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Download file2D Ultrafast HMBC 1H,31P: Obtaining Mechanistic Details on the Michaelis–Arbuzov Reaction
journal contribution
posted on 16.01.2015, 00:00 authored by María
Encarnación Fernández-Valle, Roberto Martínez-Álvarez, Dolores Molero-Vílchez, Zulay D. Pardo, Elena Sáez-Barajas, Antonio HerreraUltrafast
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.