The Systemic Approach to Teaching and Learning Heterocyclic Chemistry [SATLHC]:
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Transcript of The Systemic Approach to Teaching and Learning Heterocyclic Chemistry [SATLHC]:
The Systemic Approach to Teaching and Learning Heterocyclic Chemistry
[SATLHC]:Operational Steps for Building Teaching
Units in Heterocyclic Chemistry
Feb.2013
A. F. M. Fahmy, J.J.Lagowski*Faculty of Science, Department of Chemistry
Ain Shams University, Abbassia, Cairo, EGYPTE-mail:[email protected]
*University of Texas at Austin ,USAWebsite:satlcentral.com
Good chemistry teaching Good chemistry teaching
If their is no Teaching Chemistry their is no Chemistry
If their is no Teaching Chemistry their is no Chemistry
excellent chemistry research
#
Introduction # SATL-Teaching Strategy.
#Difficulties in Learning Heterocyclic Chemistry.
# SATL-in Building Unites [General strategy].# Scienario of Building unite on 5-
Membered Heterocycles.[Pyrrole – Furan – Thiophene]
#Conclusions.
INTRODUCTION:
-After the wide spread of the systematization in various activities including, tourism, economy, security, education,…etc ,
and after globalization became a reality that we live .
-SATL became a must and Chemical Education Reform (CER)has gained great importance internationally.
- SATL is a new way of teaching and learning, based on the idea that nowadays everything is related to everything globally .
-Students shouldn't learn isolated facts (by heart), but they should be able to connect concepts and facts in an internally logical context.
Taagepera and Noori (2000) tracked the development of student’s conceptual understanding of organic chemistry during a one-year sophomore course. They found that the
students knowledge base increased as expected, but their cognitive organization of the knowledge was
surprisingly weak . The authors concluded that instructors
should spend more time making effective connections, helping students to construct a knowledge space based on general principles.
Pungente, and Badger 2003 stated that the primary goal of teaching introductory organic chemistry is to take students beyond the simple cognitive levels of knowledge and comprehension using synthesis and analysis – rather than rote memory.
Fahmy,A.F.M.(Egypt),andLagowski,J.J.(USA)(1998) suggested an educational process based on the application of “Systemics” named (SATL).
SATL-in Heterocyclic Chemistry was experimented successfully on the third year major chemistry students at Ain Shams University( 2004).
Why Systemic Approach to Teaching and Learning ?
SATL helps students in the development of their mental framework with higher level of cognitive processes such as analysis and synthesis.
SATL helps learners in obtaining a deeper learning experience, improve their understanding, enhance their systemic thinking, and increasing their enthusiasm for learning chemistry, as well as other subjects.
SATL, will help students to understand interrelationships between concepts in a greater context.
SATL Helps teachers to teach and learners to learn.
What is the SATL?
- We mean an arrangement of concepts or issues through interacting systems in which all relationships between concepts and issues are made, clear up front, to the teacher and learner.
Fig: 1aLA
concept concept concept concept concept concept concept concept
Fig: 1bSA
concept concept
concept concept
concept concept
concept concept
Systemic teaching strategy:[STS]
- we started teaching any unit by Systemic diagram (SD0) that has determined the starting point of the unit, and we ended with a final systemic diagram (SDf) and between both we crossover several Systemics.
SD
0SD
f
SD
2
SD
1
Fig (2): Systemic teaching strategy
A list of SATLC materials were
produced in Egypt
e.g.: SATL General Chemistry for
secondary schools. SATL
Aliphatic, Aromatic, Green
chemistry and Heterocyclic
Chemistry for University Level.
The systemic diagrams involved in teaching are similar except that the number of known relationships
( )and the unknown )?)ones as indicated in the Fig.2.
-In this presentation, various examples of systemic heterocyclic teaching materials will be illustrated.
Second: The Prerequisites needed for teaching the unite from previous studies (facts, concepts, laws, reaction types and skills) should be tabulated into a list.
.
Uses of SATL-in Building Unites:
[ General Building Strategy ] In SATL building strategy of unites , we convert the linearly based unites in chemistry to systemically - based
unites according to the following building strategy;
First: The systemic aims and the operational objectives for the unit should be defined in the frame of
national standards..
Third: Then content analysis of the linearly-based unite into facts, concepts, laws, reaction types, mental, and experimental skills.
Fourth: Draw a diagram illustrating linear relations among the concepts of the unite [Fig.3].
.
HH
XX
EE
ZZ
YY
FF
GG
Fifth: We put the sign () on the already known relationships from previous studies. Then the remaining linear relations are unknown and signed by (?). So, the diagram in Fig-3 should be modified as shown in Fig. 4:
HH
XX
EE
ZZ
YY
FF
GG 1
2
34
5
6
?
