Nucleophilic addition reactions to the ethylnitrilium derivative of nido-carborane 10-EtCN-7,8-C2B9H11

Abstract

Alkylnitrilium derivatives of nido-carborane 10-RCN-7,8-C₂B₉H₁₁ (R = Me, Et) have been prepared by the reaction of the parent anion [7,8-C₂B₉H₁₂]⁻ with mercury(II) chloride in mixtures of the corresponding nitriles and benzene. Hydrolysis of 10-EtCN-7,8-C₂B₉H₁₁ resulted in iminol 10-EtC(OH)HN-7,8-C₂B₉H₁₁ which on treatment with a base gave the corresponding amide 10-EtC(O)HN-7,8-C₂B₉H₁₁. The reactions of 10-EtCN-7,8-C₂B₉H₁₁ with alcohols and thiols were found to give stable imidates and thioimidates 10-EtC(XR)HN-7,8-C₂B₉H₁₁ (X = O, R = Me, Et, iPr, Bu; X = S, R = Et, Bu, Hx) as mixtures of E- and Z-isomers that were successfully separated by column chromatography. The crystal molecular structures of E-10-EtC(OR)HN-7,8-C₂B₉H₁₁ (R = Et, i-Pr, Bu) and Z-10-EtC(SEt)HN-7,8-C₂B₉H₁₁ were determined by single crystal X-ray diffraction.