1,1'-bi-2-naphthol

1,1'-Bi-2-naphthol

Names
IUPAC name [1,1'-binaphthalene]-2,2'-diol
Other names 1,1'-bi-2-naphthol 1,1-binaphthol BINOL
Identifiers
CAS Number	602-09-5 (R/S) 18531-94-7 ((R)-(+)) 18531-99-2 (S)-(−)
3D model (JSmol)	Interactive image Interactive image
ChemSpider	11269 Y
ECHA InfoCard	100.009.104
PubChem CID	11762
InChI InChI=1S/C20H14O2/c21-17-11-9-13-5-1-3-7-15(13)19(17)20-16-8-4-2-6-14(16)10-12-18(20)22/h1-12,21-22H Y Key: PPTXVXKCQZKFBN-UHFFFAOYSA-N Y InChI=1/C20H14O2/c21-17-11-9-13-5-1-3-7-15(13)19(17)20-16-8-4-2-6-14(16)10-12-18(20)22/h1-12,21-22H Key: PPTXVXKCQZKFBN-UHFFFAOYAX
SMILES Oc4ccc1c(cccc1)c4c2c3c(ccc2O)cccc3 c1ccc2c(c1)ccc(c2c3c4ccccc4ccc3O)O
Properties
Chemical formula	C20H14O2
Molar mass	286.32 g/mol
Melting point	205 to 211 °C (401 to 412 °F; 478 to 484 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Y  (what is YN ?)
Infobox references

1,1'-Bi-2-naphthol (BINOL) is an organic compound that is often used as a ligand for transition-metal catalysed asymmetric synthesis. BINOL has axial chirality and the two enantiomers can be readily separated and are stable toward racemisation. The specific rotation of the two enantiomers is +/- 35.5° (c=1 in THF). BINOL is a precursor for another chiral ligand called BINAP.

The organic synthesis of BINOL is not a challenge as such but the preparation of the individual enantiomers is.

(S)-BINOL can be prepared directly from an asymmetric oxidative coupling of 2-naphthol with copper(II) chloride. The chiral ligand in this reaction is (S)-(+)-amphetamine.

Racemic BINOL can also be produced using iron(III) chloride as an oxidant. The mechanism involves complexation of iron(III) into the hydroxyl, followed by a radical coupling reaction of the naphthol rings initiated by iron(III) reducing into iron(II).