835-68-7Relevant academic research and scientific papers
Aminophenone compounds as well as preparation method and application thereof
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Paragraph 0047-0050; 0250-0254, (2021/02/06)
The invention belongs to the technical field of medicinal chemistry, and particularly relates to aminophenone compounds as well as a preparation method and application thereof. The aminophenone compounds provided by the invention have a good inhibition effect on PDE4, also have good bioavailability, can be applied to preparation of drugs for treating PDE4-related diseases, and increase the optionsof drugs for treating PDE4-related diseases; and the effect of a part of the aminophenone compounds is equivalent to the effect of positive drugs, and the aminophenone compounds have good developmentpotential.
Coupling Reaction between Aldehydes and Non-Activated Hydrocarbons via the Reductive Radical-Polar Crossover Pathway
Yahata, Kenzo,Sakurai, Shu,Hori, Shuhei,Yoshioka, Shin,Kaneko, Yuki,Hasegawa, Kai,Akai, Shuji
supporting information, p. 1199 - 1203 (2020/02/04)
Herein, we describe the generation of an organochromium-type carbanion species from a non-activated C-H bond and its nucleophilic addition to aldehydes. The catalytic carbanion generation occurred through formal deprotonation of a non-activated C-H bond under mild conditions and did not need the prefunctionalization or anion stabilizing group. Carbon radical intermediates generated by decatungstate photocatalyst-mediated hydrogen abstraction were captured by a chromium salt with the reductive radical-polar crossover reaction to produce organochromium carbanions.
Lewis Acid Catalyzed Transfer Hydromethallylation for the Construction of Quaternary Carbon Centers
Walker, Johannes C. L.,Oestreich, Martin
supporting information, p. 15386 - 15389 (2019/10/28)
The design and gram-scale synthesis of a cyclohexa-1,4-diene-based surrogate of isobutene gas is reported. Using the highly electron-deficient Lewis acid B(C6F5)3, application of this surrogate in the hydromethallylation of electron-rich styrene derivatives provided sterically congested quaternary carbon centers. The reaction proceeds by C(sp3)?C(sp3) bond formation at a tertiary carbenium ion that is generated by alkene protonation. The possibility of two concurrent mechanisms is proposed on the basis of mechanistic experiments using a deuterated surrogate.
Nickel-Catalyzed Addition of Aryl Bromides to Aldehydes to Form Hindered Secondary Alcohols
Garcia, Kevin J.,Gilbert, Michael M.,Weix, Daniel J.
supporting information, p. 1823 - 1827 (2019/02/14)
Transition-metal-catalyzed addition of aryl halides across carbonyls remains poorly developed, especially for aliphatic aldehydes and hindered substrate combinations. We report here that simple nickel complexes of bipyridine and PyBox can catalyze the addition of aryl halides to both aromatic and aliphatic aldehydes using zinc metal as the reducing agent. This convenient approach tolerates acidic functional groups that are not compatible with Grignard reactions, yet sterically hindered substrates still couple in high yield (33 examples, 70% average yield). Mechanistic studies show that an arylnickel, and not an arylzinc, adds efficiently to cyclohexanecarboxaldehyde, but only in the presence of a Lewis acid co-catalyst (ZnBr2).
Enantioselective Oxy-Heck–Matsuda Arylations: Expeditious Synthesis of Dihydrobenzofuran Systems and Total Synthesis of the Neolignan (?)-Conocarpan
Silva, Allan R.,Polo, Ellen C.,Martins, Nelson C.,Correia, Carlos Roque D.
, p. 346 - 365 (2018/01/26)
This work discloses the first examples of an effective enantioselective oxy-Heck–Matsuda reaction using a variety of styrenic olefins to generate chiral dihydrobenzofurans. The reaction proceeds in moderate to good yields, with high trans diastereoselectivity (up to 20:1) in enantioselectivities up to 90:10 using the N,N-ligand pyrimidine-bisoxazoline (PyriBox). The oxy-Heck–Matsuda reactions were carried out under mild conditions and rather low catalyst loadings. The feasibility and practicality of the process is demonstrated by a concise total synthesis of the neolignan (?)-conocarpan. X-ray diffraction of an advanced brominated intermediate in the route to (?)-conocarpan has allowed the unequivocal assignment of the absolute stereochemistry of the oxy-Heck–Matsuda aryldihydrobenzofuran products. A rationale for the mechanism operating in these enantioselective oxy-Heck–Matsuda reactions is also presented. (Figure presented.).
