21147-26-2Relevant academic research and scientific papers
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.
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.
