Oxidative palladium catalysis in S(N)Ar reactions leading to heteroaryl ethers from pyridotriazol-1-yloxy heterocycles with aryl boronic acids.
The palladium-catalyzed oxidative coupling of pyrido- and benzotriazol-1-yloxyquinazolines and -thienopyrimidines with aryl boronic acids in the presence of Pd(PPh(3))(4) and Cs(2)CO(3) under oxygen in DME containing 0.4-0.8% water for the preparation of heteroaryl ethers is described. These transformations of triazol-1-yloxy reagents demonstrate excellent O-chemoselective control under mild conditions and good yields. Mechanistic studies based on (18)O labeling indicate that phenols as intermediates in S(N)Ar reactions with ethers are formed in oxidative and nonoxidative pathways.
Wacharasindhu
Sumrit
S
Chemical and Screening Sciences, Wyeth Research, 401 North Middletown Road, Pearl River, New York 10965, USA.
Bardhan
Sujata
S
Wan
Zhao-Kui
ZK
Tabei
Keiko
K
Mansour
Tarek S
TS
D001897:Boronic Acids / Q000737:chemistry*; D002384:Catalysis; D002625:Chemistry, Organic / Q000379:methods*; D004987:Ethers / Q000737:chemistry*; D008956:Models, Chemical; D015394:Molecular Structure; D009584:Nitrogen / Q000737:chemistry; D010100:Oxygen / Q000737:chemistry; D010165:Palladium / Q000737:chemistry*; D019800:Phenol / Q000737:chemistry; D011743:Pyrimidines / Q000737:chemistry; D011799:Quinazolines / Q000737:chemistry*; D013455:Sulfur / Q000737:chemistry; D013997:Time Factors
D001897:Boronic Acids; D004987:Ethers; D011743:Pyrimidines; D011799:Quinazolines; D019800:Phenol; D010165:Palladium; D013455:Sulfur; D009584:Nitrogen; D010100:Oxygen