Modified aryldifluorophenylsilicates with improved activity and selectivity in nucleophilic fluorination of secondary substrates

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388963%3A_____%2F24%3A00588029" target="_blank" >RIV/61388963:_____/24:00588029 - isvavai.cz</a>

Alternative codes found

RIV/60461373:22310/24:43929264

Result on the web

<a href="https://doi.org/10.1039/D4RA04332D" target="_blank" >https://doi.org/10.1039/D4RA04332D</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1039/d4ra04332d" target="_blank" >10.1039/d4ra04332d</a>

Result language

angličtina

Original language name

Modified aryldifluorophenylsilicates with improved activity and selectivity in nucleophilic fluorination of secondary substrates

Original language description

Nucleophilic fluorination of secondary aliphatic substrates, especially of halides, still remains a challenge. Among the available reagents, TBAT belongs to one of the best choices due to its stability, affordable price and low toxicity. With the aim to improve its selectivity, we synthesized three analogues modified in the aryl part of the TBAT reagent with one or two electron donating methoxy groups or with one electron withdrawing trifluoromethyl group. All three reagents are air-stable compounds and their structure was confirmed by a single crystal X-ray analysis. In testing the reactivity and selectivity of the reagents with a library of secondary bromides, as well as of other selected primary and secondary substrates, we found that substitution with methoxy groups mostly improves both reactivity and selectivity compared to TBAT, while the substitution with trifluoromethyl group leads to inferior results. Difluorosilicates modified by more than two electron donating methoxy groups proved to be unstable and decomposed spontaneously to the HF2- anion. DFT calculations of tetramethylammonium analogues of the studied reagents disclosed that the substitution of the phenyl group with the methoxy substituent lowers the transitions state energy of the decomposition to a fluorosilane-fluoride complex, while the substitution with the trifluoromethyl group has an opposite effect.

Czech name

—

Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10406 - Analytical chemistry

Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2024

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

RSC Advances

ISSN

2046-2069

e-ISSN

2046-2069

Volume of the periodical

14

Issue of the periodical within the volume

31

Country of publishing house

GB - UNITED KINGDOM

Number of pages

9

Pages from-to

22326-22334

UT code for WoS article

001270909300001

EID of the result in the Scopus database

2-s2.0-85199080334