scholarly journals Fluorine effect in nucleophilic fluorination at C4 of 1,6-anhydro-2,3-dideoxy-2,3-difluoro-β-D-hexopyranose

2020 ◽  
Vol 16 ◽  
pp. 2880-2887
Author(s):  
Danny Lainé ◽  
Vincent Denavit ◽  
Olivier Lessard ◽  
Laurie Carrier ◽  
Charles-Émile Fecteau ◽  
...  
Keyword(s):  
Nucleophilic Substitution ◽  
Fluorine Atom ◽  
Synthetic Approach ◽  
Nucleophilic Fluorination

In this work, we have developed a simple synthetic approach using Et3N·3HF as an alternative to the DAST reagent. We controlled the stereochemistry of the nucleophilic fluorination at C4 of 1,6-anhydro-2,3-dideoxy-2,3-difluoro-4-O-triflate-β-ᴅ-talopyranose using Et3N·3HF or in situ generated Et3N·1HF. The influence of the fluorine atom at C2 on reactivity at C4 could contribute to a new fluorine effect in nucleophilic substitution. Finally, with the continuous objective of synthesizing novel multi-vicinal fluorosugars, we prepared one difluorinated and one trifluorinated alditol analogue.

scholarly journals Synthesis of Substituted 1,3-Diesters of Glycerol Using Wittig Chemistry

2014 ◽  
Vol 9 (5) ◽  
pp. 1934578X1400900
Author(s):  
Henry IC Lowe ◽  
Ngeh J. Toyang ◽  
Charah T. Watson ◽  
Joseph Bryant
Keyword(s):  
Benzoic Acid ◽  
Natural Compound ◽  
Primary Alcohol ◽  
Synthetic Approach ◽  
Triphenyl Phosphine ◽  
Phosphonium Bromide ◽  
New Compounds ◽  
First Time ◽  
Wittig Reagent

1,3-di-O-Cinnamoyl-glycerol is a natural compound isolated from a Jamaican medicinal plant commonly referred to as Ball moss (Tillandsia recurvata). The synthesis of this compound was achieved via a Wittig chemistry process. The synthetic approach started with acylation of a di-protected glycerol with cinnamoyl chloride, deprotection of the glycerol moiety, reaction of the primary alcohol with bromo acetylbromide followed by treatment with triphenyl phosphine to give the corresponding phosphonium bromide. The phosphonium bromide was then converted in situ to the Wittig reagent which is the basis for a novel route to 1,3-di-O-cinnamoyl glycerol. Four analogs were also synthesized, three of which are new and are being reported in this article for the first time. The new compounds include 3-(3,4-diemthoxy-phenyl)-acrylic acid 2-hydroxy-3-(3-ptolyl-acryloyloxy)-propyl ester (3), 2-acetoxy-5-((E)-3-(3-((E’)-3-(3,4-dimethoxyphenyl)acryloyloxy)-2-hydropropoxy)-3-oxoprop-1-enyl)benzoic acid (4) and 4-((E)-3-(3-((E)-3-(3,4-dimethoxyphenyl)acryloyloxy)-2-hydropropoxy)-3-oxoprop-1-enyl)benzoic acid (5). The compounds showed no activity in our anticancer assay.

High-throughput evaluation of in situ-generated cobalt(iii) catalysts for acyl fluoride synthesis

2017 ◽  
Vol 7 (21) ◽  
pp. 4996-5003 ◽  
Author(s):  
Graham M. Lee ◽  
Roxanne Clément ◽  
R. Tom Baker
Keyword(s):  
General Formula ◽  
High Throughput ◽  
Benzoyl Chloride ◽  
Experimental Procedure ◽  
Nucleophilic Fluorination

Using a high-throughput experimental procedure, a series of cobalt(iii) complexes of the general formula CpRCo(I)(X)(L) were prepared and screened for their activity towards the catalytic nucleophilic fluorination of benzoyl chloride.

scholarly journals Intramolecular nucleophilic addition of carbanions generated from N-benzylamides to cyclopropenes

2018 ◽  
Vol 16 (2) ◽  
pp. 285-294 ◽  
Author(s):  
Vladimir Maslivetc ◽  
Colby Barrett ◽  
Nicolai A. Aksenov ◽  
Marina Rubina ◽  
Michael Rubin
Keyword(s):  
Nucleophilic Substitution ◽  
Nucleophilic Addition ◽  
Unusual Reaction ◽  
Intramolecular Nucleophilic Substitution ◽  
Facile Preparation ◽  
Nitrogen Ylides

