Diallyl Carbonate Research Articles

Increased onset temperature of expansion in thermally expandable microspheres through combination of crosslinking agents

AbstractFree‐radical suspension polymerization was used to synthesize thermally expandable microspheres (TEMS) in which a poly(acrylonitrile‐co‐methacrylonitrile) shell encapsulates isooctane. TEMS were prepared with 1,4‐butanediol dimethacrylate (BDDMA), in combination with 1,4‐butanediol divinyl ether (BDDVE), diallyl carbonate (DAC), or allyl methacrylate, as crosslinkers. It was found that a significant increase in the onset temperature of expansion (Tstart) could be obtained when a combination of BDDMA and BDDVE or DAC was used, compared to when only BDDMA was used as crosslinker. The expansion capacity of the TEMS was excellent when BDDMA and DAC were combined. One benefit of the increased Tstart was demonstrated when poly(vinyl chloride)‐plastisols containing TEMS could be cured at higher temperatures without premature expansion. The differences in expansion obtained with different combinations of crosslinkers originate from the difference in reactivity of the vinyl‐functionalities of the crosslinkers, which regulate the incorporation of the crosslinker into the polymer and thereby, the mechanical properties of the microsphere shell. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Enzymatic Desymmetrization of Prochiral 2-Substituted-1,3-Diamines: Preparation of Valuable Nitrogenated Compounds

A wide range of prochiral 1,3-diamines were first efficiently synthesized and subsequently desymmetrized by using lipase from Pseudomonas cepacia as catalyst and diallyl carbonate as alkoxycarbonylating agent. In all cases, the amino carbamates of R-configuration were recovered. Final selective cleavage of the N-allyloxycarbonyl moiety was carried out under mild reaction conditions, which demonstrates the high versatility and potential of this chemoenzymatic route as a source of intermediates in the synthesis of related optically active nitrogenated derivatives.

Efficient access to enantiomerically pure cyclic α-amino esters through a lipase-catalyzed kinetic resolution

A series of α-amino acid derivatives containing the 2,3-dihydroindole or octahydroindole core have been chemoenzymatically synthesized in good overall yields and high enantiomeric purity under mild reaction conditions using lipases for the introduction of chirality. Candida antarctica lipase type A has shown excellent activity and high enantiodiscrimination ability toward the two cyclic amino esters used as substrates. The selectivity of the process proved to be greatly dependent on the alkoxycarbonylating agent. Thus, the enzymatic kinetic resolution of methyl indoline-2-carboxylate has been successfully achieved using 3-methoxyphenyl allyl carbonate, whereas (2 R,3a R,7a R)-benzyl octahydroindole-2-carboxylate required the less reactive diallyl carbonate.

Three-Dimensional Hierarchically Organized Magnetic Nanoparticle Polymer Composites: Achievement of Monodispersity and Enhanced Tensile Strength

Synthesis of monodisperse polymer−inorganic nanoparticle composites and the study of their mechanical properties are described. Surface-modified MPt (M = Fe, Ni) nanoparticles undergo hydrosilation reaction with siloxane backbones and make covalent networks by acting as crosslinkers. Monodispersity and the spatial resolution of nanoparticles were identified with atomic force microscopy and transmission electron microscopy. The properties of covalent bonding in the elastomeric network between nanoparticles, allyl-modified dopamine, and siloxane backbones were studied with X-ray photoelectron spectroscopy and IR. The added amount of dopamine-modified FePt nanoparticles affected the crosslinking density in the siloxane backbones. The intensity of Si−H bonding was decreased in IR spectra with increasing density of FePt nanoparticles. Mechanical properties were measured with nanoindentation. FePt nanoparticle polymer composites have more enhanced tensile strength (Er = 1.56 GPa, H = 0.126 GPa) than simple elastomers crosslinked with diallyl carbonate (Er = 0.67 GPa, H = 0.115 GPa). Further improvement of mechanical strength was achieved with increased amount of dopamine-modified nanoparticles due to the increase in the crosslinking density between siloxane backbones.

First Desymmetrization of 1,3-Propanediamine Derivatives in Organic Solvent. Development of a New Route for the Preparation of Optically Active Amines

The chemical synthesis and enzymatic desymmetrization of a panel of prochiral diamines have been successfully described for the first time using lipases in organic solvents. A family of 2-aryl-1,3-propanediamines has been obtained with high enantiopurity and good yields in the PSL-catalyzed reaction using diallyl carbonate in 1,4-dioxane.

