Synthesis of 3 or 3,3′-substituted BINOL ligands and their application in the asymmetric addition of diethylzinc to aromatic aldehydes

Three new substituted BINOL ligands (R)-3-[4,6-bis(dimethylamino)-1,3,5-triazin-2-yl]-1,1′-bi-2-naphthol (R)-1, (R)-3,3′-bis[4,6-bis(dimethylamino)-1,3,5-triazin-2-yl]-1,1′-bi-2-naphthol (R)-2 and 2,4-bis(2,2′-dihydroxy-1,1′-binaphthalen-3-yl)-6-(p-tolyl)-1,3,5-triazine (R,R)-3 have been obtained by directed ortho-lithiation or Suzuki cross-coupling process. Ligand (R)-1 shows improved catalytic properties for the asymmetric diethylzinc addition to aromatic aldehydes.

Figure optionsDownload as PowerPoint slide

(R)-3-[4,6-Bis(dimethylamino)-1,3,5-triazin-2-yl]-2,2′-bis(methoxymethoxy)-1,1′-binaphthaleneC31H33N5O4Ee = 100%[α]D25=+88.2 (c 0.51, CH2Cl2)Source of chirality: resolutionAbsolute configuration: R

(R)-3,3′-Bis[4,6-bis(dimethylamino)-1,3,5-triazin-2-yl]-2,2′-bis(methoxymethoxy)-1,1′-binaphthaleneC38H44N10O4Ee = 100%[α]D25=+16.7 (c 0.52, CH2Cl2)Source of chirality: resolutionAbsolute configuration: R

2,4-Bis[2,2′-bis(methoxymethoxy)-1,1′-binaphthalen-3-yl]-6-(p-tolyl)-1,3,5-triazineC58H49N3O8Ee = 100%[α]D25=+158.6 (c 0.57, CH2Cl2)Source of chirality: resolutionAbsolute configuration: R,R

(R)-3-[4,6-Bis(dimethylamino)-1,3,5-triazin-2-yl]-1,1′-bi-2-naphtholC27H25N5O2Ee = 100%[α]D25=+61.1 (c 0.61, CH2Cl2)Source of chirality: resolutionAbsolute configuration: R

(R)-3,3′-Bis[4,6-bis(dimethylamino)-1,3,5-triazin-2-yl]-1,1′-bi-2-naphtholC34H36N10O2Ee = 100%[α]D25=+79.2 (c 0.47, CH2Cl2)Source of chirality: resolutionAbsolute configuration: R

2,4-Bis(2,2′-dihydroxy-1,1′-binaphthalen-3-yl)-6-(p-tolyl)-1,3,5-triazineC50H33N3O4Ee = 100%[α]D25=+202.2 (c 0.81, CH2Cl2)Source of chirality: resolutionAbsolute configuration: R,R