A RuPHOX−Ru catalyzedasymmetrichydrogenation of γ‐keto acids has been developed, affording the corresponding enantiopure γ‐lactones in high yields and with up to 97% ee. The reaction could be performed on a gram scale with a relatively low catalyst loading (up to 10000 S/C) under the indicated reaction conditions and the resulting products can be transformed to several enantiopure building blocks
已开发出RuPHOX-Ru催化的γ-酮酸不对称氢化反应,可提供高收率和高达97%ee的相应对映体纯γ-内酯。该反应可以在指定的反应条件下以相对较低的催化剂负载量(最高10000 S / C)以克为单位进行,所得产物可以转化为几种对映纯结构单元,生物活性化合物和对映纯药物。
Biocatalytic Asymmetric Reduction of γ‐Keto Esters to Access Optically Active γ‐Aryl‐γ‐butyrolactones
achieved by enzymatic asymmetric reduction of the corresponding sterically demanding γ‐keto esters employing wild‐type and recombinant alcohol dehydrogenases. The best stereoselectivities for the reduction via hydrogen transfer was obtained with two short chain dehydrogenases (SDRs) of complementary stereospecificity from Aromatoleum aromaticum, namely the Prelog‐specific NADH‐dependent (S)‐1‐phenylethanol
Palladium/Zinc Co‐Catalyzed Asymmetric Hydrogenation of γ‐Keto Carboxylic Acids
作者:Keyang Zhang、Xuexin Zhang、Jingchao Chen、Zixiu Liu、Chunxiang Pan、Yuanbin Zhu、Shiyuan Wu、Baomin Fan
DOI:10.1002/asia.202100244
日期:2021.5.17
A palladium‐catalyzed asymmetric hydrogenation of levulinic acid has been successful developed by using Zn(OTf)2 as co‐catalyst. The present method not only has provided a strategy in the palladium‐catalyzed asymmetric hydrogenation of ketone, but also allowed the preparation of a wide range of chiral γ‐valerolactones in good yields with excellent enantioselectivities.
Cyclic ethers have been effectively synthesized via the intramolecular cyclization of diols using trimethyl phosphate and NaH. The present cyclization could proceed at room temperature to produce 5–7 membered cyclic ethers in good to excellent yields. Substrates possessing a chiral secondary hydroxy group were transformed into the corresponding chiral cyclic ethers along with the retention of their