Chemistry Reference
In-Depth Information
R
2
t
Bu
X
N
R
1
H
H
N
O
HO
3
t
Bu
R
3
3a
,R
1
= Bn, R
2
=H,R
3
= OMe, X = S, 70-91% ee
3b
,R
1
= Bn, R
2
=H,R
3
=OC(O)Bu
t
, X = O, 78-97% ee
3c
,R
1
= Bn, R
2
=H,R
3
=OC(O)Bu
t
, X = O, 42-95% ee
3d
,R
1
=Me,R
2
=Me,R
3
=OC(O)Bu
t
, X = S, 86-99% ee
1. TMSCN/MeOH
Catalyst
3
(2 mol %)
Toluene, -70 to -75°
C
O
R
"
R
"
N
F
3
C
N
R
'
R
'
R
2. TFAA
R
1:
R=aryloralkyl,R
'
=H,Me
R
"
=PhorCH=CH
2
2
Scheme 2B.1.
HN
Ph
NH
2
Ar
O
O
O
N
Ph
3d
(10 mol %)
Et
2
O
H
2
,Pd/C
O
O
Ar
OH
OH
+
HP
R
P
R
P
R
H
O
O
Ar
7
6
4
5
Ar
Ar = 2-nitrophenyl
81-99% ee
Scheme 2B.2.
t
Bu
S
Ph
N
H
H
N
O
HO
3e
t
Bu
t
Bu
Boc
1.
3e
(2 mol %)
To l ue ne
2. TF AA
Boc
N
OTBS
NH
O
+
O
i
Pr
Ar
H
O
i
Pr
Ar
8A
9
10
86-89% ee
84-89% isolated yield
Scheme 2B.3.
