Conjugate Cyanation using NHC-CO₂ Adducts as a Precursor to NHC Catalysts

Anand et al. have reported the 1,6-conjugate cyanation of para-quinone methides 1 using an NHC catalyst prepared from NHC-CO₂ adducts (IMes·CO₂ or IPr·CO₂). According to the report, the use of a catalytic amount of NHC-CO₂ adduct facillitates the 1,6-conjugate cyanation of 1 with trimethylsilyl cyanide (2) smoothly to give &alpha-cyanated aryl products in good yield. Furthermore, this reaction is applicable to the construction of tertially carbon centers affording tritylcyanide derivatives.