??
Fig4: Showing linear relations between concepts after defining the known from the unknown ones.
Sixth: The diagram Fig.4 is modified to a systemic diagram SD0 Fig.5 by adding unknown relations between the concepts from (7-12).SD0 is known as the starting point of teaching the unite.
.
Fig5: Showing systemic relations between concepts after defining the known from the unknown ones.
1
2
34
5
6
?
? ?
H
X
E
Z
Y
F
G
12 7
8
9
11
10
? ?
?
??
?
)SDss0)
Seventh: In the scenario for teaching
the unit the student study the relations (7, 8, and 9).So, he will be able to add
them to SD0 diagram to give SD1 diagram.Fig.6.
1
2
34
5
6
?
? ?
H
E
Z
Y
F
G
12 7
8
9
11
10
?
?
? X
Fig.6.[SD1]
At this stage of teaching the unite we can ask the students to build systemics showing the relations between the concepts (X, Y, Z, and E) via systemic assessment..
Fig.7.[SD2]
Eighth: In the next stage of the of the scenario
of teaching the unite, the student study the relations
(4, 5, 10, and 11) and then he will be able to add them
to SD1 to obtain SD2- Fig.7.1
2
34
5
6
?
H
E
Z
Y
F
G
12 7
8
9
11
10
?
X
Fig.8.[SD3]
1
2
34
5
6
H
E
Z
Y
F
G
12 7
8
9
11
10
X
Ninth: In the last stage of teaching the unit , the student studied the two relations (6, 12). Then adds them to SD2 to obtain SD3-Fig.8 where we reached to the end of the systemic teaching of the unite.
SD3 can be denoted as the terminal systemic SDf of teaching the unite .
.
Tenth: The scenario of teaching any course systemically - involves the development of a systemic diagram (SD0) that has determined the starting point of the course; it incorporates the prerequisite materials. The course ends with a terminal systemic (SDf) in which all the relationships between concepts are known (Fig. 8).
From SDO through SDf we crossover several systemics with known and unknown relationships (SD1, SD2, etc.).
Difficulties in Learning Heterocyclic Chemistry
By Traditional Methods The students find the following
difficulties in learning HC:
i) To Remember the structural formulas of
heterocycles and
chemical properties related to these
structures.
ii) To understand the systemic effect of
heteroatom on the
reactivity of both heterocycles and their
substituent's.
iii) To synthesize systemic chemical relations
between
compounds of the same or different
heterocycles.
iv) To understand the importance of
heterocycles in their life's.
v) To Design synthesis of new target
heterocycles via RSA.
vi) To connect between different heterocyclic
systems.
SATLHC
Pure Applied
- Synthesis- E-Substitution- Nu-Substitution- Addition- Cycloaddaition- Ring Opening- Het. Int. Conversion
- Pharmaceuticals- Food Additives- Plant growth regulators- Insecticides- Herbicides- Corrosion Inhibitors- Super conductors.- Dyes
- Photographic materials etc..)
[LATLHC]
Z
Het.
X
Z
Het. Y
Z
Het.
E
Z
Het.F X,Y,E,F
[SATLHC]
Z = N, O, S
)Functional Groups)
Z
Het.
Uses of SATL-in Building Unites
In Heterocyclic Chemistry: A course of heterocyclic
chemistry using the SATL
technique was organized and
taught to the 3rd year students at
Ain Shams University.
SATLHC means survey study on
the reactivity of both heterocycles
and substituent's and the effect of
heteroatom on their possible
chemical relations.
C-Heteroatom: [)Z) = NH, O, S]
D-Substituents:[)G) = R, - CH2 - X, - X, -CH2 - OH - NH2, - CHO, - COR, - COOH]
GA-Reactivity of the Nucleus
B-Reactivity of the Substituents
Z
SATL-HC
Z
Scienario of Building unite on 5-Membered Heterocycles
First: Draw a diagram summarizes linear comparative reactivites of the five membered heterocycles as model of heterocyclic compounds, and their possible chemical relations. [Fig.1]
Z CHO
ZRZ CO2H
Z
Z
O
OZ
O
Z N2Ph
Z NO2
ZBr
Z SO3H
Z COCH3
DMF/ POCl3
Z = NH, O (heat)Z = S (Cu/quinoline)
anhydride(Z = O,S)
Maletic
red. (Z = O, NH)
Z = NH, (RMgX)(Z = O,S) alkene/
H3PO4
Z = NH,
i) CH3CONR2/POCl3
ii) aq Na OAc
Z = NH (NBS)Z = O Br2/dioxanZ = S Br2/ AcOH
Z = NH, O, C6H5N-SO3
Z = S H2SO4
Z = NH, O, SAcONO2/
Ac2O
PhN2
Z = NH
+
Z CH2OH
HCHO/base(Z = NH)
Z = NH, O, S [Fig.1]
The diagram Fig.1 represents the comparative reactivates of five membered heterocyclic rings, and gives the linear separated chemical relations between (Pyrrole,Furan,Thiophene), and their compounds.
