Palladium-Catalyzed C-H Activation: Mass Spectrometric Approach to Reaction Kinetics in Solution

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216275%3A25310%2F17%3A39910831" target="_blank" >RIV/00216275:25310/17:39910831 - isvavai.cz</a>

Alternative codes found

RIV/00216208:11310/17:10363811

Result on the web

<a href="http://dx.doi.org/10.1021/acs.organomet.6b00960" target="_blank" >http://dx.doi.org/10.1021/acs.organomet.6b00960</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1021/acs.organomet.6b00960" target="_blank" >10.1021/acs.organomet.6b00960</a>

Result language

angličtina

Original language name

Palladium-Catalyzed C-H Activation: Mass Spectrometric Approach to Reaction Kinetics in Solution

Original language description

We report a new method for determination of rate constants of processes in solution using electrospray ionization mass spectrometry (ESI-MS). The investigated reaction is C-H activation of acetanilides by palladium(II)trifluoroacetate leading to stable organopalladium complexes. The rate constants can be determined from an experiment with a couple of differently substituted acetanilides being in competition for being activated by the palladium salt. The formed organopalladium complexes can be detected by ESI-MS. The time dependence is achieved by adding one of the acetanilides to the reaction mixture with a time delay. The kinetics can be then evaluated from the evolution of the ratio of the ESI-MS signals of differently substituted complexes as a function of the time delay. The Hammett analysis of the rate constants obtained for a series of meta- and para-substituted acetanilides provides a rho value of -1.5, which is in agreement with values reported for similar C-H activations. We have also investigated the very same reaction with UV-vis spectroscopy that gave us about three times smaller rate constants but the same trend with the rho value of -1.6. The rate constants determined by ESI-MS are directly linked to the occurrence of organopalladium complexes, whereas the UV-vis data are associated with an absorption spectra change that could involve more reaction steps. DFT calculations support the interpretation of the reaction mechanism as cyclopalladation and provide the rho value in the same range. The rate-determining step corresponds to the agostic C-H transition structure.

Czech name

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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

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OECD FORD branch

10401 - Organic chemistry

Project

<a href="/en/project/GA14-20077S" target="_blank" >GA14-20077S: Non-heme iron catalysts: Investigation of reaction mechanisms</a><br>

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2017

Confidentiality

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

Name of the periodical

Organometallics

ISSN

0276-7333

e-ISSN

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Volume of the periodical

36

Issue of the periodical within the volume

11

Country of publishing house

US - UNITED STATES

Number of pages

9

Pages from-to

2072-2080

UT code for WoS article

000403387300005

EID of the result in the Scopus database

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