21476-73-3Relevant academic research and scientific papers
Regioselective Synthesis of 5-Metalated 2-Pyrones by Intramolecular Oxymetalation of Carbonyl-ene-yne Compounds Using Indium Trihalide
Yata, Tetsuji,Kita, Yuji,Nishimoto, Yoshihiro,Yasuda, Makoto
, p. 14330 - 14341 (2019/11/03)
The oxyindation of carbonyl-ene-yne compounds with indium trihalides proceeded efficiently to give di-, tri-, and tetrasubstituted 2-pyrones bearing a carbon-indium bond. The metalated 2-pyrone and a zwitterion intermediate were identified by X-ray crystallographic analysis. The application of organoindium compounds to oxidation or cross-coupling provided easy access to various multifunctionalized 2-pyrones. Some 2-pyrone derivatives show intense fluorescence only in the solid state (aggregation-induced emission).
Electrochemistry-Enabled Ir-Catalyzed Vinylic C-H Functionalization
Yang, Qi-Liang,Xing, Yi-Kang,Wang, Xiang-Yang,Ma, Hong-Xing,Weng, Xin-Jun,Yang, Xiang,Guo, Hai-Ming,Mei, Tian-Sheng
supporting information, p. 18970 - 18976 (2019/12/04)
Synergistic use of electrochemistry and organometallic catalysis has emerged as a powerful tool for site-selective C-H functionalization, yet this type of transformation has thus far mainly been limited to arene C-H functionalization. Herein, we report the development of electrochemical vinylic C-H functionalization of acrylic acids with alkynes. In this reaction an iridium catalyst enables C-H/O-H functionalization for alkyne annulation, affording α-pyrones with good to excellent yields in an undivided cell. Preliminary mechanistic studies show that anodic oxidation is crucial for releasing the product and regeneration of an Ir(III) intermediate from a diene-Ir(I) complex, which is a coordinatively saturated, 18-electron complex. Importantly, common chemical oxidants such as Ag(I) or Cu(II) did not give significant amounts of the desired product in the absence of electrical current under otherwise identical conditions.
Rhodium(III)-Catalyzed Oxidative Annulation of Acrylic Acid with Alkynes: An Easy Approach to the Synthesis of α-Pyrones
Li, Yu-Ting,Zhu, Yan,Tu, Guang-Liang,Zhang, Jing-Yu,Zhao, Ying-Sheng
supporting information, p. 3281 - 3284 (2018/10/09)
A highly efficient rhodium(III)-catalyzed direct oxidative annulation of acrylic acid with alkynes to form α-pyrones was developed. Various substituted acrylic acids were compatible in this transformation, affording the corresponding products in moderate to excellent yields under mild conditions.
Tert-Butyl Nitrite-Mediated Synthesis of N-Nitrosoamides, Carboxylic Acids, Benzocoumarins, and Isocoumarins from Amides
Yedage, Subhash L.,Bhanage, Bhalchandra M.
, p. 5769 - 5781 (2017/06/07)
This work reports tert-butyl nitrite (TBN) as a multitask reagent for (1) the controlled synthesis of N-nitrosoamide from N-alkyl amides, (2) hydrolysis of N-methoxyamides to carboxylic acids, (3) metal- and oxidant-free benzocoumarin synthesis from ortho-aryl-N-methoxyamides via N-H, C-N, and C-H bond activation, and (4) isocoumarin synthesis using Ru(II)/PEG as a recyclable catalytic system via ortho-C-H activation and TBN as an oxygen source. The sequential functional group interconversion of amide to acid has also been examined using IR spectroscopic analysis. Additionally, this methodology is highly advantageous due to short reaction time, gram scale synthesis, and broad substrate scope.
Ruthenium(II)-Catalyzed Alkene C-H Bond Functionalization on Cinnamic Acids: A Facile Synthesis of Versatile α-Pyrones
Prakash, Rashmi,Shekarrao, Kommuri,Gogoi, Sanjib
supporting information, p. 5264 - 5267 (2015/11/18)
An inexpensive ruthenium(II) complex enabled oxidative annulation of alkynes by using cinnamic acid derivatives to provide diversely decorated multisubstituted α-pyrones.
Preparation and Reactions of 3,4-Dihydro-2H-pyran-2-ones
El-Kholy, Ibrahim El-Sayed,Mishrikey, Morcos Michael,Abdoul-Ela, Salah Loutfi
, p. 1329 - 1334 (2007/10/02)
The Michael reaction of ethyl cinnamates with deoxybenzoin gave ethyl 3,4,5-triaryl-5-oxopentanoates which were hydrolysed to the corresponding acids.The latter could be cyclized to the respective 3,4-dihydro-2H-pyran-2-ones which underwent ring opening w
