The First Benzo[1,2:4,5]dicyclobutenones and Their Tricarbonylchromium Complexes
作者:Ismail Abdelshafy Abdelhamid、Osama Mahmoud Ali Habib、Holger Butenschön
DOI:10.1002/ejoc.201100551
日期:2011.7.8
separation and acetal hydrolysis the title compounds 15 and 16 were obtained in high yields as the first representatives of their class. Complexation of the acetals with Cr(CO)6 gave the corresponding tricarbonylchromiumcomplexes in excellent yields. Subsequent deacetalization afforded the diketone complexes 18 and rac-20, which underwent stereoselective nucleophilic diadditions at –78 °C.
The First Bidirectional [4+2] Cycloadditions of Benzo[1,2:4,5]dicyclobutenes: Synthesis of Benzo[1,2-<i>f</i>:4,5-<i>f′</i>]diisoindole-1,3,7,9-tetraones
作者:Ismail Abdelshafy Abdelhamid、Holger Butenschön
DOI:10.1002/ejoc.201403247
日期:2015.1
respective bidirectional reactions have barely been explored. Here, the first bidirectional cycloadditions starting from benzo[1,2:4,5]dicyclobutene derivatives are presented using N-methylmaleinimide as the dienophile. The benzo[1,2:4,5]dicyclobutene derivativesused have in common that they are dimethylacetals of the respective diones. As a consequence, the cycloadducts easily undergo elimination of methanol
Bidirectional Synthesis, Photophysical and Electrochemical Characterization of Polycyclic Quinones Using Benzocyclobutenes and Benzodicyclobutenes as Precursors
The synthesis of some new extended polycyclic quinones was achieved through a one-pot procedure comprising the cycloaddition of benzocyclobutene and benzodicyclobutene derivatives with benzoquinone or naphthoquinone. Notably, a highly symmetrical nonacene-hexaone could be prepared, albeit in low yields (5–7 %).