An efficient synthesis of dinitrile derivatives by the reaction of oxime esters or acid anhydrides with cyanotrimethylsilane catalyzed by La(O(i)Pr)3

The reaction of oxime esters with cyanotrimethylsilane (Me3SiCN) under the influence of a catalytic amount of lanthanide compounds produced alpha-trimethylsilyloxydinitrile derivatives in excellent yields accompanied with the formation of trimethylsilyl oxime ethers. Among the lanthanoid catalysts examined, La((OPr)-Pr-i)(3) was found to be the best catalyst. The reaction seems to proceed through the formation- of acyl cyanides as intermediates, followed by the addition of Me3SiCN to them. Additionally, the reaction of acetic anhydride with Me3SiCN catalyzed by La((OPr)-Pr-i)(3) gave 1-trimethylsilyloxyethane dinitrile. Thus, various alpha-trimethylsilyloxydinitriles were synthesized in good yields by allowing oxime esters or acid anhydrides to react with Me3SiCN in the presence of a catalytic amount of La((OPr)-Pr-i)(3).