Naphthalene derivatives reaction with alkenes

In addition to benzene and naphthalene derivatives, heteroaromatic compounds such as ferrocene[232, furan, thiophene, selenophene[233,234], and cyclobutadiene iron carbonyl complexpSS] react with alkenes to give vinyl heterocydes. The ease of the reaction of styrene with sub.stituted benzenes to give stilbene derivatives 260 increases in the order benzene < naphthalene < ferrocene < furan. The effect of substituents in this reaction is similar to that in the electrophilic aromatic substitution reactions[236]. 

C-Alkylations may be discussed under the headings of alkene reactions and A/-alkyl rearrangements. The isopropylation of benzene and naphthalene are two important examples of alkylation with alkenes (see Alkylation). Manufacture of j butylaniline, by heating /V-butylaniline with 2inc chloride, typifies the rearrangement reaction appropriate to and higher alkyl derivatives. 

Addition of carbenes to Jt-electron excessive aromatic compounds, or those which possess a high degree of bond fixation, is well established. Dihalocarbenes react with naphthalenes with ring expansion to produce benztropylium systems (Scheme 7.8). Loss of hydrogen halide from the initially formed product leads to an alkene which reacts with a second equivalent of the carbene to yield the spirocyclopropyl derivatives in high yield (>95%) [14, 50]. Insertion into the alkyl side chain (see Section 7.2) also occurs, but to a lesser extent [14]. Not unexpectedly, dichlorocarbene adds to phenanthrenes across the 9,10-bond [9, 10, 14], but it is remarkable that the three possible isomeric spiro compounds could be isolated (in an overall yield of 0.05% ) from the corresponding reaction with toluene [14]. 

Insertion of aUcynes into aromatic C-H bonds has been achieved by iridium complexes. Shibata and coworkers found that the cationic complex [Ir(COD)2]BF4 catalyzes the hydroarylation of internal alkynes with aryl ketones in the presence of BINAP (24) [111]. The reaction selectively produces ort/to-substituted alkenated-aryl products. Styrene and norbomene were also found to undergo hydroarylation under similar condition. [Cp IrCl2]2 catalyzes aromatization of benzoic acid with two equivalents of internal alkyne to form naphthalene derivatives via decarboxylation in the presence of Ag2C03 as an oxidant (25) [112]. 

Due to their reduced aromatic character, naphthalene derivatives also frequently undergo ortho cycloaddition with alkenes (Sch. 4). 1-Cyano-naphthalene 13 reacts with cyclohexadiene to yield the regioisomeric ortho adducts 14 and 15 in good yields [34]. Two regioisomers 17 and 18 were also obtained from the intramolecular reaction of the 1-cyanonaphthalene derivative 16 [35]. The proportion of the two isomers depends on the solvent polarity. 

Only few reports deal with a para photocycloaddition as the major reaction path. Recently, however, several cinnamide derivatives like 21 were efficiently transformed into the corresponding para adducts 22 (Sch. 6) [37]. Yields higher than 90% could be achieved. The para photocycloaddition is also observed with naphthalene derivatives like 1-acetylnaphthalene 23 and captodative enamino nitriles as 24 [38]. Other captodative substituted alkenes [39] as well as the fluorinated uracil derivative 26 [40] are transformed in the same way. Especially in the cases of 21 and 23, the... 

In polar solvents the excited state of sufficiently electron deficient arenes will accept an electron from donors. The fates of the radical ion pairs produced include formation of products of addition to the arene ring. A new example of this mode of reactivity is the photochemical reaction of 1,4-dicyanonaphthalene with benzyl methyl ether in acetonitrile. This yields stereoisomers of the addition product (120). The reaction most likely involves electron transfer from the ether to the naphthalene excited state and subsequent ionisation of a proton from the benzyl ether radical cation. This produces a benzyl ether radical which adds to the naphthalene derivative. An analogous sequence is proposed to explain the photochemical formation of (121)-(124) from ultra-violet light irradiated solutions of naphthalene-1,2-dicarboxylic acid anhydride in methanolic benzene or acetonitrile containing isobutene, 2-butene or 2-methyl-2-butene. Here it is suggested that the alkene radical cation, formed by electron transfer to the excited state of the naphthalene, is attacked by methanol deprotonation... 

Acetylenes can undergo a number of thermal and transition metal promoted cycloaddition reactions. Besides the [2 + 2 + 2] cycloaddition (see Sect. 5) the reaction of acetylenes with late transition metal (so-called Fischer ) carbenes is noteworthy for the synthesis of highly and regioselectively functionalized naphthalene derivatives (Dotz reaction), while the co-cycloaddition of acetylenes with alkenes and carbon monoxide gives cyclopentenones (Pauson-Khand reaction) [159,160]. 

The reactivity of carbene-metal complexes, amongst others the reactivity with respect to alkenes and alkynes, has been reviewed by Dotz Just like free carbenes the coordinated carbenes add to triple bonds to give cyclopropene derivatives. Other reaction products, however, are also possible. For instance, the carbene ligand of chromium complex 23 reacts with diphenylacetylene to a mixture of products, including naphthalene derivative 24 and furan derivative 25 (equation 18). A carbonyl ligand has participated. Molecular orbital calculations by Hofmann and Hammerle " on this system reveal that the reaction would pass through an y-vinylcarbene type of complex (26) instead of through a planar chromacyclobutene 27. The subsequent steps to yield either phenol or furan could involve vinylketene 28, but this still is a matter of debate. Similar, but more selective, furan syntheses have been observed for carbene complexes based on iron and cobalt. ... 

