- Direct Interconversion of BINOL and H8-BINOL-Based Chiral Br?nsted Acids Using Single-Step Red/Ox Manipulations
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A direct single-step hydrogenation of BINOL-based chiral phosphoric acids, N-triflyl phosphoramides, and disulfonimides to the corresponding H8-BINOL Br?nsted acids in excellent yields and chemoselectivities is described. In addition, the conditions for t
- Tay, Jia-Hui,Arguelles, Alonso J.,Nagorny, Pavel
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supporting information
p. 3774 - 3777
(2015/08/18)
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- Synthesis, structural analysis, and catalytic properties of tetrakis(binaphthyl or octahydrobinaphthyl phosphate) dirhodium(II,II) complexes
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The X-ray structural analyses of homoleptic Rh(II) complexes made of enantiopure (R)-1,1′-binaphthyl and (R)-(5,5′,6,6′,7,7′, 8,8′-octahydro)binaphthyl phosphate ligands are for the first time presented. The possibility to introduce halogen atoms at the 3,3′-positions is also reported. The isolated dirhodium complexes were further tested as catalysts (1 mol %) in enantioselective cyclopropanations and Si-H insertion reactions, affording chiral cyclopropanes and silanes in good yield but moderate enantioselectivity (ee max 63%).
- Hrdina, Radim,Guenee, Laure,Moraleda, Delphine,Lacour, Jeroime
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p. 473 - 479
(2013/03/28)
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- Facile and efficient enantioselective strecker reaction of ketimines by chiral sodium phosphate
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A facile and efficient enantioselective Strecker reaction of ketimines catalyzed by a chiral alkali-metal salt has been developed. When 10 mol% BNPNa (BNP=1,1'-binaphthyl-2,2'-diylphosphate) prepared in situ and 10 mol% para-tert-butylortho-adamantylphenol (PBAP) were introduced into the reaction, up to 96% yield and up to 95% ee (ee=enantiomeric excess) were obtained. Both aliphatic and aromatic ketimines, especially sterically bulky cyclic ketimines derived from β-acetonaphthone, α-indanone, and α-tetralone were found suitable for this reaction. On the basis of the experimental results and previous reports, trimethylsilyl cyanide (TMSCN) was indicated to be the real reactive nucleophile despite the existence of PBAP, and a possible working model was proposed to explain the origin of the asymmetric induction. The facile availability of 1,1'-binaphthyl-2,2'-diylphosphoric acid (BNPH) and the simplicity of the procedure are beneficial for practical applications.
- Shen, Ke,Liu, Xiaohua,Cai, Yunfei,Lin, Lili,Feng, Xiaoming
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supporting information; scheme or table
p. 6008 - 6014
(2010/02/28)
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- ASYMMETRIC-SYNTHESIS CATALYST BASED ON CHIRAL BROENSTED ACID AND METHOD OF ASYMMETRIC SYNTHESIS WITH THE CATALYST
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A compound usable as an asymmetric synthesis catalyst which can be easily synthesized without using any metal such as a lanthanoid group element; a method of asymmetric synthesis with the compound; and a chiral compound obtained by the asymmetric synthesis method. A Broensted acid is used as a catalyst in asymmetric synthesis, the chiral Broensted acid being represented by formula (1) below or formula (3) below. The asymmetric synthesis method employs the catalyst. Asymmetric synthesis with the catalyst gives a chiral compound.
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Page/Page column 28-29
(2010/11/08)
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