aromatic polymers linked by three types of ether bonds (α-O-4, β-O-4, and 4-O-5 linkages) and other C?C bonds. Among the ether bonds, the bond dissociation energy of the 4-O-5 linkage is the highest and the most challenging to cleave. To date, 4-O-5 ether linkage model compounds have been cleaved to obtain phenol, cyclohexane, cyclohexanone, and cyclohexanol. The first example of direct formal cross-coupling of diaryl ether 4-O-5 linkage models with amines is reported, in which dual C(Ar)?O bond cleavages form valuable nitrogen-containing derivatives.
Competing Pathways in O-Arylations with Diaryliodonium Salts: Mechanistic Insights
Stridfeldt, Elin,Lindstedt, Erik,Reitti, Marcus,Blid, Jan,Norrby, Per-Ola,Olofsson, Berit
, p. 13249 - 13258 (2017/09/12)
A mechanistic study of arylations of aliphatic alcohols and hydroxide with diaryliodonium salts, to give alkyl aryl ethers and diaryl ethers, has been performed using experimental techniques and DFT calculations. Aryne intermediates have been trapped, and additives to avoid by-product formation originating from arynes have been found. An alcohol oxidation pathway was observed in parallel to arylation; this is suggested to proceed by an intramolecular mechanism. Product formation pathways via ligand coupling and arynes have been compared, and 4-coordinated transition states were found to be favored in reactions with alcohols. Furthermore, a novel, direct nucleophilic substitution pathway has been identified in reactions with electron-deficient diaryliodonium salts.
Low catalyst loadings for copper-catalyzed O-arylation of phenols with aryl and heteroaryl halides under mild conditions
Yong, Fui-Fong,Teo, Yong-Chua,Yan, Yaw-Kai,Chua, Guan-Leong
scheme or table, p. 101 - 106 (2012/02/03)
A practical and mild strategy has been developed for the cross-coupling of O-arylation of phenol with differently substituted aryl halides and heteroaryl iodides using low catalyst loading of copper iodide under low operating temperature in DMF with TMHD as the ligand and Cs2CO3 as the base. This method tolerates a variety of functional groups including sterically hindered phenols and heteroaryl iodides to afford products in good to excellent yields (up to 95%). Georg Thieme Verlag Stuttgart. New York.
Selective one-pot access to symmetrical or unsymmetrical diaryl ethers by copper-catalyzed double arylation of a simple oxygen source
Tlili, Anis,Monnier, Florian,Taillefer, Marc
supporting information; experimental part, p. 12299 - 12302 (2011/02/16)
Great CO-mbination: A novel method is reported for the controlled one-pot synthesis of various symmetrical or unsymmetrical diaryl ethers by double arylation of a simple inorganic oxygen source (see scheme). This versatile and highly selective process is based on the use of a cheap and low toxicity copper catalytic system.
Bicyclic benzo fused compounds
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, (2008/06/13)
Bicyclic fused benzenoid compounds of the formula STR1 and pharmaceutically acceptable cationic and acid addition salts thereof, where M is O, CH2 or NR6 ; R6 is hydrogen, formyl, carbobenzyloxy or certain carboalkoxyalkyl, alkanoyl, alkyl, aralkyl or aralkylcarbonyl groups; A' is: (1) A where one of A and B is hydrogen such that when A is hydrogen, B is C(R2 R3)(CH2)f Q and f is 1 or 2; when B is hydrogen, A is C(R2 R3)(CH2)f Q and f is 0 or 1, when taken together A and OR1 form a lactone or certain derivatives thereof; (2) A' is STR2 (3) A' is Q3 ; Q is CO2 R7, COR8, C(OH)R8 R9, CN, CONR12 R13, CH2 NR12 R13, CH2 NHCOR14, CH2 NHSO2 R17 or 5-tetrazoyl; Q3 is STR3 5-tetrazolyl, CH2 CONHCOR7, COOH or certain ester, amide, carboximido or sulfonimido derivatives thereof, CONHOH, CONHCONH2, or COCH2 Q4 where Q4 is CN or COOH or certain esters thereof; R1 is hydrogen, benzyl or certain acyl groups; R4 is hydrogen, certain alkyl or certain aralkyl groups; R5 is hydrogen or certain alkyl groups; Z is (C1 -C9)alkylene, optionally interrupted by O, S, SO or SO2 ; and W is hydrogen, methyl, certain aryl or cycloalkyl groups; useful in mammals as analgesics, tranquilizers, antiemetic agents, diuretics, anticonvulsants, antidiarrheals, antitussives, in treatment of glaucoma, and intermediates therefore.
Alkyldiphenyl ether-sulphonic acid hydrazides, their preparation and their use as blowing agents
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, (2008/06/13)
A di- or tri-sulphonic acid hydrazide of an alkylated diphenyl ether, said hydrazide being of the formula STR1 wherein R1 and R2 are identical or different and represent halogen or a lower alkyl radical and R1 and R2 can denote hydrogen, R3 denotes a lower alkyl radical and n represents the number 1 or 2. A process for the preparation of such hydrazides and the use of such hydrazides as chemical blowing agents in the production of foams from foamable compositions, especially rubbers and thermoplastic resins.
