60036-64-8Relevant articles and documents
The Cyanation of Vinyl Halides with Alkali Cyanides Catalyzed by Nickel(0)-Phosphine Complexes Generated In Situ: Synthetic and Stereochemical Aspects
Sakakibara, Yasumasa,Enami, Hiroji,Ogawa, Hiroshi,Fujimoto, Shinpei,Kato, Hiroyuki,et al.
, p. 3137 - 3144 (1995)
The cyanation of β-bromostyrenes catalyzed by Ni(PPh3)n, which was generated in situ from NiBr2(PPh3)2-Zn-PPh3 (Ni:Zn:P=1:3:2 molar ratio), was at first examined with various MCN (M=K, Na)-dipolar aprotic solvent systems by several procedures.The presence of excess cyanide ion inhibited the reaction.However, when the KCN-DMF system with some intermediate cyanide solubility was used, the nitriles were obtained in high yields and high stereoselectivity at 50 deg C by almost all of the procedures attempted.On the contrary, the KCN-HMPA and KCN-MeCN systems with cyanide solubilities accelerated the coupling of the halides to inhibit the cyanation, and in general the NaCN-DMF and NaCN-HMPA systems with high cyanide solubilities needed to reduce Ni(II) before adding MCN in order to make the catalytic reaction start.Vinyl halides such as 1- and 2-halo (Cl, Br)-1-alkenes, 2-bromo-2-butenes, 3-bromo-3-hexenes, and 1-chlorocyclohexene were also cyanated using suitable procedures and MCN-solvent systems to give the corresponding nitriles in high yields and fair-to-good stereoselectivities.However, with (Z)-2-ethoxy-1-bromoethene the (E)-nitrile, though its selectivity markedly varied with the reaction temperature, was obtained as the main product.The cyanation of ethyl (Z)-β-bromoacrylate and ethyl α-bromoacrylate was unsuccessful due to polymerization.
