391
Scheme 11 Pd-catalyzed
enantioselective direct
borylation of cycloalkane
carboxylic acids
Fig. 1 Predicted
stereochemical model for
borylation of
cyclobutane rings
Scheme 10 Transformation
of β-borylated products
effect, thereby decelerating the formation of metallacycle intermediate, and that in
the halogenated product is prone to undergo dehalogenation [49]. Nonetheless,
these reaction systems efficiently enable halogenation, e.g., β-fluorination,
β-bromination, and β-iodination of α-unsubstituted/protonated carboxamides
(Scheme 15) [50, 51].
C(sp
3
)–H Bond Hetero-functionalization of Aliphatic Carboxylic Acid Equivalents…