Diastereospecific Enantiodivergent Allylation of Pyrazolones as an Entry to β‐Aminoamides
作者:Nick Wannenmacher、Martin Heberle、Xin Yu、Aysegül Demircan、Daniel M. Wanner、Camilla Pfeffer、René Peters
DOI:10.1002/adsc.202200185
日期:2022.10.4
A diastereospecificenantiodivergentallylation of pyrazolones is reported which is catalyzed by a planar chiral pentaphenylferrocene based palladacycle. With the same catalyst batch both product enantiomers were selectively available. The method is applicable to structurally diverse substrates and gave products with enantiomeric excesses between 85 and 94%. In addition, we could show that pyrazolones
Iterative approach to polyketide-type structures: stereoselective synthesis of 1,3-polyols utilizing the catalytic asymmetric Overman esterification
作者:Jörg T. Binder、Stefan F. Kirsch
DOI:10.1039/b708248g
日期:——
An iterative systematic approach to the 1,3-polyol motif has been developed to provide access to all possible stereoisomers by utilizing the catalytic asymmetric Overman esterification for the construction of all stereogenic centres.
Asymmetric allylic substitutions usually display a pronounced preference for the formation of allylic substitution products with (E)-configured C=C double bonds as a result of π-allyl-Pd intermediates. A planar chiral palladacycle is shown to permit a catalytic asymmmetric allylationreaction maintaining the C=C double bond geometry of the allylicsubstrates in highly enantioenriched products.
由于 π-烯丙基-Pd 中间体,不对称烯丙基取代通常表现出明显优先于形成具有 ( E )-构型 C=C 双键的烯丙基取代产物。平面手性钯环可进行催化不对称烯丙基化反应,从而在高度对映体富集的产物中保持烯丙基底物的 C=C 双键几何结构。
Catalytic Asymmetric Synthesis of Allylic Aryl Ethers
作者:Stefan F. Kirsch、Larry E. Overman、Nicole S. White
DOI:10.1021/ol070110b
日期:2007.3.1
The reaction of trichloroacetimidate derivatives of (Z)-2-alken-1-ols with phenol nucleophiles in the presence of the palladium(II) catalyst [COP-OAc](2) provides 3-aryloxy-1-alkenes in high yields and high enantiomeric purity (typically 63-90% yield and 90-97% ee). The reaction is exemplified by 20 examples. The method employs 1 mol % of the commercially available catalysts (S)- or (R)-[COPOAc](2), produces the branched isomer with unprecedented regioselectivity, and is compatible with the presence of base-labile functionality in either reactant.