Arrigo Scettri

Oxidative ring opening of furan derivatives to α,β-unsaturated γ-dicarbonyl compounds, useful intermediates for 3-oxocyclopentenes synthesis

Abstract α,β-unsaturated γ-dicarbonyl compounds, easily obtained by reaction of pyridinium chlorochromate with alkylfurans, are interesting starting materials for the rapid synthesis of 3-oxo-cyclopentenes.

Asymmetric allylation of aldehydes with allyltrichlorosilane promoted by chiral sulfoxides

Allylation of aldehydes with allyltrichlorosilane in the presence of sulfoxides is reported. The use of excess of (R)-methyl-p-tolylsulfoxide resulted in the formation of the corresponding homoallylic alcohols in good yields and moderate enantiomeric excesses.

An efficient asymmetric aldol reaction of Chan's diene promoted by chiral Ti(IV)–BINOL complex

Abstract 1,3-Bis-(trimethylsilyloxy)-1-methoxy-buta-1,3-diene (Chans diene) can be conveniently used in asymmetric aldol reaction with aromatic, heteroaromatic, α,β-unsaturated and aliphatic aldehydes in the presence of catalytic amounts (2–8% mol) of chiral Ti(IV)/( R )-BINOL complex.

A new synthesis of 3-oxocyclopentenes

Abstract 5 - Methyl - 2 - furylcarbinols 3 have been converted into 3-oxocyclopentene derivatives 4 through a molecular rearrangement catalyzed by ZnCl 2 . The reaction mechanism is explained in terms of a thermal electrocyclic reaction of a 4π electrons system. An application relative to the synthesis of (±) allethrolone is reported. reported.

Lanthanides in organic synthesis: Eu+3-catalyzed Michael addition of 1,3- dicarbonyl compounds

EuCl3 proves to be an efficient catalyst for Michael addition of 1,3-dicarbonyl compounds. The employment of Eu+3 chiral complex [Eu(tfc)3] allows the formation of Michael adducts in enantioselective way.

Enantioselective aldol condensation of 1,3-bis-(trimethylsilyloxy)-1-methoxy-buta-1,3-diene promoted by chiral Ti(IV)/BINOL complex

Abstract Enantiomerically enriched δ-hydroxy-β-ketoesters are easily available by aldol condensation of 1,3-bis-(trimethylsilyloxy)-1-methoxy-buta-1,3-diene in the presence of Ti(O-iPr)4/(S)-(−)-BINOL system. All reaction mixtures were separated by column chromatography and mostly isolated in moderate to good yields and all in high enantiomeric excesses.

A convenient approach to furan derivatives by I2-induced cyclisation of 2-alkenyl substituted 1,3-dicarbonyl compounds

Abstract 5-iodoalkyl-4,5-dihydrofurans 2 , 5-alkylidine-4,5-dihydrofurans 3 and 2,3,5-trisubstituted furans 4 are obtained through a simple sequence, involving, in the key-step, a regio- and stereoselective iodoenoletherification of 2-alkenyl substituted 1,3-dicarbonyl compounds 1 .

A convenient acid-catalyzed oxidation of sulfides to sulfoxides by t-butyl hydroperoxide

Abstract a very efficient synthesis of sulfoxides is achieved by oxidation of sulfides with t -butyl hydroperoxide catalyzed by camphorsulfonic acid.

Enantioselective aldol condensation of O-silyl dienolates to aldehydes mediated by chiral BINOL–titanium complexes

Abstract Chiral BINOL–titanium complexes have been shown to catalyze enantioselective aldol reactions between dioxinone derivatives and a set of aldehydes. The aldol adducts are isolated in good yields and high enantioselectivities. A range of substitution patterns on the O-silyl dienolate is possible: alkyl and benzyl substituents are tolerated. A simple reaction protocol is described and provides an efficient alternative to the well-known methods for conducting enantioselective Mukaiyama aldol reactions.

New procedures for the enantioselective oxidation of sulfides under stoichiometric and catalytic conditions

Abstract Acid-catalyzed oxidation of 2-furylcarbinols with hydrogen peroxide affords alternatively 2-(1-hydroperoxyalkyl)-furans 2 or 6-hydroperoxy-2H-pyran-3(6H)-ones 3. Compounds of the type 2 and 3 have been used as oxygen donors in efficient stoichiometric or catalytic procedures for the asymmetric sulfoxidation of prochiral sulfides in the presence of Ti(O-i-Pr)4/L-DET or Ti(O-i-Pr)4/(R)-BINOL/H2O systems. Positive non linear effects, (+)-NLE, were observed in the enantioselective oxidation of methyl p-tolyl sulfide, promoted by enantiomerically enriched Ti(IV)/BINOL/H2O complexes.