Palladium-catalyzed Acylation of Functionalized Aryl Boronic Acids

Palladium-catalyzed Acylation of Functionalized Aryl Boronic Acids 

Miscellaneous C-Cbond Formations of Functionalized Aryl Oiganoboranes 

At = Ph, 4-MeOCeH4. 3- or4-MeCeH4 4-MeCOC6H4, 4-CHOC6H4. 3-CIC6H4, 3-ACNHC6H4 Ar = 3-NO2C6H4, X = OEt 40 % 

Rhodium(I)-complexes are known to be excellent catalysts for the conjugate additions of aryl- and alkenyl boronic acids to a,/3-unsaturated ketones, esters and amides [73,74]. Batey has recently prepared aryl and alkenyl trifluoroborates as air-and moisture-stable reagents for the nucleophilic addition to enones in the presence of a Rh(I)-catalyst to give /3-functionalized ketones in good yields [75]. A number of aryl fluoroborates with electron-withdrawing substituents were also tolerated in this reaction. An unprecedented Rh-catalyzed 1,4-addition of aryl boro- 

A first example of catalytic asymmetric synthesis of 4-arylpiperidiones (Ar= 4-FC(,H4, 4-C1C(,H4) has been described using a rhodium atalyzed 1,4-addition of 4-fluoro- or 4-chlorophenylboroxine and one equivalent of water with the chiral BINAP ligand [77]. The (R)-4-(4-fluorophenyl)-2-piperidione obtained in this reaction is a key intermediate for the synthesis of pharmacologically important (-)-par-oxetine (108). 

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