The
asymmetric cyanohydrin reaction of
benzaldehyde with trimethylsilylcyanide is made possible by employment of (R)-
Binol[1] at 1–10%
catalyst loading. This
ligand firsts reacts with a lithium alkoxy compound to form a lithium binaphtholate Complex.
Asymmetric reaction of benzaldehyde with (R)–
Binol–lithium(i-propyloxy) gives (S)-acetonitrile with 98%
ee
The chemist Urech in 1872 was the first to synthesize cyanohydrins from ketones with alkali cyanides and acetic acid[2] and therefore this reaction also goes by the name of Urech cyanohydrin method.
References
^Hatano, Manabu; Ikeno, Takumi; Miyamoto, Takashi; Ishihara, Kazuaki (2005). "Chiral Lithium Binaphtholate Aqua Complex as a Highly Effective Asymmetric Catalyst for Cyanohydrin Synthesis". J. Am. Chem. Soc.127 (31): 10776–77.
doi:
10.1021/ja051125c.
PMID16076152.
Cyanohydrin reaction of
formaldehyde to hydroxyacetonitrile or glycolonitrile with sodium cyanide in
Organic Syntheses Coll. Vol. 2, p. 387; Vol. 13, p. 56
Article