[RuCl2(p-cymene)2]2 catalyzed cross dehydrogenative coupling (CDC) toward xanthone and fluorenone analogs through intramolecular C–H bond functionalization reaction

Acylation of (Hetero)Arenes through CH Activation with Aroyl Surrogates

“…A variety of functional groups is tolerated and gave a wide range of xanthone derivatives in good yields (Scheme ). A ruthenium‐catalyzed strategy for this transformation has also been reported 27. In the presence of [{RuCl 2 ( p ‐cymene) 2 } 2 ] and TBHP in MeCN, a variety of substituted ortho ‐aryloxy/aryl benzaldehydes underwent CDC to give the corresponding six‐membered heterocycles in moderate to good yields.…”

Recent advances in the synthesis of xanthones and azaxanthones

“…158 4.1.2.1 Cyclization of diaryl ethers to xanthones by a crossdehydrogenative coupling. After the pioneering work of Wang et al 159 in 2012 on the synthesis of xanthones via a rhodiumcatalysed cross-dehydrogenative coupling (CDC) starting from 2-aryloxybenzaldehydes, alternative transition-metal catalysed strategies to construct the xanthone scaffold have been developed (Scheme 11) [160][161][162][163] For example, Wertz et al 160 reported an elegant and straightforward procedure for the synthesis of the xanthone core through a FeCp 2 -catalysed CDC reaction via a base-promoted homolytic aromatic substitution. Under the optimized conditions, several 2-aryloxybenzaldehydes bearing both electron-donating and electron-withdrawing substituents were coupled efficiently to give the corresponding xanthones with yields ranging from 30 to 78% (Scheme 11).…”

A Perspective on Synthesis and Applications of Fluorenones

“…In the presence of [RuCl 2 (p-cymene) 2 ] 2 , a variety of substituted ortho-aryloxy/aryl benzaldehydes underwent cross-dehydrogenative coupling to form the corresponding analogous of fluorenones in moderate to good yields (Scheme 40). [57] Several approaches are available for acylation of arenes by transition metal catalysts and strong acids. Transition metals have some drawbacks being expensive, having selectivity issues, and the requirement of an inert atmosphere.…”