Second:- The diagram Fig.1 is modified to a
systemic diagram SD1 Fig.2 by adding relations between
Heterocyclic derivatives.
- SD1 summarizes the comparative reactivates of both heterocyclic nucleus and substituent's.
Z CHO
ZRZ CO2H
Z
Z
O
OZ
O
Z N2Ph
Z NO2
ZBr
Z SO3H
Z COCH3
Oxidation
Wolff/Kishener
reducation
DMF/ POCl3
Z = NH, O (heat)Z = S (Cu/quinoline)
anhydride(Z = O,S)
Maletic
red. (Z = O, NH)
Z = NH, (RMgX)(Z = O,S) alkene/
HPO4
Z = NH,
i) CH3CONR2/POCl3ii) aq Na OAc
Z = NH (NBS)Z = O Br2/dioxanZ = S Br2/ AcOH
Z = NH, O, C6H5N-SO3
Z = S H2SO4
Z = NH, O, SAcONO2/
Ac2O
PhN2Z = NH
+
(4)
(5)
(6)
(7)SD 1
?
??
?
Z CH2OH
HCHO/base(Z = NH)
(3)?
?
(1)
?
(2)
Fig.2
The systemic diagram SD1 shows
unknown chemical relations (1-7)
between heterocyclic compounds.
These relations will be clarified
later during the study of the unite
[ pyrrole, furan and thiophen ].
At this stage of teaching the
unite we can ask the Students to
answer the following Systemic
Assessmet-1.
ASSESSMENT – I
ON SD1
ASSESSMENT – I
ON SD1QI) Draw systemic diagrams
illustrating the chemical relations between compounds in each of the following sets. [SSnQ,s]
Z CHO Z COOHZ
1) ,, (Clockwise)
Z CHO Z COOHZ
2) ,,
Z R
,
A I - 1
Z COOH Z CHO
Z
OxidK2Cr2O7 / H2SO4
i)DMF, POCl3
ii)AcONaZ= O,NH heat 200oCZ =S Cu/Quinoline
QII) Complete the following systemic diagrams:
Z
)Z = NH)
....................
.......... ..........
1)
Z
..........
..........
..........
CHO
i) DMF /POCl3
ii)aq. Na2CO3
CH3MgX
)Z = .......)
2)
A II - 2
Z Z CH3
Z CHOi) DMF/ POCl3
ii) Na2CO3
Wolf-Kishner reduction
CH3MgX
)Z = NH)
Reactions of pyrrole, furan, thiophene and their compounds
Reactions of pyrrole, furan, thiophene and their compoundsI-Pyrrole:
(Prerequisites SD1)I-Pyrrole:
(Prerequisites SD1) Third: From Fig.1 the student can deduce the reactions of pyrrole as in
the following diagram (Fig. 3).
NH
HN
i) DMF/POCl3
ii) aq. Na2CO3
HN
HN
Ac2O-10C
AcONO2PhN2
THFNBS
red.
(NH4)2CO3130cSealed Vessel
CO2NH4
+ -
+ -
BrHN
N2 PhHN
NO2
HN
HN
ii)HCl
NaOH
RMgX
i) C6H5NSO3
i) RCONR2
ii) NaOAc
COR
SO3HHN
RHN
CH2OHHN
Cl
N
CHO
H2/Rany Ni
N
CH2Cl2
CH3Li /
+
CHCl3/baseHCHO
)Fig. 3.(
The diagram (Fig. 3) represents
the reactivity of (pyrrole
nucleus), and gives the linear
separated chemical relations
between pyrrole and its
compounds.
Fourth: We can illustrate the
chemical relations in
(Fig.3) systemically by
modification of SD1 to SD2
(Fig.4) )Z = NH):
HN
HN
N
HN
HN
HN
N
H
HN
R=CH3
(1)
(3)CHO
Cl
?
?
ReductionOxid.
R=CH3base
HCHO
130ocbaseCHCl3/
i)DMF/POCl3
ii) aq.Na2CO3
RMgX
(2)(4)
(5)
Ac2O,-10oc
AcONO2
+PhN2
N2Ph
heat
200oC
(8)
?