Total Synthesis of (±)-Jiadifenin and Studies Directed to Understanding Its SAR: Probing Mechanistic and Stereochemical Issues in Palladium-Mediated Allylation of Enolate-Like Structures

The total synthesis of jiadifenin has been accomplished. The synthesis allows us to build an SAR profile which suggests that the jiadifenin skeleton may be less desirable from the standpoint of nominating a potential drug than that of its prerearrangement precursor. The key steps of the jiadifenin problem involve the construction of two 1,3-related quaternary carbons. The paper describes how the stereochemistry was managed in this context. The issue was studied in considerable detail at the level of a then new allyl transfer reaction arising from a palladium-mediated transfer process of an allyl carbonate. By use of externally deuterated diallyl carbonate, we could probe, for the first time, the stereochemical relationship between the inter- and intramolecular versions of this process. The existence of concurrent inter- and intramolecular allylation reactions was demonstrated by deuteration experiments. While in the particular case at hand, we find very little difference in stereochemical outcome as one partitions between the inter- and intramolecular pathways, the techniques employed are applicable to other systems.

Mechanism of Formation of Organic Carbonates from Aliphatic Alcohols and Carbon Dioxide under Mild Conditions Promoted by Carbodiimides. DFT Calculation and Experimental Study

Dicyclohexylcarbodiimide (CyN=C=NCy, DCC) promotes the facile formation of organic carbonates from aliphatic alcohols and carbon dioxide at temperatures as low as 310 K and moderate pressure of CO2 (from 0.1 MPa) with an acceptable rate. The conversion yield of DCC is quantitative, and the reaction has a very high selectivity toward carbonates at 330 K; increasing the temperature increases the conversion rate, but lowers the selectivity. A detailed study has allowed us to isolate or identify the intermediates formed in the reaction of an alcohol with DCC in the presence or absence of carbon dioxide. The first step is the addition of alcohol to the cumulene (a known reaction) with formation of an O-alkyl isourea [RHNC(OR')=NR] that may interact with a second alcohol molecule via H-bond (a reaction never described thus far). Such an adduct can be detected by NMR. In alcohol, in absence of CO2, it converts into a carbamate and a secondary amine, while in the presence of CO2, the dialkyl carbonate, (RO)2CO, is formed together with urea [CyHN-CO-NHCy]. The reaction has been tested with various aliphatic alcohols such as methanol, ethanol, and allyl alcohol. It results in being a convenient route to the synthesis of diallyl carbonate, in particular. O-Methyl-N,N'-dicyclohexyl isourea also reacts with phenol in the presence of CO2 to directly afford for the very first time a mixed aliphatic-aromatic carbonate, (MeO)(PhO)CO. A DFT study has allowed us to estimate the energy of each intermediate and the relevant kinetic barriers in the described reactions, providing reasonable mechanistic details. Calculated data match very well the experimental results. The driving force of the reaction is the conversion of carbodiimide into the relevant urea, which is some 35 kcal/mol downhill with respect to the parent compound. The best operative conditions have been defined for achieving a quantitative yield of carbonate from carbodiimide. The role of temperature, pressure, and catalysts (Lewis acids and bases) has been established. As the urea can be reconverted into DCC, the reaction described in this article may further be developed for application to the synthesis of organic carbonates under selective and mild conditions.

Catalytic Asymmetric Synthesis of Optically Active Atropisomeric Anilides Through Enantioselective N‐Allylation with Chiral Pd‐tol‐BINAP Catalyst.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Catalytic asymmetric synthesis of optically active atropisomeric anilides through enantioselective N-allylation with chiral Pd-tol-BINAP catalyst.

Catalytic asymmetric N-allylation reaction of ortho-tert-butylanilide derivatives with diallyl carbonate proceeds in the presence of tol-BINAP-Pd catalyst to give chiral N-allyl ortho-tert-butylanilides of 32-44%ee in excellent chemical yields (> or = 90%).

