The worldwide urge to embrace a sustainable and bio-compatible chemistry has led industry and academia\ud to develop of chlorine-free methodologies focused on the use of CO2 and CO2-based compounds\ud as feedstocks, promoters and reaction media. In this scenario, dialkyl carbonates (DACs) and in particular\ud dimethyl carbonate (DMC) occupy a privileged position due to their low toxicity, high biodegradability and\ud peculiar reactivity. Nowadays, the large-scale production of DACs is carried out through clean processes\ud (i.e., phosgene-free processes), which include the direct insertion of CO2 into epoxides, allowing – in\ud principle – recycling of the carbon dioxide emitted during carbonate degradation. This groundbreaking\ud achievement has definitely drawn attention toward the conception of procedures to activate the rather\ud stable DACs with the aim of employing these compounds as green alternatives to their reactive chlorinated\ud analogues. DACs are ambident electrophiles, which under appropriate conditions can undergo\ud BAc2- or BAl2-nucleophilic substitution to give, respectively, alkoxycarbonylation and alkylation reactions.\ud The many efforts devoted to improving the industrial suitability of organic carbonates have unveiled an\ud intriguing and innovative chemistry as demonstrated by the numerous publications and patents published\ud on these compounds over the last thirty years. This review reports on DACs as alkoxycarbonylating agents\ud and their applications in industry and fine synthesis, as well as alkylating agents including allylic alkylation\ud using palladium catalysts and the Pd/Ti bimetallic system and anchimerically driven alkylations via mustard\ud carbonates. Moreover, the reactivity of organic carbonates toward several substrates and under different\ud reaction conditions is described along with some distinctive DAC-mediated cyclization and transposition\ud reactions. The synthesis of olefins and ethers under both liquid and gas phase conditions via thermal decarboxylation\ud of organic carbonates is also reported

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The published data on dimethyl carbonate as a The published data on dimethyl carbonate as a non-toxic reagent and solvent in organic synthesis are non-toxic reagent and solvent in organic synthesis are generalized and discussed. The methods for dimethyl generalized and discussed. The methods for dimethyl carbonate production and its use as a methylating and carbonate production and its use as a methylating and methoxycarbonylating agent are considered. Special atten-methoxycarbonylating agent are considered. Special attention is paid to the eco-friendly processes that meet the tion is paid to the eco-friendly processes that meet thè Green chemistry' requirements. The bibliography includesGreen chemistry' requirements. The bibliography includes 104 references 104 references. . 2 MeOH + 1 2 O2 + CO Cu salt MeOCO2Me + H2O. F AricoÁ , P Tundo Interuniversity Consortium`Chemistry for the Environment', Via delle Industrie, Marghera 21/8,

Dimethyl isosorbide (DMI)a well-known biobased high boiling green solventwas used for the first time in the preparation of poly­(vinylidene fluoride)- and poly­(ether sulfone)-based membranes. Preliminary thermodynamic (Hansen and Hildebrand solubility parameters, relative energy difference) and kinetic (viscosity) studies on DMI confirmed that this solvent possesses the required physical/chemical properties to be exploited in casting membranes. Membranes were prepared by nonsolvent induced phase separation (NIPS) and a combination of vapor induced phase separation (VIPS)-NIPS techniques varying the exposure time to humidity. This latter approach led to the formation of membranes with a porous architecture avoiding the use of any pore forming additive. The so-prepared membranes were, then, fully characterized in terms of morphology, polymorphism (in case of PVDF), wettability, thickness, porosity, pore size, and water permeability. The membranes revealed different structures and a tunable pore size in the range of ultrafiltration (UF) and microfiltration (MF) that render them ideal for applications in water treatment processes.

