一些含氟单体的合成及其聚合反应的初步研究

合成了含氟单体3-氧杂全氟戊烷-1,5-二磺酰溴(3),N-烯丙基-2-(ω-碘-n-全氟烷氧基)-1,1,2,2-四氟乙磺酰胺(16～18).初步研究了含氟单体3与非共轭二烯的聚合反应、连二亚硫酸钠引发的含氟单体16～18的聚合反应以及α,ω-全氟烷基二碘代烷22,23与非共轭端二烯的聚合反应,得到了相应的含氟聚合物或寡聚物.     

Synthesis and Properties of Long-Chain Aromatic Telechelic Monodispersed Diols Radical-Initiated,Addition of 2-Mercaptoethanol onto α, ω Nonconjugated Dienes

Abstract

The synthesis of aromatic telechelic mono dispersed diols produced from the radical-initiated addition reaction of a twofold excess of 2-mercaptoethanol onto original α,ω nonconjugated dienes reaction is presented. These novel α,ω nonconjugated dienes were prepared by addition reaction of m-isopropyl α,α′dimethyl benzylisocyanate with mono dispersed telechelic diols obtained by fractionation of oligo(ethylene terephthalate)s. In these cases, the long chain α,ω diols were produced selectively and quantitatively. The products are soluble in most organic solvents in contrast to classical oligo (ethylene terephthlate)s and posses a lower glass transition and melting temperatures.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements for the following free supplemental resource: Figures S1-S3.     

Immobilized Osmium Clusters in the Processes of Liquid-Phase Oxidation of Cycloxehene

The reaction of catalytic hydroxylation of olefins by organic hydroperoxides in the presence of osmium carbonyl clusters supported on polymer matrices is studied. The process occurs with the predominant formation of unsaturated alcohols. The oxidative coupling of olefins with the formation of nonconjugated dienes and in which the double bonds remain intact occurs in parallel. In the course of the reaction, changes in the chemical structures of the initial osmium clusters are not observed.     

Synthesis of Poly(Arylene Alkenylene)s by Pd‐Catalyzed Three‐Component Coupling Polycondensation of Diiodoarenes,Non‐Conjugated Dienes,and Nucleophiles that Involves Chain Walking Isomerization

The Pd‐catalyzed three‐component coupling polycondensation of diiodoarenes, nonconjugated dienes, and carbonucleophiles afforded poly(arylene alkenylene)s with moderate molecular weight in good yield. The reaction involves Mizoroki‐Heck coupling, olefin migration via chain walking, and addition of the carbonucleophile to the resulting π‐allylpalladium species. The polymerization with a slight excess of nucleophile with respect to diiodoarene also proceeded to give the polymer without significant decrease in molecular weight in spite of the nonstoichiometric mixture of the monomers. The Pd‐catalyzed three‐component coupling polycondensation of diiodoarenes, nonconjugated dienes, and diimide also proceeded. The base used in the reaction is critical for yield and molecular weight of the product. The reaction using NaHCO₃ afforded the product with low solubility, which can be explained by the high molecular weight of the polymer and/or the strong interaction of the electron donating dimethoxyphenylene groups and electron accepting diimide groups in the polymer. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 2535–2542     

Factors influencing the autoxidation of fatty acids: effect of olefin geometry of the nonconjugated diene

Autoxidations of cis,cis, cis,trans, and trans,trans nonconjugated octadecadienoates and pentadecadienes were carried out in the presence of alpha-tocopherol to investigate the effect of olefin geometry on this oxidation process and provide insight into the factors that influence the autoxidation of fatty acids. We have found that as the trans character of the diene increases, the amount of O(2) trapping at the central (bis-allylic) position of the pentadienyl radical also increases. In addition, the rate constant for beta-fragmentation (k(beta) approximately 10(6) s(-1)) of the bis-allylic peroxyl radical decreased on going from the cis,cis to the trans,trans diene. We have also found that for the cis,trans nonconjugated dienes, there is a preference for trapping of the pentadienyl radical by O(2) at the transoid end, generating the cis,trans conjugated hydroperoxide as the major product.     

