612-15-7Relevant articles and documents
Functionalized styrene synthesis via palladium-catalyzed C[sbnd]C cleavage of aryl ketones
Zhang, Xu,Wang, Zhen-Yu,Wang, Xing,Xu, Hui,Dai, Hui-Xiong
, (2022/03/31)
We report herein the synthesis of functionalized styrenes via palladium-catalyzed Suzuki–Miyaura cross-coupling reaction between aryl ketone derivatives and potassium vinyltrifluoroborate. The employment of pyridine-oxazoline ligand was the key to the cleavage of unstrained C[sbnd]C bond. A variety of functional groups and biologically important moleculars were well tolerated. The orthogonal Suzuki–Miyaura coupling demonstrated the synthetic practicability.
Nickel-Catalyzed Reductive Cross-Coupling of Aryl Bromides with Vinyl Acetate in Dimethyl Isosorbide as a Sustainable Solvent
Su, Mincong,Huang, Xia,Lei, Chuanhu,Jin, Jian
supporting information, p. 354 - 358 (2022/01/15)
A nickel-catalyzed reductive cross-coupling has been achieved using (hetero)aryl bromides and vinyl acetate as the coupling partners. This mild, applicable method provides a reliable access to a variety of vinyl arenes, heteroarenes, and benzoheterocycles, which should expand the chemical space of precursors to fine chemicals and polymers. Importantly, a sustainable solvent, dimethyl isosorbide, is used, making this protocol more attractive from the point of view of green chemistry.
Application of tungsten oxide supported monatomic catalyst in preparation of aromatic compound by hydrogenolysis of lignin
-
Paragraph 0044-0051, (2021/05/22)
The invention provides application of a tungsten oxide supported monatomic catalyst in preparation of aromatic compounds by hydrogenolysis of lignin. According to the method, various beta-O-4 model molecules, organic lignin, lignosulfonate and alkali lignin are taken as raw materials, and high-selectivity cracking of aryl ether bonds is realized in a hydrogen atmosphere at the temperature of 150-240 DEG C and the pressure of 0.7-3.0 MPa to obtain the aromatic compound. Compared with the prior art, the method has the advantages that when renewable natural biomass is used as the raw material and different lignin is used as the raw material for conversion, the highest yield of the aromatic bio-oil is 72%. Raw materials are cheap and wide in source; inorganic acid and alkali are not needed, and generation of a large amount of alkali liquor in traditional lignin catalysis is avoided; the method has the characteristics of cheap tungsten-based catalyst, green reaction process, atom economy and the like, and also has the characteristics of mild reaction conditions, high activity and selectivity, environment-friendly reaction process and the like.
Photocatalytic carbocarboxylation of styrenes with CO2for the synthesis of γ-aminobutyric esters
Hahm, Hyungwoo,Han, Min Su,Hong, Sukwon,Kim, Jiyun,Ryoo, Jeong Yup
, p. 6301 - 6312 (2021/07/28)
Metal-free photoredox-catalyzed carbocarboxylation of various styrenes with carbon dioxide (CO2) and amines to obtain γ-aminobutyric ester derivatives has been developed (up to 91% yield, 36 examples). The radical anion of (2,3,4,6)-3-benzyl-2,4,5,6-tetra(9H-carbazol-9-yl)benzonitrile (4CzBnBN) possessing a high reduction potential (?1.72 Vvs.saturated calomel electrode (SCE)) easily reduces both electron-donating and electron-withdrawing group-substituted styrenes.
Iron-Catalyzed Direct Julia-Type Olefination of Alcohols
Landge, Vinod G.,Babu, Reshma,Yadav, Vinita,Subaramanian, Murugan,Gupta, Virendrakumar,Balaraman, Ekambaram
, p. 9876 - 9886 (2020/09/03)
Herein, we report an iron-catalyzed, convenient, and expedient strategy for the synthesis of styrene and naphthalene derivatives with the liberation of dihydrogen. The use of a catalyst derived from an earth-abundant metal provides a sustainable strategy to olefins. This method exhibits wide substrate scope (primary and secondary alcohols) functional group tolerance (amino, nitro, halo, alkoxy, thiomethoxy, and S- A nd N-heterocyclic compounds) that can be scaled up. The unprecedented synthesis of 1-methyl naphthalenes proceeds via tandem methenylation/double dehydrogenation. Mechanistic study shows that the cleavage of the C-H bond of alcohol is the rate-determining step.
