Independently from the Smith’s work, the group of Hartwig, Miyaura, and
Ishiyama discovered the excellent catalytic performance of an Ir-dtbpy
(dtbpy ¼ 4,4
0 -di-t-butyl-2,2
0 -bipyridine) complex for arene C–H borylation with
B 2 pin 2 under mild conditions even at room temperature in 2002 [16, 194, 195]. The
catalytic system could fully utilize the boryl unit of B 2 pin 2 to afford ArBpin with the
release of H 2 . Shortly afterwards, the same group demonstrated the Ir-dtbpy
Scheme 79 Ir-phosphine complex-catalyzed dehydrogenative borylation of arenes
Scheme 80 Proposed mechanism of Ir-catalyzed dehydrogenative borylation of arenes
50
T. Shimbayashi and K. Fujita