Synthesis of Multisubstituted Triphenylenes and Phenanthrenes by Cascade Reaction of o-Iodobiphenyls or (Z)-β-Halostyrenes with o-Bromobenzyl Alcohols through Two Sequential C–C Bond Formations Catalyzed by a Palladium Complex

Abstract

o-Bromobenzyl alcohol has been developed as a novel annulating reagent, bearing both nucleophilic and electrophilic substituents, for the facile synthesis of polycyclic aromatic hydrocarbons. A palladium/electron-deficient phosphine catalyst efficiently coupled o-iodobiphenyls or (Z)-β-halostyrenes with o-bromobenzyl alcohols to afford triphenylenes and phenanthrenes, respectively. The present cascade reaction proceeded through deacetonative cross-coupling and sequential intramolecular cyclization. An array of experimental data suggest that the reaction mechanism involves the equilibrium of 1,4-palladium migration.

An Annulative Synthetic Strategy for Building Triphenylene Frameworks by Multiple C−H Bond Activations

“…Benzamide-based triphenylene derivatives (3na, 3oa,a nd 3pa)w ere obtained in moderate yields (56 %, 40 %, and 51 %, respectively) with incomplete conversion of the corresponding substrates.Cyclic diaryliodonium salts 2b and 2c bearing difluoro and dimethyl groups provided good yields to afford 3ab and 3ac,r espectively.Given the difficulties in constructing adiverse array of tailored triphenylenes,a rising from the planar and (un)symmetrical structures, [15,19] the reaction scope of this approach is comparable to that of previously reported methods. [16][17][18][19][20] Overall, the electronic nature of the substrates bearing amide DGs (and substituents) significantly affects the efficiency of the annulation. With the aim of using alternative DGs,w er eacted 1-phenylpyrrolidin-2-one (1l)w ith 2a.P articularly noteworthy is the formation of phenanthro[9,10-b]triphenylene product 4la arising from 4-fold CÀHa rylation in 10 % isolated yield along with product 3la (35 %y ield, Table 2).…”

Diazatriphenylenes and their thiophene analogues: synthesis and applications

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] In this series triphenylenes [20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37] and their thiophene analogues (viz. phenanthro [9,10- A first-rate review on the chemistry of the above mentioned heteroaromatic systems, focusing on their synthesis, electronic properties, and applications in materials science, has recently been published.…”

Hypervalent‐Iodine‐Mediated Carbon–Carbon Bond Cleavage and Dearomatization of 9H‐Fluoren‐9‐ols

“…(2)]. [5] Thes econd one is the b-carbon scission of tertiary alkoxyl radicals,which has been intensively investigated. Conversely,a lkoxyl radicals usually generate more stable C(sp 3 )-carbon or other relatively stable radicals instead of aryl, vinyl, or alkynyl radicals (Scheme 1b).…”