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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Single-Molecule Observations Provide Mechanistic Insights into Bimolecular Knoevenagel Amino Catalysis

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Author(s):
Gehlen, Marcelo H. [1] ; Foltran, Larissa S. [1] ; Kienle, Daniel F. [2] ; Schwartz, Daniel K. [2]
Total Authors: 4
Affiliation:
[1] Univ Sao Paulo, Inst Chem Sao Carlos, Dept Phys Chem, BR-13566590 Sao Carlos, SP - Brazil
[2] Univ Colorado, Dept Chem & Biol Engn, Boulder, CO 80309 - USA
Total Affiliations: 2
Document type: Journal article
Source: Journal of Physical Chemistry Letters; v. 11, n. 22, p. 9714-9724, NOV 19 2020.
Web of Science Citations: 0
Abstract

While single-molecule (SM) methods have provided new insights to various catalytic processes, bimolecular reactions have been particularly challenging to study. Here, the fluorogenic Knoevenagel condensation of an aromatic aldehyde with methyl cyanoacetate promoted by surface-immobilized piperazine is quantitatively characterized using super-resolution fluorescence imaging and stochastic analysis using hidden Markov modeling (HMM). Notably, the SM results suggest that the reaction follows the iminium intermediate pathway before the formation of a fluorescent product with intramolecular charge-transfer character. Moreover, the overall process is limited by the turnover rate of the catalyst, which is involved in multiple steps along the reaction coordinate. (AU)

FAPESP's process: 18/17660-7 - Organic reaction at single molecule level: synthesis of a fluorescent imidazole
Grantee:Larissa Schumekel Foltran
Support type: Scholarships in Brazil - Scientific Initiation
FAPESP's process: 18/22159-5 - Molecular diffusion, trapping and reaction of polymeric catalysts at the solution-solid interface investigated by single molecule fluorescence microscopy
Grantee:Marcelo Henrique Gehlen
Support type: Scholarships abroad - Research