26386-94-7Relevant academic research and scientific papers
LDA (lithium diisopropylamide) mediated reactions of 1-naphthalynes with lithiated acetonitriles and 1,4-dipolar nucleophilic anions
Biehl,Rakeeb Deshmukh,Dutt
, p. 885 - 888 (1993)
3-Bromo-2-methoxy-(5) and 3-bromo-2-methoxy-6-methylnaphthalene (6) yield 1-naphthalyne intermediates which react with various α-lithiated nitriles 10 to afford both rearranged 1-arylmethyl- or 1-hetarylmethyl-3-methoxynaphthalene-2-carbonitriles 11 and 12, respectively, and α-naphthylated aryl- or hetarylacetonitriles 13 and 14, respectively. Product distributions 11:13 favoring rearranged nitriles (65:35-90:10) were obtained from LDA-mediated reactions of 5 with arylacetonitriles 9a, b and thiopheneacetonitriles 9c, d. Similar treatment of 6 with 9a-d gave product distributions 12:14 heavily in favor of rearranged nitriles (> 90:10) presumably due to the ability of the additional 7-methyl group to increase the rate of cyclization of the initial aryne-nitrile anion adduct, the crucial step in the rearrangement pathway. However treatment of either 5 or 6 with α-lithiated pyridylacetonitriles 9e, f or 2-benzimidazolylacetonitrile (9g) gave product distributions 11:13 or 12:14, respectively, heavily in favor of α-naphthylated acetonitriles (30:7010:90). Additionally, several precursors to methoxy-substituted 1-naphthalynes 5, 19 and 20 were found to undergo cycloaddition with the dipolar nucleophilic precursors 3-cyanophthalide (17) and α-cyano-o-tolunitrile (21) to give angularly substituted benz[a]anthracene derivatives 18, 22.
Rhodium-Catalyzed Reductive Esterification Using Carbon Monoxide as a Reducing Agent
Ostrovskii, Vladimir S.,Runikhina, Sofiya A.,Afanasyev, Oleg I.,Chusov, Denis
supporting information, p. 4116 - 4121 (2020/07/13)
Carbon monoxide used to have a limited number of applications in organic chemistry, but it gradually increases its role as a mild and selective reducing agent. It can be applied for the carbon–heteroatom single bond formation via the reductive addition of hydrogen-containing nucleophiles to carbonyl compounds. In this paper, rhodium-catalyzed reductive esterification is described, and a comparative study of the rhodium and ruthenium catalysis in the reductive addition reactions is provided. Rhodium performs better on highly nucleophilic substrates and ruthenium is better for compounds with less nucleophilicity.
Exhaustive Reduction of Esters Enabled by Nickel Catalysis
Cook, Adam,Prakash, Sekar,Zheng, Yan-Long,Newman, Stephen G.
supporting information, p. 8109 - 8115 (2020/05/20)
We report a one-step procedure to directly reduce unactivated aryl esters into their corresponding tolyl derivatives. This is achieved by an organosilane-mediated ester hydrosilylation reaction and subsequent Ni/NHC-catalyzed hydrogenolysis. The resulting conditions provide a direct and efficient alternative to multi-step procedures for this transformation that often require the use of hazardous metal hydrides. Applications in the synthesis of -CD3-containing products, derivatization of bioactive molecules, and chemoselective reduction in the presence of other C-O bonds are demonstrated.
Decarbonylative Methylation of Aromatic Esters by a Nickel Catalyst
Okita, Toshimasa,Muto, Kei,Yamaguchi, Junichiro
supporting information, p. 3132 - 3135 (2018/05/28)
A Ni-catalyzed decarbonylative methylation of aromatic esters was achieved using methylaluminums as methylating agents. Dimethylaluminum chlorides uniquely worked as the methyl source. Because of the Lewis acidity of aluminum reagents, less reactive alkyl esters could also undergo the present methylation. By controlling the Lewis acidity of aluminum reagents, a chemoselective decarbonylative cross-coupling between alkyl esters and phenyl esters was successful.
Intramolecular carbonyl-ene reactions in the synthesis of peri-oxygenated hydroaromatics
Basak, Shyam,Mal, Dipakranjan
, p. 1758 - 1772 (2018/03/29)
2-Methallyl aromatic aldehydes, synthesized by Suzuki coupling of 2-formylphenylboronic acids, are shown to provide cycloalkylidene ene products under acidic conditions. Susceptibility of the products to aromatization is manoeuvred by varying the reaction conditions and catalysts including binol-derived Br?nsted acid catalysts. A peri-effect is identified as a controlling factor for the aromatizations. Several oxidative transformations of an ene product are carried out as model studies of hydroaromatic polyketide natural products.
