7163-50-0Relevant academic research and scientific papers
Synthesis of α-Keto Acids via Oxidation of Alkenes Catalyzed by a Bifunctional Iron Nanocomposite
Song, Tao,Ma, Zhiming,Wang, Xiaoxue,Yang, Yong
supporting information, p. 5917 - 5921 (2021/07/31)
An efficient methodology for synthesis of α-keto acids via oxidation of alkenes using TBHP as oxidant catalyzed by a bifunctional iron nanocomposite has been established. A variety of alkenes with different functional groups were smoothly oxidized into their corresponding α-keto acids in up to 80% yield. Moreover, the bifunctional iron nanocomposite catalyst showed outstanding catalytic stability for successive recycles without appreciable loss of activity.
Visible-Light-Induced Catalyst-Free Carboxylation of Acylsilanes with Carbon Dioxide
Fan, Zhengning,Yi, Yaping,Chen, Shenhao,Xi, Chanjuan
, p. 2303 - 2307 (2021/04/05)
Intermolecular carbon-carbon bond formation between acylsilanes and carbon dioxide (CO2) was achieved by photoirradiation under catalyst-free conditions. In this reaction, siloxycarbenes generated by photoisomerization of the acylsilanes added to the C═O bond of CO2 to give α-ketocarboxylates, which underwent hydrolysis to afford α-ketocarboxylic derivatives in good yields. Control experiments suggest that the generated siloxycarbene is likely to be from the singlet state (S1) of the acylsilane and the addition to CO2 is not in a concerted manner.
Silyl Cyanopalladate-Catalyzed Friedel-Crafts-Type Cyclization Affording 3-Aryloxindole Derivatives
Ece, Hamdiye,Tange, Yuji,Yurino, Taiga,Ohkuma, Takeshi
supporting information, p. 935 - 939 (2021/02/22)
3-Aryloxindole derivatives were synthesized through a Friedel-Crafts-type cyclization. The reaction was catalyzed by a trimethylsilyl tricyanopalladate complex generated in situ from trimethylsilyl cyanide and Pd(OAc) 2. Wide varieties of diethyl phosphates derived from N -arylmandelamides were converted almost quantitatively into oxindoles. When N, N -dibenzylamide was used instead of an anilide substrate, a benzo-fused δ-lactam was obtained. An oxindole product was subjected to substitution reactions to afford 3,3-diaryloxindoles with two different aryl groups.
Iridium-catalyzed stereoselective [3+2] annulation of α-oxocarboxylic acids with 1,3-dienes
Yabe, Ryota,Ebe, Yusuke,Nishimura, Takahiro
supporting information, p. 5917 - 5920 (2021/06/18)
The stereoselective annulation of α-oxocarboxylic acids with 1,3-dienes proceeded in the presence of a hydroxoiridium catalyst to give α-hydroxy-γ-lactones in good yields with high 3,5-transrelative stereochemistry. The use of a chiral diene ligand for a cationic iridium complex enabled asymmetric annulation with high enantioselectivity.
Rapid assembly of α-ketoamides through a decarboxylative strategy of isocyanates with α-oxocarboxylic acids under mild conditions
Huang, Junjie,Liang, Baihui,Chen, Xiuwen,Liu, Yifu,Li, Yawen,Liang, Jingwen,Zhu, Weidong,Tang, Xiaodong,Li, Yibiao,Zhu, Zhongzhi
supporting information, p. 4783 - 4787 (2021/06/11)
A simple and practical method for α-ketoamide synthesis via a decarboxylative strategy of isocyanates with α-oxocarboxylic acids is described. The reaction proceeds at room temperature under mild conditions without an oxidant or an additive, showing good substrate scope and functional compatibility. Moreover, the applicability of this method was further demonstrated by the synthesis of various bioactive molecules and different application examples through a two-step one-pot operation.
Photoinduced homolytic decarboxylative acylation/cyclization of unactivated alkenes with α-keto acid under external oxidant and photocatalyst free conditions: access to quinazolinone derivatives
Sun, Bin,Shi, Rongcheng,Zhang, Kesheng,Tang, Xiaoli,Shi, Xiayue,Xu, Jiayun,Yang, Jin,Jin, Can
supporting information, p. 6050 - 6053 (2021/06/21)
A novel and green strategy for the synthesis of acylated quinazolinone derivativesviaphoto-induced decarboxylative cascade radical acylation/cyclization of quinazolinone bearing unactivated alkenes has been developed. The protocol provides a novel route to access acyl radicals from α-keto acids through a self-catalyzed energy transfer process. Most importantly, the reaction proceeded smoothly without any external photocatalyst, additive or oxidant, and could be easily scaled-up in flow conditions with sunlight irradiation.
