21945-66-4Relevant articles and documents
Experimental and density functional theory studies on hydroxymethylation of phenylboronic acids with paraformaldehyde over a Rh-PPh3 catalyst
Wang, Kuan,Lan, Jie,He, Zhen-Hong,Cao, Zhe,Wang, Weitao,Yang, Yang,Liu, Zhao-Tie
, (2020/12/01)
The synthesis of benzyl alcohols (BAs) is highly vital for their wide applications in organic synthesis and pharmaceuticals. Herein, BAs was efficiently synthesized via hydroxymethylation of phenylboronic acids (PBAs) and paraformaldehyde over a simple Rh-PPh3 catalyst combined with an inorganic base (NaOH). A variety of BAs with the groups of CH3?, CH3O?, Cl?, Br?, and so on were obtained with moderate to good yields, indicating that the protocol had a good universality. Density functional theory (DFT) calculations proposed the Hayashi-type arylation mechanism involved the arylation step of PBA and Rh(OH)(PPh3)2 catalyst to form Rh(I)-bound aryl intermediates and the hydrolysis step of Rh(I)-bound aryl intermediates and HCHO to generate BA product (the rate-determining step). The present route provides a valuable and direct method for the synthesis of BAs and expands the application range of paraformaldehyde.
Synthesis and biological evaluation of new N-substituted 4-(arylmethoxy)piperidines as dopamine transporter inhibitors
Lapa, Gennady B.,Lapa, Alla A.
, p. 203 - 205 (2019/04/25)
The library of new N-substituted 4-(arylmethoxy)piperidines as dopamine transporter inhibitors was designed and synthesized. H-Bond donors in piperidine ring were found to be important for reduced locomotor activity in mice. 4-[Bis(4-fluorophenyl)methoxy]piperidine has IC50 17.0 ± 1.0 nm for dopamine transporter and locomotor activity, which is lower than that for cocaine.
4-Methyltetrahydropyran (4-MeTHP): Application as an Organic Reaction Solvent
Kobayashi, Shoji,Tamura, Tomoki,Yoshimoto, Saki,Kawakami, Takashi,Masuyama, Araki
, p. 3921 - 3937 (2019/11/11)
4-Methyltetrahydropyran (4-MeTHP) is a hydrophobic cyclic ether with potential for industrial applications. We herein report, for the first time, a comprehensive study on the performance of 4-MeTHP as an organic reaction solvent. Its broad application to organic reactions includes radical, Grignard, Wittig, organometallic, halogen-metal exchange, reduction, oxidation, epoxidation, amidation, esterification, metathesis, and other miscellaneous organic reactions. This breadth suggests 4-MeTHP can serve as a substitute for conventional ethers and harmful halogenated solvents. However, 4-MeTHP was found incompatible with strong Lewis acids, and the C?O bond was readily cleaved by treatment with BBr3. Moreover, the radical-based degradation pathways of 4-MeTHP, THP and 2-MeTHF were elucidated on the basis of GC-MS analyses. The data reported herein is anticipated to be useful for a broad range of synthetic chemists, especially industrial process chemists, when selecting the reaction solvent with green chemistry perspectives.
I-Pr2NMgCl·LiCl Enables the Synthesis of Ketones by Direct Addition of Grignard Reagents to Carboxylate Anions
Colas, Kilian,Dos Santos, A. Catarina V. D.,Mendoza, Abraham
supporting information, (2019/10/08)
The direct preparation of ketones from carboxylate anions is greatly limited by the required use of organolithium reagents or activated acyl sources that need to be independently prepared. Herein, a specific magnesium amide additive is used to activate and control the addition of more tolerant Grignard reagents to carboxylate anions. This strategy enables the modular synthesis of ketones from CO2 and the preparation of isotopically labeled pharmaceutical building blocks in a single operation.
