849-01-4Relevant academic research and scientific papers
HFIP-Catalyzed Difluoroalkylation of Propargylic Alcohols to Access Tetrasubstituted Difluoroalkyl Allenes
Li, Jinshan,Xi, Wenxue,Liu, Saimei,Ruan, Chenxi,Zheng, Xiaochun,Yang, Jianguo,Wang, Lei,Wang, Zhiming
, p. 7264 - 7269 (2021)
A hexafluoroisopropanol (HFIP)-catalyzed difluoroalkylation of propargylic alcohols with difluoroenoxysilanes to access structurally diverse tetrasubstituted difluoroalkyl allenes has been developed. This convenient procedure enables the rapid construction of highly functionalized multisubstituted fluorinated allenes in a mild and straightforward way. Furthermore, the synthetic potential of this methodology has been demonstrated by the facile synthesis of various structurally interesting fluorine-containing molecules such as gem-difluorosubstituted dihydropyran, tetrasubstituted CF2H-allene, and multisubstituted fluorinated cyclopentanone derivatives.
Catalyst-free synthesis of 3,1-benzoxathiin-4-ones/1,3-benzodioxin-4-ones
Muthusamy, Sengodagounder,Malarvizhi, Muthukumar,Suresh, Eringathodi
, p. 1508 - 1513 (2021)
An unambiguous and precise method for the synthesis of 3,1-benzoxathiin-4-ones/1,3-benzodioxin-4-ones by the reaction of propargylic alcohols and salicylic/thiosalicylic acids under a catalyst-free and open-air atmosphere is described. This strategy is found to be quite general using various 2-mercapto and 2-hydroxybenzoic acids providing benzoxathiinones/benzodioxinones in good yields.
Ruthenium-catalyzed propargylic substitution reaction of propargylic alcohols with thiols: A general synthetic route to propargylic sulfides
Inada, Youichi,Nishibayashi, Yoshiaki,Hidai, Masanobu,Uemura, Sakae
, p. 15172 - 15173 (2002)
A novel cationic methanethiolate-bridged diruthenium complex [Cp*RuCl(μ2-SMe)2RuCp*(OH2)]OTf (1e) has been disclosed to promote the catalytic propargylic substitution reaction of propargylic alcohols bearing not only termi
Arylboronic Acid Catalyzed Dehydrative Mono-/Dialkylation Reactions of β-Ketoacids and Alcohols
Feng, Juhua,Hu, Haipeng,Ni, Hailiang,Qiu, Yuqian,Wang, Cuilin,Wang, Guangtu,Wang, Hanguang,Wang, Wei,Wu, Xin,Yue, Guizhou,Zou, Ping
supporting information, p. 832 - 836 (2022/02/05)
The dehydrative mono-/dialkylation reactions of alcohols and β-ketoacids were realized under arylboronic acid catalysis, furnishing a series of β-aryl ketones and β-ketoesters in yields of 15–99%, with CO2 and H2O being the byproduct
Photoredox Catalyzed Radical Cascade Aroylation (Sulfonylation)/Cyclization Enables Access to Fused Indolo-pyridones
Yang, De-Yong,Liu, Liang,Gu, Jia-Yi,He, Yan-Hong,Guan, Zhi
, p. 18042 - 18055 (2021/12/17)
A visible-light-initiated radical cascade reaction toward the synthesis of structurally diverse fused Indolo-pyridones is described. The reaction involves the addition of aroyl or sulfonyl radicals to N-alkyl-acryloyl-1H-indole-3-carboxamides, cyclization, and oxidative aromatization. This telescoped method circumvents lengthy prefunctionalization steps of radical precursors, which is further underpinned by the superior compatibility with a series of C-centered radicals, allowing the rapid and facile construction of numerous valuable architectures.
The visible-light-induced acylation/cyclization of alkynoates with acyl oximes for the construction of 3-acylcoumarins
Chen, Pu,Liu, Yu,Tang, Ke-Wen,Xiong, Bi-Quan,Xiong, Fang-Ting,Zhou, Quan
supporting information, p. 9012 - 9020 (2021/11/04)
A nitrogen-centered radical-mediated carbon-carbon bond cleavage strategy is described to synthesize functionalized 3-acylcoumarins. The strategy is enabled by the visible-light-induced acylation/cyclization of alkynoates with various acyl oxime compounds in acetonitrile. The difunctionalization of carbon-carbon triple bonds precedes the generation of iminyl radicals, which is followed by the formation of acyl radicals. The acyl radicals then attack the carbon-carbon triple bonds, followed by 5-exo-trigcyclization and 1,2-ester migration. This strategy has wide substrate adaptability and good substituent tolerance.
