Photoantibacterial Poly(vinyl)chloride Films Applying Curcumin Derivatives as Bio-Based Plasticizers and Photosensitizers.

Herein we describe the design of natural curcumin ester and ether derivatives and their application as potential bioplasticizers, to prepare photosensitive phthalate-free PVC-based materials. The preparation of PVC-based films incorporating several loadings of newly synthesized curcumin derivatives along with their standard solid-state characterization is also described. Remarkably, the plasticizing effect of the curcumin derivatives in the PVC material was found to be similar to that observed in previous PVC-phthalate materials. Finally, studies applying these new materials in the photoinactivation of S. aureus planktonic cultures revealed a strong structure/activity correlation, with the photosensitive materials reaching up to 6 log CFU reduction at low irradiation intensities.

Stereoisomeric Tris-BINOL-Menthol Bulky Monophosphites: Synthesis, Characterisation and Application in Rhodium-Catalysed Hydroformylation.

Four stereoisomeric monoether derivatives, based on axially chiral (R)- or (S)-BINOL bearing a chiral (+)- or (-)-neomenthyloxy group were synthesised and fully characterised by NMR spectroscopy and X-ray crystallography. The respective tris-monophosphites were thereof prepared and fully characterised. The coordination ability of the new bulky phosphites with Rh(CO)2(acac), was attested by 31P NMR, which presented a doublet in the range of δ = 120 ppm, with a 1J(103Rh-31P) coupling constant of 290 Hz. The new tris-binaphthyl phosphite ligands were further characterised by DFT computational methods, which allowed us to calculate an electronic (CEP) parameter of 2083.2 cm-1 and an extremely large cone angle of 345°, decreasing to 265° upon coordination with a metal atom. Furthermore, the monophosphites were applied as ligands in rhodium-catalysed hydroformylation of styrene, leading to complete conversions in 4 h, 100% chemoselectivity for aldehydes and up to 98% iso-regioselectivity. The Rh(I)/phosphite catalytic system was also highly active and selective in the hydroformylation of disubstituted olefins, including (E)-prop-1-en-1-ylbenzene and prop-1-en-2-ylbenzene.

A novel Pd-catalysed sequential carbonylation/cyclization approach toward bis-N-heterocycles: rationalization by electronic structure calculations.

An unprecedented palladium-catalysed sequential aminocarbonylation/cyclization synthetic strategy, using carbon monoxide and structurally different aliphatic diamines as N-nucleophiles, gives access, in one pot, to a new family of indole-based N-heterocyclic derivatives (hydropyrazinones, benzodiazepinones and hydroquinoxalines). Optimization of the reaction conditions towards double carbonylation (P CO = 30 bar, T = 80°C, iodoindole/diamine ratio = 1 : 1.5, toluene as solvent) allowed the target cyclic products, which are formed in situ via intramolecular cyclization of the ketocarboxamide intermediates, to be obtained through a nucleophilic addition/elimination reaction with the pendant terminal amine groups. The structure of the diamine nucleophile was revealed to affect the reaction's selectivity, with the best yields for the cyclic products being obtained in the presence of (1S,2S)-(+)-cyclohexane-1,2-diamine (a) as the nucleophile, using either 5- or 7-iodoindole as the substrate. The reaction's selectivity was rationalized based on electronic structure calculations, which explain the effect of the diamine structure on the predominant formation of the cyclic products.

A Cost-Efficient Method for Unsymmetrical Meso-Aryl Porphyrin Synthesis Using NaY Zeolite as an Inorganic Acid Catalyst.

Herein we report the synthesis of unsymmetrical meso-aryl substituted porphyrins, using NaY zeolite as an inorganic acid catalyst. A comparative study between this method and the several synthetic strategies available in the literature was carried out. Our method presented a better, more cost-efficient rationale and displayed a significantly lower environmental impact. Furthermore, it was possible to verify the scalability of the process as well as the reutilization of the inorganic catalyst NaY (up to 6 times) without significant yield decrease. In addition, this method was applied to the synthesis of several other unsymmetrical porphyrins, from a low melting point porphyrin to mono-carboxylated halogenated unsymmetrical porphyrins, in yields higher than those found in the literature. Additionally, for the first time, two acetamide functionalized halogenated porphyrins were prepared in high yields. This methodology opens the way to the preparation of high yielding functionalized porphyrins, which can be easily immobilized for a variety of applications, either in catalysis or in biomedicine.

Crystal structure of (R)-2'-benz-yloxy-[1,1'-binaphthalen]-2-yl tri-fluoro-methane-sulfonate.

In the title compound, C28H19F3O4S, a new 2'-benz-yloxy (R)-BINOL derivative containing a tri-fluoro-methane-sulfonate group in the 2-position, the planes of the two naphthyl ring systems (r.m.s. deviations = 0.012 and 0.019 Å) are at an angle of 73.36 (2)°, and the planes of the benzyl ring and the naphthyl ring system bound to the ether O atom are at an angle of 75.67 (4)°. In the crystal, mol-ecules are linked via C-H⋯F hydrogen bonds, forming chains propagating along [100]. The chains are linked via a weak C-F⋯π inter-action and weak π-π inter-actions [shortest inter-centroid distance = 3.9158 (12) Å], forming a three-dimensional structure. The absolute structure of the mol-ecule in the crystal was determined by resonant scattering [Flack parameter = 0.02 (6)].

Highly active phosphite gold(I) catalysts for intramolecular hydroalkoxylation, enyne cyclization and furanyne cyclization.

New and highly active mononuclear phosphite gold(I) catalysts are described. Turn-over numbers up to 37,000 for the furan-yne reaction and up to 28,000,000 for the two-fold hydroalkoxylation of alkynes are reported.

Synthesis of binaphthyl based phosphine and phosphite ligands.

The development of large scale synthesis of enantiopure and thermally stable (R)- and (S)-BINOL molecules constitutes a key milestone in the field of asymmetric catalysis. Particularly, a great variety of chiral binaphthyl-based phosphorus compounds, herein represented by phosphite and phosphine classes, have earned considerable relevance due to their versatility as ligands in enantioselective metal-catalysed reactions, allowing the preparation of optically active products with the desired enantiopurity. This review highlights the most relevant concepts and accounts regarding general synthetic procedures for binaphthyl-based mono- and bidentate phosphites and phosphines. Furthermore, the search for environmentally benign chemical catalytic processes compelled us to also give special attention to the functionalisation of binaphthyl-based phosphorus ligands for use in alternative reaction media. When available, a critical selection of their applications in catalysis is briefly assessed.

2,2'-Bis(meth-oxy-meth-oxy)-3-methyl-1,1'-binaphth-yl.

The title compound, C(25)H(24)O(4), a meth-oxy-methyl (MOM) bis-protected BINOL derivative containing a methyl substituent in position 3, is a key inter-mediate for the synthesis of a great variety of chiral auxiliaries. The planes of the naphthyl aromatic rings are at an angle of 70.74 (3)°. There are no conventional hydrogen bonds binding the mol-ecules.