Palladium-Catalyzed Mizoroki-Heck Reaction of Nitroarenes and Styrene Derivatives
Okita, Toshimasa,Asahara, Kitty K.,Muto, Kei,Yamaguchi, Junichiro
supporting information, p. 3205 - 3208 (2020/04/10)
We have developed a Mizoroki-Heck reaction of nitroarenes with alkenes under palladium catalysis. The use of a Pd/BrettPhos catalyst promoted the alkenylation, whereas other catalysts led to a decrease in the product yield. In addition to nitroarenes, nitroheteroarenes were also applicable to the present reaction. The combination of a nucleophilic aromatic substitution (SNAr) with the denitrative alkenylation produced a multifunctionalized arene in a one-pot operation.
Ruthenium catalyzed synthesis method of primary amine
-
Paragraph 0049-0052, (2020/03/09)
The invention belongs to the field of organic synthesis, and discloses a ruthenium catalyzed synthesis method of primary amine. A ruthenium complex is taken as a catalyst; and a compound (A) and a compound (B) carry out reactions to obtain a compound (C); wherein R1 represents hydrogen or an alkyl group; R2 represents hydrogen or an alkyl group; R3 represent hydrogen, an alkyl group, or a phenyl group; R4 represent one of following structures shown in the description; n represents 0, 1, 2, or 3; R5 represents an alkyl group, an alkoxyl group, an ester group, a phenyl group, or a halogen atom,when n>=2, at least two R5(s) can be identical or different, m represents 0, 1, 2, or 3, R6 represents an alkyl group, an alkoxyl group, an ester group, or a halogen atom, and when m>=2, at least twoR6(s) can be identical or different. The method has the advantages of simple operation, mild conditions, small using amount of catalysts, wide substrate application range, no need of inert gas, and high yield.
Nickel(ii)-catalyzed direct olefination of benzyl alcohols with sulfones with the liberation of H2
Landge, Vinod G.,Yadav, Vinita,Subaramanian, Murugan,Dangarh, Pragya,Balaraman, Ekambaram
supporting information, p. 6130 - 6133 (2019/06/03)
A nickel(ii)-catalyzed direct olefination of benzyl alcohols with sulfones to access various terminal and internal olefins with the liberation of hydrogen gas is reported.
Mechanism of the Bis(imino)pyridine-Iron-Catalyzed Hydromagnesiation of Styrene Derivatives
Neate, Peter G. N.,Greenhalgh, Mark D.,Brennessel, William W.,Thomas, Stephen P.,Neidig, Michael L.
supporting information, p. 10099 - 10108 (2019/07/04)
Iron-catalyzed hydromagnesiation of styrene derivatives offers a rapid and efficient method to generate benzylic Grignard reagents, which can be applied in a range of transformations to provide products of formal hydrofunctionalization. While iron-catalyzed methodologies exist for the hydromagnesiation of terminal alkenes, internal alkynes, and styrene derivatives, the underlying mechanisms of catalysis remain largely undefined. To address this issue and determine the divergent reactivity from established cross-coupling and hydrofunctionalization reactions, a detailed study of the bis(imino)pyridine iron-catalyzed hydromagnesiation of styrene derivatives is reported. Using a combination of kinetic analysis, deuterium labeling, and reactivity studies as well as in situ 57Fe M?ssbauer spectroscopy, key mechanistic features and species were established. A formally iron(0) ate complex [iPrBIPFe(Et)(CH2a?CH2)]- was identified as the principle resting state of the catalyst. Dissociation of ethene forms the catalytically active species which can reversibly coordinate the styrene derivative and mediate a direct and reversible β-hydride transfer, negating the necessity of a discrete iron hydride intermediate. Finally, displacement of the tridentate bis(imino)pyridine ligand over the course of the reaction results in the formation of a tris-styrene-coordinated iron(0) complex, which is also a competent catalyst for hydromagnesiation.
Pd-Catalyzed Synthesis of Vinyl Arenes from Aryl Halides and Acrylic Acid
Gao, Yang,Ou, Yang,Goo?en, Lukas J.
supporting information, p. 8709 - 8712 (2019/06/17)
Acrylic acid is presented as an inexpensive, non-volatile vinylating agent in a palladium-catalyzed decarboxylative vinylation of aryl halides. The reaction proceeds through a Heck reaction of acrylic acid, immediately followed by protodecarboxylation of the cinnamic acid intermediate. The use of the carboxylate group as a deciduous directing group ensures high selectivity for monoarylated products. The vinylation process is generally applicable to diversely substituted substrates. Its utility is shown by the synthesis of drug-like molecules and the gram-scale preparation of key intermediates in drug synthesis.