Nickel Catalyzed Intermolecular Carbonyl Addition of Aryl Halide
Ishida, Seima,Suzuki, Hiroyuki,Uchida, Seiichiro,Yamaguchi, Eiji,Itoh, Akichika
supporting information, p. 7483 - 7487 (2019/12/11)
In this study, we develop a nickel-catalyzed carbonyl arylation reaction employing aldehydes with aryl and allyl halides. Various aryl, α,β-unsaturated aldehyde and aliphatic aldehydes can be converted into their corresponding secondary alcohols in moderate-to-high yields. In addition, we extended this approach to develop an asymmetric reductive coupling reaction that combines nickel salts with chiral bisoxazoline ligands to give secondary alcohols with moderate enantioselectivity.
CoI-Catalyzed Barbier Reactions of Aromatic Halides with Aromatic Aldehydes and Imines
Presset, Marc,Paul, Jér?me,Cherif, Ghania Nait,Ratnam, Nisanthan,Laloi, Nicolas,Léonel, Eric,Gosmini, Corinne,Le Gall, Erwan
supporting information, p. 4491 - 4495 (2019/02/27)
The reductive Barbier coupling of aromatic halides and electrophiles has been achieved using a CoBr2/1,10-phenanthroline catalytic system and over stoichiometric amounts of zinc. The reaction displayed a broad scope of substrates, including (hetero)aryl chlorides as pro-nucleophiles and aldehydes or imines as electrophiles, leading to diarylmethanols and diarylmethylamines in moderate to excellent yields, respectively.
Base-Promoted Aerobic Oxidation/Homolytic Aromatic Substitution Cascade toward the Synthesis of Phenanthridines
Maiti, Debabrata,Halder, Atreyee,De Sarkar, Suman
supporting information, p. 4941 - 4948 (2019/11/03)
The current protocol represents a transition metal-free synthesis of polysubstituted phenanthridines from abundant starting materials like benzhydrol and 2-iodoaniline derivatives. The reaction involves sequential oxidation of alcohol and direct condensation reaction with the amine resulting in a C?N bond formation followed by a radical C?C coupling in a cascade sequence. The used base potassium tert-butoxide plays a dual role in dehydrogenation and homolytic aromatic substitution reaction. Using this methodology, twenty substituted phenanthridine derivatives were synthesized with up to 85% isolated yield. (Figure presented.).
The carbonyl group tuned electron-deficient phosphorus ligands and their application in Rhodium catalyzed arylation to aldehydes
Yang, Jiefang,Chen, Xingyu,Wang, Zhiqian
supporting information, p. 5673 - 5675 (2015/09/15)
Acylphosphines, which could be efficiently prepared from acid chlorides and secondary phosphines, were developed as a type of carbonyl group tuned electron-deficient phosphorus ligand. They were found to be a kind of efficient ligand in Rhodium catalyzed arylation to aldehydes through accelerating the transmetalation process. Chiral acylphosphine ligands could be generated from carboxylic acids bearing the chiral framework correspondingly.
Electronic effects on the substitution reactions of benzhydrols and fluorenyl alcohols. Determination of mechanism and effects of antiaromaticity
George, Stephen R. D.,Elton, Timothy E.,Harper, Jason B.
supporting information, p. 10745 - 10750 (2015/11/17)
A range of substituted benzhydrols and fluorenols were prepared and subjected to acid catalysed methanolysis. Analysis of the rates of each of these processes showed correlation with Hammett σ+ parameters as is consistent with the significant build-up of positive charge adjacent to the ring. In combination with the similarity of the electronic susceptibility of the processes, these data suggest that both reactions proceed through a unimolecular rate-determining step. This shows that the effect of fusion of the phenyl systems (and hence potentially introducing an antiaromatic carbocation intermediate) is only to slow the rate of reaction rather than change the mechanism of the process.
Rhodium-catalyzed arylation of acylsilanes with sodium tetraarylborates
Matsuda, Takanori,Mizuno, Kohei,Watanuki, Shoichi
supporting information, p. 64 - 67 (2014/06/09)
Rhodium(I)-catalyzed arylation of benzoylsilanes with sodium tetraarylborates affords α-silyl benzhydrols, benzhydryl silyl ethers, benzhydrols, and diaryl ketones selectively depending on the catalyst, solvent, and temperature.
