Naphthalene catalytic aromatic alkylation

GaCU interacts even with the a electrons of cycloalkane C-H bonds, which could be used for catalytic aromatic alkylation (Scheme 7.56) [88, 90]. The reaction of cis-perhydronaphthalene and naphthalene in the presence of a catalytic amount of... 

Lund and coworkers [131] pioneered the use of aromatic anion radicals as mediators in a study of the catalytic reduction of bromobenzene by the electrogenerated anion radical of chrysene. Other early investigations involved the catalytic reduction of 1-bromo- and 1-chlorobutane by the anion radicals of trans-stilhene and anthracene [132], of 1-chlorohexane and 6-chloro-l-hexene by the naphthalene anion radical [133], and of 1-chlorooctane by the phenanthrene anion radical [134]. Simonet and coworkers [135] pointed out that a catalytically formed alkyl radical can react with an aromatic anion radical to form an alkylated aromatic hydrocarbon. Additional, comparatively recent work has centered on electron transfer between aromatic anion radicals and l,2-dichloro-l,2-diphenylethane [136], on reductive coupling of tert-butyl bromide with azobenzene, quinoxaline, and anthracene [137], and on the reactions of aromatic anion radicals with substituted benzyl chlorides [138], with... 

From the systematic investigation of the Park and Jew group, several highly efficient and practical polymeric cinchona PTCs were developed (Scheme 6.6). Interestingly, polymeric catalysts with a specific direction of attachment between aromatic linkers (e.g., benzene or naphthalene) and each cinchona unit were found to be effective in the asymmetric alkylation of 4b. The phenyl-based polymeric PTCs with the meta-relationship between cinchona units such as 14, 15, and 18 showed their high catalytic efficiencies. Furthermore, the 2,7-dimethylnaphthalene moiety as in 16 and 17 was ultimately found to be the ideal spacer for dimeric cinchona PTC for this asymmetric alkylation. For example, with 5 mol% of 16, the benzylation of 4b was completed within a short reaction time of 30 min at 0 ° C, affording (S)-5a in 95% yield with 97% ee. Almost optically pure (>99% ee) (S)-5a was obtained at lower reaction temperature (—40 °C) with 16, and moreover, even with a smaller quantity (1 mol%), its high catalytic efficiency in terms of both reactivity and enantioselectivity was well conserved. 

Zeolite catalysts due to their shape selectivity, thermostability, the easy separation from the products and the possibility of regeneration of the deactivated catalysts, have been widely used in the field of petrochemistry [2,3]. However, their use in fine organic synthesis has been limited. Recently, zeolite catalysts were found to be active in the alkylation of aromatics, however, there is no report to date on the benzylation of naphthalene. In this paper, we disclose a new catalytic method for the benzylation of naphthalene using zeolite H-beta as the catalyst and benzyl chloride as the benzylating agent. The optimum reaction conditions for the production of more 2-benzylnaphthalene are also examined in this study. The results obtained over H-beta catalyst are compared with zeolite H-Y and the conventional catalyst, AICI3. 

Aromatization of enediynes with catalytic insertion of C-H bond—In the case of the enediynes 3.718 bearing long alkyl substituents terminating one alkyne branch, the cycloaromatization occurs with radical insertion into a C-H bond of the alkyl group (Scheme 3.80) [257, 263]. The route taken by catalysis with ruthenium differs from that with rhodium [257]. In the rhodium system, cyclization is initiated by a rhodium-vinylidene intermediate which forms OTe i2-diradical naphthalene intermediate A. In the case of ruthenium, the cyclization comprises primary of the formation of a ruthenium-Ti-alkyne, which forms para-dirsidicsil B that converts to the product 3.719. 

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