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Reaction of nitrilimines with 2-substituted aza-heterocycles Adel M. Awadallah Chemistry Department, Faculty of Science, Islamic University of Gaza, P. O. Box108, Gaza, Palestine; Tel. +970-8-2823311, Fax: +970-8-2823310, e-mail [email protected]. Nirilimines As 1,3-Dipoles 1,3-Dipoles - PowerPoint PPT Presentation
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•Reaction of nitrilimines with 2-substituted aza-heterocycles
•Adel M. Awadallah
• Chemistry Department, Faculty of Science,•Islamic University of Gaza, P. O. Box108, Gaza, Palestine;
• Tel. +970-8-2823311, Fax: +970-8-2823310 ,•e-mail [email protected]
• Nirilimines As 1,3-Dipoles• 1,3-Dipoles• A 1,3-Dipole is a three-atom π-electron system with 4π-
electrons delocalized over the three atoms.
•
ab
ca b + __ +
c
• Nitrilimines:• Nitrilimines are flexible system of three atoms over which
four π- electrons are delocalized, they are typical 1,3-dipolar species having the resonance structures shown below:
• Resonance structures of Nitrilimines
NNAr
MeO
ONNAr
Me
O
R C N N Ar
_
R C N N Ar
R C N N Ar R C N N Ar
..
..
..
.......... R C N N Ar
..
......
.._
__ ++
++
CCCC
Blue: Electrophilic Red: Nucleophilic
• Reactions of 1,3-Nitrilimines:
NNAr
Me
O
O
EtO
R
NH2 NH2
N
NNO
Me
Ar
R
NH
R
NH
NO
Me
Ar
NH
NNO
MeO
Ar
NHN
N NH
MeAr
R
CC
C N
C
H2N
H2N
Cycloaddition
Nucleophilic addition
Cyclocondensation
•Reaction of Dinucleophiles with NitriliminesReaction with 2-aminopyridine and 2-aminopyrazine
Cl
NH
NCH3
O
Ar
X
NNH2X
NN
CH3 N NAr
+Et3N
X= CH, N
• Reaction with 2,3-diaminobenzene and 2,3-diaminopyridine;
Cl
NH
NY
O
Ar
NNH2
NH2
NN
Y N NAr
NH2
NH2
NH2
NHN
N NH
Ar
CH3 NNH2
NH2
NN
O N NH
Ar
NH2
Et3N, Y = OCH3
Et3N, Y = CH3 Et3N, Y = CH3
•Our Work
Cl
NH
N
O
ArY
N
NH
NH2
NH
NN
N NH
O
Ar
NH
NN
N NCH3
Ar
N
NNH2
N NH
CH3
Ar
O
N
NNH2
N NH
Ar
O
MeO
+
Et3NEt3N
Y = OCH3Y = CH3
Expected Expected
Found Found
• Reaction with 2-Cyanomethylbenzimidazole• Quite recently, Awadalah reported that nitrilimines react with 2-
cyanomethyl benzimidazole to afford pyrrolo(1,2-a)benzimidazoles.
Cl
NH
NCH3
O
Ar
N
NH
CH2
NC
NH
N
N NCH3
Ar
N
NN
Ar
NH
NN
CH3
+Et3N1
2
3
4
The structure of compound 4 was confirmed by X-ray crystal structure.
• Our Work•Reaction of Nitrilimines (containing ester moiety)
with cyanomethyl-benzimidazole.
Cl
NH
N
O
ArMeO
N
NH
CH2
NC
NH
N
N NH
O
Ar
N
N
N
N NH
Ar
O
CH2
MeO
NC
+Et3N
Expected
Found
Et3N
• Reaction of Nitrilimines with Ethyl Pyridine-2-acetate.
Cl
NH
NY
O
Ar
N NCH3
Ar
N
EtO2C
NCH2
EtO2C
N NH
Ar
N
EtO2C
O
N NH
Ar
N
EtO2C
O
MeO H NH
N
O
Ar
NEtO2C
MeO
H
Chemical shift
+Et3N
Y = CH3
Et3N
Y = OCH3
Expected
and Found
Expected
Expected
Found
1H NMr 4.1 ppm13C NMR 76.6 ppm
•Reaction of Nitrilimines with 2-benzothiazole acetonitrile.
Cl
NH
NY
O
Ar
N
SCH2
NCS
N
N NCH3
Ar
N
S
N
N NH
O
Ar
NY= CH3
Y = OMe
Cl
NH
NY
O
Ar
N
SNH2
S
NN
N NCH3
Ar
+ Et3NEt3N
ExpectedExpected
+
Expected
??????? Found ???????
وتقدير • شكراألردنية. - • الجامعة زهرة أحم�د جالل د
اإلسالمية / – • الجامعة العشي دينا األستاذةاإلسالمية / – • الجامعة العصار منى الطالبة
استماعكم • لحسن لكم شكراالله • ورحمة عليكم والسالم
وبركاته