N-isocyaniminotriphenylphosphorane (Ph₃PNNC) as an efficient reagent for the synthesis of ferrocene-containing 1,3,4-oxadiazole derivatives

GRAPHICAL ABSTRACT

ABSTRACT

Reaction of N-isocyaniminotriphenylphosphorane (Ph₃PNNC) with an aromatic aldehyde in the presence of ferrocene carboxylic acid and a secondary amine proceeds smoothly at room temperature under neutral conditions to afford sterically congested ferrocene-containing 1,3,4-oxadiazole derivatives in high yields. The reaction progresses smoothly and clearly under mild conditions and no side reactions were observed.

KEYWORDS:

• N-isocyaniminotriphenylphosphorane (Ph₃PNNC)
• aromatic aldehyde
• ferrocene carboxylic acid
• secondary amine
• 1,3,4-oxadiazole
• aza-Wittig reaction

Funding

This work is funded by 2015 Yeungnam University Research Grant.