[Ir(COD)Cl]2/tris(2,4-di-t-butylphenyl)phosphite-catalyzed addition reactions of arylboronic acids with aldehydes
Liao, Yuan-Xi,Dong, Jie,Hu, Qiao-Sheng
supporting information, p. 1548 - 1550 (2018/03/26)
[Ir(COD)Cl]2/tris(2,4-di-t-butylphenyl)phosphite-catalyzed addition reactions of arylboronic acids with aldehydes were described. The Ir(I) catalyst, generated from [Ir(COD)Cl]2 and tris(2,4-di-t-butylphenyl)phosphite, was an efficient catalyst system for the addition reactions of a variety of arylboronic acids with aromatic and aliphatic aldehydes. The easy availability of the catalyst and good yields make these reactions potentially useful in organic synthesis.
Calcium-catalyzed carboarylation of alkynes
Fu, Liang,Niggemann, Meike
supporting information, p. 6367 - 6370 (2015/04/22)
The first transition-metal-free carboarylation of alkynes with commercial and readily available alcohols as alkylating agents was realized in the presence of an environmentally benign calcium catalyst. Thereby, a novel protocol for the one-step synthesis of highly congested, all-carbon tetrasubstituted alkenes, as incorporated in potentially bioactive, complex dihydronaphthalene, chromene and dihydroquinoline structures, is provided. The reaction features an unprecedented, particularly wide substrate scope, good functional-group tolerance and simple experimental operation under mild reaction conditions. Finally free: The first transition-metal-free one-step synthesis of highly congested, all-carbon tetrasubstituted olefins has been realized by a calcium-catalyzed carboarylation reaction. Internal alkynes react with alcohols as alkylating reagent under mild reaction conditions, which provides access to a variety of useful structural scaffolds via highly reactive trisubstituted vinyl cations.
The cooperative effect of Lewis pairs in the Friedel-Crafts hydroxyalkylation reaction: A simple and effective route for the synthesis of (±)-carbinoxamine
Harikrishnan, Adhikesavan,Sanjeevi, Jayakumar,Ramanathan, Chinnasamy Ramaraj
, p. 3633 - 3647 (2015/03/30)
An efficient C-C bond formation strategy between aromatic/heteroaromatic π-nucleophiles and Lewis acid activated aldehydes is described. This aromatic electrophilic substitution reaction of arenes or heteroarenes is facilitated by Lewis acid AlBr3. Aromatic rings with electron donating substituents are excellent nucleophilic counterparts in this reaction, generating carbinols in excellent yields (61-94%). The formation of triarylmethanes is also witnessed in the case of certain reactive aldehydes and aromatic π-nucleophiles through reactive carbocation formation. The formation of triarylmethane is reduced to a greater extent via retardation of the second π-nucleophile addition through a Lewis base, for example, pyridine, coordination with an aluminium alkoxide intermediate. Various aliphatic aldehydes also underwent Friedel-Crafts type hydroxyalkylation and generated the expected carbinols in moderate yields (41-53%) in the presence of AlBr3. This protocol has been successfully applied to the synthesize of the (±)-carbinoxamine, a therapeutically important histamine H1 antagonist, in a one-pot manner.
Rh(I)/diene-catalyzed addition reactions of aryl/alkenylboronic acids with aldehydes
Xing, Chun-Hui,Liu, Tao-Ping,Zheng, Jin Rong,Ng, Jaclynn,Esposito, Michelle,Hu, Qiao-Sheng
supporting information; experimental part, p. 4953 - 4957 (2009/12/03)
[Rh(COD)Cl]2-catalyzed addition reactions of arylboronic acids with aldehydes, with low Rh(I) catalyst loading, are described. We also found that the reaction of arylboronic acids with α,β-unsaturated aldehydes greatly depends on the solvent and the steric hindrance of the reagents/substrates.
Novel intermediate and processes for its preparation and conversion into a pharmacologically-active agent
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, (2008/06/13)
Processes for the preparation of Venlafaxine (IX) via the novel epoxy-nitrile intermediate (I), which when subjected to hydrogenation forms compound (X), and may subsequently be reduced to yield the desired product (IX). The epoxy-nitrile intermediate (I) itself may be synthesised via various alternative reaction strategies, from a range of starting materials. E.g. 4-methoxy-benzaldehyde (VI), upon treatment with cyclohexyl magnesium bromide yields compound (V). This in turn may be oxidised to yield compound (III), which forms compound (II) on treatment with an (x-keto-halogenation agent. Cyanation of compound (II), then yields the desired epoxy nitrile intermediate (I), from which Venlafaxine (IX) may be synthesised.
