837-80-9Relevant academic research and scientific papers
Tandem Synthesis of 1,3-Disubstituted Naphthalenes via TfOH-Promoted Directed-Aldol and Friedel-Crafts Reactions
Li, Hongchen,Shan, Lidong,Min, Lin,Weng, Yunxiang,Wang, Xinyan,Hu, Yuefei
, p. 15011 - 15019 (2021/10/25)
A TfOH-promoted tandem synthesis of 1,3-disubstituted naphthalenes is developed via a directed-aldol reaction and a Friedel-Crafts reaction. Two new C-C bonds and one new benzene ring are created efficiently in one pot due to the discovery of a TfOH-promoted highly chemoselective directed-aldol reaction between two different ketones with α-hydrogens.
Palladium-Catalyzed Cascade Reaction of o-Bromobenzaldehydes with N-Sulfonylhydrazones: An Efficient Approach to the Naphthalene Skeleton
Zhang, Heng,Yu, Yinghua,Huang, Shenlin,Huang, Xueliang
, p. 1576 - 1581 (2019/02/16)
A new strategy for the construction of the naphthalene backbone is described. The reaction essentially starts from two simple aldehydes. The key step is enabled by a palladium-carbene migratory insertion. After that, a sequence of reversible allylic alkylation and intramolecular condensation takes place to give the substituted naphthalene derivatives. Additional manipulations on the sulfonyl group in the product via palladium-catalyzed Kumada coupling were also investigated. (Figure presented.).
Synthesis of Naphthalenyl Triflates via the Cationic Annulation of Benzodiynes with Triflic Acid
Ge, Chenxin,Wang, Guohua,Wu, Panpan,Chen, Chao
supporting information, p. 5010 - 5014 (2019/07/08)
A highly efficient and regioselective annulation of benzodiynes promoted by triflic acid has been developed. This protocol provides a step and atom-economic access to a series of naphthalenyl triflates. Furthermore, direct synthetic applications of this r
Alkenes as alkyne equivalents in radical cascades terminated by fragmentations: Overcoming stereoelectronic restrictions on ring expansions for the preparation of expanded polyaromatics
Mohamed, Rana K.,Mondal, Sayantan,Gold, Brian,Evoniuk, Christopher J.,Banerjee, Tanmay,Hanson, Kenneth,Alabugin, Igor V.
supporting information, p. 6335 - 6349 (2015/06/02)
Chemoselective interaction of aromatic enynes with Bu3Sn radicals can be harnessed for selective cascade transformations, yielding either Sn-substituted naphthalenes or Sn-indenes. Depending on the substitution at the alkene terminus, the initial regioselective 5-exo-trig cyclizations can be intercepted at the 5-exo stage via either hydrogen atom abstraction or C-S bond scission or allowed to proceed further to the formal 6-endo products via homoallylic ring expansion. Aromatization of the latter occurs via β-C-C bond scission, which is facilitated by 2c,3e through-bond interactions, a new stereoelectronic effect in radical chemistry. The combination of formal 6-endo-trig cyclization with stereoelectronically optimized fragmentation allows the use of alkenes as synthetic equivalents of alkynes and opens a convenient route to α-Sn-substituted naphthalenes, a unique launching platform for the preparation of extended polyaromatics.
Gold(I)-catalyzed cycloisomerizations and alkoxycyclizations of ortho-(alkynyl)styrenes
Sanjun, Ana M.,Rashid, Muhammad A.,Garca-Garca, Patricia,Martnez-Cuezva, Alberto,Fernndez-Rodrguez, Manuel A.,Rodrguez, Flix,Sanz, Roberto
supporting information, p. 3042 - 3052 (2015/02/05)
Indenes and related polycyclic structures have been efficiently synthesized by gold(I)-catalyzed cycloisomerizations of appropriate ortho-(alkynyl)styrenes. Disubstitution at the terminal position of the olefin was demonstrated to be essential to obtain products originating from a formal 5-endo-dig cyclization. Interestingly, a complete switch in the selectivity of the cyclization of o-(alkynyl)-a-methylstyrenes from 6-endo to 5-endo was observed by adding an alcohol to the reaction media. This allowed the synthesis of interesting indenes bearing an all-carbon quaternary center at C1. Moreover, dihydrobenzo[a]fluorenes can be obtained from substrates bearing a secondary alkyl group at the β-position of the styrene moiety by a tandem cycloisomerization/1,2-hydride migration process. In addition, diverse polycyclic compounds were obtained by an intramolecular gold-catalyzed alkoxycyclization of o-(alkynyl)styrenes bearing a nucleophile in their structure. Finally, the use of a chiral gold complex allowed access to elusive chiral 1H-indenes in good enantioselectivities.
