BICMAP-rhodium(I)-catalyzed asymmetric 1,4-addition of arylboronic acids to coumarins

Rhodium(I)-catalyzed asymmetric 1,4-addition of arylboronic acids 2 to coumarins 1 using (S)-BICMAP as a chiral ligand gave the desired 4-arylchroman-2-one derivatives 2 in good yields and with high enantioselectivities (up to 99% ee).

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(S)-4-Phenylchroman-2-oneC15H12O2ee = 99% from HPLC[α]D20 = +41.2 (c 0.62, CHCl3)Source of chirality: Asymmetric synthesisAbsolute configuration: (S)

(S)-4-(4-Methylphenyl)chroman-2-oneC16H14O2ee = 98% from HPLC[α]D20 = +45.5 (c 0.45, CHCl3)Source of chirality: Asymmetric synthesisAbsolute configuration: (S)

(S)-4-(4-Methoxyphenyl)chroman-2-oneC16H14O3ee = 95% from HPLC[α]D20 = +35.7 (c 0.51, CHCl3)Source of chirality: Asymmetric synthesisAbsolute configuration: (S)

(S)-4-(3-Methylphenyl)chroman-2-oneC16H14O2ee = 95% from HPLC[α]D20 = +41.5 (c 0.50, CHCl3)Source of chirality: Asymmetric synthesisAbsolute configuration: (S)

(S)-4-(3,5-Dimethylphenyl)chroman-2-oneC17H16O2ee = 99% from HPLC[α]D20 = +40.1 (c 0.40, CHCl3)Source of chirality: Asymmetric synthesisAbsolute configuration: (S)

(S)-4-(2-Naphthalenyl)chroman-2-oneC19H14O2ee = 80% from HPLC[α]D20 = +42.6 (c 0.45, CHCl3)Source of chirality: Asymmetric synthesisAbsolute configuration: (S)

(S)-4-(2-Methylphenyl)chroman-2-oneC16H14O2ee = 99% from HPLC[α]D20 = +75.5 (c 0.35, CHCl3)Source of chirality: Asymmetric synthesisAbsolute configuration: (S)

(S)-6-Methyl-4-phenylchroman-2-oneC16H14O2ee = 96% from HPLC[α]D20 = +3.5 (c 0.51, CHCl3)Source of chirality: Asymmetric synthesisAbsolute configuration: (S)

(S)-7-Methyl-4-phenylchroman-2-oneC16H14O2ee = 96% from HPLC[α]D20 = +33.4 (c 0.51, CHCl3)Source of chirality: Asymmetric synthesisAbsolute configuration: (S)

(S)-7-Methoxy-4-phenylchroman-2-oneC16H14O2ee = 98% from HPLC[α]20D = +41.0 (c 0.37, CHCl3)Source of chirality: Asymmetric synthesisAbsolute configuration: (S)