Effects of Hydrogen Bonding Solvation by Diverse Fluorinated Bulky Alcohols on the Reaction Rate and Selectivity in Crown Ether Mediated Nucleophilic Fluorination in an Aprotic Solvent DOI Creative Commons
Eloah P. Ávila, Mauro Vieira de Almeida, Marcelo Siqueira Valle

и другие.

ACS Organic & Inorganic Au, Год журнала: 2024, Номер 5(1), С. 69 - 83

Опубликована: Ноя. 28, 2024

Solvent effects play a critical role in ionic chemical reactions and have been research topic for long time. The solvent molecules the first solvation shell of solute are most important solvating species. Consequently, manipulation structure this can be used to control reactivity selectivity reactions. In work, we report extensive experimental insightful computational studies adding diverse fluorinated bulky alcohols with different abilities fluorination reaction alkyl bromides potassium fluoride promoted by 18-crown-6. We found that stoichiometric amount these acetonitrile solution has an effect on kinetics selectivity. effective alcohol was 2-trifluoromethyl-2-propanol (TBOH-F3), use 3 equiv fluorinate primary bromide led 78% yield just 6 h time at mild temperature 82 °C, 8% E2 yield. more challenging secondary substrate obtained 44% 56% 18 More six or fluorine atoms resulted relatively acidic alcohols, leading large amounts corresponding ethers as side products. widely hexafluoroisopropanol (HFIP) least one monofluorination, indicating both acidity bulkiness features promoting using KF salt. Nevertheless, ether HFIP easily formed substrate, generating highly product. Theoretical calculations predict ΔG ‡ close agreement experiments explain higher induced relation crown alone.

Язык: Английский

Aryne Aminohalogenation Using Protic Amines Enabled by Halogen Transfer DOI
Joshua Gavin,

Lars Anderson,

Courtney C. Roberts

и другие.

Organic Letters, Год журнала: 2024, Номер 26(36), С. 7530 - 7534

Опубликована: Авг. 28, 2024

Methods for aryne difunctionalization have been the focus of recent research, but one limitation is use nucleophiles with proton sources. Herein, we demonstrate halogen transfer reagents to enable protic amines in aminohalogenation difunctionalizations up 86% yield. This method uses and arynes a variety N-heterocyclic scaffolds. Through derivatizations, synthetic utility these products demonstrated.

Язык: Английский

Процитировано

2
Modified aryldifluorophenylsilicates with improved activity and selectivity in nucleophilic fluorination of secondary substrates DOI Creative Commons
Michal Trojan, Adam Hroch, Evelin Gruden

и другие.

RSC Advances, Год журнала: 2024, Номер 14(31), С. 22326 - 22334

Опубликована: Янв. 1, 2024

Difluorosilicates with MeO group(s) gave improved nucleophilic fluorination activity and selectivity of secondary substrates, while the CF 3 group inferior results.

Язык: Английский

Процитировано

1
Effects of Hydrogen Bonding Solvation by Diverse Fluorinated Bulky Alcohols on the Reaction Rate and Selectivity in Crown Ether Mediated Nucleophilic Fluorination in an Aprotic Solvent DOI Creative Commons
Eloah P. Ávila, Mauro Vieira de Almeida, Marcelo Siqueira Valle

и другие.

ACS Organic & Inorganic Au, Год журнала: 2024, Номер 5(1), С. 69 - 83

Опубликована: Ноя. 28, 2024

Solvent effects play a critical role in ionic chemical reactions and have been research topic for long time. The solvent molecules the first solvation shell of solute are most important solvating species. Consequently, manipulation structure this can be used to control reactivity selectivity reactions. In work, we report extensive experimental insightful computational studies adding diverse fluorinated bulky alcohols with different abilities fluorination reaction alkyl bromides potassium fluoride promoted by 18-crown-6. We found that stoichiometric amount these acetonitrile solution has an effect on kinetics selectivity. effective alcohol was 2-trifluoromethyl-2-propanol (TBOH-F3), use 3 equiv fluorinate primary bromide led 78% yield just 6 h time at mild temperature 82 °C, 8% E2 yield. more challenging secondary substrate obtained 44% 56% 18 More six or fluorine atoms resulted relatively acidic alcohols, leading large amounts corresponding ethers as side products. widely hexafluoroisopropanol (HFIP) least one monofluorination, indicating both acidity bulkiness features promoting using KF salt. Nevertheless, ether HFIP easily formed substrate, generating highly product. Theoretical calculations predict ΔG ‡ close agreement experiments explain higher induced relation crown alone.

Язык: Английский

Процитировано

1