Coordination Chemistry of Ester-Functionalized Cp Ligands. The Atom-Economy Synthesis of Na[C5H4CO2(CH2)2OH] and Solid State Structures of [Rh{C5H4CO2(CH2)2OH}(CO)2] and [Rh2{μ-(C5H4CO2CH2)2}(NBD)2

The one-step synthesis of Na[C5H4CO2CH2CHCH2] (1) from NaCp and diallyl carbonate is presented together with a simple pathway for the synthesis of sodium hydroxyalkoxycarbonylcyclopentadienide, Na[C5H4CO2(CH2)2OH] (2). The latter new reagent is obtained in high yield by reacting NaCp with 1,3-dioxolan-2-one (ethylene carbonate). When (±)-4-methyl-1,3-dioxolan-2-one [(±)-1,2-propylene carbonate] is used, the ring-opening reaction leads to a mixture of the two regioisomers Na[C5H4CO2CH2CH(Me)OH] (3a) and Na[C5H4CO2CH(Me)CH2OH] (3b) in a 7:3 ratio. Reactions of 1 and 2 with FeCl2 and [Rh(L,L)Cl]2 [L,L = CO or L,L = 2,5-norbornadiene (NBD)] lead to the respective metal complexes [Fe(C5H4CO2CH2CHCH2)2] (4), [Fe{C5H4CO2(CH2)2OH}2] (5), [Rh(C5H4CO2CH2CHCH2)(CO)2] (6), [Rh{C5H4CO2(CH2)2OH}(CO)2] (7), and [Rh{C5H4CO2(CH2)2OH}(NBD)] (8). Additionally in the reaction of 2 with [Rh(L,L)Cl]2 the diester-bridged dinuclear adducts [Rh2{μ-(C5H4CO2CH2)2}(L,L)2] [L,L = CO (9); L,L = NBD (10)] are isolated. The reaction of ...

Investigations into free radical polymerizations of allyl carbonates—II. An mndo study of hydrogen atom abstraction by hydroxyl radical

Semi-empirical molecular orbital calculations using the MNDO Hamiltonian were performed for the reaction of hydroxyl radical with diethylene glycol bis (allyl carbonate) [CR39] (1), methyl allyl carbonate (4), ethyl allyl carbonate (5), diallyl carbonate (6), isobutyl allyl carbonate (7), methoxy ethyl allyl carbonate (8) and ethoxy ethyl allyl carbonate (9). In contrast with what has generally been believed to be the preferred site of hydrogen abstraction in (1), and in agreement with our experimental results, hydrogen abstraction from C8 is found to be preferred over abstraction at C3, the allylic position.

Crosslinking of polyol(allylcarbonates) by gamma radiation

Polyolallylcarbonate networks were synthesized in a vacuum at room temperature, with gamma irradiation, in a quiescent radical crosslinking polymerization. The polyfunctional monomers studied here were: diallylcarbonate (DAC), monoethylene glycol bis-allylcarbonate (MEGBAC), propylene glycol bis-allylcarbonate (PGBAC), dipropylene glycol bis-allylcarbonate (DPGBAC) and tris-allylcarbonate of glycerol (TACG). The results of the sol-gel analysis of irradiated monomers and characterization by IR, elemental analysis and GPC of different extracted fractions were that polyol(allylcarbonate of crosslinking via their π-bonds (allylic group). The gelation doses are a function of the monomer reactivities, and of the monomer's chemical composition. TACG was the most reactive, while DAC crosslinked at the highest irradiation doses.

Catalytic allylation of 1-trimethylsilyloxycyclopent-1-ene into 2-allylcyclopentanone over palladium supported on silica

1-Trimethylsilyloxycyclopent-1-ene can be catalytically converted into 2-allylcyclopen-tanone through reaction with diallyl carbonate over palladium supported on silica. The selection of solvent was crucial, ethylene glycol dimethyl ether being the most effective solvent giving 74.9% yield of 2-allylcyclopentanone and 95.7% selectivity over palladium (4.1 wt.%) supported on silica at 333 K for 24 h. The catalytic activity depended strongly on the dispersion of palladium.

ChemInform Abstract: Catalytic Allylation of 1‐Trimethylsilyloxycyclopent‐1‐ene into 2‐Allylcyclopentanone Over Palladium Supported on Silica.

