Revisiting the Hirao Cross-coupling: Improved Synthesis of Aryl and Heteroaryl Phosphonates.
The palladium-catalyzed cross-coupling of dialkylphosphite with aromatic electrophiles (Hirao coupling) was re-investigated. Some limitations in terms of palladium loadings and substrate reactivity are alleviated with the use of Pd(OAc)(2) complexed to 1,1'-bis(diphenylphosphino)ferrocene (dppf) as a ligand. Various aryl and heteroaryl halides are employed to deliver both known and novel substituted phosphonates. The first examples of aryl chloride couplings are also reported.
Belabassi
Yamina
Y
Department of Chemistry, Box 298860, Texas Christian University, Fort Worth, Texas 76129, USA.
Alzghari
Saeed
S
Montchamp
Jean-Luc
JL