An unusual reaction is described, involving a formal intramolecular nucleophilic substitution of bromocyclopropanes with nitrogen ylides generated in situ from N-benzyl carboxamides. This reaction involves cyclopropene intermediates and allows for the facile preparation of 3-azabicyclo[3.1.0]hexan-2-ones.

scholarly journals Synthesis of meso-2,2’-bipyridyl-substituted calix[4]arenes and their response to metal cations

2020 ◽  
Vol 7 (4) ◽  
pp. 215-221
Author(s):  
T. D. Moseev ◽  
A. F. Khasanov ◽  
M. V. Varaksin ◽  
D. S. Kopchuk ◽  
I. S. Kovalev ◽  
...  
Keyword(s):  
Metal Cations ◽  
Alder Reaction ◽  
Diels Alder ◽  
Synthetic Approach ◽  
Fluorescence Response ◽  
Uv Fluorescence ◽  
Diels Alder Reaction ◽  
Convenient Synthetic Approach

A convenient synthetic approach to meso-substituted with 2,2’-bipyridine and 1-(pyridin-2-yl)isoquinoline residues calix[4]arenes is reported. This approach involves the reaction of generated in situ 2-lithio-calix[4]arene with 1,2,4-triazine precursor with the following aromatization of the obtained adduct, and the aza-Diels-Alder reaction of the 1,2,4-triazinyl-substituted calix[4]arene with 2,5-norbornadien or in-situ generated 1,2-dehydrobenzene. The UV/fluorescence response of thus obtained meso-pyridyl-substituted calix[4]arenes to metal cations is studied.

scholarly journals The reactions of 2-ethoxymethylidene-3-oxo esters and their analogues with 5-aminotetrazole as a way to novel azaheterocycles

2015 ◽  
Vol 11 ◽  
pp. 385-391 ◽  
Author(s):  
Marina V Goryaeva ◽  
Yanina V Burgart ◽  
Marina A Ezhikova ◽  
Mikhail I Kodess ◽  
Viktor I Saloutin
Keyword(s):  
Nucleophilic Substitution ◽  
Alternative Pathway ◽  
Synthetic Approach ◽  
Reaction Routes

The interaction of 2-ethoxymethylidene-3-oxo esters and their analogues with 5-aminotetrazole is an efficient synthetic approach to novel azaheterocycles. 2-Ethoxymethylidene-3-oxo esters bearing alkyl substituents react with 5-aminotetrazole to form ethyl 2-azido-4-alkylpyrimidine-5-carboxylates which are capable of subsequent nucleophilic substitution. The use of diethyl 2-ethoxymethylidenemalonate in this reaction resulted in ethyl 7-hydroxytetrazolo[1,5-a]pyrimidine-6-carboxylate, while ethyl 2-ethoxymethylidenecyanoacetate yielded 5-[2,6-diamino-3,5-bis(ethoxycarbonyl)pyridinium-1-yl]tetrazol-1-ide through an alternative pathway. Ethyl 2-benzoyl-3-ethoxyprop-2-enoate reacted with 5-aminotetrazole by two reaction routes to form ethyl 2-benzoyl-3-(1H-tetrazol-5-ylamino)prop-2-enoate and ethyl 7-(1-ethoxy-1,3-dioxo-3-phenylpropan-2-yl)-5-phenyl-4,7-dihydrotetrazolo[1,5-a]pyrimidine-6-carboxylate.

Modification of β-positions in porphyrazines by substitution reactions

2000 ◽  
Vol 04 (05) ◽  
pp. 555-563 ◽  
Author(s):  
OL'GA G. KHELEVINA ◽  
NATALIYA V. CHIZHOVAN ◽  
PAVEL A. STUZHIN
Keyword(s):  
Nucleophilic Substitution ◽  
Synthetic Approach ◽  
Substitution Reactions ◽  
Nucleophilic Substitution Reactions ◽  
Radical Substitution

Peripheral modification of the porphyrazine macrocycle is an important synthetic approach to β-substituted porphyrazine derivatives, especially those which cannot be obtained via direct template cyclotetramerization of maleodinitriles and other similar synthons. The paper presents the last results of the systematical investigation of the reactivity of unsubstituted porphyrazine (tetraazaporphine) in the reactions of electrophilic and radical substitution in pyrrole rings (bromination, chlorination, chloromethylation, nitration and sulfonation) and nucleophilic substitution reactions of chloro-, bromo- and sulfo-substituted porphyrazines.

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