|Molar mass||622.67 g·mol−1|
|Melting point||239 to 241 °C (462 to 466 °F; 512 to 514 K) (R)
238–240 °C (S)
Except where noted otherwise, data is given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
|what is: / ?)(|
BINAP (2,2'-bis(diphenylphosphino)-1,1'-binaphthyl) is an organophosphorus compound. This chiral ligand is widely used in asymmetric synthesis. It consists of a pair of 2-diphenylphosphinonaphthyl groups linked at the 1 and 1´ positions. This C2-symmetric framework lacks a stereogenic atom, but has axial chirality due to restricted rotation (atropisomerism). The barrier to racemization is high due to steric hindrance, which limits rotation about the bond linking the naphthyl rings. The dihedral angle is approximately 90˚.
Use as ligand in asymmetric catalysis
BINAP is used in organic synthesis for enantioselective transformations catalyzed by its complexes of ruthenium, rhodium, and palladium. As pioneered by Ryōji Noyori and his co-workers, Rh complexes of BINAP are useful for the synthesis of (–)-menthol.
BINAP is prepared from BINOL via its bis-triflate derivatives. Both the (R)- and (S)-enantiomers, as well as the racemate, are commercially available. One of the wide applications include chemoselective hydrogenation, where BINAP is conjugated to Rh.
- Kitamura, Masato; M. Tokunaga; T. Ohkuma; R. Noyori (1998). "Asymmetric hydrogenation of 3-oxo carboxylates using BINAP-ruthenium complexes". Org. Syn. 9: 589.
- Akutagawa, S (1992). "A practical synthesis of (−)-menthol with the Rh-BINAP catalyst". Chirality Ind.: 313–323.
- Kumobayashi, Hidenori; Sayo, Noboru; Akutagawa, Susumu; Sakaguchi, Toshiaki; Tsuruta, Haruki (1997). "Industrial asymmetric synthesis by use of metal-BINAP catalysts". Nippon Kagaku Kaishi 12: 835–846.
- Yanagisawa, Akira; Touge, Taichiro; Takayoshi, Arai (2005). "Enantioselective Protonation of Silyl Enolates Catalyzed by a Binap⋅AgF Complex". Angewandte Chemie International Edition 44 (10): 1546–8. doi:10.1002/anie.200462325.
- Shimizu, H., Nagasaki, I., Matsumura, K., Sayo, N., Saito, T. (2007). "Developments in Asymmetric Hydrogenation from an Industrial Perspective". Acc. Chem. Res. 40 (12): 1385–1393. doi:10.1021/ar700101x. PMID 17685581.
- "BINAP: An industrial approach to manufacture". Rhodia (company). Retrieved 2008-10-20.
- Cai, Dongwei; J. F. Payack; D. R. Bender; D. L. Hughes; T. R. Verhoeven; P. J. Reider (2004). "(R)-(+)- and (S)-(−)-2,2'-bis(diphenylphosphino)-1,1'-binapthyl (BINAP)". Org. Syn. 10: 112.
- Nakajima, Makoto; S. Kotani; T. Ishizuka; S. Hashimoto (2005). "Chiral Phosphine Oxide BINAPO as a Catalyst for Enantioselective Allylation of Aldehydes with Allyltrichlorosilanes". ChemInform 36 (16). doi:10.1002/chin.200516031.