Hypervalent Iodine in Synthesis. Part 86

N ‐Arylation of uracil and its derivatives 2 with diaryliodonium salts 1 was investigated in order to explore a new synthetic methodology associated with N ‐aryluracil derivatives. In the presence of K 2 CO 3 , the copper‐catalyzed arylation gave N 1 , N 3 ‐diarylation products with high selectivity and in good yields ( Table 2 ). However, the use of NaOAc as the base in the copper‐catalyzed arylation of 6‐methyluracil ( 2a ) resulted in N 3 ‐arylation products with high selectivity, and, in the copper‐catalyzed arylation of uracil ( 2b ) or 5‐methyluracil (=thymine; 2c ), N 1 ‐arylation products were the major products ( Table 3 ).