Hypervalent Iodine(III)-Promoted Radical Oxidative C-H Annulation of Arylamines with α-Keto Acids
Long, Lipeng,Wang, Jieyan,Gu, Liuqing,Yang, Shiguang,Qiao, Liang,Luo, Guotian,Chen, Zhengwang
supporting information, p. 12084 - 12092 (2021/08/24)
A novel catalyst-free radical oxidative C-H annulation reaction of arylamines with α-keto acids toward benzoxazin-2-ones synthesis under mild conditions was developed. This hypervalent iodine(III)-promoted process eliminated the use of a metal catalyst or additive with high levels of functional group tolerance. Hypervalent iodine(III) was both an oxidant and a radical initiator for this reaction. The synthetic utility of this method was confirmed by the synthesis of the natural product cephalandole A.
Possible competitive modes of decarboxylation in the annulation reactions ofortho-substituted anilines and arylglyoxylates
Laha, Joydev K.,Panday, Surabhi,Tomar, Monika,Patel, Ketul V.
supporting information, p. 845 - 853 (2021/02/09)
Annulation reactions ofortho-substituted anilines and arylglyoxylates in the presence of K2S2O8at 80 °C under metal-free neutral conditions have been investigated, which extended a platform for the tandem synthesis of nitrogen heterocycles. While arylglyoxylic acids are known to undergo decarboxylation to form an acyl radical in the presence of K2S2O8and used in the Minisci acylation of electron-deficient (hetero)aromatics, their reactions with electron-richortho-substituted anilines to form nitrogen heterocycles have recently been studied. Depending upon the experimental conditions used in the reactions, the mechanism of the formation of heterocycles involving reactions of an acyl radical or aryl iminocarboxylic acids has been postulated. Given the subtle understanding of the mechanisms of annulation reactions of 2-substituted anilines and arylglyoxylates in the presence of K2S2O8, an extensive mechanistic investigation was undertaken. In the current study, the various mechanistic pathways including the generation of acyl, imidoyl, aminal, and N,O-hemiketal radicals have been postulated based on different possible decarboxylation modes. Some of the proposed intermediates are supported based on the available analytical data. The protocol uses a single, inexpensive reagent K2S2O8, which offers not only transition-metal-free conditions but also serves as the reagent for the key decarboxylation step. Taken together, this study complements the current development of the annulation reactions of 2-substituted anilines and arylglyoxylates in terms of synthesis and mechanistic understanding.
Direct 1,2-Dicarbonylation of Alkenes towards 1,4-Diketones via Photocatalysis
Chen, Bin,Cheng, Yuan-Yuan,Hou, Hong-Yu,Lei, Tao,Tung, Chen-Ho,Wu, Li-Zhu,Yu, Ji-Xin
supporting information, p. 26822 - 26828 (2021/11/17)
1,4-Dicarbonyl compounds are intriguing motifs and versatile precursors in numerous pharmaceutical molecules and bioactive natural compounds. Direct incorporation of two carbonyl groups into a double bond at both ends is straightforward, but also challenging. Represented herein is the first example of 1,2-dicarbonylation of alkenes by photocatalysis. Key to success is that N(n-Bu)4+ not only associates with the alkyl anion to avoid protonation, but also activates the α-keto acid to undergo electrophilic addition. The α-keto acid is employed both for acyl generation and electrophilic addition. By tuning the reductive and electrophilic ability of the acyl precursor, unsymmetric 1,4-dicarbonylation is achieved for the first time. This metal-free, redox-neutral and regioselective 1,2-dicarbonylation of alkenes is executed by a photocatalyst for versatile substrates under extremely mild conditions and shows great potential in biomolecular and drug molecular derivatization.
Visible-Light-Promoted Switchable Synthesis of C-3-Functionalized Quinoxalin-2(1H)-ones
Aganda, Kim Christopher C.,Hong, Boseok,Lee, Anna
supporting information, p. 1443 - 1448 (2021/01/26)
A visible-light-promoted synthesis of quinoxalin-2(1H)-ones has been developed using 9-mesityl-10-methylacridinium perchlorate as an organo-photocatalyst. The atmosphere-controlled method (Ar/air) enabled the selective synthesis of hydroxyl- and acyl-containing quinoxalin-2(1H)-ones under mild reaction conditions without the use of any metal catalysts or toxic reagents. A fluorescent labelling experiment showed that hydroxyl-containing quinoxalin-2(1H)-ones may have utility in various biological applications as potent fluorophores. (Figure presented.).
