14252-23-4Relevant academic research and scientific papers
Boron-catalyzed silylative reduction of quinolines: Selective sp3 C-Si bond formation
Gandhamsetty, Narasimhulu,Joung, Seewon,Park, Sung-Woo,Park, Sehoon,Chang, Sukbok
, p. 16780 - 16783 (2014)
A silylative reduction of quinolines to synthetically versatile tetrahydroquinoline molecules involving the formation of a C(sp3)-Si bond exclusively β to nitrogen is described. Triarylborane is a highly efficient catalyst (up to 1000 turnovers), and silanes serve as both a silyl source and a reducing reagent. The present procedure is convenient to perform even on a large scale with excellent stereoselectivity. Mechanistic studies revealed that the formation of a 1,4-addition adduct is rate-limiting while the subsequent C(sp3)-Si bond-forming step from the 1,4-adduct is facile.
Substrate or Solvent-Controlled PdII-Catalyzed Regioselective Arylation of Quinolin-4(1H)-ones Using Diaryliodonium Salts: Facile Access to Benzoxocine and Aaptamine Analogues
Mehra, Manish K.,Sharma, Shivani,Rangan, Krishnan,Kumar, Dalip
supporting information, p. 2409 - 2413 (2020/03/16)
Regioselective C3, C5, and C8 arylation of quinolin-4(1H)-ones have been accomplished either by substrate-control or by tuning the reaction solvent. A variety of aryl(mesityl)iodonium triflates could smoothly deliver arylated products in good to excellent yields. Additionally, it offers great flexibility by arylating medicinally potent quinolone related heterocycles such as acridin-9(10H)-one, and phenanthridin-6(5H)-one under standard reaction conditions. This strategy was further extended with diphenyleneiodonium triflate to access oxacine fused quinolines. The post-modifications of synthesized products enhance the further utility of this protocol in organic synthesis. To the best of our knowledge, this is the first report on C5 arylation of quinolin-4(1H)-ones using iodine(III) reagents.
High-yield gram-scale organic synthesis using accelerated microdroplet/thin film reactions with solvent recycling
Chen, Xingshuo,Cooks, R. Graham,Holden, Dylan T.,Nie, Honggang,Qiu, Lingqi,Wei, Zhenwei
, p. 2356 - 2361 (2020/04/07)
A closed system has been designed to perform microdroplet/thin film reactions with solvent recycling capabilities for gram-scale chemical synthesis. Claisen-Schmidt, Schiff base, Katritzky and Suzuki coupling reactions show acceleration factors relative to bulk of 15 to 7700 times in this droplet spray system. These values are much larger than those reported previously for the same reactions in microdroplet/thin film reaction systems. The solvent recycling mode of the new system significantly improves the reaction yield, especially for reactions with smaller reaction acceleration factors. The microdroplet/thin film reaction yield improved on recycling from 33% to 86% and from 32% to 72% for the Katritzky and Suzuki coupling reactions, respectively. The Claisen-Schmidt reaction was chosen to test the capability of this system in gram scale syntheses and rates of 3.18 g per h and an isolated yield of 87% were achieved.
Sterically hindered N-heterocyclic carbene/palladium(ii) catalyzed Suzuki-Miyaura coupling of nitrobenzenes
Chen, Kai,Chen, Wei,Yi, Xiaofei,Chen, Wanzhi,Liu, Miaochang,Wu, Huayue
supporting information, p. 9287 - 9290 (2019/08/08)
Palladium-catalyzed denitrative Suzuki coupling of nitroarenes using 2-aryl-5-(2,4,6-triisopropylphenyl)-2,3-imidazolylidene[1,5-a]pyridines as the ligands is described. The key to success is the use of the NHC ligands which show strong donating ability and suitable steric hindrance allowing the successful oxidative addition of Ar-NO2 bonds. Both aromatic and aliphatic boronic acids are tolerated, and a variety of biphenyls and alkylarenes were obtained in good to excellent yields.
