loading, with acetophenone as the substrate, 2-propanol as the reducing agent and in
the presence of tBuOK (5 mol%) afforded 2-phenylethanol in 99% conversion, after
15 min of treatment at 20
C, with an e.r. of 76/24. Working at À30
C, a conversion
of 97%, with 84.5/15.5 e.r., was achieved after 1 h of reaction.
Cp*Ir(III) complexes with chalcogenated Schiff bases of anthracene-9carbaldehyde 38–41 (Scheme 9) were tested for the TH of aldehydes A1, A23,
A24, A30, A31, A38 and A61 (Scheme 3) and ketones B1, B15, B21, B47 B101 and
Ir
Cp*
N
H
Me
Cl
N
Ir
Cp*
E = S (38)
Me
37
E
Se (39)
PF 6
N
Ir
Cp*
E = S (40)
E
Se (41)
PF 6
Cl
Ir
Cp*
Cl
42
N
O
43
OMe
O
Ir
Cp*
Cl
N
O
O
O
N
N
Ir
Cp*
Cl
N
N
N
-
+
44
N
N
Ir
Cp*
Cl
N
N
N
45
N
N
Ir
Cp*
H
N
N
N
46
Ir
Cp*
Cl
N
N
N
47
HN
Ir
Cp*
N
48
Ph
Ph
SO 2 C 6 Me 5
Cl
Ir
Cp*
Cl
49
N
N
O
O
I
I
N
N
SO 3
- K +
N
N
SO 3
- K +
50
Ir
I
N
N
Cp*
N
N
Ir
I
Cp*
N
N
51
52
N
Scheme 9 Half-sandwich iridium catalyst precursors (37–52)
86
M. Pilar Lamata et al.