Synthesis of Soai Type 2‐Arylpyrimidine‐5‐carbaldehydes through Desulfurative Cross‐Coupling with Arylboronic Acids

Abstract

AbstractA two‐step synthesis of 2‐arylpyrimidine‐5‐carbaldehydes, which are of relevance as substrates for Soai's asymmetric autocatalysis, was realized by exploiting a hidden threefold symmetry in the target core structure. Condensation of Arnold's C3‐symmetric vinamidinium cation with S‐methylisothiouronium sulfate provides 2‐methylsulfanyl‐pyrimidine‐5‐carbaldehyde; introduction of aryl groups at C‐2 of the latter was accomplished by a Liebeskind–Srogl palladium‐catalyzed desulfurative (de‐methylsulfanylative) coupling with aryl boronic acids to obtain the target compounds 1 (14 examples, 60–95 % yield).