Introducing deep eutectic solvents to polar organometallic chemistry: chemoselective addition of organolithium and Grignard reagents to ketones in air.
Despite their enormous synthetic relevance, the use of polar organolithium and Grignard reagents is greatly limited by their requirements of low temperatures in order to control their reactivity as well as the need of dry organic solvents and inert atmosphere protocols to avoid their fast decomposition. Breaking new ground on the applications of these commodity organometallics in synthesis under more environmentally friendly conditions, this work introduces deep eutetic solvents (DESs) as a green alternative media to carry out chemoselective additions of ketones in air at room temperature. Comparing their reactivities in DES with those observed in pure water suggest that a kinetic activation of the alkylating reagents is taking place, favoring nucleophilic addition over the competitive hydrolysis, which can be rationalized through formation of halide-rich magnesiate or lithiate species.
Laboratorio de Compuestos Organometálicos y Catálisis (Unidad Asociada al CSIC), Departamento de Química Orgánica e Inorgánica, Instituto Universitario de Química Organometálica, "Enrique Moles", Facultad de Química, Universidad de Oviedo, 33071 Oviedo (Spain).
Cristian
C
Vidal
Joaquín
J
García-Álvarez
Alberto
A
Hernán-Gómez
Alan R
AR
Kennedy
Eva
E
Hevia
Grignard reagents; addition reactions; deep eutectic solvents; green chemistry; organolithium compounds