Synthesis of allyl cyanamides and N-cyanoindoles via the palladium-catalyzed three-component coupling reaction.
The palladium-catalyzed three-component coupling reaction (TCCR) of aryl isocyanides, allyl methyl carbonate, and trimethylsilyl azide was conducted in the presence of Pd(2)(dba)(3).CHCl(3) (2.5 mol %) and dppe (1,2-bis(diphenylphosphino)ethane) (10 mol %). Allyl aryl cyanamides with a wide variety of functional groups were obtained in excellent yields. This palladium-catalyzed TCCR was further utilized for the synthesis of N-cyanoindoles. The reaction of 2-alkynylisocyanobenzenes, allyl methyl carbonate, and trimethylsilyl azide in the presence of Pd(2)(dba)(3).CHCl(3) (2.5 mol %) and tri(2-furyl)phosphine (10 mol %) at higher temperatures afforded N-cyanoindoles in good to allowable yields. (eta(3)-Allyl)(eta(3)-cyanamido)palladium complex, an analogue of the bis-pi-allylpalladium complex, is a key intermediate in the TCCR, and a pi-allylpalladium mimic of the Curtius rearrangement is involved to generate the (eta(3)-allyl)(eta(3)-cyanamido)palladium intermediate.
D018360:Crystallography, X-Ray; D003484:Cyanamide / Q000138:chemical synthesis / Q000737:chemistry; D003486:Cyanides / Q000138:chemical synthesis* / Q000737:chemistry; D007211:Indoles / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D010165:Palladium / Q000737:chemistry
D003486:Cyanides; D007211:Indoles; D003484:Cyanamide; D010165:Palladium