ChemInformVolume 21, Issue 40 Isocyclic Compounds ChemInform Abstract: Catalytic Allylation of 1-Trimethylsilyloxycyclopent-1-ene into 2-Allylcyclopentanone Over Palladium Supported on Silica. T. BABA, T. BABA Grad. School Sci. Technol., Kobe Univ., Rokkodai, Kobe 657, JapanSearch for more papers by this authorK. NAKANO, K. NAKANO Grad. School Sci. Technol., Kobe Univ., Rokkodai, Kobe 657, JapanSearch for more papers by this authorS. NISHIYAMA, S. NISHIYAMA Grad. School Sci. Technol., Kobe Univ., Rokkodai, Kobe 657, JapanSearch for more papers by this authorS. TSURYA, S. TSURYA Grad. School Sci. Technol., Kobe Univ., Rokkodai, Kobe 657, JapanSearch for more papers by this authorM. MASAI, M. MASAI Grad. School Sci. Technol., Kobe Univ., Rokkodai, Kobe 657, JapanSearch for more papers by this author T. BABA, T. BABA Grad. School Sci. Technol., Kobe Univ., Rokkodai, Kobe 657, JapanSearch for more papers by this authorK. NAKANO, K. NAKANO Grad. School Sci. Technol., Kobe Univ., Rokkodai, Kobe 657, JapanSearch for more papers by this authorS. NISHIYAMA, S. NISHIYAMA Grad. School Sci. Technol., Kobe Univ., Rokkodai, Kobe 657, JapanSearch for more papers by this authorS. TSURYA, S. TSURYA Grad. School Sci. Technol., Kobe Univ., Rokkodai, Kobe 657, JapanSearch for more papers by this authorM. MASAI, M. MASAI Grad. School Sci. Technol., Kobe Univ., Rokkodai, Kobe 657, JapanSearch for more papers by this author First published: October 2, 1990 https://doi.org/10.1002/chin.199040138AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume21, Issue40October 2, 1990 RelatedInformation

Catalytic allylation of 1-trimethylsilyloxycyclopent-1-ene into 2-allylcyclopentanone over palladium supported on silica

1-Trimethylsilyloxycyclopent-1-ene can be catalytically converted into 2-allylcyclopentanone by its reaction with diallyl carbonate over palladium supported on silica.

Identification of relativistic nuclei with 10 ⪷ Z ⪷ 92

Using Bevalac beams, we have studied the sensitivity and charge resolution of silica glass, Melinex (polyethylene terephthalate), Lexan polycarbonate, Tuffak polycarbonate, CR-39, and bisphenol-A diallyl carbonate. We find that CR-39(DOP) has outstanding charge resolution over the range of values of Z/β from ∼10 to 40, and probably extending up to at least Z β ≈ 60; that Tuffak polycarbonate is an excellent detector for relativistic nuclei in the vicinity of Au and U and probably throughout the interval 50 ⪅ Z/β ⪅ 180, and that for particles with 150 ⪅ Z/β ⪅ 250, silica glass is adequate.

Synthesis of symmetrical unsaturated mono-and polycarbonates by carbonylation of allyl alcohol with carbon monoxide in presence of mercuric acetate

1. Allyl alcohol reacts with CO at 150–220° and 100 atm in the presence of mercuric acetate to give unsaturated mono- and poly-allyl carbonates. 2. An increase in the yield of diallyl carbonate is facilitated by running the reaction in THF.

Kinetic study of the polymerization of diallyl carbonate.

Abstract The polymerization of diallyl carbonate was carried out at 60°C, benzoyl peroxide being used as the initiator; here it has been discussed kinetically from the point of view of cyclopolymerization. The rate of polymerization, Rp, was not proportional to the square root or the first power of the initiator concentration, (I), but Rp/(I)1⁄2 and (I)1⁄2 bore a linear relationship. The rate of polymerization, the residual unsaturation, and the degree of polymerization decreased with a decrease in the monomer concentration. The relation between the rate of polymerization over the degree of polymerization, Rp/\barPn,o and the monomer concentration, (M), was also linear, as in Rp/(I)1⁄2 and (I)1⁄2. The ratio of the rate constant of the unimolecular cyclization reaction to that of the bimolecular propagation reaction of the uncyclized radical, Kc, was estimated to be 4.0 mol/l from the dependence of the residual unsaturation on the monomer concentration.