Synthesis of Annulated Arenes and Heteroarenes by Hydriodic Acid and Red Phosphorus Mediated Reductive Cyclization of 2-(Hetero)aroylbenzoic Acids or 3-(Hetero)arylphthalides
作者:Arasambattu Mohanakrishnan、Settu Rafiq
DOI:10.1055/s-0036-1588337
日期:——
Annulated arenes and hetarenes were prepared in good to very good yields by hydriodic acid/red phosphorus mediated reductive cyclization of 3-(hetero)aryl phthalides. The reductive cyclization also proceeded successfully with 2-aroylbenzoic acids and 2-aroylnaphthoic acids.
Dinitrogen oxide was employed as a clean oxidant for various oxidations in the presence of a catalytic amount of dioxoruthenium tetramesitylporphyrin complex (Ru(tmo)(O) 2 ). A variety of olefins, secondary alcohols, and benzyl alcohols were smoothly oxidized to the corresponding epoxides, ketones, and aldehydes in high yields. In the oxidation of 9,10-dihydroanthracene derivatives, the competitive
Synthesis of Annulated Anthracenes, Carbazoles, and Thiophenes Involving Bradsher-Type Cyclodehydration or Cyclization-Reductive-Dehydration Reactions
作者:Settu Muhamad Rafiq、Ramakrishnan Sivasakthikumaran、Jayachandran Karunakaran、Arasambattu K. Mohanakrishnan
DOI:10.1002/ejoc.201500493
日期:2015.8
A conventional BF3·OEt2-mediated Bradsher-type cyclodehydration of 2-arylmethyl benzaldehydes in CH2Cl2 at room temperature gave polycyclic aromatic and heteroaromatic compounds. Alternatively, these compounds could be synthesized in better yields from 2-arylmethylbenzoic acids by triflic-acid-mediated cyclization followed by reductive dehydration.
Efficient Oxidative Aromatization of 9,10-Dihydroanthracenes with Molecular Oxygen Catalyzed by Ruthenium Porphyrin Complex
作者:Tohru Yamada、Hirotaka Tanaka、Taketo Ikeno
DOI:10.1055/s-2003-37531
日期:——
In the presence of a catalytic amount of a ruthenium porphyrin complex, various 9,10-dihydroanthracene derivatives were aromatized with molecularoxygen to the corresponding anthracenes. It was found that the addition of sulfuric acid accelerated the aromatization at room temperature under atmospheric pressure of oxygen to afford various anthracenes in high yields.