Facile synthesis of vicinal halohydrins via organocatalytic halogen nucleophile-induced regioselective opening of epoxides

2021 ◽  
Vol 18 ◽  
Author(s):  
Niharika Sinha ◽  
Anchal Singhal ◽  
Deeksha Sharma ◽  
Shiv Murat Singh Chauhan
Keyword(s):  
Ring Opening ◽  
Functional Group ◽  
Solvent Polarity ◽  
Halide Ions ◽  
Facile Synthesis ◽  
Reaction Conditions ◽  
Halide Anion ◽  
Ring Opening Of Epoxides ◽  
Non Covalent Interactions ◽  
Covalent Interactions

Background: The calix[4]pyrrole is reported as a novel organocatalyst for regioselective ring opening of epoxides under mild reaction conditions. Methods: The reaction involves elemental halogen as a nucleophile to afford vicinal halohydrins in good to excellent yield (75-95%). Results : The reactivity of the halide anion in the reaction is governed by different factors, including solvent polarity, temperature and non-covalent interactions of the functional group present on calix[4]pyrrole moiety with halide ions. Conclusion: An efficient methodology has been developed for the regioselective synthesis of halohydrins in good to excellent yields.

scholarly journals Functional group interaction profiles: a general treatment of solvent effects on non-covalent interactions

2020 ◽  
Vol 11 (17) ◽  
pp. 4456-4466 ◽  
Author(s):  
Mark D. Driver ◽  
Mark J. Williamson ◽  
Joanne L. Cook ◽  
Christopher A. Hunter
Keyword(s):  
Free Energy ◽  
Solvent Effects ◽  
Functional Group ◽  
Group Interaction ◽  
General Treatment ◽  
Effect Of Solvent ◽  
Non Covalent Interactions ◽  
Covalent Interactions ◽  
Quantitative Tool

Functional group interaction profiles are a quantitative tool for predicting the effect of solvent on the free energy changes associated with non-covalent interactions.

Synthesis of unsymmetrical porphyrin triad containing three different porphyrin subunits assembled by covalent and non-covalent interactions

2008 ◽  
Vol 12 (09) ◽  
pp. 1030-1040 ◽  
Author(s):  
Sokkalingam Punidha ◽  
Smita Rai ◽  
Mangalampalli Ravikanth
Keyword(s):  
Building Block ◽  
Functional Group ◽  
Photophysical Properties ◽  
Time Resolved Fluorescence ◽  
Efficient Energy Transfer ◽  
Time Resolved ◽  
Fluorescence Studies ◽  
Efficient Energy ◽  
Non Covalent Interactions ◽  
Covalent Interactions

Cis-21,23-dithiaporphyrin building block containing one iodophenyl and one pyridyl functional group at meso positions was synthesized by condensing unsymmetrical thiophene diol and symmetrical 16-thiatripyrrin under refluxing propionic acid conditions. The 21,23-dithiaporphyrin building block was coupled with mono-functionalized 21-thiaporphyrin building block containing meso-phenylethyne functional group under mild Pd (0) coupling conditions. The steady-state and time-resolved fluorescence studies support an efficient energy transfer in the singlet excited state from N 3 S porphyrin subunit to N 2 S 2 porphyrin subunit in the dyad. The N 3 S - N 2 S 2 porphyrin dyad was then treated with RuTPP ( CO )( EtOH ) in toluene at refluxing temperature and purified by column chromatography to afford a porphyrin triad containing N 3 S , N 2 S 2 and RuN 4 porphyrin subunits assembled using both covalent and non-covalent interactions. The photophysical properties showed the fluorescence quenching of N 3 S and N 2 S 2 porphyrin subunits in triad due to heavy ruthenium ion which was coordinated to meso-pyridyl ' N ' of N 2 S 2 porphyrin subunit of porphyrin triad.

Facile Synthesis of Hydroxy-Substituted Thiacrown Ethers via Nucleophilic Ring Opening of Epoxides

Synthesis ◽  
2019 ◽  
Vol 51 (10) ◽  
pp. 2214-2220 ◽  
Author(s):  
Monika Stefaniak ◽  
Jarosław Romański
Keyword(s):  
Click Chemistry ◽  
Ring Opening ◽  
Facile Synthesis ◽  
Step Procedure ◽  
Ring Opening Of Epoxides ◽  
One Step ◽  
Thiacrown Ethers ◽  
Hydroxy Groups ◽  
First Time ◽  
Nucleophilic Ring Opening

The title thiacrown ethers were prepared in a one-step procedure to give a series of unique macrocycles possessing two unsubstituted hydroxy groups that can be easily functionalized. In addition, epoxides and macrocycles derived from Cookson’s birdcage diketone, were prepared. The nucleophilic ring opening of epoxides synthesis can be classified in the frame of click chemistry. Surprisingly, some of the prepared allyl substituted polyglycols as well as bis-epoxides, especially sulfur analogues, were prepared for the first time.