CAN-mediated nitration provides a convenient route for the introduction of a nitro group into a variety of substrates. Alkenes on treatment with an excess of sodium nitrite and CAN in chloroform under sonication afford nitroalkenes. When acetonitrile is used as the solvent, nitroacetamidation occurs in a Ritter-type fashion. However, the attempted nitroacetamidation of cyclo-pentene-1 -carboxaldehyde under similar conditions resulted in the formation of an unexpected dinitro-oxime compound. A one-pot synthesis of 3-acetyl- or 3-benzoylisoxazole derivatives by reaction of alkenes (or alkynes) with CAN in acetone or acetophenone has been reported. The proposed mechanism involves a-nitration of the solvent acetone, oxidation to generate the nitrile oxide, and subsequent 1,3-dipolar cycloaddition with alkenes or alkynes. The nitration of aromatic compounds such as carbozole, naphthalene, and coumarins by CAN has also been investigated. As an example, coumarin on treatment with 1 equiv of CAN in acetic acid gives 6-nitrocoumarin in 92% yield. ... 

Reactions with organic compounds. HOF converts alkenes into a-fluoro alcohols, acetylenes mainly into a-fluoro carbonyl compounds [11], aromatic compounds (benzene and its monosubstituted derivatives, p-xylene, naphthalene) into phenolic products [12], and octa-ethylporphyrin into the N-oxide [13]. 

The reaction of 11 with ordinary alkenes with a Cu(OTf)2 catalyst gave 1,2-dihydronaphthalenes. However, reaction with p-methoxystyrene 8 afforded the naphthalene derivative 12 in 83% yield. Probably, retro-Michael addition occurred and the methoxy group was eliminated as methanol [24], This protocol can be applied to the formation of benzo-fused heteroaromatic compounds such as indols 35 and benzofuranes (Scheme 15.13) [25]. 

Dimethyl acetylenedicarboxylate (DMAD) (125) is a very special alkyne and undergoes interesting cyclotrimerization and co-cyclization reactions of its own using the poorly soluble polymeric palladacyclopentadiene complex (TCPC) 75 and its diazadiene stabilized complex 123 as precursors of Pd(0) catalysts, Cyclotrimerization of DMAD is catalyzed by 123[60], In addition to the hexa-substituted benzene 126, the cyclooctatetraene derivative 127 was obtained by the co-cyclization of trimethylsilylpropargyl alcohol with an excess of DMAD (125)[6l], Co-cyclization is possible with various alkenes. The naphthalene-tetracarboxylate 129 was obtained by the reaction of methoxyallene (128) with an excess of DMAD using the catalyst 123[62],... 

The cyclic phosphate and phosphoramidate derivatives of v/c-diols undergo a two-step reductive elimination on treatment with Li/NHs, Na-naphthalene, TiCl4-Mg(Hg) or TiClt-K. In acyclic systems the reaction is only moderately stereoselective. The reaction has particular value in the synthesis of tetra-substituted alkenes from highly hindered v/c-diols. Scheme 20 illustrates its use in the synthesis of [10,10]-betweenanene (49). ... 

Other Addition Reactions - The photochemical addition in the gas phase of ammonia to a,P-unsaturated nitriles has been studied. The reactions are carried under conditions where all, or most, of the light is absorbed by the ammonia and this results in N-H bond fission and the production of NH2 radicals. These radicals add to the a-position of the substrate to yield 2-amino-propionitrile from acrylonitrile and analogous products are formed from crotononitrile, methacrylonitrile and 1-cyclohexenecarbonitrile. Additions also occur to but-2-yne nitrile which yields the Z, -isomers of 3-amino-crotononitrile with the E -isomer being predominant. The SET-induced amina-tion (using 1,4-dicyanobenzene as the sensitiser) of alkenylnaphthalene derivatives affords products of addition to both the alkene and the naphthalene skeleton. Suau et al. have examined the irradiation of phthalimide in the presence of low concentrations of hydroxide ion and alkenes. ° The result of this treatment is addition of the phthalimide moiety to the alkene. A SET... 

The shock against benzene produced H2, light alkanes from Ci to C3, light alkenes from C2 to C3, C2H2, and aromatic hydrocaibons with molecular weights ranging from 102 (phenylacetylene) to 306 (quaterphenyl). This reaction produced H2, CH4, polyphenyl compounds such as biphenyl, terphenyl, and quaterphenyl. Other major products were naphthalene, fluorene, trans-stilbene, phe-nanthrene, isomers of phenylnaphthalene and chrysene. The shock produced ethenyl in greater abundance than ethyl derivatives. 

Iwasawa et al. developed a tungsten-mediated benzannulation reaction (Scheme 15.15). On treatment of o-ethynylphenyl ketones 11 with 3 equiv of preformed W(C0)5(THF), followed by the addition of electron-rich alkenes 8, such as enam-ines and enol ethers, the corresponding naphthalenes 19 were produced together with W(CO)6 [26]. Ohe, Miki, and co-workers prepared pyranyUdene-metal complexes from conjugated enyne-carbonyl compounds using Mo, W, and Cr complexes, which were treated with dimethyl acetylenedicarboxylate to give benzene derivatives [27]. 

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