Microwave-promoted palladium(II)-catalyzed C-P bond formation by using arylboronic acids or aryltrifluoroborates.
The first Pd(II)-catalyzed P arylation has been performed by using palladium acetate, the rigid bidentate ligand dmphen (dmphen=2,9-dimethyl-1,10-phenanthroline), and without the addition of base or acid. Couplings of arylboronic acids or aryl trifluoroborates with H-phosphonate dialkyl esters were conducted in 30 min with controlled microwave (MW) heating under non-inert conditions. Aryl phosphites were also synthesized at room temperature with atmospheric air as the sole reoxidant. The arylated phosphonates were isolated in 44-90 % yields. The excellent chemoselectivity of the method was illustrated in the synthesis of a Mycobacterium tuberculosis glutamine synthetase (MTB-GS) inhibitor. Online ESIMS was used to detect cationic palladium species in ongoing reactions directly, and a catalytic cycle has been proposed based on these results.
Andaloussi
Mounir
M
Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry, Uppsala University, BMC, Box-574, 751 23 Uppsala, Sweden.
Lindh
Jonas
J
Sävmarker
Jonas
J
Sjöberg
Per J R
PJ
Larhed
Mats
M
D001897:Boronic Acids / Q000737:chemistry*; D002384:Catalysis; D004952:Esters; D008024:Ligands; D008872:Microwaves; D009942:Organometallic Compounds / Q000737:chemistry*; D010165:Palladium / Q000737:chemistry*; D013237:Stereoisomerism
D001897:Boronic Acids; D004952:Esters; D008024:Ligands; D009942:Organometallic Compounds; D010165:Palladium