A Facile and Divergent Synthesis of Substituted Pyridine-2,4(1H,3H)-diones and 4H-Thiopyran-4-ones from α-Alkenoyl-α-carbamoyl Ketene-S,S-acetals

2010 ◽  
Vol 63 (8) ◽  
pp. 1267 ◽  
Author(s):  
Jinying Liu ◽  
Xiaolan Fu ◽  
Yang Zhou ◽  
Guangyuan Zhou ◽  
Yongjiu Liang ◽  
...  
Keyword(s):  
Substitution Reaction ◽  
Substitution Reactions ◽  
Nucleophilic Vinyl Substitution ◽  
High Yields

A facile and divergent synthesis of substituted pyridine-2,4(1H,3H)-diones and 4H-thiopyran-4-ones from readily available α-alkenoyl-α-carbamoyl ketene-S,S-acetals has been developed. Subjected to N,N-dimethylformamide at 125°C, α-alkenoyl-α-carbamoyl ketene-S,S-acetals underwent an intramolecular aza-nucleophilic vinyl substitution reaction, a formal [5C + 1N] annulation, to give the corresponding substituted pyridine-2,4(1H,3H)-diones in high yields, whereas in the presence of Na2S·9H2O in DMF at 75°C, tandem intermolecular and intramolecular thia-nucleophilic vinyl substitution reactions, a formal [5C + 1S] annulation, occurred to produce the corresponding substituted 4H-thiopyran-4-ones in good yields.

scholarly journals NUCLEOPHILIC SUBSTITUTION REACTION OF CYANIDE AND METHOXYDE IONS TO QUATERNARY MANNICH BASE FROM VANILLIN

2010 ◽  
Vol 5 (3) ◽  
pp. 203-206
Author(s):  
Bambang Purwono ◽  
Estiana R. P. Daruningsih
Keyword(s):  
Nucleophilic Substitution ◽  
Mannich Reaction ◽  
Substitution Reaction ◽  
Mannich Base ◽  
Nucleophilic Substitution Reaction ◽  
Substitution Reactions ◽  
Halide Salt ◽  
Leaving Group ◽  
Dimethyl Amine ◽  
Halide Salts

The nucleophilic substitution reaction to quaternary Mannich base from vanillin has been investigated. Mannich reaction to vanillin was carried out by refluxing mixture of vanillin, formaldehyde and dimethyl amine. Quaternary ammonium halide salt was obtained from reaction of Mannich vanillin base with methyl iodide in THF solvents and yielded 93.28 %. Nucleophilic substituion to the halide salts with cyanide nucleophile produced 4-hidroxy-3-methoxy-5-(cyano)methylbenzaldehyde in 54.39% yield. Reaction with methoxyde ion yielded 4-hydroxy- 3-methoxy-5-(methoxy) -methylbenzaldehyde in 67.80% yield. The nucleophilic substitution reaction showed that trimethylamino substituent of quaternary Mannich base can act as a good leaving group on nucleophilic substitution reactions. Keywords: Mannich reaction, vanillin, nucleophilic substitution

Catalytic Asymmetric Substitution Reaction of 3-Substituted 2-Indolylmethanols with 2-Naphthols

Synthesis ◽  
2020 ◽  
Vol 52 (23) ◽  
pp. 3684-3692
Author(s):  
Feng Gao ◽  
Yu-Chen Zhang ◽  
Feng Shi ◽  
Jin-Ping Lan ◽  
Yi-Nan Lu ◽  
...  
Keyword(s):  
Phosphoric Acid ◽  
Substitution Reaction ◽  
Enantioselective Synthesis ◽  
Chiral Phosphoric Acid ◽  
Catalytic Asymmetric ◽  
High Yields

A catalytic asymmetric substitution of 3-substituted 2-indolylmethanols with 2-naphthols has been established under the catalysis of chiral phosphoric acid. By this approach, a series of structurally diversified triarylmethane derivatives were obtained in moderate to high yields with good enantioselectivities (up to 97% yield, 95:5 er). This approach not only enriches the chemistry of 2-indolylmethanol-inolved catalytic asymmetric substitutions, but also provides a useful method for the enantioselective synthesis of chiral triarylmethane derivatives.

scholarly journals Direct synthesis of covalent triazine-based frameworks (CTFs) through aromatic nucleophilic substitution reactions

