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An anthracenyl-modified chiral bis(oxazoline) copper complex has been demonstrated to efficiently promote nitroaldol reactions between structurally varying aldehydes and nitromethane or nitroethane. The catalyst was recovered through formation of a charge transfer complex between the chiral ligand and trinitrofluorenone and its subsequent precipitation with pentane. The efficiency of this procedure was proved through several consecutive catalytic cycles that allowed the sturdy formation of the expected product with a high enantioselectivity. The catalyst′s stability was also put to the test in an original multi-substrate procedure. Following the same recovery concept, a new heterogeneous procedure was tested for which trinitrofluorenone was covalently linked to a silica support. Asymmetric heterogeneous catalysis was performed under these conditions as one of the few examples demonstrating the potential catalyst recycling in nitroaldol reactions through reversible, non-covalent interactions.

Stereochemically-biased bicyclic allylic acetates endo- and exo-1 were shown as being allyl donors for Pd-catalyzed carbonyl allylation using stoichiometric quantities of samarium diodide. Cyclopentenyl acetate and bicyclic derivatives 1 react with cyclic ketones in the presence of SmI2 without requirement of palladium catalysis. Use of enantiomerically enriched substrate suggests that the reaction goes through a π-allyl samarium complex. However, this reactivity appears to be restricted to strained cyclopentenyl acetates since other linear and cyclic allylic acetates do not give the carbonyl allylation product.

The transformation of N-acyloxazolidinones into esters is readily performed using catalytic amounts of samarium diiodide in tetrahydrofuran at room temperature. This method allows the isolation of various esters without racemization in the case of scalemic substrates and the recovery of oxazolidinones in good yields.

The transformation of N-acyloxazolidinones into esters is readily performed using catalytic amounts of samarium diiodide in tetrahydrofuran at room temperature. This method allows the isolation of various esters without racemization in the case of scalemic substrates and the recovery of oxazolidinones in good yields.

International audience; The first examples of assembling monodentate oxazoline donor and acceptor ligands by charge transfer interactions are described to mimic bidentate ligands in asymmetric catalysis. The corresponding copper(II) complexes were used in an enantioselective Diels-Alder reaction and showed very high efficiency, but only moderate stereoselectivity. These complexes were successfully recovered and reused after precipitation in pentane.

Vinyl tridecafluorohexyl sulfoxide 1 and sulfone 2 are shown to be highly reactive towards Michael addition with a broad range of secondary and primary amines. Full selectivity for monofunctionalization of primary amines can be achieved by a proper choice of reagent 1 or 2 depending on amine basicity.