Efficient Synthesis of N-Aryl-Aza-Crown Ethers via Palladium-Catalyzed Amination
“Efficient Synthesis of N-Aryl-Aza-Crown Ethers via Palladium-Catalyzed Amination”, J. Org. Chem., 2000, 65(23), 8027-8031.
N-Aryl-aza-crown ethers were efficiently prepared by reaction of an aza-crown ether with an aryl bromide via a palladium-catalyzed amination. The combination of Pd-2(dba)(3) and a biphenyl-based electron-rich bulky monophosphine is effective for catalyzing the coupling of 1-aza-15-crown-5 with both electron-deficient and electron-rich aryl bromides under mild conditions. N-Aryl-aza-crown ethers were produced in 75-91% yields. N-Aryl-aza-crown ethers with o-aryl substituents can also be synthesized using this catalyst system, albeit in lower yields (similar to 40%).