Towards the synthesis of N-heterocycle containing BINOL-phosphoramidites

The first synthesis of a 3,3′-bis-N-heterocycle BINOL-based chiral phosphoramidite ligand is described. The synthesis of a 3,3′-dipyridyl-BINOL-phosphoramidite was prohibited by rapid oxidation at phosphorus. The 3,3′-bistriazolyl-BINOL compound was synthesised using an azide-alkyne cycloaddition, in which the choice of solvent and amine base proved critical.

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(S)-3,3′-Diiodo-2,2′-bismethoxymethoxy-1,1′-binaphthylC24H20I2O4[α]D20=-7.4 (c 1.0, THF)Source of chirality: BINOLAbsolute configuration: (S)

(S)-3,3′-Diethynyl-2,2′-dihydroxy-1,1′-binaphthylC24H14O2[α]D20=-83 (c 1.0, THF)Source of chirality: BINOLAbsolute configuration: (S)

(S)-3,3′-Diethynyl-1,1′-binaphthyl-2,2′-diyl 1-pyrrolidylphosphoniteC28H20NO2P[α]D20=-17 (c 1.0, THF)Source of chirality: BINOLAbsolute configuration: (S)

(S)-3,3′-Di(1-benzyl-1,2,3-triazol-4-yl)-1,1′-binaphthyl-2,2′-diyl 1-pyrrolidylphosphoniteC42H34N7O2P[α]D20=-8.3 (c 0.4, THF)Source of chirality: BINOLAbsolute configuration: (S)