Isosterically designed chiral catalysts: Rationale, optimization and their application in enantioselective nucleophilic addition to aldehydes
作者:En Gao、Qiao Li、Lili Duan、Lin Li、Yue-Ming Li
DOI:10.1016/j.tet.2020.131648
日期:2020.11
enantioselective nucleophilic addition to aldehydes. In the presence of 10 mol% of chiral ligand 1b, enantioselective addition of diethylzinc to aldehydes provided the corresponding secondary alcohols in up to 90% isolated yield and up to 99% ee. Similarly, using 3e as chiral ligand, enantioselective arylation and alkynylation of aldehydes also proceeded readily, leading to the desired chiral alcohols in up to
Enantioselective addition of diethylzinc to aromatic aldehydes catalyzed by titanium-5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-bi-2-naphthol complex
作者:Fu-Yao Zhang、Albert S.C. Chan
DOI:10.1016/s0957-4166(97)00501-6
日期:1997.11
The use of Ti(H8-BINOL) (H8-BINOL=5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-bi-2-naphthol) as a catalyst for the diethylzinc addition to aldehydes has been studied, and high e.e.s (up to 98.5%) were obtained for the chiral alcohol products. The results were significantly better than those obtained with the corresponding Ti(BINOL) catalyst (BINOL=1,1′-bi-2-naphthol).
L-Alanine-derived Chiral Ligands for Asymmetric Addition of Diethylzinc to Aldehydes
作者:Seock-Yong Kang、Jin-Ho Baek、Kyoung-Hee Kang、Jeong-Ae Lee、Yong-Sun Park
DOI:10.5012/bkcs.2012.33.9.3125
日期:2012.9.20
of efficient chiralligands for catalytic asymmetric addition of dialkylzinc. Among the various types of chiralligands explored several β-aminoalcohols have proven to be especially efficient ligands for the additions. However, the development of stable and easily accessible β-aminoalcoholligands is still desirable for practical applications. It is convenient that β-aminoalcohols can be prepared
Design of a Chiral Ionic Liquid System for the Enantioselective Addition of Diethylzinc to Aldehydes
作者:Mariana Ferrari Bach、Cassiana Herzer Griebeler、Caroline Gross Jacoby、Paulo Henrique Schneider
DOI:10.1002/ejoc.201701426
日期:2017.12.15
immobilisation in ionic solvents to provide a chiral supramolecular structure. These new catalytic systems were used in the enantioselective addition of alkylzinc to aldehydes and proved to be very efficient, capable of providing chiral secondary alcohols in excellent enantiomeric excesses and yields. This system also enabled the recycling of the ionic media and the ionic ligand, taking into account green chemistry
Several chiral diamines, (S)-1-alkyl-2-(arylamino)methylpyrrolidine, were used as chiral catalysts for the enantioselective addition of diethylzinc to aldehydes. The best results were obtained by employing 0.15 equiv of (S)-2-anilinomethyl-1-benzylpyrrolidine, and chiral secondary alcohols were obtained with high enantiomeric excesses (up to 94% ee).