A convenient electrochemical methodology for the hydrogenation of benzoxazinones and aryl-substituted α-ketoester substrates is presented, using carbon electrodes sustainable Brønsted acids.

In the last few years we demonstrated the utility of the phthalimidesulfenyl chloride (PhthNSCl, Phth = Phthaloyl) mediated generation of α,α’-dioxothiones and several related thiocarbonyl species. These reactive thione derivatives can be used as efficient electron-poor dienes in inverse electron demand Diels-Alder reactions with a plethora of electron rich alkenes, giving rise to interesting s...

Isoxazole-5(4H)-ones are heteropentacycle compounds found in several bioactive molecules with pharmaceutical and agrochemical properties. A well-known multicomponent reaction between β-ketoester, hydroxylamine, aromatic aldehydes leads to 3-methyl-4-arylmethylene isoxazole-5(4H)-ones, mild conditions. The initial purpose of this work was investigate whether the might be induced by light, as des...

Highly efficient asymmetric aldol reactions between α,β-unsaturated keto esters and acyclic ketones catalyzed by chiral diamines are reported. The corresponding products were obtained in excellent yields with excellent enantioselectivities. The absolute configuration for the product was determined by X-ray analysis. A variety of substrates were tolerable in the present catalytic system.

A total synthesis of the antimalarial indolo[3,2-j]phenanthridine alkaloid calothrixin B is reported. The key intermediate, ketoester 11, was assembled using sequential Sonogashira coupling and intra/intermolecular fashioned copper-catalyzed oxidative cyclization reactions.

A concise approach to the algal metabolite 1 is described, which also determines the previously unknown stereostructure of this natural product. Compound 1 is distinguished by a rare brominated 4-pyrone nucleus linked as a ketene-acetal to a polyunsaturated macrocyclic scaffold comprising an extra homoallylic bromide entity. The synthesis of 1 is based on the elaboration and selective functiona...

The cyclization of a ribose-derived pentenose oxime with various halogen electrophiles showed bromine to be the most effective reagent, leading to 80% of L-lyxo/D-ribo-pyrroline N-oxides in an 84:16 diastereomeric ratio. In order to explore the scope of this facile process, several other γ ,δ unsaturated oximes were submitted to this reaction. Depending on the substitution pattern, 23 – 87%, yi...

This communication reports a significant breakthrough on the novel catalytic amide allylation to the acyclic α-ketoester systems, achieving satisfactorily high yields and extremely high levels of the asymmetric induction to allow for highly enantioselective synthesis of ester functionalised α-methylene-γ-butyrolactones.