Highly Efficient Route to Fused Polycyclic Aromatics via Palladium-Catalyzed Aryne Annulation by Aryl Halides
作者:Zhijian Liu、Richard C. Larock
DOI:10.1021/jo0619534
日期:2007.1.1
Polycyclic aromatic and heteroaromatic hydrocarbons have been synthesized in high yield by two different processes involving the Pd-catalyzed annulation of arynes. The first process involves a Pd-catalyzed annulation of arynes by 2-halobiaryls and related vinylic halides. The second process utilizes a Pd-catalyzed double annulation of arynes by simple aryl halides. Both processes appear to involve
routes have been developed to construct its skeleton. However, synthesis of unsymmetric phenanthrenes remains a challenge. Here, an efficient one-pot tandem reaction for the preparation of phenanthrenes via sequential γ-C(sp2)–H arylation, cationic cyclization, dehydration, and 1,2-migration was developed. A wide range of symmetric and unsymmetric phenanthrenes with diversified functional groups were synthesized
Facile sonochemical synthesis of carbon nanotube-supported bimetallic Pt–Rh nanoparticles for room temperature hydrogenation of arenes
作者:Horng-Bin Pan、Chien M. Wai
DOI:10.1039/c1nj20028c
日期:——
Bimetallic Pt–Rh nanoparticles can be deposited uniformly on surfaces of carboxylate functionalized multi-walled carbonnanotubes (MWNTs) using a simple one-step sonochemical method. The bimetallicnanoparticle catalyst exhibits a strong synergistic effect relative to the individual Pt or Rh metal nanoparticles for catalytic hydrogenation of polycyclic aromatic hydrocarbons (PAHs), neat benzene and
for hydrogenation of polycyclicaromatichydrocarbons (PAHs) containing 2–4 rings undermild reaction conditions. These compounds were partially hydrogenated with good to excellent selectivities just by optimizing the reaction conditions. The influence of the nature of substituents present in different positions of naphthalene on the selectivity of hydrogenation was also studied. Hydrogenation of products
Synthesis of Multisubstituted Triphenylenes and Phenanthrenes by Cascade Reaction of <i>o</i>-Iodobiphenyls or (<i>Z</i>)-β-Halostyrenes with <i>o</i>-Bromobenzyl Alcohols through Two Sequential C–C Bond Formations Catalyzed by a Palladium Complex
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