Table 3. Ortho-Iodination of Benzamidesa, b, c, d, e.
Reaction conditions: 0.30 mmol of benzamide, 2 mol % Pd(OAc)2, 0.75 mmol I2, 0.36 mmol CsOAc, 0.06 mmol K2S2O8, 150 mg 4 Å molecular sieves and 4.0 mL DMSO in a sealed tube, 65 °C, 16 h.
For 4a, 5 mol % Pd(OAc)2 was used, the loadings of I2 and CsOAc were doubled, and the reaction time was shortened to 5 h.
For 4e, 5 mol % Pd(OAc)2 was used.
For 4f, 10 mol % Pd(OAc)2 was used and the reaction solvent was changed to DMF.
Yields of the isolated product.
Trace dimer was formed.