?
?
?
R
CH2OH
NO2
Br
SO3H
COR`
i) R`CONR2/POCl3
ii) NaOAc
i) C6H5NSO3
ii) HCl
?
H
?
HN
NH
CO2NH4
CH2Cl2/
CH3Li
(NH4)2CO3
N COOH
NBS/THF
(6)
(7)
+ -
N
N
Wolff/ Kishner
red.
SD 2SD 2
Systemic diagram (SD2) shows; (i) known chemical relations between pyrrole and its compounds (ii) unknown chemical relations between pyrrole compounds (1-8),
should be clarified during the study of pyrrole compounds.
)Fig.4(
Fifth : After Study of pyrrole compounds [G = R, CH2OH, CHO, RCO,
COOH , NH2):
HN
HN
HN
HN
NH
HN
CHOCl
Oxid
CH2O/NaOH
baseCHCl3/
AlkylationRMgx
Wolff-kishner
red.
Nitration
Ac2O-10C
AcONO2
+PhN2
R = CH3
Oxid., chromic acid
heat200c
CH2OH
rearang.Curtius
redNO2
SO3H
i) R`CONR2/POCl3
ii) aq. Na2CO3i) C6H5NSO3
ii) HCl
aq. alkaline KMnO4
i) DMF/poCl3;
ii) aq Na2 CO3
HN
HN
(NH4)2CO3
hydroCO2NH4
NH
COR`
HN CHBr2
DiboraneR=CH3 NBS,CHCl3
refulx
R=CH3
(R= CH3) hydrolysis
H2/PdR= CH3
NaBH4
HN
HN
HN
Ag2CO3/CeliteLTA/AcOH,
PhN2
CO2H
N2Ph NBS/THF
CON3
HN
pyridneSOCl2/
NaN3
COClNNH2
HNH
bromination Br
CH2Cl2 / CH3Li
150-200C
NN
H2-Rany Ni
R
KMnO4
Vap.
Phase
decarbonylation
SD 3SD 3
+
The student can modify (SD 2 to SD 3) Fig.5 by adding chemical relations (1 – 8).
Fig.5
At this stage of teaching the unite we can
ask the Students to answer the following
Systemic Assessmet-2.
ASSESSMENT – IION SD3
ASSESSMENT – IION SD3
QI) Draw systemic diagrams illustrating the chemical relations between compounds of each of the following sets:[ SSnQ,s] )clockwise)
NH
NNH
COOH CHO
,,1-
H
NH
,,,NO2
NH
COOH NH
CHONH
2-
H H HH
N
,,,N N N2PhNCOONH4 COOH
3-
A I - 1
NH
NH
CHO
NH
COOH
aq. alk.200oC
heatKMnO4
i)DMF, POCl3
ii) aq. Na2 CO3
QII)
A) a: ))
The systemic diagram represents the correct chemical relations between pyrrole
and its related compounds is one of the following:
[SMCQ,s]NH
NH
COOH NH
CHO
NH CHO
NH
NH
CH3
NH
NH
CH2OH NH
CHO
NH CO2H
NH NO2
NH
a)
i) DMF/ POCl3ii) aq. Na2CO3
(......................)
b)
(......................)
c)
(......................)
d)
(......................)
Vap. Phase
i) DMF/ POCl3ii) aq. Na2CO3
i) CH3MgBrii) hydro.
H2/Pd
i) DMF/ POCl3ii) aq. Na2CO3
aq. alk.KMnO4
heat 200oC
Nitration
Conc. HNO3H3SO4
heat 200oC
NaBH4
QIII) Which of the following systemics are true and which are false:
[STFQ,s]NH
NH
COOH NH
CHO
( )
i) DMF/ POCl3
ii) aq. Na2CO3
heat 100oC
aq. alk.KMnO4
NH
CHO
NH N
HCH3
( )
i) DMF/ POCl3
ii) aq. Na2CO3
Wolff.kishner
red
i) CH3 MgBrii) hydro.
