M. Larcheveque

Asymmetric catalytic allylation of β-diketones or β-ketoesters with allylic ethers using a palladium-DIOP catalyst: A mechanistic study

Abstract Allylation of β-diketone, β-ketoesters and methine active hydrogen compounds by allyl phenyl ethers or allyl esters with palladium/phosphine catalytic systems has been studied, and a mechanism is suggested. The use of DIOP (2,3- O -isopropylidene-2,3-dihydroxy-1,4-bis(diphenylphosphino)butane) as chiral phosphine ligand produces optically active allylated compounds with up to 10% e.e.

Clivage réducteur des sulfonamides et des sulfonates par les métaux alcalins dissous dans le hmpt

Abstract Alkali metal solutions in hexamethylphosphotriamide effect the cleavage of various sulfonamides and sulfonates under mild conditions. Sulfonamides give amines in good yields: the presence of a protic cosolvent is not necessary. Sulfonates of all types (e.g. tosylate, benzylate, mesylate) give the alcohol always contaminated with a little of the corresponding hydrocarbon.

Transformation regioselective de cetones en cetols α primaires ou secondaires

Abstract The oxidation of α ketone imine carbanions gives primary α ketols from methylketones, and secondary α ketols from symmetric ketones. Secondary α ketols may also be isolated by oxidation of carbanions of methylketone oximes. By using manganese dioxide, these secondary ketols may be oxidized to α diketones.

Recherches sur les alcoylamidures de lithium. Synthèse de β hydroxy nitriles

Resume The anionic derivatives of nitriles prepared at −78° with lithium alkylamides in HMPT have been condensed with several aldehydes and ketones: β hydroxy nitriles are obtained with excellent yields.

Nouvelle synthèse de nitriles cyclaniques

Abstract Lithium diethylamide in HMPT has been used to prepare and cyclise ω-halogenated nitriles. Cyclobutane derivatives are easily obtained with good yields from δ-chloronitriles.

Preparation d’aldehydes ω Halogenes et de Dialdehydes a partir des aldimines lithiees

Abstract Metallated aldimines are prepared by means of activated lithium amides and alkylated with various ω,ω′-chlorobromoalkanes at −60°C to give, after aqueous acid hydrolysis, good yields of ω-halogenated aldehydes and dialdehydes.