Selective ortho-Metalation of a Fluoroarene with Knochel–Hauser Base and Reactions with Various Electrophiles

Synthesis ◽  
2019 ◽  
Vol 51 (07) ◽  
pp. 1649-1654
Author(s):  
Markus Baenziger ◽  
Sumesh Eswaran ◽  
Yifan Jiang ◽  
Gopu Kasinathan
Keyword(s):  
Aromatic Ring ◽  
Negishi Coupling ◽  
Ortho Metalation

Selective ortho-metalation of 1-bromo-2-(1,1-difluoroethyl)-4-fluorobenzene was achieved with the Knochel–Hauser base (TMPMgCl·LiCl) in position 5 of the aromatic ring. The magnesiated intermediate was reacted with a variety of electrophiles to obtain the products in good yields. The work was successfully extended to a Negishi coupling, after transmetalation with ZnCl2 and Pd-catalyzed reaction with 4-iodotoluene.

scholarly journals A short and efficient synthesis of valsartan via a Negishi reaction

2010 ◽  
Vol 6 ◽  
Author(s):  
Samir Ghosh ◽  
A Sanjeev Kumar ◽  
G N Mehta
Keyword(s):  
Angiotensin Ii ◽  
Aryl Bromide ◽  
Efficient Synthesis ◽  
Negishi Coupling ◽  
Ortho Metalation ◽  
Key Steps

An efficient synthesis of the angiotensin-II inhibitor valsartan (Diovan®) is presented. Directed ortho-metalation of 5-phenyl-1-trityl-1H-tetrazole (6) and its Negishi coupling with aryl bromide 5 are the key steps of the synthesis. This method overcomes many of the drawbacks associated with previously reported syntheses.

Photoreaction of N-butyl 3,4-dimethoxy-6-nitrobenzamide with butylamine. A model study for lysine-directed photoaffinity labelling

1987 ◽  
Vol 52 (7) ◽  
pp. 1780-1785 ◽  
Author(s):  
Petr Kuzmič ◽  
Libuše Pavlíčková ◽  
Milan Souček
Keyword(s):  
Nitro Group ◽  
Aromatic Ring ◽  
Ultraviolet Irradiation ◽  
Title Compound ◽  
Reductive Coupling ◽  
Photoaffinity Labelling ◽  
Photolysis Rate ◽  
Model Study ◽  
A Minor

Ultraviolet irradiation of the title compound I in the presence of butylamine gave predominantly products of nucleophilic photosubstitution by the amine, i.e., nitroanilines IIa and IIb. Besides, small amounts of products of hydrolysis (phenol III) and reductive coupling (azoxybenzene IV) were also formed. Comparison of the overall photolysis rate of I with that of 3,4-dimethoxy-1-nitrobenzene (V) indicates a minor loss of reactivity, most probably due to some deviation from coplanarity of the activating nitro group and the aromatic ring.

Dirhodium-Catalyzed Chemo- and Site-Selective C–H Amidation of N,N-Dialkylanilines

Synlett ◽  
2020 ◽  
Author(s):  
Yoshihiro Ueda ◽  
Gong Chen ◽  
Kenta Arai ◽  
Kazuhiro Morisaki ◽  
Takeo Kawabata
Keyword(s):  
Nitrogen Atom ◽  
Aromatic Ring ◽  
Methyl Group ◽  
Site Selective

AbstractA method for dirhodium-catalyzed C(sp3)–H amidation of N,N-dimethylanilines was developed. Chemoselective C(sp3)–H amidation of N-methyl group proceeded exclusively in the presence of C(sp2)–H bonds of the electron-rich aromatic ring. Site-selective C(sp3)–H amidation proceeded exclusively at the N-methyl group of N-methyl-N-alkylaniline derivatives with secondary, tertiary, and benzylic C(sp3)–H bonds α to a nitrogen atom.

scholarly journals Oxidation Reactions of Marchantin A Trimethyl Ether and Some Aromatic Compounds using m-Chloroperbenzoic Acid. Formation of Muconic Acid Ester and m-Chlorobenzoate

1999 ◽  
Vol 23 (8) ◽  
pp. 470-471
Author(s):  
Motoo Tori ◽  
Masakazu Sono ◽  
Keiko Takikawa ◽  
Reiko Matsuda ◽  
Masao Toyota ◽  
...  
Keyword(s):  
Aromatic Ring ◽  
Methyl Ether ◽  
Aromatic Compounds ◽  
Acid Ester ◽  
Acid Formation ◽  
Oxidation Reactions ◽  
Muconic Acid ◽  
Trimethyl Ether

On treatment with m-chloroperbenzoic acid, dihydroeugenol methyl ether and marchantin A trimethyl ether afford muconic acid ester derivatives by oxidation of the aromatic ring as well as hydroxylated derivatives; the m-chlorobenzoate of the dihydroeugenol derivative is also observed for the former.

scholarly journals Dihydroquinolines, Dihydronaphthyridines and Quinolones by Domino Reactions of Morita-Baylis-Hillman Acetates

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 890
Author(s):  
Joel K. Annor-Gyamfi ◽  
Ebenezer Ametsetor ◽  
Kevin Meraz ◽  
Richard A. Bunce
Keyword(s):  
Aromatic Ring ◽  
Aromatic Amines ◽  
Control Experiment ◽  
Ring Closure ◽  
Domino Reaction ◽  
Side Chain ◽  
Initial Reaction ◽  
Dual Reactivity ◽  
Michael Acceptor ◽  
Nitrogen Nucleophile

An efficient synthetic route to highly substituted dihydroquinolines and dihydronaphthyridines has been developed using a domino reaction of Morita-Baylis-Hillman (MBH) acetates with primary aliphatic and aromatic amines in DMF at 50–90 °C. The MBH substrates incorporate a side chain acetate positioned adjacent to an acrylate or acrylonitrile aza-Michael acceptor as well as an aromatic ring activated toward SNAr ring closure. A control experiment established that the initial reaction was an SN2′-type displacement of the side chain acetate by the amine to generate the alkene product with the added nitrogen nucleophile positioned trans to the SNAr aromatic ring acceptor. Thus, equilibration of the initial alkene geometry is required prior to cyclization. A further double bond migration was observed for several reactions targeting dihydronaphthyridines from substrates with a side chain acrylonitrile moiety. MBH acetates incorporating a 2,5-difluorophenyl moiety were found to have dual reactivity in these annulations. In the absence of O2, the expected dihydroquinolines were formed, while in the presence of O2, quinolones were produced. All of the products were isolated in good to excellent yields (72–93%). Numerous cases (42) are reported, and mechanisms are discussed.

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