Enantioselective Catalysis for Enolate Arylation

Buchwald and coworkers elaborated a protocol for the enantioselective palladium-catalyzed arylation of ketones 143 with various aryl bromides. 

As all the protocols mentioned earlier rely on the use of a strong base — mostly sodium t-butoxide - in excess to generate the corresponding enolate. As a consequence, these procedures are well suitable for the enantioselective preparation 

R = 4-MeOCeH4, 3-MeOC0H4, 4-CF3CgH4, 2-naphthyl, 3-CICgH4, 3,5-Me2CgH3, 3-(dioxolanyl)CeH4, ( )-MeCH=CH, 

Intramolecular variants of the reaction were reported for the enolates of amides and aldehydes through the corresponding in situ generated enolates. The palladium-catalyzed conversion of ort/zo-bromoaniline-derived amides 157 into oxindoles 160 was first studied by Hartwig and Lee who noticed that 

4-(Et02C)C6H4, 3-(PhCO)C6H4, 2-MeCeH4, 2-MeOCeH4, 2-CNCeH4, 2-NO2C6H4, 1-naphthyl, 2-naphthyl, 1 -(6-MeO)naphthyl 

---