RSC Advances ◽  
2019 ◽  
Vol 9 (31) ◽  
pp. 18008-18012 ◽  
Author(s):  
Tao Chen ◽  
Wen-Qian Li ◽  
Wei-Bo Hu ◽  
Wen-Jing Hu ◽  
Yahu A. Liu ◽  
...  
Keyword(s):  
Nucleophilic Substitution ◽  
Substitution Reaction ◽  
Direct Synthesis ◽  
Nucleophilic Substitution Reaction ◽  
Substitution Reactions ◽  
Aromatic Nucleophilic Substitution ◽  
Nucleophilic Substitution Reactions ◽  
Synthetic Strategy ◽  
Aromatic Nucleophilic Substitution Reaction

Triazine-based frameworks (CTFs) were synthesized through a new synthetic strategy in which C–C bonds were formed through aromatic nucleophilic substitution reaction.

Nucleophilic Cyclization/Electrophilic Substitution of (2,2-Dialkoxyethyl)ureas: Highly Regioselective Access to Novel 4-(Het)arylimidazolidinones and Benzo[d][1,3]diazepinones

Synthesis ◽  
2020 ◽  
Vol 52 (21) ◽  
pp. 3263-3271
Author(s):  
Andrey V. Smolobochkin ◽  
Almir S. Gazizov ◽  
Nazerke K. Otegen ◽  
Julia K. Voronina ◽  
Anna G. Strelnik ◽  
...  
Keyword(s):  
Substitution Reaction ◽  
Electrophilic Substitution ◽  
Biologically Active ◽  
Electrophilic Substitution Reaction ◽  
Reaction Sequence ◽  
Active Compounds ◽  
Acid Catalyzed ◽  
High Yields ◽  
Nucleophilic Cyclization ◽  
Mechanism Of The Reaction

Imidazolidin-2-one and 1,3-benzodiazepin-2-one scaffolds are structural motifs of many biologically active compounds. Herein, we report a highly regioselective acid-catalyzed intramolecular nucleophilic cyclization/intermolecular electrophilic substitution reaction sequence of (2,2-dialkoxyethyl)ureas. The reaction benefits from readily available starting materials, a simple workup procedure, moderate to high yields of target compounds, and provides a convenient entry to previously unknown 4-(het)arylimidazolidinones and 5-(het)arylbenzodiazepinones. The proposed mechanism of the reaction is also discussed.

Electron transfer in nucleophilic vinyl substitution reactions involving bromovinyl sulfones

1981 ◽  
Vol 30 (12) ◽  
pp. 2320-2322 ◽  
Author(s):  
E. A. Berdnikov ◽  
A. A. Vafina ◽  
V. L. Polushina ◽  
R. M. Zaripova ◽  
F. R. Tantasheva ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Substitution Reactions ◽  
Nucleophilic Vinyl Substitution

scholarly journals Modular synthesis of the pyrimidine core of the manzacidins by divergent Tsuji–Trost coupling

2016 ◽  
Vol 12 ◽  
pp. 1111-1121 ◽  
Author(s):  
Sebastian Bretzke ◽  
Stephan Scheeff ◽  
Felicitas Vollmeyer ◽  
Friederike Eberhagen ◽  
Frank Rominger ◽  
...  
Keyword(s):  
Phosphoric Acid ◽  
Substitution Reaction ◽  
Grignard Reagent ◽  
Design Development ◽  
Practical Application ◽  
Efficient Procedure ◽  
Modular Synthesis ◽  
Cross Metathesis ◽  
Facile Preparation ◽  
High Yields

The design, development and application of an efficient procedure for the concise synthesis of the 1,3-syn- and anti-tetrahydropyrimidine cores of manzacidins are reported. The intramolecular allylic substitution reaction of a readily available joint urea-type substrate enables the facile preparation of both diastereomers in high yields. The practical application of this approach is demonstrated in the efficient and modular preparation of the authentic heterocyclic cores of manzacidins, structurally unique bromopyrrole alkaloids of marine origin. Additional features of this route include the stereoselective generation of the central amine core with an appending quaternary center by an asymmetric addition of a Grignard reagent to a chiral tert-butanesulfinyl ketimine following an optimized Ellman protocol and a cross-metathesis of a challenging homoallylic urea substrate, which proceeds in good yields in the presence of an organic phosphoric acid.

