AbstractCarbazoles have attracted high interest among synthetic chemists due to their unique structural features and potential pharmacological activities. Compared to linear aryliodoniums, cyclic diphenyleneiodoniums are more inert and have not attracted much attention to their application as building blocks. Employing our synthetic strategy, diversified carbazoles can be efficiently obtained from a single cyclic diphenyleneiodonium under mild conditions. The reactions catalyzed by copper(II) acetate have provided a variety of carbazoles in modest to good yields with a broad range of amines including anilines, aliphatic amines and sulfonamides. Moreover, one of the obtained carbazoles has displayed an outstanding ability to protect HT‐22 neuronal cells from the damage induced by neurotoxins glutamate and homocysteic acid.magnified image
A highly efficient palladium‐catalyzed disilylation reaction of arylhalides through C−H activation has been developed for the first time. The reaction has broad substrate scope. A variety of arylhalides can be disilylated by three types of C−H activation, including C(sp2)−H, C(sp3)−H, and remote C−H activation. In particular, the reactions are also unusually efficient. The yields are essentially
for the synthesis of fluorene and its derivatives starting from 2-iodobiphenyls and CH2Br2. A range of fluorene derivatives can be synthesized under relatively mild conditions. The reaction proceeds via a tandem palladium-catalyzed dual C–C bond formation sequence through the key dibenzopalladacyclopentadiene intermediates, which are obtained from 2-iodobiphenyls through palladium-catalyzed C–H activation
Copper‐Catalyzed Diphenylation of P(O)‐OH Bonds with Cyclic Diaryliodonium Salts
作者:Gang Wang、Biquan Xiong、Congshan Zhou、Yu Liu、Weifeng Xu、Chang‐An Yang、Ke‐Wen Tang、Wai‐Yeung Wong
DOI:10.1002/asia.201901284
日期:2019.12.2
A copper-catalyzed diphenylation of P(O)-OH bonds with cyclic diaryliodonium salts is described. Valuable 2'-iodo substituted biaryl phosphinic/phosphoric acid esters were obtained in good to excellent yields, which could be further transformed to diversified building blocks for the synthesis of bioactive compounds, pharmaceuticals and functional materials.
Synthesis of 9-Fluorenylidenes via Pd-Catalyzed C–H Vinylation with Vinyl Bromides
作者:Shuai Yang、Yanghui Zhang
DOI:10.1021/acs.orglett.1c02722
日期:2021.10.15
A facile and efficient approach for the synthesis of 9-fluorenylidenes has been developed via the palladium-catalyzed cross-coupling of 2-iodobiphenyls and vinyl bromides. The reaction involves the C–H activation of 2-iodobiphenyls and dual C–C bond formations. A range of 9-fluorenylidene derivatives, including diphenyldibenzofulvenes, can be synthesized with the reaction.
protocol for the construction of 9-(diorganomethylidene)fluorenes through palladium-catalyzed coupling reactions of 2-iodobiphenyls with alkenyl bromides has been reported. The reaction proceeds through the C–H activation/oxidative addition/reduction elimination/intramolecular Heck coupling reaction to afford a series of 9-(diorganomethylidene)fluorenes with good yields. Control experiments demonstrate that