Preparation styryl

To increase efficiency and ease of product separation from reaction mixtures, we also prepared styryl-substituted TADDOL-dendrimers that can act as crosslinkers in styrene suspension polymerizations, and thus lead to beads with intimately incorporated TADDOL sites [106,107]. Due to the presence of the con-formationally flexible dendritic spacers between the chiral ligand and the poly-... 

Hayashi [6] prepared styryl aUcoxyamine comonomers, (V), that behaved as high molecular regulators by releasing CO2 and 2,2,6,6-tetramethyl-4-hydroxy-l-piperinyloxy at elevated temperatures. 

In an interesting extension of the oxidative addition reaction. Cook and Jauhal prepared several platinum-carbon compounds which were not available by conventional reactions. They prepared styryl, trityl, and cyclohexyl compounds of platinum(II) which could not be obtained by the anionic alkylating route 44). 

As mentioned previously, aldehydes can be prepared by Stephen s method of reduction of nitriles by stannous chloride (37, 91). Polaro-graphic reduction of thiazolecarboxylic acids and their derivatives gives lower yields of aldehydes (58). Ozonolysis of styrylthiazoles, for example, 2-styryl-4-methylthiazole, followed by catalytic reduction gives aldehyde with 47% yield of crude product (30). 

The use of free-radical reactions for this mode of ring formation has received rather more attention. The preparation of benzo[Z)]thiophenes by pyrolysis of styryl sulfoxides or styryl sulfides undoubtedly proceeds via formation of styrylthiyl radicals and their subsequent intramolecular substitution (Scheme 18a) (75CC704). An analogous example involving an amino radical is provided by the conversion of iV-chloro-iV-methylphenylethylamine to iV-methylindoline on treatment with iron(II) sulfate in concentrated sulfuric acid (Scheme 18b)(66TL2531). 

In the attempted thermolytic preparation of pyrroloisoxazole (32) from azidoisoxazole (31a), only cinnamoyl cyanide was isolated. The assumed intermediate nitrene (33) did not insert into the styryl bond, but rather ring rupture and loss of acetonitrile produced the product. Similar products were obtained from the homolog (31b) (Scheme 7) (79TL4685). The stabilized nitrene intermediate is similar to that postulated for diazofuryl- and diazoisoxazolyl-methanes (78JA7927, 79TL2961). 

A series of 2-aryloxazolo[4,5-/i]quinoline-5-arylidines was prepared by the reaction of 5,7-diamino-8-hydroxyquinoline with aromatic or aliphatic aldehydes in the presence of a basic catalyst such as piperidine. On the other hand, 2-styryl-5-diacetylamino-oxazolo[4,5-/i]quinolines were prepared by interaction of 2-methyl-5-diacetylamino-oxazolo[4,5-/i]quinoline with aromatic aldehydes (77MI1, 82MI2) (Scheme 6). 

Cycloaddition of 2-styryl-4/7-3,l-benzoxazines and malononitrile gave 1 -amino-3-aryl-2-cyano-1 //,6//-pyrido[l, 2-n][3, l]benzoxazin-4-ones (99ZN(B)923). These tricyclic derivatives were also prepared in the reaction of 2-methyl-4//-3,l-benzoxazin-4-one and arylidenemalononitrile in AcOH in the presence of NaOAc. 

A methyl group in the 2-position of the selenazole ring shows the same reactivity as the analogous thiazoles toward carbonyl compounds. By reaction of 2,4-dimethylselenazole with benzaldehyde in the presence of anhydrous zinc chloride catalyst, 4-methyl-2-styryl-selcnazole (9), mp 74-75°C, could be prepared. ... 

A useful method of utilizing vinyl sulfones (specifically methyl styryl sulfones) for the preparation of thiane dioxides in good yields is illustrated in equation 125333. 

As well as phenyl derivatives, other products have been prepared by hydrolysis of alkoxysilanes such as cyclohexenyl or naphthyl derivatives as well as heterocyclic compounds based on thienyl rings (Table 31, entries 28-33). Few practical applications have been reported for this type of compound, except for the styryl compound T81C6H4-A-CFI = CH2]s, and the fluorinated TslCeFsJs which have been used in polymer blending (Table 31, entries 13 and 28). ... 

There can be significant differences in the rates of elimination of the stereoiso-meric (3-hydroxysilanes. Van Vranken and co-workers took advantage of such a situation to achieve a highly stereoselective synthesis of a styryl terpene. (The lithiated reactant is prepared by reductive lithiation see p. 625). The syn adduct decomposes rapidly at -78° C but because of steric effects, the anti isomer remains unreacted. Acidification then promotes anti elimination to the desired /i-isomer.275... 