Catalysis with palladium colloids supported in poly(acrylic acid)-grafted polyethylene and polystyrene

2006 ◽  
Vol 84 (10) ◽  
pp. 1343-1350 ◽  
Author(s):  
David E Bergbreiter ◽  
Andrew Kippenberger ◽  
Zhenqi Zhong
Keyword(s):  
Acrylic Acid ◽  
Substitution Reaction ◽  
Supported Catalysts ◽  
Product Formation ◽  
Allylic Substitution ◽  
Heck Reactions ◽  
Substitution Reactions ◽  
Substitution Chemistry ◽  
Polyethylene Powder ◽  
Poly Acrylic Acid

Grafts of poly(acrylic acid) on polyethylene powder (PE-g-PAA) or polystyrene (PS-g-PAA) can be used to support Pd(0) crystallites that function like a homogeneous Pd(0) catalyst in some reactions. These Pd–PE-g-PAA catalysts were active in allylic substitution reactions in the presence of added phosphine ligand. A catalyst analogous to the Pd–PE-g-PAA powder catalyst on polystyrene (Pd–PS-g-PAA) was similarly active for allylic substitution and could also be used in Heck reactions at 80–100 °C in N,N-dimethylacetamide (DMA). Analysis of the product solutions for Pd leachate and a correlation of the Pd leaching with product formation in the allylic substitution chemistry for both types of catalysts suggests that the active catalysts in these reactions are leached from the support. In the case of the allylic substitution reaction, external triphenylphosphine and substrate together are required for the chemistry and Pd leaching.Key words: catalysis, palladium, allylic substitution, grafted polystyrene, supported catalysts.

Direct enantioselective allylic substitution of 4-hydroxycoumarin derivatives with branched allylic alcohols via iridium catalysis

2020 ◽  
Vol 56 (60) ◽  
pp. 8404-8407
Author(s):  
Ruigang Xu ◽  
Kai Li ◽  
Jiaqi Wang ◽  
Jiamin Lu ◽  
Lina Pan ◽  
...  
Keyword(s):  
Substitution Reaction ◽  
Allylic Alcohols ◽  
Allylic Substitution ◽  
Iridium Catalysis ◽  
High Yields

An iridium catalysed direct asymmetric allylic substitution reaction of 4-hydroxycoumarin derivatives with allylic alcohols with remarkably high yields and excellent enantioselectivities was realized.

Potential hypnotics and anxiolytics in the 4H-s-triazolo[4,3-a]-1,4-benzodiazepine series: 8-Chloro-6-(2-chlorophenyl)-1-[4-(2-methoxyethyl)piperazino]-4H-s-triazolo[4,3-a]-1,4-benzodiazepine and some related compounds

1983 ◽  
Vol 48 (8) ◽  
pp. 2395-2410 ◽  
Author(s):  
Zdeněk Polívka ◽  
Miroslav Ryska ◽  
Jiří Holubek ◽  
Emil Svátek ◽  
Jan Metyš ◽  
...  
Keyword(s):  
Title Compound ◽  
Substitution Reaction ◽  
Gradual Decrease ◽  
Substitution Reactions ◽  
Bromo Derivative ◽  
Related Compounds ◽  
Very High

1-Bromo derivatives XIIa and XIIb were prepared by bromination of 8-chloro-6-phenyl-4H-s-triazolo[4,3-a]-1,4-benzodiazepine (XIa) and its 6-(2-chlorophenyl) analogue XIb with bromine in chloroform in the presence of pyridine. Substitution reactions with 1-(2-methoxyethyl)piperazine (XIVb), 1-(3-methoxypropyl)piperazine (XVb), 1-(2-ethoxyethyl)piperazine (XVIb) and 1-(2-methylthioethyl)piperazine (XVIIb) afforded the title compound IIb and analogues IIa and IIIb-Vb. A substitution reaction of the bromo derivative XIIb with piperazine gave the 1-piperazino derivative VIIIb which was alkylated with 2-phenoxyethyl bromide and 2-phenylthioethyl bromide to give compounds VIb and VIIb. The title compound IIb has very high anticonvulsant and discoordinating activities in mice. The enlargement of the substituent R1 (compounds IIIb-VIIb) results in a gradual decrease of the effects mentioned.

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