Benzene, allylic

UV irradiation of hexafluorobenzene with indene or cycloalkenes gives high yields of 2+2 adducts, which undergo further intramolecular cycloaddition to form hexafluoropolycycloalkanes [754] (equation 38) Photolysis of fluormated deriva tives of vinylbenzenes afford benzocyclobutenes, whereas allyl benzenes yield Dewar benzene-type products [755]... 

Alk = Et), a-methylstyrene (156, Ar = Ph), and allyl-benzene (160, Ar = Ph) are representatives of the four types of monosubstituted propenes (olefins 157 and 158, etc. written in Table I as equilibrium pairs undergo equilibration during the course of the reaction and yield the same pyrylium salt on diacylation). Disubstituted propenes which gave pyrylium salts on diacylation are 2-pentene (163, Alk = Me) and 1,2-diphenylpropene (164, Ar = ph),305 3-ethyl-2-pentene represents a trisubstituted propene... 

The reaction has been extended to allylic benzenes (in this case C-3 substituents are not required),to p,y-unsaturated ketones (the latter reaction, which is... 

As described above, when CuCl is regenerated in the reaction, the process can be catalytic in copper. In other cases, a stoichiometric amount (2 equiv.) of CuCl is used. Although CuCN shows similar reactivity, CuBr and Cul are not so effective as compared to CuCl. Allylation benzene, naphthalene, and anthracene formation, as well as acylation are representative examples, which are described below. 

Solvents and reagents used were of the highest available purity. Ru was obtained from Strem Chemicals, Inc. Allyl-benzene and dimethylpropargyl malonate were obtained from... 

Recently Roos and Orchin (72) studied the isomerization of allyl-benzene with DCo(CO)4. They found that isomerization to the pro-penylbenzenes proceeded very nicely but that no significant quantity of deuterium had been incorporated into either recovered allylbenzene or its isomerized products. These authors propose an interval 1,3-hydrogen shift. 

This simple, convenient procedure eliminates the use of strong acids which sometimes cause unwanted molecular rearrangements and the isolation and handling of toxic organomercuric halides. It also allows you to apply the borohydride reduction directly to the adduct, without precipitating it as the chloride. The main precursor is any allyl benzene eliminating the need for conversion to a propenyl benzene. 

N-acetyl-phenethylamine. Place 100 ml of acetonitrile and 64.8 g (.2 mole) of mercuric nitrate in a flask with stirring and cool to 25°. To this externally cooled and stirred mixture add 0.2 mole of allyl benzene at such a slow rate as to keep the temp under 30°. After the addition, stir at room temp for 1 hour, cool again, and achieve the reduction by adding 200 ml of 3 M sodium hydroxide, followed by 200 ml of. 5 M sodium borohydrate in 3 M sodium hydroxide. After 1 hour the water layer is saturated with sodium chloride and the product taken up with (extracted with) ether. Distillation, collect the fraction coming over at 101-105°. Yields 20 g of product. 

The first reactions concerned (Simons and Archer, 27) alkylation of benzene with propylene to form isopropylbenzene, with isobutene to form f-butylbenzene and di-f-butylbenzene, and trimethylethylene to form amylbenzene. Later on (Simons and Archer, 28) studied these and other reactions in more detail and showed that high yields could be obtained and that the product was not contaminated with tars or other obnoxious impurities. It was shown that the products obtained with trimethylethylene were mono- and di-f-amylbenzene, that phenyl-pentane resulted from the use of pentene-2, and that cyclohexene produced cyclohexylbenzene. Cinnamic acid reacted with benzene (Simons and Archer, 29) to form /3-phenylpropionic acid and allyl benzene reacted with benzene to form 1,2-diphenylpropane. It is interesting to note that although allyl alcohol reacted with benzene to form 1,2-diphenylpropane, the intermediate in the reaction, allylbenzene, was isolated and identified. This shows that in this case the hydroxyl reacted at a more rapid rate than the double bond. Both di- and triisobutylene reacted with phenol (Simons and Archer, 30) at 0°, when using hydrogen fluoride containing only relatively small quantities of water, to form f-butyl-benzene, but diisobutylene with 70% hydrogen fluoride produced p-f-octylphenol. Cyclohexene reacted with toluene to form cyclohexyl-toluene and octene-1 rapidly reacted with toluene to form 2-octyltoluene (Simons and Basler, 31). 

The 2,5-dimethoxy-3,4-methylenedioxy pattern. The parent allyl benzene is apiole (with a final e ) or parsley camphor, and it is the major component of parsley seed oil. Its conjugated isomer is called isoapiole, and they are valuable as the chemical precurors to the amination product, DMMDA. Whereas both of these essential oils are white solids, there is a green oily liquid that... 

Kinetic investigations83 into the bromination of methylidene adamantane (31) and allyl-benzene (32) reveals the importance of the assistance of the solvent to the rate-limiting ionization to form bromonium ion from the CT complex. 

One of the best known reactions of 1-azirines is the acid/catalyzed hydrolysis to aminoketones. Since the Neber reaction also accomplishes this same synthetic end, this reaction may appear to have little practical value. This is not the situation because with the Neber reaction there is no control over the aminoketone that will be obtained from a given ketone. For example, when oxime (127) derived from benzyl methyl ketone (126) is subjected to the Neber reaction aminoketone 128 is obtained.59 The amino function is substituted for the most acidic a-hydrogen. The isomeric aminoketone (132) that could not be prepared by the Neber reaction can be formed by the hydrolysis of 1-azirine (131). The synthesis of this 1-azirine has been accomplished from allyl benzene (129) through vinyl azide (130) using iodine azide.22... 

Figure 1.30 illustrates that the allyl radical intermediate of several Wohl-Ziegler brominations can be accessed from isomeric alkene substrates as starting materials. This is worth considering when one substrate is more easily accessible or cheaper than its isomer. The price of allyl benzene, for example, is just a fraction of what has to be paid for 1 -phenylpropene and would thus be preferred for the synthesis shown in Figure 1.30. 

Phenylallylsuccinic anhydride and the derived acid have been prepared by heating maleic anhydride with excess allyl-benzene in an autoclave at 170-175° for 24 h urs.3 The above procedure is more convenient since an autoclave is unnecessary. 

Mechanistically, the latter sequence rationalizes as follows (Scheme 47). The Pd-catalyzed arylamination with the bulky monodentate phosphane stops at the stage of the N-aryl allyl benzene 128. Upon addition of the chelating ligand dpephos, a subsequent cycle is opened that commences with the oxidative addition of the aryl bromide to the Pd-dpephos chelate. After the complexation of 128 to the Pd complex, the insertion of the alkene takes place to furnish an alkyl aryl Pd species that, due to the chelating dpephos, undergoes reductive elimination rather than /1-hydride elimination to furnish the product 127. 

SYNS l-ALLYL-3,4-DIMETHOXYBENZENE 4-ALLYLVERATROLE l,2-DIMETHOXY-4-ALLYL-BENZENE l-(3,4-DIMETHOXYPHENYL)-2-PROPENE ENT 21,040 1,3,4-EUGENOL METHYL ETHER EL GENYL METHYL ETHER FEMA No. 2475 METHYL EUGENOL (FCC) VERATROLE METHYL ETHER... 

C6H40Pr ) [12] and the 3-bromopyridine derivative (H2lMes)(3-BrPy)(Cl)2Ru=CHPh [12] (Figure 6.7) are capable of reactions such as CM between acrylonitrile and allyl-benzene. This improvement in activity is presumably because the corresponding cy-ano-carbene species are less likely to remain trapped by the more weakly bound ether and pyridine ligands. 

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