The photopolymerization of St with catalytic amount of 52 as the pho-toiniferter gave a benzene-soluble polymer that contains a styryl double bond and a DC group at the polymer chain ends. When this macromonomer-iniferter 54 was copolymerized with a second monomer in the presence of an azo initiator, the formation of a high molecular weight graft copolymer was confirmed by GPC data. The monomer iniferter 52 was also used for the preparation of photoresist polymers [189]. 

Ma et al. also studied PVK-based PPLEDs using rhenium complex in [28,51], They have prepared the PPLED in configuration ITO/PVK bpyRe (27) DCM (28)/Al (DCM is 4-(dicyanomethylene)-2-methyl-6-[p-(dimethylamino)styryl]-4//-pyran), where the bpyRe... 

Most of the facts in Sections 2.2.1 to 2.2.10 are actually sufficient to dispose of this view and, taken together, they form an array of concordant and compatible observations which are all incompatible with it. In addition, it must be noted that amongst reagents of the type which interest us here, equilibria between ions and esters are unknown, and that attempts to prepare some of the active esters, e.g., styryl triflate, in the absence of a stabilising agent, always produce intractable mixtures [49]. 

Preparation of (l,4-diphenyl-l,3-butadiene)ZrCp2 (33) may be accomplished by photolysis of (/l-styryl)(benzyl)zirconocene (34)67 or by displacement of isoprene from (isoprene)ZrCp2 (35) at elevated temperature (Scheme 6)17. For complex 33, the s-trans/s-cis equilibrium lies far toward the s-trans isomer (95 5). 

Amination (11) and solution carbonation (8) reactions were carried out as described previously. For solid-state carbonations, a benzene solution of poly(styryl)lithium was freeze-dried on the vacuum line followed by introduction of high-purity, gaseous carbon dioxide (Air Products, 99.99% pure). Analysis and characterization of polymeric amines (11) and carboxylic acids (8) were performed as described previously. Benzoyl derivatives of the aminated polystyrenes were prepared in toluene/pyridine (2/1. v/v) mixtures with benzoyl chloride (Aldrich, 99%). 

A variety of procedures were utilized to analyze this reaction mixture and to characterize a,10-diaminopolystyrene. Thin layer chromatographic analysis using toluene as eluent exhibited three spots with Rf values of 0.85, 0.09, and 0.05 which corresponded to polystyrene, poly(styryl)amine and a,w-diaminopolystyrene (see Figure 1). Pure samples of each of these products were obtained by silica gel column Chromatography of the crude reaction mixture initially using toluene as eluent [for polystyrene and poly(styryl)amine] followed by a methanol/toluene mixture (5/100 v/v) for the diamine. Size-exclusion chromatography could not be used to characterize the diamine since no peak was observed for this material, apparently because of the complication of physical adsorption to the column packing material. Therefore, the dibenzoyl derivative (eq. 5) was prepared and used for most of the analytical characterizations. 

Dynamic formation of graft polymers was synthesized by means of the radical crossover reaction of alkoxyamines by using the complementarity between nitroxide radical and styryl radical (Fig. 8.13) [40]. Copolymer 48 having alkoxyamine units on its side chain was synthesized via atom transfer radical polymerization (ATRP) of TEMPO-based alkoxyamine monomer 47 and MMA at 50°C (Scheme 8.9). The TEMPO-based alkoxyamine-terminated polystyrene 49 was prepared through the conventional nitroxide-mediated free radical polymerization (NMP) procedure [5,41], The mixture of copolymers 48 and 49 was heated in anisole... 

A recent review on four-membered heterocycles formed from imino-phosphoranes concentrates on the preparation and the reactivity of 2,4-diimino-l,3-diazetidine and related compounds (93JPR305). As an example, the synthesis via bisiminophosphorane 85 is described in Scheme 42. The bisiminophosphorane has both a heteroaryl and a styryl site. From a mechanistic view, the reaction of the bisiminophosphorane proceeds with aryl isocyanate formation via an aza-Wittig mechanism. Intermediate car-bodiimide formation (86) occurs directly on the iminophosphorane moiety... 

For this reason Long (7, 8) and Erskine 8—11) prepared two series of ligands the ortho, meta and para-styryl dimethyl arsines Long), and the o, m and -allylphenyldimethylarsines Erskine) and studied the bromination of these compounds, their methiodides and their platinum (II) and rhodium(III) complexes. 

The most widely used chain reaction block copolymers are those prepared by the addition of a new monomer to a macroanion. AB and ABA block copolymers called Soprene and Kraton, respectively, are produced by the addition of butadiene to styryl macroanions or macrocarbanions (Equation 7.32). This copolymer is normally hydrogenated (Equation 7.33). 

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