Oxazole, 4-bromo-2,5-diphenyl

Bromo- and 4-bromoalkyl-2,5-diphenyloxazole 38 were subjected to the Stille coupling with a range of commercially available tributyltin reagents. Tri-2-furylphosphine/ Pd2(dba)3 was used as an effective catalyst. Copper(n) oxide enhanced the Stille coupling reactions of 2,5-diphenyl-4-tributylstannanyloxazole with various electrophiles [41]. Such method offered an efficient synthetic route to prepare resins from oxazole-containing monomers such as 2,5-diphenyl-4-vinyloxazole. 

Clapham and Sutherland developed a general synthesis of 2,5-diphenyl-4-substituted oxazoles 1659 in the context of preparing monomers for scintillating polymers. Stille coupling of 4-bromo-2,5-diphenyloxazole 1658 with a variety of stannanes produced the target oxazoles in modest to excellent yield (Scheme 1.426). Alternatively, the authors reversed the StiUe-couphng approach... 

Sodium Salts of Stabilized Carbanions. The carbosubstitution in 4- and 5-bromo-2,4- or 5,6-diphenyl-l,3-azoles 140 (oxazoles, thiazoles, and imidazoles) with phenylsul-fonylacetonitrile in the presence of a strong base is promoted by palladium catalysis... 

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