We synthesized a series of phosphine–olefin-type chiral aminophosphines, and we confirmed that these each exists as two rotamers at the C(aryl)–N(amine) bond. We also investigated the ability of these aminophosphines to act as chiralligands for Pd-catalyzed asymmetricallylicsubstitutionreactions, such as the alkylation of allylic acetates with malonates or indoles, and we found they gave high
The palladium-catalyzed asymmetric allylicalkylation of indoles with 1,3-diphenyl-2-propenyl acetate using P/N-type ligands such as N-aryl indole, C–N bond axially chiral aminophosphine (aS)-L4, gave the desired products 1 in good yields and with moderate to high enantioselectivities (up to 90% ee).
We synthesized cinnamoyl amide type chiral P,olefin ligand (S)-4. We successfully obtained separable diastereomers of 4d and demonstrated Pd-catalyzed asymmetric allylic substitution reactions of indoles using (S,aS)-4d as a chiral ligand with high enantioselectivities (up to 98% ee).
我们合成了肉桂酰胺型手性P,烯烃配体( S ) -4。我们成功地获得了4d的可分离非对映异构体,并证明了使用 ( S , aS ) -4d作为具有高对映选择性(高达 98% ee)的手性配体的Pd 催化的吲哚不对称烯丙基取代反应。
Axially chiral <i>N</i>-alkyl-<i>N</i>-cinnamoyl amide type P,olefin ligands for Pd-catalyzed reactions
type phosphine–olefin compounds 1 and found axial chirality in a C(aryl)–N(amide) bond in compounds 1 by HPLC analysis using a chiral stationary phase column. We successfully obtained enantiomeric isomers of 1 and demonstrated the use of (–)-1 for chiral ligands in Pd-catalyzed asymmetric allylic substitution reactions of allylic esters with indoles (up to 97% ee).
Palladium‐Catalyzed Enantioselective Indole Allylic Alkylation with Chiral Phosphoramidite‐Selenide‐Based Ligands
作者:Bin Feng、Yun‐Fan Zhang、Shan Li、Ge‐Yun You、Jun Xuan
DOI:10.1002/ejoc.202300861
日期:2024.1.8
A convenient Pd-catalyzed allylicalkylation of indoles was developed using a P−Se ligand, and the scope of the reaction was demonstrated with various substituted indoles. The corresponding products were obtained in good to excellent yields (up to 95 %) and up to 99 % ee.
使用 P−Se 配体开发了一种方便的 Pd 催化吲哚烯丙基烷基化,并用各种取代的吲哚证明了该反应的范围。相应的产物以良好到优异的收率(高达 95%)和高达 99% ee 获得。