3674-65-5Relevant articles and documents
Tandem acylation-cycloalkylation: A novel synthesis of phenanthrenes
Ramana,Potnis, Prashant V.
, p. 1090 - 1092 (1996)
Cyclohexene-1-acetic acid (1) undergoes reaction with various aromatic substrates 2a-k in the presence of polyphosphoric acid (PPA) to give 1,2,3,4,4a,10a-hexahydrophenanthren-9(10H)-ones 3a-k by tandem acylation-cycloalkylation, which on dehydrogenation with Pd-C afforded the corresponding phenanthrenes 4a-k in high yields.
Palladium-catalyzed annulation of 1,2-diborylalkenes and -arenes with 1-bromo-2-[(Z)-2-bromoethenyl]arenes: A modular approach to multisubstituted naphthalenes and fused phenanthrenes
Shimizu, Masaki,Tomioka, Yosuke,Nagao, Ikuhiro,Kadowaki, Tsugumi,Hiyama, Tamejiro
experimental part, p. 1644 - 1651 (2012/09/08)
(Z)-1,2-Diaryl-1,2-bis(pinacolatoboryl)ethenes underwent double-cross-coupling reactions with 1-bromo-2-[(Z)-2-bromoethenyl]arenes in the presence of [Pd(PPh3)4] as a catalyst and 3 M aqueous Cs2CO3 as a base in THF at 80 °C. The double-coupling reaction gave multisubstituted naphthalenes in good to high yields. Annulation of 1,2-bis(pinacolatoboryl)arenes with bromo(bromoethenyl)arenes in the presence of a catalyst system that consisted of [Pd2(dba)3] (dba=dibenzylideneacetone) and 2-dicyclohexylphosphino-2′,6′- dimethoxybiphenyl (SPhos) under the same conditions produced fused phenanthrenes in good to high yields. The first annulation coupling occurred regiospecifically at the bromoethenyl moiety. This procedure is applicable to the facile synthesis of polysubstituted anthracenes, benzothiophenes, and dibenzoanthracenes through a double annulation pathway by using the corresponding dibromobis[(Z)-2-bromoethenyl]benzenes as diboryl coupling partners. Copyright