Butadiene phenyl terminated

The amination of styrene, however, led to two products (1-phenyl-1-ethylamine and 2-phenyl-l-ethylamine) in a 1 3 ratio [113], indicating that the hydrozirconation was not completely regioselective [114,115]. Since it is well known that hydrozirconation of trisubsti-tuted alkenes places zirconium at the least hindered carbon of the chain by a process involving zirconium migration, this class of alkenes was not investigated [5,116], On the other hand, hydrozirconation/amination of 3-methyl-l,2-butadiene gave an allylic amine. Reaction of the latter could either occur at the terminal carbon or proceed with... 

Chloroprene (2-chloro-l,3-butadiene 105), which is a mass-produced, inexpensive industrial material, is an excellent precursor to a variety of terminal allenes 107 [97]. The palladium-catalyzed reaction of 105 with pronucleophiles 106 in the presence of an appropriate base gave the terminal allenes 107 in good yields (Scheme 3.53). The palladium species generated from Pd2(dba)3-CHC13 and DPEphos was a good catalyst for these reactions of chloroprene. In contrast, (Z)-l-Phenyl-2-chloro-l,3-buta-diene, which is isostructural with the bromo-substrate 101, was nearly inert under these conditions. There is no substituent at the vicinal ris-position to the chloride in 105, which allows oxidative addition of the C-Cl bond in 105 to the Pd(0) species. 

Conjugation in the form of a phenyl substituent at the 2-position leads to 8-10 ppm deshielding of the fluorines of a terminal vinylic CF2 group, whereas for a conjugating vinyl group at the 2-position (as in 1,1-difluoro-l,3-butadiene) such deshielding is somewhat less... 

Summary New silacyclopropanes were synthesized quantitatively under mild thermal conditions by reaction of olefins with cyclotrisilane (cyclo-(Ar2Si)3, Ar = Me2NCH2QH4) 1, which transfers all of its three silylene subunits to terminal and strained internal olefins. Thermolysis of silacyclopropanes 3a und 3b indicated these compounds to be in a thermal equilibrium with cyclotrisilane 1 and die corresponding olefin. Silaindane 13 was synthesized by reaction of 1 with styrene via initially formed 2-phenyl-1-silacyclopropane 3d. Reaction of 1 with conjugated dienes such as 2,3-dimethyl-l,3-butadiene, 1,3-cyclohexadiene or anthracene resulted in the formation of the expected 1,4-cycloaddition products in high yield. 

Dithienothiophenes give cation polymeric radicals capable of further copolymer addition" while polystryene with a narrow polydispersity has been prepared through the use of an end-capped photoactive anthryl group. ° Large differences in radical termination rates have been found to be responsible for the marked variations in molecular weights of polymer from the UV flash polymerisation of 1,3-butadiene. tra 5-l,2-bis(5-Phenyl-2-oxazolyl)ethene has been found to exhibit low laser conversion efficiency due to preferential dimerisation while thermally activated patterns can be formed on the surface of poly(methyl methacrylate) by coating with photodimerisable 9-anthraldehyde. " ... 

Active methylene compounds can be added to polar double bonds such as those in acrylate esters and methyl vinyl ketone as has been described in the previous section. Active methylene compounds can also be added to carbon-carbon multiple bonds in allenes and alkynes with the aid of the transition metal complexes as the catalyst. The addition of methylmalononitrile to 3-phenyl-l,2-butadiene takes place in the presence of Pd2(dba)3-CHCl3 to give the corresponding addition product with E-stereochemistry (Eq. 67) [137 a]. The C-C bond formation occurs exclusively at the terminal position of the allenes. Trost et al. independently reported the similar results with respect to palladium-catalyzed addition of C-H bonds in active methylene compounds to allenes [137 b. ... 

ATBN Amine-terminated butadiene nitrile liquid rubber ATR Attenuated total reflection (in FT-IR) a-TREE Analytical temperature rising elution fractionation BAE Tetrakis[3,5-bis(trifluoromethyl)phenyl]borate BC Branch content... 

In 1998, Du Pont claimed the synthesis of bis(pyrrolyl) and bis(indolyl) ligands 1-3 characterized by a binaphthol backbone (Scheme 2.124) [10]. Unfortunately, the synthesis was detailed only for ligand 1. It was tested in the hydroformylation of methyl 3-pentenoate at 5 bar syngas pressure, where almost perfect selectivity for the formation of the terminal aldehyde was observed. The ligand was also used to convert 1- and 2-hexene. In comparison to a corresponding diphosphite with electron-withdrawing 3,5-CFg-phenyl groups, improved 1-heptanal selectivity was achieved. In the reaction with 1,3-butadiene, mainly pentenal was formed. 

Polymerization is carried out at 50°C and is allowed to continue for about 12 hours until conversion reaches 72%. Reaction is terminated at this point by the addition of hydroquinone in order to minimize the formation of cross-linked material. Unreacted monomers are removed, butadiene by flash-stripping under reduced pressure and styrene by steam-stripping. An antioxidant (e.g., A -phenyl-2-naphthylamine) is added to protect the rubber during drying and subsequent storage. The latex is then coagulated by the addition of a sodium chloride-sulphuric acid solution. The coarse crumb is washed with hot water and finally dried for about 2 hours at 80°C. 

PMR spectroscopy has been applied to the characterisation of a wide range of homopolymers including PMMA [286-289], PVC [290-294], PS [293, 295, 296], polyvinyl ethers [297-300], polyacrylic acid [301], poly(methyl-a-chloroacrylate) [302], carboxy terminated polybutadiene [303], poly(a-methyl styrene) [304], natural rubber [305-307], chlorinated polyisobutylenes [308], sulfonated PS resins [309, 310], polyvinyl phenyl ether [311], lactone polyester [312], chlorinated PVC [313], PC [314], poly 1,3 butadiene [315], poly-2-allyl phenyl acrylate [316], poly(4-methyl-pentene-1) [317], polymethacrylic acid [318], PP [296], cyclic ethers [319], polymethacrylonitrile [320], poly(a-methyl styrene) tetramer [321], PEG [322], PE [289], polyacrylamide [311], polymethylacrylamide [323], polypyrrolidone [324], polychloroprene [325], phenol formaldehyde resins [326, 327], Nylon 66 [328], polyvinylidene fluoride [329], polyvinyl formate [330], polyacrylonitrile [331], epoxy resins [332], allyl biguanide [333], poly(2-isopropyl-2-oxazollines) [334] and trehalose vinyl benzyl ether [335]. 

Recently, Gnanou et al reported that l,l-bis(4-bromophenyl)ethylene (4) can be used in a way similar to that for the above-mentioned TERMINI in the synthesis of dendrimer-like star-branched (PS)s and poly(1,3-butadiene)s (PB)s (Matmour and Gnanou, 2008). The synthetic outline is illustrated in Scheme 5.4. In each reaction step, 4 reacted with the terminal potassium alkoxide in a 1 1 addition manner to introduce two phenyl bromide moieties at the chain end, which was subsequently transformed into two phenyl lithiums by the Li-Br exchange reaction with sec-BuLi. Following the living anionic polymerization of styrene or 1,3-butadiene. 

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