Metal-free transamidation of benzoylpyrrolidin-2-one and amines under aqueous conditions
Joseph, Devaneyan,Lee, Sunwoo,Park, Myeong Seong
supporting information, p. 6227 - 6232 (2021/07/28)
N-Acyl lactam amides, such as benzoylpyrrolidin-2-one, benzoylpiperidin-2-one, and benzoylazepan-2-one reacted with amines in the presence of DTBP and TBAI to afford the transamidated products in good yields. The reactions were conducted under aqueous conditions and good functional group tolerance was achieved. Both aliphatic and aromatic primary amines displayed good activity under metal-free conditions. A radical reaction pathway is proposed.
Ynonylation of Acyl Radicals by Electroinduced Homolysis of 4-Acyl-1,4-dihydropyridines
Luo, Xiaosheng,Wang, Ping
supporting information, p. 4960 - 4965 (2021/07/20)
Herein we report the conversion of 4-Acyl-1,4-dihydropyridines (DHPs) into ynones under electrochemical conditions. The reaction proceeds via the homolysis of acyl-DHP under electron activation. The resulting acyl radicals react with hypervalent iodine(III) reagents to form the target ynones or ynamides in acceptable yields. This mild reaction condition allows wider functionality tolerance that includes halides, carboxylates, or alkenes. The synthetic utility of this methodology is further demonstrated by the late-stage modification of complex molecules.
Visible-Light-Induced Decarboxylative Acylation of Pyridine N-Oxides with α-Oxocarboxylic Acids Using Fluorescein Dimethylammonium as a Photocatalyst
Hou, Chuanfu,Sun, Shouneng,Liu, Ziqi,Zhang, Hui,Liu, Yue,An, Qi,Zhao, Jian,Ma, Junjie,Sun, Zhizhong,Chu, Wenyi
supporting information, p. 2806 - 2812 (2021/04/15)
Herein, the development of a visible-light-induced catalytic system to achieve the decarboxylative acylation of pyridine N-oxides with α-oxocarboxylic acids, at room temperature and using the organic dye fluorescein dimethylammonium as a new type of photocatalyst, is reported. A series of 2-arylacylpyridine N-oxides were selectively synthesized in moderate to good yields by controlling the polarity of the reaction solvent. The developed strategy was successfully applied in the synthesis of an important intermediate of the drug, acrivastine, on a gram scale. Notably, this is the first time that fluorescein dimethylammonium has been used to catalyze the Minisci-type C?H decarboxylative acylation reaction. The mechanism of decarboxylative acylation was studied by capturing adducts of acyl radicals and 1,1-diphenylethylene to confirm a radical mechanism. The disclosed catalytic system provides a green synthetic strategy for decarboxylative acylation without the use of additional oxidants or metal catalysts. (Figure presented.).
Palladium-Catalyzed Direct and Specific C-7 Acylation of Indolines with 1,2-Diketones
Xie, Guilin,Zhao, Yuhan,Cai, Changqun,Deng, Guo-Jun,Gong, Hang
supporting information, p. 410 - 415 (2021/01/26)
The indole scaffold is a ubiquitous and useful substructure, and extensive investigations have been conducted to construct the indole framework and/or realize indole modification. Nevertheless, the direct selective functionalization on the benzenoid core must overcome the high activity of the C-3 position and still remains highly challenging. Herein, a palladium-catalyzed direct and specific C-7 acylation of indolines in the presence of an easily removed directing group was developed. This strategy usually is considered as a practical strategy for the preparation of acylated indoles because indoline can be easily converted to indole under oxidation conditions. In particular, our strategy greatly improved the alkacylation yield of indolines for which only an unsatisfactory yield could be achieved in the previous studies. Furthermore, the reaction can be scaled up to gram level in the standard reaction conditions with a much lower palladium loading (1 mol %).
