Benzo-Fused 1,4-Heterocycles via Dialkyl Carbonate Chemistry

A novel halogen-free synthesis of benzo-fused six-membered 1,4-heterocycles through the chemistry of dialkyl carbonates is reported. Commercially available catechol, 2-aminophenol, and 2-aminothiophenol were reacted first with ethylene carbonate in an autoclave to give O -hydroxyethyl, N -hydroxyethyl, and S -hydroxyethyl derivatives respectively, through a B Al 2 mechanism. Then 2-(2-hydroxyethoxy)phenol and 2-(2-hydroxyethylamino)phenol were cyclized in excellent yields by reaction with dimethyl carbonate (DMC) and DABCO as a bicyclic organic base to give the corresponding benzodioxine and benzoxazine derivative, respectively. Moreover, 2-(2-aminophenylthio)ethanol afforded the benzothiazine derivative in good yield by reaction with DMC with an excess of a strong base such as NaH. The investigation on the cyclization reaction has highlighted that several equilibria are involved leading to the formation of carbonate and carbamate intermediates through B Ac 2 mechanisms. Depending on the reaction conditions employed, these intermediates may undergo either kinetic-controlled ring closure by a B Al 2 mechanism or by-product formation

Recent studies of docking and molecular dynamics simulation for liquid‐phase enantioseparations

Liquid‐phase enantioseparations have been fruitfully applied in several fields of science. Various applications along with technical and theoretical advancements contributed to increase significantly the knowledge in this area. Nowadays, chromatographic techniques, in particular HPLC on chiral stationary phase, are considered as mature technologies. In the last thirty years, CE has been also recognized as one of the most versatile technique for analytical scale separation of enantiomers. Despite the huge number of papers published in these fields, understanding mechanistic details of the stereoselective interaction between selector and selectand is still an open issue, in particular for high‐molecular weight chiral selectors like polysaccharide derivatives. With the ever growing improvement of computer facilities, hardware and software, computational techniques have become a basic tool in enantioseparation science. In this field, molecular docking and dynamics simulations proved to be extremely adaptable to model and visualize at molecular level the spatial proximity of interacting molecules in order to predict retention, selectivity, enantiomer elution order, and profile noncovalent interactions patterns underlying the recognition process. On this basis, topics and trends in using docking and molecular dynamics as theoretical complement of experimental LC and CE chiral separations are described herein. The basic concepts of these computational strategies and seminal studies performed over time are presented, with a specific focus on literature published between 2015 and November 2018. A systematic compilation of all published literature has not been attempted

«We are come to this great stage of fools»: «Lear», ossia Shakespeare nel Novecento

Il saggio affronta un'opera del secondo Novecento che quasi entrata nel repertorio, e che i grandi teatri danno abitualmente. Si tratta del'adattamento per le scene liriche di una fra i drammi più sconvolgenti del Bardo, King Lear, soggetto già vagheggiato da Verdi. Lear del compositore tedesco Aribert Reimann,, andò in scena a Monaco di Baviera nel 1978, con Fischer-Dieskau nel ruolo del protagonista. La partitura è complessa, lo stile eclettico, ma la resa a teatro è davvero ragguardevole. Il saggio si chiude con una guida alla difficilissima partitura d'orchestra.The essay deals with a work of the late twentieth century that almost entered the repertoire, and which the great theaters usually give. This is the adaptation for the lyrical scenes of one of the most disturbing dramas of the Bardo, King Lear, a subject already envisaged by Verdi. Lear by the German composer Aribert Reimann ,, went on stage in Munich in 1978, with Fischer-Dieskau in the title role. The score is complex, the style is eclectic, but the performance at the theater is really remarkable. The essay ends with a guide to the extremely difficult orchestral score

Valentine de Saint-Point au Japon à l'ère Taishō: le rôle de Tai Kanbara

Dans cette contribution, je voudrais analyser une dernière facette de la réception de l’œuvre de Valentine de Saint-Point, non pas dans le cadre de l’histoire littéraire française, européenne ou « occidentale », mais dans le contexte japonais, durant la seconde moitié de l’ère Taishō (1912-1926). C’est donc un autre type de lecture que je souhaiterais aborder ici, pour analyser les effets d’une réception singulière, marquée par un effet de perspective à la fois géographique et culturel. Plus précisément, je vais me concentrer sur l’entre-deux-guerres et en particulier sur les textes d’un des plus importants experts japonais des avant-gardes européennes de cette époque : Tai Kanbara (1898-1997), qui fut un lecteur attentif de Valentine de Saint-Point