title: 2D ultrafast HMBC 1H,31P: obtaining mechanistic details on the Michaelis–Arbuzov reaction.
abstract: Ultrafast NMR spectroscopy (UF-NMR) can be used to monitor chemical reactions in real time and to provide insights into their mechanisms and the nature of the intermediates formed. Here, we have developed a 2D 1H,31P UF-HMBC method and the corresponding NMR experimental setup to enable the study of a Michaelis–Arbuzov reaction at two different temperatures, 25 and 70 °C. The specific reaction studied was between triethyl phosphite and benzyl bromide to produce diethylbenzyl phosphonate. Our results show that at 70 °C the reaction takes place directly, without the detection of an intermediate by 1H,31P UF-HMBC. In contrast, at 25 °C, using zinc bromide as a catalyst, our results show the formation of benzyltriethoxy phosphonium bromide as an intermediate. The experiments again show the power of UF-NMR in mechanistic studies of reactions involving various phosphorus chemical species.
authors.forename: María Encarnación
authors.initials: ME
authors.lastname: Fernández-Valle
authors.forename: Roberto
authors.initials: R
authors.lastname: Martínez-Álvarez
authors.forename: Dolores
authors.initials: D
authors.lastname: Molero-Vílchez
authors.forename: Zulay D
authors.initials: ZD
authors.lastname: Pardo
authors.forename: Elena
authors.initials: E
authors.lastname: Sáez-Barajas
authors.forename: Antonio
authors.initials: A
authors.lastname: Herrera
mesh_terms: D001593:Benzyl Compounds / Q000138:chemical synthesis* / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D063065:Organophosphonates / Q000737:chemistry*; D013696:Temperature
chemical_list: D001593:Benzyl Compounds; D063065:Organophosphonates