Axially chiral N-heterocyclic carbene gold(I) complex catalyzed asymmetric Friedel–Crafts/cyclization reaction of nitrogen-tethered 1,6-enynes with indole derivatives

A class of axially chiral NHC–Au(I) complexes has been applied to the asymmetric Friedel–Crafts/cyclization reaction of nitrogen-tethered 1,6-enynes 14 with indole derivatives 15, affording the corresponding Friedel–Crafts and intramolecular cyclization products 16 in good yields and with moderate ee values under mild conditions.

A class of axially chiral NHC–Au(I) complexes has been applied to the asymmetric Friedel–Crafts/cyclization reaction of 1,6-enynes 14 with indole derivatives 15, affording the corresponding Friedel–Crafts and intramolecular cyclization products 16 in good yields with moderate ee values under mild conditions.Figure optionsDownload as PowerPoint slide

NHC–Au(I) complex (aR)-1C36H26Au2I2N4ee = 100%[α]D20=+24 (c 0.25, CHCl3)Source of chirality: resolutionAbsolute configuration: (R)

NHC–Au(I) complex (aS)-2aC30H23AuIN3Oee = 100%[α]D20=-52 (c 0.25, CHCl3)Source of chirality: resolutionAbsolute configuration: (S)

NHC–Au(I) complex (aS)-2bC36H27AuIN3Oee = 100%[α]D20=-31 (c 0.25, CHCl3)Source of chirality: resolutionAbsolute configuration: (S)

NHC–Au(I) complex (aS)-3C35H25AuIN3Oee = 100%[α]D20=-149 (c 0.25, CHCl3)Source of chirality: resolutionAbsolute configuration: (S)

NHC–Au(I) complex (aR)-4C48H34Au2Cl2N4ee = 100%[α]D20=+60 (c 0.45, CHCl3)Source of chirality: resolutionAbsolute configuration: (R)

NHC–Au(I) complex (aS,R)-5C38H36AuIN4O3ee = 100%[α]D20=-86 (c 0.25, CHCl3)Source of chirality: resolutionAbsolute configuration: (S,R)

NHC–Au(I) complex (aS,S)-5C38H36AuIN4O3ee = 100%[α]D20=-102 (c 0.25, CHCl3)Source of chirality: resolutionAbsolute configuration: (S,S)

NHC–Au(I) complex (aR)-6C32H27AuIN3ee = 100%[α]D20=-134 (c 0.25, CHCl3)Source of chirality: resolutionAbsolute configuration: (R)

NHC–Au(I) complex (aS)-6C32H27AuIN3ee = 100%[α]D20=+172 (c 0.25, CHCl3)Source of chirality: resolutionAbsolute configuration: (S)

NHC–Au(I) complex (aS)-7C30H25AuIN3ee = 100%[α]D20=+48 (c 0.25, CHCl3)Source of chirality: resolutionAbsolute configuration: (S)

NHC–Au(I) complex (aS)-8C35H27AuIN3ee = 100%[α]D20=+20 (c 0.25, CHCl3)Source of chirality: resolutionAbsolute configuration: (S)

NHC–Au(I) complex (aS)-9C42H33AuIN3ee = 100%[α]D20=+51 (c 0.25, CHCl3)Source of chirality: resolutionAbsolute configuration: (S)

NHC–Au(I) complex (aS)-10C35H25AuIN3Oee = 100%[α]D20=-49 (c 0.25, CHCl3)Source of chirality: resolutionAbsolute configuration: (S)

NHC–Au(I) complex (aS)-11C35H25AuIN3ee = 100%[α]D20=-42 (c 0.25, CHCl3)Source of chirality: resolutionAbsolute configuration: (S)