Stereospecific 1,4-cis-hydrogenation of conjugated dienes,dienynes, and dienediynes catalyzed by chromium carbonyl complexes in stereocontrolled syntheses of physiologically active olefins

Synthesis of insect pheromones provides a good illustration of versatility, flexiblility, and practical convenience of the chromium carbonyl complexes-mediated 1,4-cis-hydrogenation of conjugated dienes as the tool for for stereocontrolled construction of di-, tri-, and tetrasubstituted olefins and nonconjugated dienes. A new strategy for synthesizing homoconjugated all-Z-dienes and trienes by hydrogenation of diene-alkyne conjugated systems using the same catalysts is proposed.     

How large is the conjugative stabilization of diynes?

The conjugation stabilization energies of dienes and diynes are considerably larger than estimates based on heat of hydrogenation differences between 1,3-butadiyne and 1-butyne as well as between 1,3-butadiene and 1-butene. Such comparisons do not take into account the counterbalancing hyperconjugative stabilization of the partially hydrogenated products by their ethyl groups. When alkyl hyperconjugation is considered, the conjugation stabilization of diynes ( approximately 9.3 kcal/mol) is found by two methods (involving isomerization of nonconjugated into conjugated isomers and heats of hydrogenation) to be larger than that of dienes ( approximately 8.2 kcal/mol).     

Base-Modulated 1,3-Regio- and Stereoselective Carboboration of Cyclohexenes

While chain-walking stimulates wide interest in both polymerization and organic synthesis, site- and stereoselective control of chain-walking on rings is still a challenging task in the realm of organometallic catalysis. Inspired by a controllable chain-walking on cyclohexane rings in olefin polymerization, we have developed a set of chain-walking carboborations of cyclohexenes based on nickel catalysis. Different from the 1,4-trans-selectivity disclosed in polymer science, a high level of 1,3-regio- and cis-stereoselectivity is obtained in our reactions. Mechanistically, we discovery that the base affects the reduction ability of B₂pin₂ and different bases lead to different catalytic cycles and different regioselective products (1,2- Vs 1,3-addition). This study provides a concise and modular method for the synthesis of 1,3-disubstituted cyclohexylboron compounds. The incorporation of a readily modifiable boronate group greatly enhances the value of this method, the synthetic potential of which was highlighted by the synthesis of a series of high-valued commercial chemicals and pharmaceutically interesting molecules.     

Modified polypropylenes by copolymerization with nonconjugated dienes and additional chemical reactions

Modified polypropylenes were synthesized by copolymerization of propene with several nonconjugated dienes using a constrained geometry catalyst in combination with methylaluminoxane. The incorporation of the dienes yields in polymer structures containing both cyclic units and linear branches, respectively. By variation of the polymerization conditions the cyclization tendency can be reduced. The resulting propene/diene copolymers are equipped with higher amounts of pendant double bonds which can be used for following chemical reactions. As an example, the epoxidation of the free double bonds was carried out using several epoxidation reagents. In a further modification step, the ring opening of the epoxy groups is presented demonstrating the simplicity of the chemical modification possibilities of such polypropylene materials.     

Rh-Catalyzed Coupling of Aldehydes with Allylboronates Enables Facile Access to Ketones

We present herein a novel strategy for the preparation of ketones from aldehydes and allylic boronic esters. This reaction involves the allylation of aldehydes with allylic boronic esters and the Rh-catalyzed chain-walking of homoallylic alcohols. The key to this successful development is the protodeboronation of alkenyl borylether intermediate via a tetravalent borate anion species in the presence of KHF₂ and MeOH. This approach features mild reaction conditions, broad substrate scope, and excellent functional group tolerance. Mechanistic studies also supported that the tandem allylation and chain-walking process were involved.     

