Chemistry Reference
In-Depth Information
R
1
R
2
R
1
O
N
O
H
R
2
O
(EtO)
2
P
(EtO)
2
P
OH
O
N
R
2
(EtO)
2
P
H
R
1
R
2
R
1
TMG (
1
)
(ex) R
1
= Ph, R
2
= H (86%)
R
1
= Et, R
2
= Me (78%)
(ex) R
1
=Ph, R
2
= CH
2
Ph (81%)
Scheme 4.9
Preparation of alkyl phosphonate by TMG (1) catalysed aldol-type addition
O
TMG (
1
)
(10 mol%)
P(OEt)
2
CHO
O
S
S
(MeO)
2
P
H
+
NH
2
+
H
toluene, reflux
N
N
N
H
N
H
85%
Scheme 4.10
TMG (1) catalysed one-pot synthesis of aminophosphonate
Imine Substrate
TMG (1) catalyses one-pot simultaneous reaction of indole-3-carboxaldehyde, a dialkyl- or
diphenyl phosphite, and a primary amine to give the corresponding
-aminophosphonates
in good yield (60-85%) (Scheme 4.10) [30]. It is known as Kabachnik-Fields reaction.
a
4.3.1.2 Aza-Henry (Nitro-Mannich) Reaction
The aza-Henry (nitro-Mannich) reaction of N-diphenylphosphinoylimines with nitroalk-
anes under solvent-free conditions was efficiently catalysedwith TMG (1) to give a series of
b
-nitroamines in excellent yields and high diastereoselectivity [31] (Table 4.1).
Table 4.1
Solvent-free aza-Henry reaction catalysed with TMG (1)
H
P(O)Ph
2
R
2
R
3
CHNO
2
P(O)Ph
2
N
N
R
2
TMG (
1
)
R
1
R
3
R
1
rt
NO
2
R
1
R
2
R
3
Run
Time (h)
Yield (%)
anti
:
syn
1
Ph
Et
H
2
96
94 : 6
2
4-ClPh
Et
H
2
95
84 : 16
3
4-(MeO)Ph
Et
H
24
92
95 : 5
4
2-furanyl
Et
H
2
90
95 : 5
t
Bu
5
Et
H
170
95
98 : 2
>
6
Ph
Me (CH
2
)
4
H
24
90
98 : 2
>
7
Ph
Me
Me
3
96
—