Rerouting radical cascades: Intercepting the homoallyl ring expansion in enyne cyclizations via C-S scission
Mondal, Sayantan,Gold, Brian,Mohamed, Rana K.,Phan, Hoa,Alabugin, Igor V.
, p. 7491 - 7501 (2014/11/08)
The switch from 5-exo- to 6-endo-trig selectivity in the radical cyclization of aromatic enynes was probed via the combination of experimental and computational methods. This transformation occurs by kinetic self-sorting of the mixture of four equilibrating radicals via 5-exo-trig cyclization, followed by homoallyl (3-exo-trig/fragmentation) ring expansion to afford the benzylic radical necessary for the final aromatizing C-C bond fragmentation. The interception of the intermediate 5-exo-trig product via β-scission of a properly positioned weak C-S bond provides direct mechanistic evidence for the 5-exo cyclization/ring expansion sequence. The overall cascade uses alkenes as synthetic equivalents of alkynes for the convenient and mild synthesis of Bu3Sn-functionalized naphthalenes.
Cyclization of (2-alkenylphenyl)carbonyl compounds to polycyclic arenes catalyzed by copper(II) trifluoromethanesulfonate or trifluoromethanesulfuric acid
Liu, Wei-Min,Tnay, Ya Lin,Gan, Kian Ping,Liu, Zhen-Hong,Tyan, Wan Huei,Narasaka, Koichi
, p. 1953 - 1969,17 (2012/12/12)
Various polycyclic arenes, such as naphthalenes, tetrahydroantharacenes, tetrahydrotetracenes, dihydropentacenes, and dihydropentaphenes are prepared from 2-alkenylphenyl ketones and aldehydes by the catalytic use of copper(II) trifluoromethanesulfonate (Cu(OTf)2) or trifluoromethanesulfuric acid (TfOH). Copyright
Cyclization of (2-alkenylphenyl)carbonyl compounds to polycyclic arenes catalyzed by copper(II) trifluoromethanesulfonate or trifluoromethanesulfuric acid
Liu, Wei-Min,Tnay, Ya Lin,Gan, Kian Ping,Liu, Zhen-Hong,Tyan, Wan Huei,Narasaka, Koichi
, p. 1953 - 1969 (2013/01/15)
Various polycyclic arenes, such as naphthalenes, tetrahydroantharacenes, tetrahydrotetracenes, dihydropentacenes, and dihydropentaphenes are prepared from 2-alkenylphenyl ketones and aldehydes by the catalytic use of copper(II) trifluoromethanesulfonate (Cu(OTf)2) or trifluoromethanesulfuric acid (TfOH). Copyright
Cyclization reaction for the synthesis of polysubstituted naphthalenes in the presence of Au(I) precatalysts
Jagdale, Arun R.,Park, Jong Hyub,Youn, So Won
experimental part, p. 7204 - 7215 (2011/10/17)
Au(I)-catalyzed cyclization of alkenyl carbonyl compounds leading to a variety of substituted naphthalenes has been developed. This process exploits a dual function of the Au(I) catalyst: (1) the oxophilic nature of the Au(I) catalyst, counterintuitive to the π-acidic reactivities generally associated with Au catalysts, and (2) olefin isomerization supported by the outcome of isotope scrambling experiments. It cannot be completely excluded that TfOH is a true operative catalyst in this protocol. In view of the practicality, the unnecessity of isomerically pure starting material in this reaction is particularly attractive and valuable.
Copper-catalyzed asymmetric ring-opening reaction of oxabenzonorbornadienes with Grignard and aluminum reagents
Millet, Renauds,Gremaud, Ludovic,Bernardez, Tania,Palais, Laetitia,Alexakis, Alexandre
experimental part, p. 2101 - 2112 (2009/12/31)
A highly enantioselective method for the copper-catalyzed desymmetrization of oxabenzonorbornadienes with aluminum reagents and SimplePhos as chiral ligand has been developed. The same reaction with Grignard reagents is also reported. A wide range of alky
