Nitro-Assisted Brønsted Acid Catalysis: Application to a Challenging Catalytic Azidation

Autor:	Malik Hellal, Florian C. Falk, Joseph Moran, Marian Dryzhakov, Eléna Wolf
Rok vydání:	2015
Předmět:	Azides Hydrocarbons Fluorinated Molecular Structure Concentration dependence Chemistry General Chemistry Nitro Compounds First order Biochemistry Catalysis Colloid and Surface Chemistry Alcohols Nitro Organic chemistry Molecule Boranes Brønsted–Lowry acid–base theory
Zdroj:	Journal of the American Chemical Society. 137:9555-9558
ISSN:	1520-5126 0002-7863
Popis:	A cocatalytic effect of nitro compounds is described for the B(C6F5)3·H2O catalyzed azidation of tertiary aliphatic alcohols, enabling catalyst turnover for the first time and with a broad range of substrates. Kinetic investigations into this surprising effect reveal that nitro compounds induce a switch from first order concentration dependence in Brønsted acid to second order concentration dependence in Brønsted acid and second order dependence in the nitro compounds. Kinetic, electronic, and spectroscopic evidence suggests that higher order hydrogen-bonded aggregates of nitro compounds and acids are the kinetically competent Brønsted acid catalysts. Specific weak H-bond accepting additives may offer a new general approach to accelerating Brønsted acid catalysis in solution.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::3346082c8b4030697a8d2e6285c9b9c5 https://doi.org/10.1021/jacs.5b06055 Zobrazit plný text záznamu