Esther d'Incan

Electrosynthesis of alcohols from organic halides and ketones or aldehydes

Abstract The electrosynthesis of a wide range of alcohols from organic halides and ketones or aldehydes is achieved under simple and mild conditions in an undivided electrolytic cell using different sacrificial anodes.

Electrosynthesis of ketones from organic halides and anhydrides

Abstract The electroreduction of benzylic and allylic halides in the presence of anhydrides affords ketones in moderate to good yields. The electrolysis is performed in an undivided cell, under constant current, using an aluminium or magnesium anode.

Electroreductive coupling of methallylchloride or methyl chloroacetate with carbonyl compounds catalyzed by nickel bipyridine complexes

Abstract An efficient electrosynthesis of homoallyl alcohols or β-hydroxy esters in the presence of catalytic amounts of the NiBr 2 (2,2′-bipyridine) complex has been developped from mixed electrolysis of methallylchloride, or methylchloroacetate with several carbonyl compounds, using a one-compartment cell equiped of a sacrificial zinc anode.

Selectivite de la reduction de l'androsten-4 dione-3,17 et de la progesterone par divers borohydrures: role de l'assistance electrophile par le cation ou un solvant hydroxyle

Abstract The reduction of Δ 4 -androsten-3, 17 dione 1 and of progesterone 2 by n Bu 4 NBH 4 is highly chemioselective: in THF only the a -enone moiety is reduced, the saturated C 17 or C 20 keto group being kept unchanged. When TMEDA is added, saturated alcohols are obtained, without any allylic alcohol when the reaction goes to completion. However this reduction is poorly stereoselective as 70:30 mixtures of A/B cis and trans ring junction compounds are obtained. In MeOH, the saturated keto group is more than 90% selectively reduced. However, the reduction of 1 and 2 by LiBH 4 and Zn(BH 4 ) 2 is poorly chemioselective. These results are interpreted in terms of competition between electrophilic assistance and steric effects.

Borohydride reduction of Δ1,9 2-octalone: Cation influence and amine addition effects

Abstract Proton removal of Δ 1,9 2-octalone ocaurs uhen reacted with NBu 4 BH 4 in aprotic solvents while 1-2 reduction is important uith NaBH 4 in THF. Both are inhibited uhen NaBH 4 reduction is performed in the presence of amines, leading thus to highly selective formation of saturated alcohols.

Nickel-catalysed electroreductive coupling of α-halogenoesters with aryl or vinyl halides

β, γ-Unsaturated esters are obtained in moderate to good yields by a one-step electrochemical procedure from α-chloroesters and aryl or vinyl halides; a sacrificial aluminium anode, dimethylformamide as solvent, and a catalytic amount of nickel bromide-2,2′-bipyridine complex are used.

Electroformylation of organic halides in N,N-dimethylformamide: an efficient electrosynthesis of aldehydes

In a cell fitted with a sacrificial magnesium anode and a modified cathode, the electroreduction of organic halides in N,N-dimethylformamide (DMF) gives aldehydes in good yields.

Selectivite de la reduction d'α-enones polycycliques par les borohydrures: effet de l'addition de tetramethyl-ethylenediamine au borohydrure de tetrabutylammonium

Abstract ‡1,9octalone, ‡1,9-10-methyl octalone and testosterone were reduced by NBu4BH4. alone or in the presence of tetramethylethylenediamine (TMEDA), in THF and in toluene. With TMEDA, the first step of the reduction is the regioselective 1,4 attack by BH−4 which leads either to the saturated ketones or to the corresponding saturated alcohols. The results observed under different conditions were interpreted by the intervention of various reductive species: diborane, enoxyborohydrides in the absence of TMEDA, amine-borane in its presence.

Sand-supported organic reactions: NaBH4 reduction of carbonyl compounds

‘Fontainebleau sand’ is an efficient support for the NaBH4 reduction of carbonyl compounds in the absence of organic solvent.