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.
Arynes were found to be inserted into a C(sp)–Br σ-bond of bromoalkynes in the presence of a copper catalyst, giving (alkynyl)bromoarenes in a straightforward manner.
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
One-Pot Synthesis of Diarylmethylidenefluorenes and Phenanthrenes by Palladium-Catalyzed Multiple CH Bond Functionalization
作者:Vedhagiri S. Thirunavukkarasu、Kanniyappan Parthasarathy、Chien-Hong Cheng
DOI:10.1002/chem.200902726
日期:2010.2.1
A palladium‐catalyzed rapid synthesis of diarylmethylidenefluorenes and phenanthrenes by multiple CH bond activation, CC bond formation, and Heck‐type cyclization is described (see scheme).
regioselectivity by aryl or hetaryl thioketones forming also sterically crowded 2-trimethylsilyl-1,3-dithiolanes. The obtained 1,3-dithiolanes, by treatment with an equimolar amount of TBAF in a one-pot procedure, are converted in high yields into hetaryl/aryl-substituted ethenes or dibenzofulvenes, respectively, via a cycloreversion reaction of the intermediate 1,3-dithiolane carbanion. The presented protocol