7661-55-4Relevant articles and documents
Transition metal eight-coordination. IV. Tetrakis(5,7-disubstituted-8-quinolinolato)tungsten(V) salts
Archer, Ronald D.,Bonds Jr., Wesley D.,Pribush, Robert A.
, p. 1550 - 1555 (1972)
Violet, paramagnetic [WQ4]+ ions have been synthesized by a variety of methods and appear to be the first complexes of tungsten(V) possessing four chelate ligands. The 5,7-dichloro-8-quinolinol derivative has been synthesized by the reaction of either K3W2Cl9 or W(CO)6 with excess ligand at elevated temperatures for extended time periods or by treating the corresponding tungsten(IV) inner complex with Cl2, Br2, or HClO4 at room temperature or with additional ligand at elevated temperatures. The 7-bromo-5-methyl-8-quinolinol-tungsten(V) species is rapidly produced in the melt reaction of the ligand with W(CO)6. The [WQ4]X salts, where X- = Cl-, Br-, ClO4-, or Q-, disproportionate in alcoholic or aqueous KOH to WQ4 and tungsten(VI). Electronic transitions of the [WQ4] species consist of several bands in the near-infrared and visible region in addition to the normal ligand spectral transitions. A magnetic moment of 1.7 BM, a 〈g〉 value of 1.872, and a 183W hyperfine splitting of 85 G were observed for the dichloro derivative at room temperature. Low-temperature electron spin resonance spectra exhibit three anisotropic g values indicative of isomerization from the D2d-mmmm isomer found for a related 5-bromo-8-quinolinol-tungsten(IV) chelate.1a.
A methylation platform of unconventional inert aryl electrophiles: Trimethylboroxine as a universal methylating reagent
Feng, Boya,Yang, Yudong,You, Jingsong
, p. 6031 - 6035 (2020/07/10)
Methylation is one of the most fundamental conversions in medicinal and material chemistry. Extension of substrate types from aromatic halides to other unconventional aromatic electrophiles is a highly important yet challenging task in catalytic methylation. Disclosed herein is a series of transition metal-catalyzed methylations of unconventional inert aryl electrophiles using trimethylboroxine (TMB) as the methylating reagent. This transformation features a broad substrate type, including nitroarenes, benzoic amides, benzoic esters, aryl cyanides, phenol ethers, aryl pivalates and aryl fluorides. Another important merit of this work is that these widespread "inert"functionalities are capable of serving as directing or activating groups for selective functionalization of aromatic rings before methylation, which greatly expands the connotation of methylation chemistry.
Method for preparation of quinoline compounds
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Paragraph 0046-0048, (2020/11/12)
The invention discloses a green preparation method of quinoline compounds. According to the method, cheap and easily available copper salt and N-hydroxyphthalimide are used as catalysts, oxygen is used as an oxidizing agent, oxidation of tetrahydroquinoline compounds is performed in an organic solvent, and synthesis of quinoline compounds is realized. The method has the advantages of simple reaction operation, low reaction cost, high yield, low metal pollution and the like.