Kinetic Resolutions - The Stoltz Group

(±)-
R
R 1
OH
R 2
OH
KR Through Hydrogenation of Allylic Alcohols - Noyori
R 3
MeO
0.05-0.5 mol% 12
H2 (1-100 atm)
O
MeOH
Typically done in 1-3 hours at 25 o C
OH
R 1
OH
(R)-12 also used to yield other enantiomer of allylic alcohol
R = H, s = 62
R = Me, s = 76
R 2
OH
R 3
+
R 1
OH
R 2
R 3
OH
OH
Ph 2
P
O
Ru
P
Ph2O
(S)-12
s = 16 s = 11 s = 1.7 s = 20 s = 11
Increasing the H 2 pressure tends to decrease selectivity
Lowering the temperature slightly improves the selectivity
(±)-
Jacobsen
(±)-
Katsuki
R
O R
R = i-Bu, i-Pr, n-Hexyl, prenyl
R = Me, i-Pr, s = 2.6-7.5
Epoxidation of Alkenes and Allenes - Salen
4 mol% Catalyst 13a
MCPBA, NMO
CH 2Cl 2, -78 o C
< 10 min
2 mol% 13b or 14
NaOCl, PPNO
CH 2Cl 2, -20 o C
< 10 min
cis and trans epoxides recovered in >80% ee
R
O
O R
s = 4.5-9.3
R
R
O
O
O
OH
Noyori, et. al., J. Org. Chem., 1988, 53, 708
N N
Mn
R O Cl O
R
t-Bu
N N
Mn
O O
Ph Ph
- OAc
t-Bu
(S,S)-13
a: R = OTIPS
b: R = t-Bu
Velde, Jacobsen, J. Org. Chem., 1995, 60, 5380
14
Katsuki, et. al., Tet. Lett., 1996, 37(26), 4533
O
16