- Oxidation of BINOLs by Hypervalent Iodine Reagents: Facile Synthesis of Xanthenes and Lactones
-
Xanthene derivatives have broad applications in medicines, fluorescent probes, dyes, food additives, etc. Therefore, much attention was focused on developing the synthetic methods to prepare these compounds. Binaphthyl-based xanthene derivatives were prepared through the oxidation of BINOLs promoted by the hypervalent iodine reagent iodosylbenzene (PhIO). Nine-membered lactones were obtained through a similar oxidative reaction when iodoxybenzene (PhIO2) was used. Additionally, one-pot reactions of BINOLs, PhIO and nucleophiles such as alcohols and amines were also investigated to provide alkoxylated products and amides in good to excellent yields.
- Zhang, Huaiyuan,Wirth, Thomas
-
-
- Enantioselective Synthesis of 3,3′-Disubstituted 2-Amino-2′-hydroxy-1,1′-binaphthyls by Copper-Catalyzed Aerobic Oxidative Cross-Coupling
-
A challenging direct asymmetric catalytic aerobic oxidative cross-coupling of 2-naphthylamine and 2-naphthol, using a novel CuI/SPDO system, has been successfully developed for the first time. Enantioenriched 3,3′-disubstituted NOBINs were achieved and could be readily derived to divergent chiral ligands and catalysts. This reaction features high enantioselectivities (up to 96 % ee) and good yields (up to 80 %). The DFT calculations suggest that the F–H interactions between CF3 of L17 and H-1,8 of 2-naphthol, and the π–π stacking between the two coupling partners could play vital roles in the enantiocontrol of this cross-coupling reaction.
- Zhao, Xiao-Jing,Li, Zi-Hao,Ding, Tong-Mei,Tian, Jin-Miao,Tu, Yong-Qiang,Wang, Ai-Fang,Xie, Yu-Yang
-
supporting information
p. 7061 - 7065
(2021/02/27)
-
- Synthesis of structurally diversified BINOLs and NOBINs via palladium-catalyzed C-H arylation with diazoquinones
-
Privileged biaryl frameworks, BINOL and NOBIN, were efficiently constructed with sole 1-DNQs as arylation reagents under one set of reaction conditions. The judicious selection of palladium-catalytic system plays a pivotal role in the excellent selectivities. This transformation accommodated fairly broad substrate generality for both 2-naphthol and N-Boc-2-naphthylamine and afforded the structurally diversified BINOLs and NOBIN derivatives in high efficiency. Notably, the bromo-substituents which cannot survive in conventional palladium-catalyzed reactions were well-compatible with this set of conditions, providing an effective handle for further enriching the library of BINOLs and NOBINs. Preliminary attempts on the asymmetric variant of this reaction were also performed with up to 80:20 er for BINOLs synthesis. [Figure not available: see fulltext.].
- Zhang, Ji-Wei,Jiang, Fei,Chen, Ye-Hui,Xiang, Shao-Hua,Tan, Bin
-
p. 1515 - 1521
(2021/07/06)
-
- Copper-Complex-Catalyzed Asymmetric Aerobic Oxidative Cross-Coupling of 2-Naphthols: Enantioselective Synthesis of 3,3′-Substituted C1-Symmetric BINOLs
-
A novel chiral 1,5-N,N-bidentate ligand based on a spirocyclic pyrrolidine oxazoline backbone was designed and prepared, and it coordinates CuBr in situ to form an unprecedented catalyst that enables efficient oxidative cross-coupling of 2-naphthols. Air serves as an external oxidant and generates a series of C1-symmetric chiral BINOL derivatives with high enantioselectivity (up to 99 % ee) and good yield (up to 87 %). This approach is tolerant of a broader substrates scope, particularly substrates bearing various 3- and 3′-substituents. A preliminary investigation using one of the obtained C1-symmetric BINOL products was used as an organocatalyst, exhibiting better enantioselectivity than the previously reported organocatalyst, for the asymmetric α-alkylation of amino esters.
- Tian, Jin-Miao,Wang, Ai-Fang,Yang, Ju-Song,Zhao, Xiao-Jing,Tu, Yong-Qiang,Zhang, Shu-Yu,Chen, Zhi-Min
-
supporting information
p. 11023 - 11027
(2019/07/08)
-
- The Interrupted Pummerer Reaction in a Sulfoxide-Catalyzed Oxidative Coupling of 2-Naphthols
-
A benzothiophene S-oxide catalyst, generated in situ by sulfur oxidation with H2O2, mediates the oxidative coupling of 2-naphthols. Key to the catalytic process is the capture and inversion of reactivity of a 2-naphthol partner, using an interrupted Pummerer reaction of an unusual benzothiophene S-oxide, followed by subsequent coupling with a second partner. The new catalytic manifold has been showcased in the synthesis of the bioactive natural products, (±)-nigerone and (±)-isonigerone. Although Pummerer reactions are used widely, their application in catalysis is rare, and our approach represents a new catalytic manifold for metal-free C?C bond formation.
- He, Zhen,Pulis, Alexander P.,Procter, David J.
-
supporting information
p. 7813 - 7817
(2019/05/15)
-
- Enantioenriched synthesis of C 1-symmetric BINOLs: Iron-catalyzed cross-coupling of 2-naphthols and some mechanistic insight
-
Highly enantioselective aerobic oxidative cross-coupling of 2-naphthols with broad substrate scope was achieved using an iron(salan) complex as the catalyst. Enantiomeric excesses of the products ranged from 87 to 95%. The scope of the cross-coupling reac
- Egami, Hiromichi,Matsumoto, Kenji,Oguma, Takuya,Kunisu, Takashi,Katsuki, Tsutomu
-
supporting information; experimental part
p. 13633 - 13635
(2010/11/17)
-
- Enantioselective catalytic conjugate addition of dialkylzinc reagents using copper-phosphoramidite complexes; ligand variation and non-linear effects
-
A variety of new chiral phosphoramidites was synthesised and tested in the copper-catalysed enantioselective conjugate addition of diethylzinc to cyclohexenone and chalcone in order to assess the structural features that are important for stereocontrol. A
- Arnold, Leggy A.,Imbos, Rosalinde,Mandoli, Alessandro,De Vries, André H.M.,Naasz, Robert,Feringa, Ben L.
-
p. 2865 - 2878
(2007/10/03)
-
- Polymerization of enantiomerically pure 2,3-dicarboalkoxynorbornadienes and 5,6-disubstituted norbornenes by well-characterized molybdenum ring-opening metathesis polymerization initiators. Direct determination of tacticity in cis, highly tactic and trans
-
The ring-opening metathesis polymerization (ROMP) of enantiomerically pure dicarboalkoxynorbornadienes (2,3-(CO2R*)2-norbornadiene where R* = (1R,2S,5R)-(-)-menthyl (2a) or (R)-(-)-pantalactonyl (2b)) with Mo-(CHCMe2Ph)(NA
- O'Dell, Richard,McConville, David H.,Hofmeister, Gretchen E.,Schrock, Richard R.
-
p. 3414 - 3423
(2007/10/02)
-
