C7‐Functionalization of Indoles via Organocatalytic Enantioselective Friedel‐Crafts Alkylation of 4‐Amino‐ indoles with 2‐Butene‐1,4‐diones and 3‐Aroylacrylates
作者:Tongkun Huang、Yunlong Zhao、Shanshui Meng、Albert S. C. Chan、Junling Zhao
DOI:10.1002/adsc.201900377
日期:2019.8.5
An efficient protocol for the enantioselective C7 Friedel‐Crafts alkylation between 4‐aminoindoles and 2‐butene‐1,4‐diones or 3‐aroylacrylates was reported. This process was catalyzed by a chiral phosphoric acid, affording the corresponding 1,4‐disubstituted indoles in moderate to high yields with good to high enantioselectivities. This reaction could be performed on a gram scale without loss of efficiency
Catalytic Asymmetric C-7 Friedel–Crafts Alkylation/<i>N</i>-Hemiacetalization of 4-Aminoindoles
作者:Hualing He、Yang Cao、Jun Xu、Jon C. Antilla
DOI:10.1021/acs.orglett.1c00699
日期:2021.4.16
unique catalytic asymmetric C-7 Friedel–Craftsalkylation/N-hemiacetalization cascade reaction of 4-aminoindoles with β,γ-unsaturated α-keto esters has been described. Using a chiral magnesium H8–BINOL-derived bis(phosphate) complex as catalyst, the resulting functionalized 1,7-annulated indole scaffolds are obtained in high yields (up to 98%) and with good to excellent enantioselectivities (up to
Chiral Phosphoric-Acid-Catalyzed Regioselective and Enantioselective C7-Friedel–Crafts Alkylation of 4-Aminoindoles with Trifluoromethyl Ketones
作者:Lu Cai、Yunlong Zhao、Tongkun Huang、Shanshui Meng、Xian Jia、Albert S. C. Chan、Junling Zhao
DOI:10.1021/acs.orglett.9b00821
日期:2019.5.17
trifluoromethyl ketones promoted by a spirocyclic phosphoric acid was developed. This strategy was applicable to various substituted trifluoromethyl ketones and 4-aminoindole derivatives, affording the corresponding C7-functionalized indole derivatives, bearing a pharmaceutically interesting trifluoromethylated tertiary alcohol scaffold, in 21%–98% yields with up to >99% enantiomeric excess (ee).
Regio and Enantioselective Organocatalytic Friedel–Crafts Alkylation of 4-Aminoindoles at the C7-Position
作者:Wen Xun、Bo Xu、Bo Chen、Shanshui Meng、Albert S. C. Chan、Fayang G. Qiu、Junling Zhao
DOI:10.1021/acs.orglett.7b03703
日期:2018.2.2
acid catalyzed highly regio- and enantioselective Friedel–Crafts alkylation at the indole C7-position was developed via the introduction of an alkylamine moiety at the C4-position of the indole ring. The methodology is applicable to a wide range of 4-aminoindoles and β,γ-unsaturated α-ketimino esters to furnish the corresponding C7-position functionalized chiral indole derivatives in high yields with