An efficient, one-pot, and cheap metal-catalyzed tandem Chan-Lam coupling/deprotection/oxidation reaction to access unsymmetrical azobenzenes is disclosed. In this protocol, phthaloyl is automatically fallen off under this basic catalytic system, without...
A new route to various substituted fluoren-9-ones has been developed via an efficient Pd-catalyzed carbonylative multiple C-C bond formation. Under a CO atmosphere, using commercially available aryl halides and arylboronic acids as substrates, this three-component reaction proceeded smoothly in moderate to excellent yields with good functional-group compatibility. The mechanistic investigations suggested a sequential process for the reaction that forms o-bromobiaryls in the first stage followed by a cyclocarbonylation reaction. This chemistry has been successfully extended to construct ladder-type oligo-p-phenylene cores.
The homo anion-cation of cyclic diaryl λ3-bromanes/diarylbrominiums, which was not reported in previous reports, has been disclosed for the first time. The competitive experiments indicates that the anion-cation coupling is...
C–H annulations at N- and C2-aryls of an imidazole have been well researched, while the annulation on C4(5)-aryls especially the reactivity and site-selectivity among these aryls remain unknown. Herein, a...
A dual ring-opening, decarboxylative/decarbonylative [3 + 4] annulation of readily available (6-membered) isatoic anhydrides with (5-membered) cyclic iodoniums to efficiently build (7-membered) tribenzo[b,d,f]azepines through Pd(0) catalysis is disclosed. The tandem...
Selective C–H activation of a molecule containing
multiple
directing groups is an important but challenging issue in organic
chemistry. Herein, a combined directing group (hydrazone-oxime) selectively
directed [4 + 2] annulation cascade to synthesize novel 1,1′-biisoquinoline
mono-N-oxides has been developed. Owing to the subtle
differences in electronic properties between hydrazone and oxime,
the first C–H annulation with alkynes preferentially occurs
at the hydrazone side to form 1-oximido isoquinolines, which then
undergoes a second C–H annulation with iodonium ylides at the
oxime side. The two [4 + 2] annulations work smoothly under redox-neutral
conditions and can be performed in one pot, without utilization of
stoichiometric external oxidants. Moreover, ESI-MS and DFT calculations
have been conducted to corroborate the reaction mechanism. Such novel
biisoquinoline skeletons can pave the way for future research prospects
with synthetic value.
Cu/Fe-mediated arylation of pyridines with arylboronic acids, featuring low-cost catalytic system and easy operation, is disclosed. A series of length-controllable linear (the number of aryls ranges from 2 to 6)...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.