19578-68-8Relevant articles and documents
An efficient synthesis of [ring-14C]-L-tyrosine from [U-14C ]-phenol
Kendall, John T.
, p. 505 - 514 (2000)
The title compound was prepared in good overall yield and high enantiopurity via a five step route beginning with [U-14C]-phenol, 4. Benzyl ether 5 was prepared from 4 under standard conditions and underwent selective iodination at the 4-position in the presence of iodine and mercuric oxide. Palladium catalysed cross coupling of the resulting aryl iodide 6 and the organozinc intermediate derived from N-tert-butoxycarbonyl-3-iodo-alanine methyl ester, 7, proceeded smoothly to give 8. Debenzylation and acid hydrolysis afforded the deprotected amino acid as the hydrochloride salt. Purification (flash chromatography) was necessary in only two of the five steps in the synthesis.
Room temperature regioselective iodination of aromatic ethers mediated by Selectfluor(TM) reagent F-TEDA-BF4
Zupan, Marko,Iskra, Jernej,Stavber, Stojan
, p. 6305 - 6306 (1997)
Monosubstituted phenyl ethers were regioselectively iodinated with a mixture of iodine and F-TEDA in acetonitrile at room temperature at the para position, while 1-methoxy-4-substituted benzene derivatives were converted to 2-iodo products in high yield.
Transition-Metal-Free and Base-Promoted Carbon-Heteroatom Bond Formation via C-N Cleavage of Benzyl Ammonium Salts
Liu, Long,Tang, Yuanyuan,Wang, Kunyu,Huang, Tianzeng,Chen, Tieqiao
, p. 4159 - 4170 (2021/03/09)
A facile and general method for constructing carbon-heteroatom (C-P, C-O, C-S, and C-N) bonds via C-N cleavage of benzyl ammonium salts under transition-metal-free conditions was reported. The combination of t-BuOK and 18-crown-6 enabled a wide range of substituted benzyl ammonium salts to couple readily with different kinds of heteroatom nucleophiles, i.e. hydrogen phosphoryl compounds, alcohols, thiols, and amines. Good functional group tolerance was demonstrated. The scale-up reaction and one-pot synthesis were also successfully performed.
Design of an Electron-Withdrawing Benzonitrile Ligand for Ni-Catalyzed Cross-Coupling Involving Tertiary Nucleophiles
Edjoc, Racquel K.,Mills, L. Reginald,Rousseaux, Sophie A. L.
supporting information, p. 10422 - 10428 (2021/07/26)
The design of new ligands for cross-coupling is essential for developing new catalytic reactions that access valuable products such as pharmaceuticals. In this report, we exploit the reactivity of nitrile-containing additives in Ni catalysis to design a benzonitrile-containing ligand for cross-coupling involving tertiary nucleophiles. Kinetic and Hammett studies are used to elucidate the role of the optimized ligand, which demonstrate that the benzonitrile moiety acts as an electron-acceptor to promote reductive elimination over β-hydride elimination and stabilize low-valent Ni. With these conditions, a protocol for decyanation-metalation and Ni-catalyzed arylation is conducted, enabling access to quaternary α-arylnitriles from disubstituted malononitriles.
A facile and versatile electro-reductive system for hydrodefunctionalization under ambient conditions
Huang, Binbin,Guo, Lin,Xia, Wujiong
supporting information, p. 2095 - 2103 (2021/03/26)
A general electrochemical system for reductive hydrodefunctionalization is described, employing the inexpensive and easily available triethylamine (Et3N) as a sacrificial reductant. This protocol is characterized by facile operation, sustainable conditions, and exceptionally wide substrate scope covering the cleavage of C-halogen, N-S, N-C, O-S, O-C, C-C and C-N bonds. Notably, the selectivity and capability of reduction can be conveniently switched by simple incorporation or removal of an alcohol as a co-solvent.
Choline Hydroxide as a Versatile Medium for Catalyst-Free O-Functionalization of Phenols
Joo, Seong-Ryu,Kim, Seung-Hoi,Kwon, Gyu-Tae,Park, Soo-Youl
, p. 1200 - 1205 (2020/11/30)
A versatile synthetic protocol for benzyl phenyl ether preparation via O-alkylation of phenolic oxygen with readily available benzyl derivatives was demonstrated. The newly designed procedure was carried out using an eco-friendly medium, room-temperature ionic liquid (choline hydroxide), under metal- and base-catalyst-free aerobic conditions. The reaction platform was also successfully applied to phenol protection strategy.
Palladium-Catalyzed Chlorocarbonylation of Aryl (Pseudo)Halides Through In Situ Generation of Carbon Monoxide
Bismuto, Alessandro,Boehm, Philip,Morandi, Bill,Roediger, Sven
supporting information, p. 17887 - 17896 (2020/08/19)
An efficient palladium-catalyzed chlorocarbonylation of aryl (pseudo)halides that gives access to a wide range of carboxylic acid derivatives has been developed. The use of butyryl chloride as a combined CO and Cl source eludes the need for toxic, gaseous carbon monoxide, thus facilitating the synthesis of high-value products from readily available aryl (pseudo)halides. The combination of palladium(0), Xantphos, and an amine base is essential to promote this broadly applicable catalytic reaction. Overall, this reaction provides access to a great variety of carbonyl-containing products through in situ transformation of the generated aroyl chloride. Combined experimental and computational studies support a reaction mechanism involving in situ generation of CO.
Copper-catalyzed and additive free decarboxylative trifluoromethylation of aromatic and heteroaromatic iodides
Johansen, Martin B.,Lindhardt, Anders T.
supporting information, p. 1417 - 1425 (2020/03/03)
A copper-catalyzed decarboxylative trifluoromethylation of (hetero)aromatic iodides has been developed. Importantly, this new copper-catalyzed reaction operates in the absence of any ligands and metal additives. The protocol shows good functional group tolerance and is compatible with heteroaromatic systems. The reaction proved scalable to a 15 mmol scale with increased yield. Finally, late-stage installation of the trifluoromethyl functionality afforded the N-trifluoroacetamide variant of the antidepressant agent, Prozac, demonstrating the applicability of the developed method.
Carbon Dioxide as a Directing Group for C-H Functionalization Reactions Involving Lewis Basic Amines, Alcohols, Thiols, and Phosphines for the Synthesis of Compounds
-
Paragraph 0133, (2019/07/03)
Methods of synthesizing compounds using CO2 as a directing group for C—H functionalization, and compounds made thereby, are described.
Carbon Dioxide-Mediated C(sp3)-H Arylation of Amine Substrates
Kapoor, Mohit,Liu, Daniel,Young, Michael C.
supporting information, p. 6818 - 6822 (2018/05/31)
Elaborating amines via C-H functionalization has been an important area of research over the past decade but has generally relied on an added directing group or sterically hindered amine approach. Since free-amine-directed C(sp3)-H activation is still primarily limited to cyclization reactions and to improve the sustainability and reaction scope of amine-based C-H activation, we present a strategy using CO2 in the form of dry ice that facilitates intermolecular C-H arylation. This methodology has been used to enable an operationally simple procedure whereby 1° and 2° aliphatic amines can be arylated selectively at their γ-C-H positions. In addition to potentially serving as a directing group, CO2 has also been demonstrated to curtail the oxidation of sensitive amine substrates.