Method for synthesizing aromatic compound by coupling palladium/imidazole salt with nitroaromatic hydrocarbon and boric acid compound (by machine translation)
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Paragraph 0104-0108, (2019/10/01)
The invention discloses a method, for coupling a palladium/imidazole salt with a nitroaromatic hydrocarbon and a boric acid compound to synthesize an aromatic compound. The method comprises: in organic solvent, taking nitroaromatic hydrocarbon and boric acid compound as substrate, palladium/imidazole salt as a catalyst, carrying out coupling reaction under the action of alkali, and carrying out post-treatment to obtain the aromatic compound. The method is simple, easy to store, low in price, relatively low in ligand consumption, high in product yield, good in substrate applicability, and suitable for alkyl boronic acid. The process of the invention can be used to synthesize a series of aromatic compounds, for example. The compound has wide application value in the fields of pesticides, medicines, materials and the like. (by machine translation)
METHOD FOR PRODUCING AROMATIC COMPOUND
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Paragraph 0038; 0062; 0063; 0064; 0110; 0111; 0112; 0152, (2018/05/16)
In a cross coupling reaction, in a case where a halogen atom is selected as the leaving group of the raw material compound, a harmful halogen waste forms as a by-product after the reaction, and disposal of the waste liquid is complicated and environmental burden is high. In a carbon-hydrogen activation cross coupling reaction which requires no halogen atom as the leaving group, although no halogen waste forms as a by-product, the reaction substrate is considerably restricted, and the reaction remains a limited molecular construction method. A method for producing an aromatic compound, which comprises subjecting an aromatic nitro compound and a boronic acid compound to a cross coupling reaction in the presence of a metal catalyst.
The Suzuki-Miyaura Coupling of Nitroarenes
Yadav, M. Ramu,Nagaoka, Masahiro,Kashihara, Myuto,Zhong, Rong-Lin,Miyazaki, Takanori,Sakaki, Shigeyoshi,Nakao, Yoshiaki
supporting information, p. 9423 - 9426 (2017/07/24)
Synthesis of biaryls via the Suzuki-Miyaura coupling (SMC) reaction using nitroarenes as an electrophilic coupling partners is described. Mechanistic studies have revealed that the catalytic cycle of this reaction is initiated by the cleavage of the aryl-nitro (Ar-NO2) bond by palladium, which represents an unprecedented elemental reaction.
Chemoselective One-Pot Synthesis of Functionalized Amino-azaheterocycles Enabled by COware
Clohessy, Thomas A.,Roberts, Alastair,Manas, Eric S.,Patel, Vipulkumar K.,Anderson, Niall A.,Watson, Allan J. B.
supporting information, p. 6368 - 6371 (2017/12/08)
Functionalized bicyclic amino-azaheterocycles are rapidly accessed in a one-pot cross-coupling/reduction sequence enabled by the use of COware. Incompatible reagents are physically separated in a single reaction vessel to effect two chemoselective transformations - Suzuki-Miyaura cross-coupling and heteroarene reduction. The developed method allows access to novel heterocyclic templates, including semisaturated Hedgehog and dual PI3K/mTOR inhibitors, which show enhanced physicochemical properties compared to their unsaturated counterparts.
Synthesis and utility of dihydropyridine boronic esters
Panda, Santanu,Coffin, Aaron,Nguyen, Q. Nhu,Tantillo, Dean J.,Ready, Joseph M.
supporting information, p. 2205 - 2209 (2016/02/18)
When activated by an acylating agent, pyridine boronic esters react with organometallic reagents to form a dihydropyridine boronic ester. This intermediate allows access to a number of valuable substituted pyridine, dihydropyridine, and piperidine products.
General copper-catalyzed coupling of alkyl-, aryl-, and alkynylaluminum reagents with organohalides
Shrestha, Bijay,Thapa, Surendra,Gurung, Santosh K.,Pike, Ryan A. S.,Giri, Ramesh
, p. 787 - 802 (2016/02/18)
We report the first example of a very general Cu-catalyzed cross-coupling of organoaluminum reagents with organohalides. The reactions proceed for the couplings of alkyl-, aryl-, and alkynylaluminum reagents with aryl and heteroaryl halides and vinyl bromides, affording the cross-coupled products in good to excellent yields. Both primary and secondary alkylaluminum reagents can be utilized as organometallic coupling partners. These reactions are not complicated by β-hydride elimination, and as a result rearranged products are not observed with secondary alkylaluminum reagents even for couplings with heteroaryl halides under "ligand-free" conditions. Radical clock experiment with a radical probe and relative reactivity study of Ph3Al with two haloarenes, 1-bromonaphthalene and 4-chlorobenzonitrile, having two different redox potentials indicates that the reaction does not involve free aryl radicals and radical anions as intermediates. These results combined with the result of the Hammett plot obtained by reacting Ph3Al with iodoarenes containing p-H, p-Me, p-F, and p-CF3 substituents, which shows a linear curve (R2 = 0.99) with a ρ value of +1.06, suggest that the current transformation follows an oxidative addition-reductive elimination pathway.
