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

Autor(es)

Gehlen, Marcelo H. ^[1] ; Foltran, Larissa S. ^[1] ; Kienle, Daniel F. ^[2] ; Schwartz, Daniel K. ^[2]

Afiliação do(s) autor(es)

^[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

• Tipo de documento: Artigo Científico
• Fonte: Journal of Physical Chemistry Letters; v. 11, n. 22, p. 9714-9724, NOV 19 2020.
• Citações Web of Science: 0

Resumo

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)

• Processo FAPESP: 18/17660-7 - Acompanhamento de reação orgânica catalisada no limite de molécula única: aplicação na síntese de derivado fluorescente de imidazol
• Beneficiário: Larissa Schumekel Foltran
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica
• Processo FAPESP: 18/22159-5 - Difusão molecular, localização e reação de catalisadores poliméricos na interface sólido-solução investigados através de microscopia de fluorescência de molécula única
• Beneficiário: Marcelo Henrique Gehlen
• Modalidade de apoio: Bolsas no Exterior - Pesquisa