Cross-coupling reaction with lithium methyltriolborate
Yamamoto, Yasunori,Ikizakura, Kazuya,Ito, Hajime,Miyaura, Norio
, p. 430 - 439 (2013/03/13)
We newly developed lithium methyltriolborate as an air-stable white solid that is convenient to handle. The good performance of this triolborate for metal-catalyzed bond-forming reactions was demonstrated in palladium-catalyzed cross-coupling reactions wi
Direct arylation/alkylation/magnesiation of benzyl alcohols in the presence of grignard reagents via Ni-, Fe-, or Co-catalyzed sp3 C-O Bond activation
Yu, Da-Gang,Wang, Xin,Zhu, Ru-Yi,Luo, Shuang,Zhang, Xiao-Bo,Wang, Bi-Qin,Wang, Lei,Shi, Zhang-Jie
supporting information, p. 14638 - 14641 (2012/11/07)
Direct application of benzyl alcohols (or their magnesium salts) as electrophiles in various reactions with Grignard reagents has been developed via transition metal-catalyzed sp3 C-O bond activation. Ni complex was found to be an efficient catalyst for the first direct cross coupling of benzyl alcohols with aryl/alkyl Grignard reagents, while Fe, Co, or Ni catalysts could promote the unprecedented conversion of benzyl alcohols to benzyl Grignard reagents in the presence of nhexylMgCl. These methods offer straightforward pathways to transform benzyl alcohols into a variety of functionalities.
Unusual demethylation of O,O′-dimethyl chlorothiophosphate with aryllithiums
Ribeiro, Nigel,Maeda, Jin,Ishida, Yasuhiro,Kobayashi, Yuka,Saigo, Kazuhiko
, p. 1412 - 1413 (2008/03/14)
The reaction of O,O′-dimethyl chlorothiophosphate with aryllithiums took place easily to afford the corresponding methylated aryl compounds in place of expected O,O′-dimethyl aryl(thiophosphonate)s. Copyright
Suzuki-Miyaura and related cross-couplings in aqueous solvents catalyzed by di(2-pyridyl)methylamine-palladium dichloride complexes
Najera, Carmen,Gil-Molto, Juan,Karlstroem, Sofia
, p. 1798 - 1811 (2007/10/03)
Di(2-pyridyl)methylamine-based palladium dichloride complexes 4 are versatile catalysts for different types of cross-coupling reactions in water or aqueous solvents under aerobic conditions. The Suzuki-Miyaura reaction of arylboronic acids can be performed with bromoarenes under water reflux using K2CO3 as base or at room temperature or 60°C in aqueous methanol using KOH as base. For aryl chlorides the corresponding cross-couplings with arylboronic acids can be carried out in refluxing water with K2CO3 as base and TBAB as additive to provide biaryls and heterobiaryls. Arylboronic acids react with benzylic chlorides and allylic substrates such as chlorides, acetates or carbonates also in refluxing water with K2CO3 as base or at room temperature in aqueous acetone and KOH as base, to give diarylmethanes and arylpropenes. Trimethylboroxine and alkylboronic acids are coupled with bromo- and chloroarenes under water at reflux with K2CO3 as base and TBAB as additive to furnish methyl- and butylarenes. These cross-couplings have also been performed in shorter times under microwave irradiation. Several important intermediates such as, 4′-methylbiphenyl-2-carbonitrile, 4-biphenylacetic acid, 3-(3-methylphenyl)benzoic acid, 4,5-diphenyl-2-methyl- 3(2H)pyridazinone and 2-(4′-fluorobenzyl)thiophene have been prepared under aqueous and aerobic conditions in good yields.
Electroorganic reactions. Part 56: Anodic oxidation of 2-methyl- and 2-benzylnaphthalenes: Factors influencing competing pathways
Utley, James H.P,Rozenberg, Gregor G
, p. 5251 - 5265 (2007/10/03)
A systematic investigation of the anodic oxidation in nucleophilic media of 2-methyl and 2-benzylnaphthalenes, substituted at the 6-position in the naphthalene nucleus and at the 4-phenyl position of the benzylic side chain, has been carried out to identify factors favouring side-chain substitution. Cyclic voltammetry confirms that 6-substitution has a profound effect on the oxidation potentials of the naphthalene nucleus and 13C chemical shifts indicate polar effects at the benzylic carbon. However, little side-chain anodic oxidation is observed under any conditions tried; the radical-cations of electron-rich substrates preferentially dimerise and a strongly electron-withdrawing substituent at the 6-position (EtOSO2) promotes nuclear substitution. In contrast, oxidation with DDQ in aqueous acetic acid gives efficient side-chain oxidation for electron rich substrates, consistent with hydride transfer, possibly intramolecularly via a charge transfer complex.
