5469-51-2Relevant articles and documents
Construction of an isoquinolinone framework from carboxylic-ester-directed umpolung ring opening of methylenecyclopropanes
Wei, Hao-Zhao,Wei, Yin,Shi, Min
supporting information, p. 11201 - 11204 (2021/11/09)
An interesting type of reaction involving functionalized methylenecyclopropanes (MCPs) has been revealed. Here, a nucleophilic attack of an anionic species onto a partially polarity-reversed MCP was realized by treating a neighbouring carboxylic ester tethered to the MCP and amine with KHMDS to realize an umpolung ring opening of the MCP. This work established an operationally convenient protocol for the rapid construction of isoquinolinone frameworks. This journal is
Ruthenium-Catalyzed Enantioselective Hydrogenation/Lactonization of 2-Acylarylcarboxylates: Direct Access to Chiral 3-Substituted Phthalides
Lu, Bin,Zhao, Mengmeng,Ding, Guangni,Xie, Xiaomin,Jiang, Lili,Ratovelomanana-Vidal, Virginie,Zhang, Zhaoguo
, p. 3989 - 3996 (2017/09/13)
Highly enantioselective tandem hydrogenation/lactonization of various 2-acylarylcarboxylates including 2-aroylarylcarboxylates were realized by using [RuCl(benzene)(S)-SunPhos]Cl as the catalyst under mild reaction conditions. Excellent enantioselectivities (up to 99.6 % ee) and activities (S/C=1000) were obtained. This convenient and practical method enables a direct access to a series of highly optically pure 3-substituted phthalides that are very important molecules as valuable pharmacological compounds and diversified synthons for medicinal chemistry. Moreover, a gram-scale reaction was performed to further demonstrate the practicality of this approach.
Palladium-catalyzed chemoselective decarboxylative ortho acylation of benzoic acids with α-oxocarboxylic acids
Miao, Jinmin,Ge, Haibo
supporting information, p. 2930 - 2933 (2013/07/26)
Palladium-catalyzed chemoselective decarboxylative cross coupling of benzoic acids with α-oxocarboxylic acids was realized via an arene sp 2 C-H functionalization process. This work represents the first example of transition-metal-catalyzed cro
Photoenolization of 2-(2-methyl benzoyl) benzoic acid, methyl ester: Effect of e photoenol lifetime on the photochemistry
Konosonoks, Armands,Wright, P. John,Tsao, Meng-Lin,Pika, Jana,Novak, Kevin,Mandel, Sarah M.,Krause Bauer, Jeanette A.,Bohne, Cornelia,Gudmundsdottir, Anna D.
, p. 2763 - 2770 (2007/10/03)
(Chemical Equation Presented) Photolysis of 3 in argon-saturated 2-propanol led to formation of 5 via intermolecular H-atom abstraction followed by lactonization. Irradiation of 4 in 2-propanol gave compounds 6 and 7 that also come from intermolecular H-atom abstraction. In contrast, photolysis of an oxygen-saturated solution of 3 in 2-propanol yields products 8, 9, and 10, which were all formed from intramolecular H-atom abstraction and trapping of the corresponding biradical with oxygen. Laser flash photolysis of 3 in methanol showed formation of biradical 3BR (γmax 330 nm, and τ = 50 ns) via intramolecular H-atom abstraction as the main photoreactivity of 3. Biradical 3BR decayed into photoenols 3Z and 3E (γmax 390 nm, τ= 6.5 μs and τ = 162 μs, respectively). In comparison, laser flash photolysis of 4 yielded photoenols 4Z and 4E (γmax 390 nm, τ = 15 μs and τ = 3.6 ms, respectively). Thus photoenol 3E is unusually short-lived, and therefore it does not undergo the intramolecular lactonization as we have observed for the analogous photoenol 1E. Photoenol 3Z decays back to 3 via an intramolecular 1,5-H shift, whereas photoenol 3E reforms 3 efficiently via the solvent with the aid of the ortho ester group. The intramolecular lactonization of photoenols 1E and 3E must be a slow process, presumably because the photoenols are rigid and the hydroxyl group is inhibited, by intramolecular hydrogen bonding, from acquiring the correct geometry for lactonization. Thus only photoenols that are resistant to reformation of their ketone via the solvent are long-lived enough to undergo lactonization and release the alcohol moiety.
Process for preparing 2-(alkylbenzoyl)benzoic acid
-
, (2008/06/13)
An environmentally acceptable process is provided to synthesize a 2-(alkylbenzoyl)benzoic acid suitable for synthesizing a 2-alkylanthraquinone without further purification. Usually the crude product is isolated from the reaction mixture by a succession of steps which generate a large volume of aqueous waste. The present process eliminates or decreases these wastes and produces a product of sufficient purity for synthesizing as 2-alkylanthraquinone.
Photoenolisation. XI. Photooxydation des o-methylbenzophenones
Pfau, Michel,Molnar, James,Heindel, Ned D.
, p. 164 - 169 (2007/10/02)
Photoenols 2 of 2- (1a), 2,4- (1b), 2,5- (1c), 2,6- (1d), 2,2'- (1e) and 2,3'-dimethylbenzophenones (1f) were trapped by (3)O2.When a 350 nm wavelength Hg lamp (Rayonet RPR 100) was used (benzene solution) with ketones 1a-c, the corresponding 2-formyl- 4 and 2-carboxybenzophenones 8 were formed as well as 3-phenyl-phtalides 10.Compounds 4 arose from dehydration of the intermediate endoperoxydes 3.Throught photoenolisation, 2-formylbenzophenones 4 gave the intermediate ketene-enols 5 which either isomerised to phtalides 10 or added oxygen to form the corresponding endoperoxydes 6; the latter isomerised to peracids 7, which, by reaction with aldehydes 4, yielded the carboxylic acids 8.When the aerated irradiations were performed simultaneously with 350 nm light and with light above 380 nm (Hanovia 679 A-36, benzene solution), ketones 1a-f yielded the same compounds 4, 8 and 10 but also anthraquinones 13.The latter arose from reversible cyclisation of photoenols 2 E giving dihydroanthranols 11 which were trapped by oxygen, yielding the anthrones 12 which were subsequently photooxidized to anthraquinones 13.With 2,6-dimethylbenzophenone (1d), the corresponding photoenols 2 were trapped for the first time.Compounds 8d, and 13d were absent, but instead 1-carboxyanthraquinone 15 was obtained.The latter can arise from 1-methylanthraquinone 13d trough photoenolisation-oxidation process alredy reported for this compound.With 2,2'-dimethylbenzophenone 1e, 3,3'-spirobiphtalide 14 was obtained instead 2-methyl-2'-carboxybenzophenone 8e; the latter, through a photoenolisation-oxidation process analogous to that described in the second paragraph, yielded 2,2'-dicarboxybenzophenone which underwent dehydration to compound 14.Under the same conditions (Hanovia) but in acetic acid solution, anthraquinones 13 were not formed with ketones 1a-f, due to rapid reketonisation of photoenols 2 E in this medium; however, compounds 4, 8, 10 and 14 were produced.Products 8, 10, 13, 14 and 15 were isolated and characterised or identified.Yields were deduced from actual weights of the isolated compounds (carboxylic acids 8 and 15) and from GLC determinations (compounds 4, 10, 13 and 14).
Process for the preparation of anthraquinone and its substituted derivatives
-
, (2008/06/13)
A process for the preparation of anthraquinone compounds by condensation of phthalic anhydride with a benzene derivative wherein a mixture of hydrofluoric acid and boron trifluoride is utilized as catalyst.