Recently, the versatility of dynamic covalent chemistry (DCC) 1 has been demonstrated 2 in the multicomponent construction of complex mechanically interlocked compounds, such as molecular bundles 3 and nanoscale Borromean rings, 4 as well as in the highly efficient template-directed synthesis 5 of [2]rotaxanes. 6 Previously, we have reported 7 that, by employing DCC in the form of reversible imine bond formation, [2]rotaxanes with dialkylammonium ion (-CH 2 NH 2 + CH 2 -) recognition sites 8 encircled by [24]crown-8 macrocycles can be prepared in high yields by a thermodynamically controlled, templated self-assembly process, that is, a kind of clipping procedure (Figure 1), as a result of the mixing together of three different components, namely, a dialdehyde, a diamine, and a dumbbell compound containing a -CH 2 NH 2 + CH 2 -center to template the [2]rotaxane formation. 7 In the context of constructing mechanically interlocked dendrimers 9,10 by employing a convergent templation procedure, we have explored 11 the feasibility of using DCC to introduce dendrons onto multivalent cores carrying -CH 2 NH 2 + CH 2 -centers on their sidearms to act as "hooks" round which "eyes" in the shape of diimine-containing [24]crown-8 macrocycles can be constructed in an activating environment. We report herein that dendritic dialdehydes 1a-c from generation zero [G0] to generation two [G2], the diamine 2, and the trisammonium salt 3-H 3 ‚3PF 6 can be self-assembled (Scheme 1) as three collections of seven components, each in one-pot, under equilibrium conditions to afford the imine-containing [G0]-[G2] mechanically interlocked dendrimers 4a-c-H 3 ‚3PF 6 in yields in excess of 90%. These dynamic dendrimers can be converted into their kinetically stable, neutral amine-containing dendrimers 5a-c by reduction (fixation) of the imine bonds using the BH 3 ‚THF complex as the reducing agent, and then subsequently isolated as their fully protonated counterparts 5a-c-H 3 ‚3TFA after acidification with trifluoroacetic acid (H-TFA). 12 (see Supporting Information), the diamine 2 7 and the trisammonium salt 3-H 3 ‚3PF 6 1m were prepared according to procedures already described in the literature. The template-directed formation 5 of the [G0]-[G2] dendrimers requires only the mixing of 3 molar equiv of dendritic dialdehydes 1a-c with 3 molar equiv of the diamine 2 and 1 molar equiv of the dialkylammonium salt 3-H 3 ‚3PF 6 in either CD 3 CN or CD 3 NO 2 (concentration ∼35 mM) at room temperature. Such clipping experiments were monitored directly by 1 H NMR spectroscopy. By way of an example, Figure 2 shows (upper trace) the 1 H NMR spectrum (500 MHz, CD 3 NO 2 , 298 K) of the dynamic [G2]-dendrimer 4c-H 3 ‚3PF 6 recorded 5 min after mixing the three components in the requisite amounts (3:3:1 for 1:2:3-H 3 ‚3PF 6 ). The spectrum can be interpreted in terms of trace amounts of the starting materials plus the dynamic [G2]-dendrimer While the [G0]-[G2] dendritic dialdehydes 1a-c were obtained from their corresponding [G0]-[G2] dendritic brom...

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In this review the reactivity of the bio-based platform compounds D-sorbitol and isosorbide with green reagents and solvent dimethyl carbonate (DMC) is reported. Dehydration of D-sorbitol via DMC in the presence of catalytic amounts of base is an efficient and viable process for the preparation of the industrially relevant anhydro sugar isosorbide. This procedure is “chlorine-free”, one-pot, environmental friendly and high yielding. The reactivity of isosorbide with DMC is equally interesting as it can lead to the formation of dicarboxymethyl isosorbide, a potential monomer for isosorbide-based polycarbonate, and dimethyl isosorbide, a high boiling green solvent. The peculiar reactivity of isosorbide and the non-toxic properties of DMC represent indeed a green match leading to several industrial appealing potential applications.

Der Nicht‐Häm‐Eisen(III)‐Komplex [(PaPy3)Fe(NO2)](ClO4) (1) überträgt in Acetonitril bei 45–65 °C Sauerstoff auf PPh3 unter Bildung von OPPh3. Das Produkt, [(PaPy3)Fe(NO)](ClO4), eine {Fe‐NO}7‐Spezies, bildet in Gegenwart von Disauerstoff rasch wieder den ursprünglichen Komplex 1, was dem System katalytischen Charakter verleiht (siehe Schema). Durch Bildung einer Oxo‐verbrückten Spezies wird der Sauerstoff‐Transfer abgebrochen. PaPy3H=N‐[N,N‐Bis(2‐pyridylmethyl)aminoethyl]‐2‐pyridincarboxamid.