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An efficient, simple and general protocol for the selective hydration of terminal alkynes into the corresponding methyl ketones has been developed by using a cheap, easy-to-synthesise and sustainable Fe III -based eutectic mixture [FeCl 3  ⋅ 6H 2 O/Gly (3 : 1)] as both promoter and solvent for the hydration reaction, working: i) under mild (45 °C) and bench-type reaction conditions (air); and ii) in the absence of ligands, co-catalysts, co-solvents or toxic, non-abundant and expensive noble transition metals (Au, Ru, Pd). When the final methyl ketones are solid/insoluble in the eutectic mixture, the hydration reaction takes place in 30 min, and the obtained methyl ketones can be isolated by simply decanting the liquid Fe III -DES, allowing the direct isolation of the desired ketones without VOC solvents. By using this straightforward and simple isolation protocol, we have been able to recycle the Fe III -based eutectic mixture system up to eight consecutive times. Furthermore, the Fe III -eutectic mixture is able to promote the selective and efficient formal oxidation of internal alkynes into 1,2-diketones, with the possibility of recycling this system up to three consecutive times. Preliminary investigations into a possible mechanism for the oxidation of the internal alkynes seem to indicate that it proceeds through the formation of the corresponding methyl ketones and α-chloroketones., (© 2023 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH.)

Invited for the cover of this issue is the group of Vicente del Amo, Alejandro Presa Soto and Joaquín García-Álvarez (QuimSinSos Group) at the University of Oviedo. The image depicts the use of the Fe III -based deep eutectic mixture [FeCl 3 ⋅6 H 2 O/Gly (3:1)] (Gly = glycerol) as both promoter and solvent for the straightforward and selective hydration of alkynes, working under mild (45 °C), bench-type reaction conditions (air) and in the absence of ligands, co-catalysts or co-solvents. Read the full text of the article at 10.1002/chem.202301736., (© 2023 Wiley-VCH GmbH.)

The preparation of long-term-stable giant unilamellar vesicles (GUVs, diameter ≥ 1000 nm) and large vesicles (diameter ≥ 500 nm) by self-assembly in THF of the crystalline-b-coil polyphosphazene block copolymers [N=P(OCH2CF3)2 ]n-b-[N=PMePh]m (4 a: n=30, m=20; 4 b: n=90, m=20; 4 c: n=200, m=85), which combine crystalline [N=P(OCH2CF3)2] and amorphous [N=PMePh] blocks, both of which are flexible, is reported. SEM, TEM, and wide-angle X-ray scattering experiments demonstrated that the stability of these GUVs is induced by crystallization of the [N=P(OCH2CF3)2] blocks at the capsule wall of the GUVS, with the [N=PMePh] blocks at the corona. Higher degrees of crystallinity of the capsule wall are found in the bigger vesicles, which suggests that the crystallinity of the [N=P(OCH2CF3)2] block facilitates the formation of large vesicles. The GUVs are responsive to strong acids (HOTf) and, after selective protonation of the [N=PMePh] block, they undergo a morphological evolution to smaller spherical micelles in which the core and corona roles have been inverted. This morphological evolution is totally reversible by neutralization with a base (NEt3), which regenerates the original GUVs. The monitoring of this process by dynamic light scattering allowed a mechanism to to be proposed for this reversible morphological evolution in which the block copolymer 4 a and its protonated form 4 a(+) are intermediates. This opens a route to the design of reversibly responsive polymeric systems in organic solvents. This is the first reversibly responsive vesicle system to operate in organic media., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

New advances into the chirality effect in the self-assembly of block copolymers (BCPs) have been achieved by tuning the helicity of the chiral-core-forming blocks. The chiral BCPs {[N=P(R)-O2C20H12](200-x)[N=P(OC5H4N)2](x)}-b-[N=PMePh]50 ((R)-O2C20H12 = (R)-1,1'-binaphthyl-2,2'-dioxy, OC5H4N = 4-pyridinoxy (OPy); x = 10, 30, 60, 100 for 3 a-d, respectively), in which the [N=P(OPy)2] units are randomly distributed within the chiral block, have been synthesised. The chiroptical properties of the BCPs ([α]D vs. T and CD) demonstrated that the helicity of the BCP chains may be simply controlled by the relative proportion of the chiral and achiral (i.e., [N=P(R)-O2C20H12] and [N=P(OPy)2], respectively) units. Thus, although 3 a only contained only 5% [N=P(OPy)2] units and exhibited a preferential helical sense, 3 d with 50% of this unit adopted non-preferred helical conformations. This gradual variation of the helicity allowed us to examine the chirality effect on the self-assembly of chiral and helical BCPs (i.e., 3 a-c) and chiral but non-helical BCPs (i.e., 3 d). The very significant influence of the helicity on the self-assembly of these materials resulted in a variety of morphologies that extend from helical nanostructures to pearl-necklace aggregates and nanospheres (i.e., 3 b and 3 d, respectively). We also demonstrate that the presence of pyridine moieties in BCPs 3 a-d allows specific decoration with gold nanoparticles., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

