18795-02-3Relevant articles and documents
Michael Reaction Inspired Atroposelective Construction of Axially Chiral Biaryls
Li, Shaoyu,Song, Qiuling,Tan, Bin,Xia, Wang,Xiang, Shao-Hua,Yan, Shengyi
, p. 7322 - 7327 (2020/08/05)
The first copper-catalyzed atroposelective Michael-type addition between azonaphthalenes and arylboronic acids for the construction of biaryl atropisomers was established using a novel BINOL-derived phosphoramidite as a chiral ligand. A broad range of atropisomeric biaryls were obtained with good efficiency, and the practicality of this approach was verified by versatile transformations toward axially chiral ligands, catalysts, and other functional atropisomers. This set of catalytic systems successfully inhibited the routine 1,2-addition and promoted the formation of an aryl-aryl chiral axis. Meanwhile, this strategy bypassed the use of an oxidant as well as the harsh conditions normally necessary for transition-metal-mediated arene C-H coupling with arylboronic acids as an arylation counterpart, offering a straightforward alternative to access optically active biaryls.
Synthesis of substituted helicenes by Ir-catalyzed annulative coupling of biarylcarboxylic acid chlorides with alkynes
Kamikawa, Ken,Den, Hiroakira,Tsurusaki, Akihiro,Nagata, Tomoya,Miura, Masahiro
supporting information, p. 1069 - 1074 (2018/07/29)
A series of substituted [4] and [5]helicenes were synthesized in moderate to good yields by an Ir-catalyzed annulative coupling of biarylcarboxylic acid chlorides with internal alkynes, which involves facile C-H bond cleavage and decarbonylation. The double annulative coupling of 1, 1′:5′, 1″-ternaphthalene- 2, 2″-dicarboxylic acid dichloride with 4-octyne was also accomplished to give rise to an S-shaped double helicene. Unexpectedly, a π-extended benzofluoranthene-merged [5]- helicene was constructed through the annulative coupling and the successive C(aryl)-C(aryl) bond forming reaction when 1, 1′:4′, 1″-ternaphthalene-2, 2″-dicarboxylic acid dichloride was employed as the substrate. The crystal structure and the optical properties of the latter unique product were also investigated.
Ortho-lithium/magnesium carboxylate-driven aromatic nucleophilic substitution reactions on unprotected naphthoic acids
Aissaoui, Regadia,Nourry, Arnaud,Coquel, Ariane,Dao, Thi Thanh Ha,Derdour, Aicha,Helesbeux, Jean-Jacques,Duval, Olivier,Castanet, Anne-Sophie,Mortier, Jacques
experimental part, p. 718 - 724 (2012/02/16)
Substitution of an ortho-fluoro or methoxy group in 1- and 2-naphthoic acids furnishing substituted naphthoic acids occurs in good to excellent yields upon reaction with alkyl/vinyl/aryl organolithium and Grignard reagents, in the absence of a metal catalyst without the need to protect the carboxyl (CO 2H) group. This novel nucleophilic aromatic substitution is presumed to proceed via a precoordination of the organometallic with the substrate, followed by an addition/elimination.