Palladium-Catalyzed Cyanation of Aryl Triflates

Abstract

A simple catalyst system comprising Pd(OAc)₂ and DPPF was proved to be efficient for the cyanation of aryl triflates with potassium hexacyanoferrate(II) as cyanide source.

Keywords:

• Aryl nitriles
• aryl triflates
• cyanation
• palladium
• potassium hexacyanoferrate(II)

Notes

^a Reaction conditions: 1 mmol phenyl triflate, 20 mol% dry K₄[Fe(CN)₆], 3 mL DMAc, 5 mol% Pd source, 100 mol% Na₂CO₃, 140 °C, 24 h.

^b Ligand–Pd source = 2:1.

^c Yields were determined by GC with 1,3-dimethoxybenzene as the internal standard.

^d 0.1 mol% Pd(OAc)₂ was used.

^e 2 mol% Pd(OAc)₂ was used.

^a Reaction conditions: 1 mmol phenyl triflate, 20 mol% dry K₄[Fe(CN)₆], 5 mol% Pd(OAc)₂, 10 mol% DPPF, 3 mL solvent, 100 mol% base, 140 °C, 24 h.

^b Yields were determined by GC with 1,3-dimethoxybenzene as the internal standard.

^c A large amount of phenol was obtained.

^d C₄H₄O₆KNa · 4H₂O–potassium sodium tartrate tetrahydrate.

^a Reaction conditions: 1 mmol aryl triflate, 20 mol% dry K₄[Fe(CN)₆], 3 mL DMAc, 5 mol% Pd(OAc)₂, 10 mol% DPPF, 100 mol% Na₂CO₃, 140 °C, 24 h.

^b Yields were determined by GC with 1,3-dimethoxybenzene as the internal standard. All prepared benzonitriles are commercially available.

^c Number in parentheses was obtained by slow addition of aryl triflate.