钯催化的1,4-环己二烯的立体选择性1,3-双芳基化反应

基于金属迁移的策略,发展了钯催化的1,4-环己二烯的1,3-双芳基化反应,得到单一的非对映选择性的双芳基化的产物.此反应具有优秀的区域选择性和单一的非对映选择性.实验结果表明在钯迁移的过程中烯烃并没有从钯上解离下来.这一研究为cis-1,3-双芳基取代的环己烷类化合物的合成提供了简便的方法.     

Unlocking the Chain-Walking Process in Gold Catalysis**

The successful realization of gold-catalyzed chain-walking reactions, facilitated by ligand-enabled Au(I)/Au(III) redox catalysis, has been reported for the first time. This breakthrough has led to the development of gold-catalyzed annulation reaction of alkenes with iodoarenes by leveraging the interplay of chain-walking and π-activation reactivity mode. The reaction mechanism has been elucidated through comprehensive experimental and computational studies.     

Copolymerization of propene-nonconjugated dienes: Derivatization through hydroboration and epoxydation

Copolymerization of propylene and nonconjugated dienes such as 1–9 decadiene (α–ω symmetric) and 7-methyl-1,6 octadiene (asymmetric) is carried out in the presence of highly active isospecific catalysts for propene polymerization. The incorporation of the diene is random and does not affect the isospecificity of the catalytic system. For a low amount of diene, whatever its structure, an activation effect is observed. For the symmetric diene, the reactivity of the second double bond gives rise to crosslinking. Derivatization through hydroboration or epoxydation is carried out in suspension, using a toluenetetrahydrofuran solvent mixture that is able to swell the polypropylene and dissolve the reactants. After hydroboration the copolymer is transformed into hydroxylated polymer through oxidation in a phase transfer condition. The epoxydized copolymer shows excellent adhesive properties on anodized stainless steel.     

Synthesis of functional olefin copolymers with controllable topologies using a chain-walking catalyst

The branching topology of ethylene polar copolymers was for the first time successfully controlled by copolymerization of ethylene with polar olefins using a palladium-bisimine chain-walking catalyst, in which ethylene pressure and comonomer concentration were used to control the competition between isomerization (chain-walking) and monomer insertion processes. Although the overall branching density changes very slightly, the topology of the copolymers becomes more dendritic as the ethylene pressure and comonomer feed concentration are decreasing. This provides a straightforward one-pot synthesis to access a full range of functional copolymers having controllable branching topologies. To demonstrate the utility of this methodology, dendritic functional copolymers having hydroxyl, epoxide, and carbohydrate groups were prepared in a one-pot polymerization as potential functional materials.     

Redox-Neutral Nickel(II) Catalysis: Hydroarylation of Unactivated Alkenes with Arylboronic Acids

Reported here is the discovery of a redox-neutral Ni^II/Ni^II catalytic cycle which is capable of the linear-selective hydroarylation of unactivated alkenes with arylboronic acids for the first time. This novel catalytic cycle, enabled by the use of an electron-rich diimine ligand, features broad substrate scope, and excellent functional-group and heterocycle compatibility under mild reaction conditions in the absence of additional oxidants and reductants. Mechanistic investigations using kinetic analysis and deuterium-labelling experiments revealed the protonation to be the rate-determining step in this redox-neutral catalysis, and the reversible chain-walking nature of the newly developed diimine-Ni catalyst.     

Selective initiation of nonconjugated dienes containing electron donor–electron acceptor systems. IV. Polymerization of vinyl ether–styrene monomers

Three isomeric nonconjugated dienes, o-, m- and p-(2-vinyloxyethoxy)styrenes, were selectively polymerized by anionic or radical initiators through the styryl double bond while leaving the vinyl ether moiety intact. The anionic-initiated polymeric products are of high molecular weight and narrow molecular weight distribution as characterized by membrane osmometry and gel-permeation chromatography, respectively. These polymers were subsequently crosslinked by cationic initiators via the vinyl ether moiety on the polymer side chains. Acid-catalyzed hydrolysis of the poly(2-vinyloxyethoxy)styrenes yielded their respective hydroxy-containing polymers, polyvinylphenoxyethanols. The latter were physically and spectroscopically identical to authentic samples prepared by radical polymerization of the corresponding vinylphenoxyethanols, which, in turn, were synthesized by hydrolysis of the (2-vinyloxyethoxy)styrenes. The polyvinylphenoxyethanols were shown to undergo many chemical transformations, such as esterification with 3,5-dinitrobenzoyl chloride, cyanoethylation, and urethane formation.     

