121726-27-0Relevant articles and documents
Synthese de cetones a partir de N-phenyl imidothioesters et par l'intermediaire de cetenimines
El-Jazouli, Mustapha,Lage, Nadia,Masson, Serge,Thuillier, Andre
, p. 883 - 888 (2007/10/02)
The thermal decomposition of metallated N-phenyl imidothioesters (lithium or magnesium alkylthio-enaminates generated by either deprotonation or 1,4-addition) led to ketenimines which were trapped in situ by organo-lithium or magnesium compounds to give metallated imines, readily hydrolysed into ketones.This sequence allowed the use of imidothioesters as acyl cation equivalents and also successive and regioselective > 1,3-additions of two different organometallics to an α-unsaturated imidothioester.Ar-turmerone, 2,6-dimethyl-2,7-octadien-4-one, iso-artemisia ketone, α-atlantone and other unsymmetrical ketones were synthesized by this procedure.
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.
METALLATION ET ALKYLATION DES THIOIMIDOESTERS: APPLICATION EN SYNTHESE
Masson, S.,Mothes, V.,Thuillier, A.
, p. 1573 - 1580 (2007/10/02)
Alkylation of delocalized anions resulting from metallation of N-phenyl thioimidoesters (precursors of dithioesters and thiolesters) takes place on nitrogen with "saturated" thioimidoesters (alkane thiomidates).On the contrary, unsaturated thiomidoesters (α or β-ethylenic, α-arylated) are regioselectively alkylated on the α carbon atom by alkyl or allylic halides.The possibilities for synthesis offered by successive uses of the reactivities of thioimidoester and dithioester functions (allowing in particular two electrophilic additions on two vicinal carbons) are illustrated by syntheses of terpenic compounds lavandual (and lavandulol) and ar-curcumene.