Cyanuric Chloride: an Efficient Catalyst for Ring Opening of Epoxides with Thiols Under Solvent-Free Conditions

2008 ◽  
Vol 61 (3) ◽  
pp. 231 ◽  
Author(s):  
Babasaheb P. Bandgar ◽  
Neeta S. Joshi ◽  
Vinod T. Kamble ◽  
Sanjay S. Sawant
Keyword(s):  
Reaction Time ◽  
Ring Opening ◽  
Solvent Free ◽  
Cyanuric Chloride ◽  
Reaction Conditions ◽  
Efficient Catalyst ◽  
Short Reaction Time ◽  
Solvent Free Conditions ◽  
Ring Opening Of Epoxides

2,4,6-Trichloro-1,3,5-triazine-catalyzed convenient and efficient ring opening of epoxides with thiols under solvent-free conditions is described. Short reaction time, mild reaction conditions, inexpensive and readily available catalyst, and excellent yields of products are attractive features of this methodology.

Enantioselective formation and ring-opening of epoxides catalysed by halohydrin dehalogenases

2006 ◽  
Vol 34 (2) ◽  
pp. 291-295 ◽  
Author(s):  
D.B. Janssen ◽  
M. Majerić-Elenkov ◽  
G. Hasnaoui ◽  
B. Hauer ◽  
J.H. Lutje Spelberg
Keyword(s):  
Ring Opening ◽  
Building Blocks ◽  
Epoxide Ring ◽  
Structural Studies ◽  
Halide Ions ◽  
Catalytic Promiscuity ◽  
Agrobacterium Radiobacter ◽  
Enzymatic Production ◽  
Ring Opening Reactions ◽  
Ring Opening Of Epoxides

Halohydrin dehalogenases catalyse the conversion of vicinal halohydrins into their corresponding epoxides, while releasing halide ions. They can be found in several bacteria that use halogenated alcohols or compounds that are degraded via halohydrins as a carbon source for growth. Biochemical and structural studies have shown that halohydrin dehalogenases are evolutionarily and mechanistically related to enzymes of the SDR (short-chain dehydrogenase/reductase) superfamily. In the reverse reaction, which is epoxide-ring opening, different nucleophiles can be accepted, including azide, nitrite and cyanide. This remarkable catalytic promiscuity allows the enzymatic production of a broad range of β-substituted alcohols from epoxides. In these oxirane-ring-opening reactions, the halohydrin dehalogenase from Agrobacterium radiobacter displays high enantioselectivity, making it possible to use the enzyme for the preparation of enantiopure building blocks for fine chemicals.

scholarly journals Symmetry-Adapted Perturbation Theory Decomposition of the Reaction Force: Insights into Substituent Effects Involved in Hemiacetal Formation Mechanisms

2019 ◽  
Author(s):  
Wallace Derricotte
Keyword(s):  
Perturbation Theory ◽  
Functional Group ◽  
Reaction Force ◽  
Substituent Effects ◽  
Formation Mechanisms ◽  
Lower Activation ◽  
Non Covalent Interactions ◽  
Force Components ◽  
Covalent Interactions ◽  
Lower Activation Energy

<div>The decomposition of the reaction force based on symmetry-adapted perturbation theory (SAPT) has been proposed. This approach was used to investigate the subtituent effects along the reaction coordinate pathway for the hemiacetal formation mechanism between methanol and substituted aldehydes of the form CX<sub>3</sub>CHO (X = H, F, Cl, and Br), providing a quantitative evaluation of the reaction-driving and reaction-retarding force components. Our results highlight the importance of more favorable electrostatic and induction effects in the reactions involving halogenated aldehydes that leads to lower activation energy barriers. These substituent effects are further elucidated by applying the functional-group partition of symmetry-adapted</div><div>perturbation theory (F-SAPT). The results show that the reaction is largely driven by favorable direct non-covalent interactions between the CX<sub>3</sub> group on the aldehyde and the OH group on methanol.</div>

scholarly journals Crystal structures ofp-substituted derivatives of 2,6-dimethylbromobenzene with ½ ≤Z′ ≤ 4

2016 ◽  
Vol 72 (12) ◽  
pp. 1762-1767
Author(s):  
Angélica Navarrete Guitérrez ◽  
Gerardo Aguirre Hernández ◽  
Sylvain Bernès
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Crystal Structures ◽  
Functional Group ◽  
Molecular Symmetry ◽  
Asymmetric Unit ◽  
Structure Feature ◽  
Non Covalent Interactions ◽  
Derivatives Of ◽  
Covalent Interactions

The crystal structures of four bromoarenes based on 2,6-dimethylbromobenzene are reported, which are differentiated according the functional groupXplacedparato the Br atom:X= CN (4-bromo-3,5-dimethylbenzonitrile, C9H8BrN), (1),X= NO2(2-bromo-1,3-dimethyl-5-nitrobenzene, C8H8BrNO2), (2),X= NH2(4-bromo-3,5-dimethylaniline, C8H10BrN), (3) andX= OH (4-bromo-3,5-dimethylphenol, C8H9BrO), (4). The content of the asymmetric unit is different in each crystal,Z′ = ½ (X= CN),Z′ = 1 (X= NO2),Z′ = 2 (X= NH2), andZ′ = 4 (X= OH), and is related to the molecular symmetry and the propensity ofXto be involved in hydrogen bonding. In none of the studied compounds does the crystal structure feature other non-covalent interactions, such as π–π, C—H...π or C—Br...Br contacts.

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