Palladium-catalyzed asymmetric allylic alkylation of indoles by C–N bond axially chiral phosphine ligands

The palladium-catalyzed asymmetric allylic alkylation 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).

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(R)-(–)-3-[(E)-1,3-Diphenyl-2-propen-1-yl]-6-methyl-1H-indoleC24H21Nee = 33% from HPLC[α]D20 = –13.2 (c 0.50, CHCl3)Source of chirality: asymmetric synthesisAbsolute configuration: (R)

(R)-(–)-3-[(E)-1,3-Diphenyl-2-propen-1-yl]-6-methoxy-1H-indoleC24H21NOee = 75% from HPLC[α]D20 = –37.0 (c 0.50, CHCl3)Source of chirality: asymmetric synthesisAbsolute configuration: (R)

(R)-(–)-6-Benzyoxy-3-[(E)-1,3-diphenyl-2-propen-1-yl]-1H-indoleC30H25NOee = 34% from HPLC[α]D20 = –11.6 (c 0.50, CHCl3)Source of chirality: asymmetric synthesisAbsolute configuration: (R)

(R)-(–)-6-Chloro-3-[(E)-1,3-diphenyl-2-propen-1-yl]-1H-indoleC23H18ClNee = 86% from HPLC[α]D20 = –13.3 (c 0.50, CHCl3)Source of chirality: asymmetric synthesisAbsolute configuration: (R)

(R)-(–)-6-Fluoro-3-[(E)-1,3-diphenyl-2-propen-1-yl]-1H-indoleC23H18FNee = 44% from HPLC[α]D20 = –14.2 (c 0.50, CHCl3)Source of chirality: asymmetric synthesisAbsolute configuration: (R)