Reactivity of 1-nitronaphthalene and 1,3-dinitronaphthalene with conjugated dienes. An easy access to N-naphthylpyrroles

1-Nitronaphthalene reacts at high temperature with poor and moderately reactive dienes affording N-naphthylpyrroles while, with the same dienes, 1,3-dinitronaphthalene exhibits the dienophilic character of naphthalenic C3C4 bond producing the corresponding phenanthrenes through a classical Diels-Alder process.     

Cu(I)-catalyzed cycloguanidination of olefins

This paper describes a novel cycloguanidination process using CuCl as catalyst and diaziridinimines as the nitrogen source. A variety of conjugated dienes, trienes, and terminal olefins can be effectively diaminated under mild reaction conditions. For dienes and trienes, the reaction occurs at the terminal double bond with high regioselectivity.     

Photochemistry in solution-XX : Triplet reactivity of aliphatic aldehydes

The triplet self-quenching process of three aliphatic aldehydes has been investigated by inhibition with dienes (taking into account the singlet interaction with the dienes) and by laser flash photolysis. The results obtained for intersystem crossing, the setf-quenching process and product formation have been rationalized. The main reactivity observed for the three aldehydes is the self-quenching process which occurs from both the singlet and triplet state. The laser flash photolysis experiments carried out with butanal show two absorptions of a transient at 320 aod 355 nm; no evidence for two different species could be put forward. The similar decay of the two absorption maximas of the transient, as the concentration of aldehyde is increased, would be indicative of only one single absorbing species which could be either the triplet state of the aldehyde or a radical-pair formed by the self-quenching process or the 1,4-biradical resulting from γ-H abstraction. The fact that both the quenching experiments (by dienes or by 1-methylnaphthalene) and the laser flash measurements lead to about the same lifetime also indicates only one species.The products formed from the triplet setf-quenching process have also been obtained by a different method: excitation of benzophenone at 365 nm in the presence of butanal. The quantum yields for product formation is about the same as those obtained for the triplet by direct irradiation of butanal, except that of octane-4,5-dione which is increased if the photoreaction is carried out at 365 nm in the presence of beazophenone.     

Triplet energy transfer insight in coordination of unsaturated hydrocarbons by d(0) bent metallocenes (Zr, Hf)

For a class of pi-complexes as energy donors, with the use of highly emissive d(0) metallocenes Cp(2)MCl(2) where M = Zr and Hf, it is shown that radiationless triplet energy transfer to unsaturated hydrocarbons in a rigid nonpolar methylcyclohexane (MCH) matrix (where molecular diffusion is absent) obeys the Perrin equation, occurs at radii R(0), being close to the diameter of interacting molecules, and is well described by an electron-exchange resonant (Dexter) mechanism of interaction. Principle correlation between values of the critical radius and a number of C atoms in a linear alpha-olefin is for the first time reported, viz. R(0) (Angstrom) = -2.47 + 1.35n (obtained for systems [Cp(2)HfCl(2) + CnH(2)n + MCH] at 77 K). Pronounced blue shifts (up to 1000 cm(-1)) of low-temperature emission spectra of Cp(2)ZrCl(2) in MCH in the presence of dienes, possessing nonconjugated C=C bonds, are observed, thus suggesting inner-sphere diene coordination. In view of the experimental data, inner- and outer-sphere coordinative interaction between the components of catalytic systems for polymerization (d(0) metallocene precatalysts and alkenes and dienes) is rationalized.