95503-05-2Relevant academic research and scientific papers
Reactions des organolithiens et des reactifs de Grignard avec les N-phenyl imidothioesters et les dithioesters α-insatures
El-Jazouli, Mustapha,Masson, Serge,Thuillier, Andre
, p. 875 - 882 (2007/10/02)
The reactivity of α-unsaturated N-phenyl imidothioesters towards organomagnesium and lithium compounds was studied.From an α or β-non ramified imidothioester (methyl N-phenyl 2-butenimidothioate) 1,4-additions were observed with alkyl-, vinyl- and aryl-Grignard reagents, alkyllithium and lithiated limonene, and with benzenethiolate and benzenesulfinate anions.After sulfhydrolysis, new β-ramified or functionalized dithioesters were isolated and one of them was used in a synthesis of 2,6-dimethyl-1,7-octadiene-4-one.A 1,2-addition, with inversion of the allylic chain, was observed with allylic Grignard reagents, followed by a second 1,2-addition to the imine formed after elimination of magnesium methylthiolate.This double addition was not observed with prenylmagnesium bromide, the reaction of which with methyl 3-methyl N-phenyl 2-butenimidothioate led, after hydrolysis, to artemisia ketone.The regoiselectivities of the additions of organometallics to methyl 2-butenedithioate (prepared in situ from methyl phenylsulfonyl-3 butanedithioate) were also examined and they appeared completely different to those observed with the corresponding imidothioester; a thiophilic addition was the first step in the reaction of methyllithium or ethylmagnesium bromide and 1,4-γ-additions were observed with allylic Grignard reagents.
