Chemistry Reference
In-Depth Information
R
R
R
R
P
P
P
P
R
R
R
R
BPE
DuPhos
N
R
R
R
R
R
R
P
P
P
P
P
P
R
R
R
R
R
R
P
P
R
R
R
R
16
14
15
R
R
R
R
R
R
P
P
P
P
P
P
R
R
R
R
R
R
17
18
19
R
R
P
P
R
R
Fe
Fe
R
R
P
P
R
R
20
FerroTANE
Figure 7.6.
BPE, DuPhos, and analogues.
which have been challenging substrates for other types of catalysts. Prompted by the
good performance of PHOX, a number of P,N-ligands were developed thereafter (Figs.
7.11). A few ligands possessing ferrocene and other structural motifs also represent
excellent examples (Figs. 7.12 and 7.13 ).
7.3. ASYMMETRIC HYDROGENATION OF UNSATURATED COMPOUNDS
Asymmetric hydrogenation has been successfully applied to the preparation of many
types of chiral compounds. Extensive studies have been conducted on the hydrogenation
of dehydroamino acids, ketones, and imines. In many cases, asymmetric hydrogenation
has been used as the key step in the multistep synthesis of important products. Many
industrial-scale hydrogenation reactions have also been performed with good results.
These achievements are reviewed in three sections based on the double bond that is