We describe a new and very versatile method to place chosen chemical functionalities at the edge of the pores of macroporous materials. The method is based on the synthesis and self-assembly of inorganic block copolymers (BCPs) having chiral rigid segments bearing controllable quantities of randomly distributed functional groups. The synthesis of a series of optically active block copolyphosphazenes (PP) with the general formula [N=P(R-O2C20H12)(0.9)(FG)(0.2)]n-b-[N=PMePh]m (FG=-OC5H4N (6), -NC4H8S (7), and -NC4H8O (8)), was accomplished by the sequential living cationic polycondensation of N-silylphosphoranimines, using the mono-end-capped initiator [Ph3P=N=PCl3][Cl] (3). The self-assembly of the phosphazene BCPs 6-8 led to chiral porous films. The functionality present on those polymers affected their self-assembly behaviour resulting in the formation of pores of different diameters (D(n)=111 (6), 53 (7) and 77 nm (8)). The specific functionalisation of the pores was proven by decorating the films with gold nanoparticles (AuNPs). Thus, the BCPs 6 and 7, having pyridine and thiomorpholine groups, respectively, were treated with HAuCl4, followed by reduction with NaBH4, yielding a new type of block copolyphosphazenes, which self-assembled into chiral porous films specifically decorated with AuNPs at the edge of the pores., (Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A series of optically active helical polyphosphazene block copolymers of general formula R-[N=P(O2C20H12)]n-b-[N=PMePh]m (R-7 a-c) was synthesized and characterized. The polymers were prepared by sequential living cationic polycondensation of N-silylphosphoranimines using the mono-end-capped initiator [Ph3 P=N=PCl3][PCl6] (5) and exhibit a low polydispersity index (ca. 1.3). The temperature dependence of the specific optical activity ([α]D) of R-7 a,b relative to that for the homopolymers R-[N=P(O2C20H12)]n (R-8 a) and the R/S analogues (R/S-7 a,b), revealed that the binaphthoxy-phosphazene segments induce a preferential helical conformation in the [N=PMePh] blocks through a "sergeant-and-soldiers" mechanism, an effect that is unprecedented in polyphosphazenes. The self-assembly of drop-cast thin films of the chiral block copolymer R-7 b (bearing a long chiral and rigid R-[N=P(O2C20H12)] segment) evidenced a transfer of helicity mechanism, leading to the formation of twisted morphologies (twisted "pearl necklace"), not observed in the nonchiral R/S-7 b. The chiral R-7 a and the nonchiral R/S-7 a, self-assemble by a nondirected morphology reconstruction process into regular-shaped macroporous films with chiral-rich areas close to edge of the pore. This is the first nontemplate self-assembly route to chiral macroporous polymeric films with pore size larger than 50 nm. The solvent annealing (THF) of these films leads to the formation of regular spherical nanostructures (ca. 50 nm), a rare example of nanospheres exclusively formed by synthetic helical polymers., (Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A simple and convenient one-pot synthesis of THF solutions of high molecular weight poly(dichlorophosphazene) [NPCl(2)](n), or the (15)N isotopomer [(15)NPCl(2)](n), starting directly from PCl(5) and NH(4)Cl or (15)NH(4)Cl in a solution of 1,2,4-trichlorobenzene in the presence of sulfamic acid and calcium sulfate dihydrate, is described. The solutions of [NPCl(2)](n) in THF, which are obtained free of poly(tetrahydrofuran) by preparing them in the presence of K(2)CO(3), can be reacted directly with phenols, biphenols, or even HO-CH(2)CF(3) in the presence of K(2)CO(3) or Cs(2)CO(3) to obtain, after a very simple workup, the corresponding polyphosphazene derivatives almost free of chlorine.