Palladium–copper catalyzed C(sp³)–C(sp²) bond C–H activation cross-coupling reaction: selective arylation to synthesize 9-aryl-9H-xanthene and 9,9-diaryl-xanthene derivatives

Abstract

A novel palladium–copper catalyzed C(sp3)–C(sp2) bond C–H activation cross-coupling reaction has been developed. A series of 9-aryl-9H-xanthenes and 9,9-diaryl-xanthenes were selectively synthesized in moderate to good yields by controlling the reaction time and temperature.

Asphaltene oxide promotes a broad range of synthetic transformations

“…Metal-free C-C cross couplings. Next, our efforts with AO were directed toward catalyzing C-C cross coupling reactions which have historically been accomplished with the aid of metal catalysts, such as those based on palladium and/or copper 28 . Acidic carbon-based materials, including GO 7,8 , have also been shown to be effective in facilitating C-C bond forming reactions with certain substrates.…”

Facile fabrication of bimetallic Fe–Mg MOF for the synthesis of xanthenes and removal of heavy metal ions

“…Various methods for the formation of xanthenes derivatives have been reported in the literature. 12,13 Numerous catalysts have been used in the preparation of xanthene, for example, Fe 3 O 4 -HAD-SO 3 H, 14 sulfated starch, 15 ZrO 2 , 16 WO x /ZrO 2 (ref. 17) and sulfamic acid/Cr-MIL-101.…”

Organosoluble and transparent cardo polyimides with high Tg derived from 9,9-bis(4-aminophenyl)xanthene

“…Monomer synthesis Figure 1 outlined the synthetic route to the diamine monomer, BAPX. Recently, BAPX was prepared in relatively low yield (55%) by C-H activation and cross-coupling reactions of xanthene and aniline catalyzed by Pd(OAc) 2 and Cu(OTf) 2 under a nitrogen atmosphere at 140 C for 24 h. 27 However, in view of the establishment of environmentally benign, less toxic, and less expensive methods for its effective synthesis without the use of transition metals under mild conditions, that is, low reaction temperature and short reaction time, is required. Inspired by our previous research results, 25 we attempted to develop a versatile method for preparation of BAPX from xanthone and aniline.…”

“…The crude product was washed successively with n-hexane for two times (2 Â 15 mL of each) to afford 23.7 g (85% yield) of yellow crystals; mp 268-269 C (by differential scanning calorimetry (DSC) at 2 C min À1 ) (Lit. 27 267-270 C). 1…”