25776-12-9Relevant articles and documents
Palladium-Assisted "Aromatic Metamorphosis" of Dibenzothiophenes into Triphenylenes
Vasu, Dhananjayan,Yorimitsu, Hideki,Osuka, Atsuhiro
supporting information, p. 7162 - 7166 (2015/06/08)
Abstract Two new palladium-catalyzed reactions of aromatic sulfur compounds enabled the conversion of dibenzothiophenes into triphenylenes in four steps. This transformation of one aromatic framework into another consists of 1) 4-chlorobutylation of the dibenzothiophene to form the corresponding sulfonium salt, 2) palladium-catalyzed arylative ring opening of the sulfonium salt with a sodium tetraarylborate, 3) an intramolecular SN2 reaction to form a teraryl sulfonium salt, and 4) palladium-catalyzed intramolecular C-S/C-H coupling through electrophilic palladation. Symmetrical as well as unsymmetrical triphenylenes of interest were synthesized in a tailor-made fashion in satisfactory overall yields. A change of heart: The invention of two palladium-catalyzed arylation reactions of organosulfur compounds enabled the transformation of dibenzothiophenes into triphenylenes and thus a fundamental change in the core aromatic structure (see scheme). Both symmetrical and unsymmetrical triphenylenes were synthesized in a tailor-made fashion in satisfactory overall yield.
Rhodium-Catalyzed asymmetric synthesis of spirocarbocycles: arylboron reagents as surrogates of 1,2-dimetalloarenes
Shintani, Ryo,Isobe, Shingo,Takeda, Momotaro,Hayashi, Tamio
experimental part, p. 3795 - 3798 (2010/08/20)
(Figure Presented) Revolutionary Rh-oad: A rhodium/dienecatalyzed addition of sodium tetraarylborates to alkyne-tethered 2-cydoalken-lones has been developed for the synthesis of splrocarbocycles. The tetraarylborates catalytlcally form two new carbon-carbon bonds. A chlral diene ligand also asymmetrically creates quaternary spirocarbon stereocenters with high enantiomeric purity.