294190-47-9Relevant academic research and scientific papers
Synthesis of various acylating agents directly from carboxylic acids
Pilathottathil, Fathima,Vineet Kumar, Doppalapudi,Kaliyamoorthy, Alagiri
supporting information, p. 1622 - 1632 (2020/04/27)
A straightforward synthesis of acylating reagents such as Weinreb and MAP amides from aromatic, aliphatic carboxylic acids, and amino acids using PPh3/NBS combination is described. A chemo-selective modification of the carboxylic acid group into Weinreb amide in the presence of more reactive aldehydes and ketones is presented. All reactions were performed at ambient temperature under air using undried commercial grade solvent. Furthermore, the present methodology could be performed at a gram scale under inert-free reaction conditions. In addition, 7-azaindoline amide auxiliary (used for catalytic asymmetric aldol- and Mannich-type reactions), which behaves like Weinreb amide is also synthesized under similar reaction conditions.
One-pot synthesis of Weinreb amides employing 3,3-dichloro-1,2-diphenylcyclopropene (CPI-Cl) as a chlorinating agent
Shekharappa,Roopesh Kumar,Sureshbabu, Vommina V.
, p. 790 - 798 (2019/03/26)
The synthesis of Nα-protected amino alkyl Weinreb amides starting from the corresponding α-amino acids as well as carboxylic acids has been delineated through the in situ generation of acid chlorides using CPI-Cl as a chlorinating agent. The protocol is simple; the reaction conditions employed were mild, and compatible with all the three commonly used urethane protecting groups namely, Boc, Cbz and Fmoc groups. The resulting Weinreb amides are obtained in good yields as optically pure products.
Phenylidene phenyl peptide compounds and medicinal composition and application thereof
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Paragraph 0154-0156, (2018/11/22)
The invention provides phenylidene phenyl peptide compounds, a medicinal composition using the phenylidene phenyl peptide compounds as active components, and application thereof as monoamine oxidase B(MAO-B) inhibitors and application thereof to preparation of medicines for treating Parkinson's disease (PD). Monoamine oxidase B (MAO-B) has been proved to be closely related to the pathogenesis ofthe Parkinson's disease (PD) and is a classic target for research and development of the medicines for treating the Parkinson's disease (PD). The invention provides application of the phenylidene phenyl peptide compounds to preparation of the monoamine oxidase B (MAO-B) inhibitors. In-vitro kinase activity experiments prove that the phenylidene phenyl peptide compounds have a significant monoamineoxidase B (MAO-B) inhibiting effect.
Weinreb Amide Directed Versatile C?H Bond Functionalization under (η5-Pentamethylcyclopentadienyl)cobalt(III) Catalysis
Kawai, Kentaro,Bunno, Youka,Yoshino, Tatsuhiko,Matsunaga, Shigeki
supporting information, p. 10231 - 10237 (2018/07/29)
The (η5-pentamethylcyclopentadienyl)cobalt(III) (Cp*CoIII)-catalyzed C?H bond functionalization of aromatic, heteroaromatic, and α,β-unsaturated Weinreb amides was explored. C?H allylation reactions with the use of allyl carbonate and a perfluoroalkene, oxidative alkenylation reactions with the use of ethyl acrylate, iodination reactions with the use of N-iodosuccinimide, and amidation reactions with the use of dioxazolones were catalyzed by Cp*Co(CO)I2 in the presence of a cationic Ag salt and AgOAc to afford various synthetically useful building blocks. Mechanistic studies of the C?H allylation disclosed that the C?H activation step was rate determining and virtually irreversible.
Palladium-Catalyzed, ortho-Selective C-H Halogenation of Benzyl Nitriles, Aryl Weinreb Amides, and Anilides
Das, Riki,Kapur, Manmohan
, p. 1114 - 1126 (2018/06/18)
A palladium-catalyzed, ortho-selective C-H halogenation methodology is reported herein. The highlight of the work is the highly selective C(sp2)-H functionalization of benzyl nitriles in the presence of activated C(sp3)-H bond, which results in good yields of the halogenated products with excellent regioselectivity. Along with benzyl nitriles, aryl Weinreb amides and anilides have been evaluated for the transformation using aprotic conditions. Mechanistic studies yield interesting aspects with respect to the pathway of the reaction and the directing group abilities.
