Solvent‐Mediated C3/C7 Regioselective Switch in Chiral Phosphoric Acid‐Catalyzed Enantioselective Friedel‐Crafts Alkylation of Indoles with α‐Ketiminoesters
作者:Yunlong Zhao、Lu Cai、Tongkun Huang、Shanshui Meng、Albert S. C. Chan、Junling Zhao
DOI:10.1002/adsc.201901380
日期:2020.3.17
The first solvent‐mediated tunable C3/C7 regio‐ and enantioselective Friedel‐Crafts alkylation of 4‐aminoindoles with α‐ketimino esters has been developed. This catalysis allows the highly regioselective formation of indole C3 and C7 alkylation products, both in high yields (up to 96%) and excellent enantioselectivities (up to 99% ee). Mechanism study revealed that the hydrogen‐bonding interactions
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
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
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