The First Catalytic Enantioselective Aldol-Type Reaction of Ethyl Diazoacetate to Ketones
作者:Fides Benfatti、Seda Yilmaz、Pier Giorgio Cozzi
DOI:10.1002/adsc.200900435
日期:——
The aldol-type addition to ketones still represents a great challenge in asymmetric catalysis. Recently, the direct aldol reaction between the commercially available ethyl diazoacetate and aldehydes has attracted increasing attention. Ethyl diazoacetate is economical and allows further transformation of the aldol adduct obtained. We present a solution for the arduous, and not previously described,
Highly Enantioselective Synthesis
of α-Diazo-β-hydroxy Esters Using a Bifunctional
Titanium Complex
作者:Xiaoming Feng、Wentao Wang、Ke Shen、Xiaolei Hu、Jun Wang、Xiaohua Liu
DOI:10.1055/s-0029-1217322
日期:——
A bifunctional titanium catalyst system has been developed for the asymmetric direct-type aldol reaction of ethyl diazo-acetate with aldehydes, which produced the desired products in good yields (up to 83%) with excellent enantioselectivities (up to 94% ee). A wide range of aromatic, heteroaromatic and aliphatic aldehydes were found to be suitable substrates in the presence of (S)-BINOL (5 mol%), cinchonine
已经开发了一种双功能钛催化剂体系,用于重氮乙酸乙酯与醛的不对称直接型羟醛反应,以良好的收率(高达 83%)和优异的对映选择性(高达 94% ee)生产所需的产物。在 (S)-BINOL (5 mol%)、辛可宁 (5 mol%)、Ti(Oi-Pr) 4 (5 mol%) 存在下,广泛的芳香族、杂芳香族和脂肪族醛被发现是合适的底物和 H 2 O (15 mol%)。在实验结果和之前的报告的基础上,提出了一种可能的工作模型来解释激活和不对称感应的起源。
Direct Catalytic Asymmetric Aldol-Type Reaction of Aldehydes with Ethyl Diazoacetate
作者:Wengang Yao、Jianbo Wang
DOI:10.1021/ol0343257
日期:2003.5.1
The directaldol-type condensation of aldehydes with ethyl diazoacetate catalyzed by the chiral complex of BINOL derivatives-Zr(O(t)Bu)(4) gave beta-hydroxy alpha-diazo carbonyl compounds with moderate enantioselectivities (53-87% ee). [reaction: see text]
Unusual Reaction of β-Hydroxy α-Diazo Carbonyl Compounds with Cl<sub>3</sub>CCN/NaH and Rh(II)-Catalyzed Reaction of β-Trichloroacetylamino α-Diazo Carbonyl Compounds
作者:Weifeng Shi、Nan Jiang、Shiwei Zhang、Weiming Wu、Daming Du、Jianbo Wang
DOI:10.1021/ol034550o
日期:2003.6.1
The hydroxyl group was directly converted into the trichloroacetylamino group by reacting beta-hydroxy alpha-diazo carbonylcompounds with Cl(3)CCN and NaH. Rh(II)-catalyzed reactions of the beta-amino alpha-diazo carbonylcompounds were discussed. [reaction: see text]