Synthesis of Difluoromethyl Ketones from Weinreb Amides, and Tandem Addition/Cyclization of o-Alkynylaryl Weinreb Amides
Phetcharawetch, Jongkonporn,Betterley, Nolan M.,Soorukram, Darunee,Pohmakotr, Manat,Reutrakul, Vichai,Kuhakarn, Chutima
supporting information, p. 6840 - 6850 (2017/12/26)
[Difluoro(phenylsulfanyl)methyl]trimethylsilane (PhSCF2SiMe3) underwent a fluoride-induced nucleophilic addition to the carbonyl group of Weinreb amides to provide the corresponding difluoro(phenylsulfanyl)methyl ketones. These were
A new strategy for accessing (S)-1-(furan-2-yl)pent-4-en-1-ol: a key precursor of Ipomoeassin family of compounds and C1–C15 domain of halichondrins
Jammula, Subba Rao,Anna, Venkateswara Rao,Tatina, Sudhakar,Krishna, Thalishetti,Sreenivas, B. Yogi,Pal, Manojit
supporting information, p. 3924 - 3928 (2016/08/09)
A highly efficient synthesis of (S)-1-(furan-2-yl)pent-4-en-1-ol, known to be an initial precursor of Ipomoeassin family of compounds and C1–C15 domain of halichondrins has been achieved via a sequence involving the use of Weinreb amide formation followed by Weinreb ketone synthesis and finally CBS (Corey–Bakshi–Shibata) reduction. Detailed study on improvement of each step is described. The title compound was converted to a potential cytotoxic agent for further pharmacological studies.
One-pot transition-metal-free synthesis of weinreb amides directly from carboxylic acids
Niu, Teng,Wang, Ke-Hu,Huang, Danfeng,Xu, Changming,Su, Yingpeng,Hu, Yulai,Fu, Ying
, p. 320 - 330 (2014/02/14)
Weinreb amides were prepared directly from carboxylic acids, N,O-dimethylhydroxylamine, and phosphorus trichloride in one pot at 60 °C in toluene in high yields, thus avoiding the separation of the moisture and air sensitive intermediate P[NMe(OMe)]3 in advance. Sterically hindered carboxylic acids also give the corresponding Weinreb amides in excellent yields. Various functional groups are tolerated on the carboxylic acid. The method, which is a simple process and gives high yields, is suitable for large-scale production. Georg Thieme Verlag KG Stuttgart · New York.
Copper(II)chloride-mediated cyclization reaction of N-alkoxy- orthoalkynylbenzamides
Jithunsa, Manita,Ueda, Masafumi,Miyata, Okiko
supporting information; experimental part, p. 518 - 521 (2011/04/16)
A regioselective intramolecular cyclization/halogenation reaction of N-alkoxy-o-alkynylbenzamides with CuCl2/NCS was developed. The corresponding 3-(chloromethylene)isobenzofuran-1-ones were exclusively obtained via 5-exo-dig cyclization in moderate to excellent yields within 0.5-1 h. This approach has been successfully used to synthesize a biaryl compound by the Suzuki-Miyaura reaction.
Carbamoylimidazolium and thiocarbamoylimidazolium salts: Novel reagents for the synthesis of ureas, thioureas, carbamates, thiocarbamates and amides
Grzyb, Justyna A.,Shen, Ming,Yoshina-Ishii, Chiaki,Chi,Brown, R. Stanley,Batey, Robert A.
, p. 7153 - 7175 (2007/10/03)
Carbamoylimidazolium salts act as efficient N,N-disubstituted carbamoylating reagents. These salts are readily prepared by the sequential treatment of secondary amines with N,N′-carbonyldiimidazole (CDI) and iodomethane. The carbamoylimidazolium salts are more efficient carbamoyl transfer reagents than the intermediate carbamoylimidazoles, as a result of the 'imidazolium' effect. Kinetic studies on the base promoted hydrolysis of both carbamoylimidazoles and carbamoylimidazolium salts reveal over a hundred-fold rate acceleration. The salts react with amines, thiols, phenols/alcohols, and carboxylic acids in high yields, without the need for subsequent chromatographic purification of the products, producing ureas, thiocarbamates, carbamates, and amides, respectively. Analogous thiocarbamoylimidazolium salts were also synthesized from secondary amines and N,N′-thiocarbonyldiimidazole (TCDI), followed by methylation with iodomethane.
