Quantifiable polarity match effect on C–H bond cleavage reactivity and its limits in reaction design

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388955%3A_____%2F23%3A00567641" target="_blank" >RIV/61388955:_____/23:00567641 - isvavai.cz</a>

Výsledek na webu

<a href="https://hdl.handle.net/11104/0338871" target="_blank" >https://hdl.handle.net/11104/0338871</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1039/D2DT04018B" target="_blank" >10.1039/D2DT04018B</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Quantifiable polarity match effect on C–H bond cleavage reactivity and its limits in reaction design

Popis výsledku v původním jazyce

When oxidants favour cleaving a strong C−H bond at the expense of weaker ones, which are otherwise inherently preferred due to their favourable reaction energy, reactivity factors such as the polarity match effect are often invoked. Polarity match follows the intuition of electrophilic (nucleophilic) oxidants reacting faster with nucleophilic (electrophilic) C−H bonds. Nevertheless, this concept is purely qualitative and is best suited for a posteriori rationalization of experimental observations. Here, we propose and inspect two methods to quantify polar effects in C−H cleavage reactions, one by computation via the difference of atomic charges (Δq) of reacting atoms, and one amenable to experimental measurement through asynchronicity factors, η. By their application to three case studies, we observe that both Δq and η faithfully capture the notion of polarity match. The polarity match model, however, proves insufficient as a predictor of H-atom abstraction reactivity and we discourage its use as a standalone variable in reaction design. Besides this caveat, η and Δq (through its mapping on η) allow the implementation of polarity match into a Marcus-type model of reactivity, alleviating its shortcomings and making reaction planning feasible.n

Název v anglickém jazyce

Quantifiable polarity match effect on C–H bond cleavage reactivity and its limits in reaction design

Popis výsledku anglicky

When oxidants favour cleaving a strong C−H bond at the expense of weaker ones, which are otherwise inherently preferred due to their favourable reaction energy, reactivity factors such as the polarity match effect are often invoked. Polarity match follows the intuition of electrophilic (nucleophilic) oxidants reacting faster with nucleophilic (electrophilic) C−H bonds. Nevertheless, this concept is purely qualitative and is best suited for a posteriori rationalization of experimental observations. Here, we propose and inspect two methods to quantify polar effects in C−H cleavage reactions, one by computation via the difference of atomic charges (Δq) of reacting atoms, and one amenable to experimental measurement through asynchronicity factors, η. By their application to three case studies, we observe that both Δq and η faithfully capture the notion of polarity match. The polarity match model, however, proves insufficient as a predictor of H-atom abstraction reactivity and we discourage its use as a standalone variable in reaction design. Besides this caveat, η and Δq (through its mapping on η) allow the implementation of polarity match into a Marcus-type model of reactivity, alleviating its shortcomings and making reaction planning feasible.n

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10403 - Physical chemistry

Projekt

<a href="/cs/project/GA21-10383S" target="_blank" >GA21-10383S: Řízení reakční selektivity faktorem asynchronicity</a><br>

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2023

Kód důvěrnosti údajů

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

Název periodika

Dalton Transactions

ISSN

1477-9226

e-ISSN

1477-9234

Svazek periodika

52

Číslo periodika v rámci svazku

5

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

14

Strana od-do

1399-1412

Kód UT WoS článku

000913034100001

EID výsledku v databázi Scopus

2-s2.0-85147235722