Spiro Indane-Based Phosphine-Oxazolines as Highly Efficient P,N Ligands for Enantioselective Pd-Catalyzed Allylic Alkylation of Indoles and Allylic Etherification
作者:Zhongxuan Qiu、Rui Sun、Kun Yang、Dawei Teng
DOI:10.3390/molecules24081575
日期:——
were examined for palladium-catalyzedasymmetricallylic alkylation of indoles. Under optimized conditions, high yields (up to 98%) and enantioselectivities (up to 98% ee) were obtained with a broad scope of indole derivatives. The ligand was determined to be the most efficient P,N-ligand for this reaction. Moreover, the ligand was also efficient for Pd-catalyzed asymmetricallylic etherification with
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 preparation of various (R)-Sulfur-MOP ligands with aryl and alkyl substituents on sulfur, and the application of these ligands to Pd-catalyzed asymmetric allylic alkylation of indoles is reported. The sulfur substituent served as an effective stereocontrol element, and in the case of the 2-i-PrPh substituent on sulfur, the allylation products from an array of simple and substituted indoles were
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。