a) b)
A) a: )x); b: )) c: )x); d: ))
NH CO2H
NH
N2Ph NH
( )
heat 100oC
NH
CHO
NH
NH
CH2OH
( )
i) DMF/ POCl3
ii) aq. Na2CO3
i) CH2O/ii) NaOH
NaBH4
PhN2
+
PhN2
+
d)c)
QIV) Choose heterocyclic compounds from
column (A) and reaction conditions from column (B) to build the systemic diagram in column (C):
[SMQ,s]
)A))C))B)
DMF/POCl3
Aq. Na2CO3
H2/Pd
Alk. KMnO4
Heat 200oC
NH
NH
CHO
NH
COOH
NH
CH3
QV) Rearrange the compounds in the following SD to give correct chemical relations:[ SRQ,s]
NH
COOH NH
NH
NBS/THF
COONH4 NH
Brhydrolysis
)NH4)2 CO3/130C
Seald vesselBr2
200Cheat
A)
NH
COOH
NH
NH
NBS/THF
COONH4
NH
Br
hydrolysis
)NH4)2 CO3/130C
Seald vesselBr2
200Cheat
II-Furan: Prerequisite SD1
II-Furan: Prerequisite SD1Sixth: From Fig.1 the student can
deduce all the reactions
of furan [Z=O] as in Fig.6.
O
OO
O
O
O
O NO2
O Br
O Li
N
O CH3
O Et
CHO
O
N O
COOEt
i) DMF, POCl3
ii) aq Na2 CO3Maleic anhydride
2,3-Pyridyne
130C
N3COOEt
CH2N2/ hv
ii) pyridine
i) AcONO2
O SO3H
Br2/dioxan
-5Cii) HCl
i)C6H5N.SO3
O COR`
ii) aq. Na2CO3
ZnCl2 /175C
(CH3)2 C=CH2
i) R`CONR2/POCl3
O B ut
EtI
CH3I
Bun Li
O
OOH H
H2/CatH/H2O+
The above diagram represents the reactivity of furan nucleus, and gives the linear separated chemical relations between furan and its compounds.
Fig.6
Seventh: From SD1 the student can illustrate the systemic chemical
relations in (Fig. 7) by modifying (SD1 to SD4) [Z=O]
The Systemic diagram SD4 shows; (i) known chemical relation between furan and its compounds (ii) unknown chemical relations between furan compounds. (1-7)
SD 4SD 4?
O
O
O
O
O
O
O NO2
O4
Br
?
?
O Li
O CH3
O CH2CH3
CHO
O
N O
COOEt
i) DMF, POCl3
ii) aq Na2 CO3
Malic anhydride
(2,3)Pyridyne
130C
N3COOEt
CH2N2/hv
ii) pyridine
Heat (200C)
i) AcONO2
O SO3H
Br2/dioxan
-5C i) C6H5NSO3
ii) HCl
O
ZnCl2 /175C
(CH3)2 C=CH2
Ac2O, SnCl4
O But
EtI
CH3I
Bun Li
O
OOH HH2/Cat
H/H2O
O CO2H
6
?
?
2
7
5
3
1
?
?
Oxidation Reduction
+
COCH3
N
O CH2OH
Fig. 7
Eighth: After the next stage of the study of furan compounds [G = R, X, CH2OH, CHO, RCO, COOH] the student can modify (SD4 to SD5) Fig.8 by additions chemical relations (1-7).
In the systemic diagram (SD5) the chemical relations between furan compounds are clarified.
- At this stage of teaching the unite we can ask the Students to answer the following
Systemic Assessmet-3
SD5SD5
O
O
O
O
O
O NO2
O LiO CH3
O CH2CH3
CHO
O
N O
CO2Et
2,3 pyridyne
130C
CH2N2
ii) pyridine
Heat (200C)
i) AcONO2
Br2/dioxan
H2SO4
H2SO4
0Ci)C6H5N.SO3
ii) HCl O COCH3
ZnCl2 /175C
(CH3)2 C=CH2
Ac2O, SnCl4
O But
EtI
CH3I
Bun Li
O
OOH H
H2/Cat
H /H2O
O CO2H
Red.wolff Kishner
250C red.
Cu-Cr2O3/ -C
N3COOEt
O MgBr
HNO3
ii)hydro
i)CO2
Mg/cuether
COOHBr
O
red
NaBH4
H2 / Ni-Co
CH2OH
K2Or2 O7/dil H2SO4
Oxid
N
+
O
Br2
heatCu-Quinoline
O O SO3HBr
Maleic anhydride
i) DMF/ POCl3
ii) Na2CO3
O
Fig.8
ASSESSMENT – IIION SD5
ASSESSMENT – IIION SD5
QI) Draw systemic diagrams illustrating the possible chemical relations between compounds of each of following sets:[SSyQ,s]
O , ,, O EtOOLi CCH3
O3-
O ,, OO COOHCHO
2-
O , ,, O CO2HOO Br COOHBr
1-
A I – 1
O O
Br2
Cu/quinoline
heat200oc
COOH
Br2 / dioxan
-5oCOO Br
BrCOOH
QII) Which of the following systemics are true and which are false:
[STFQs]O
O Br O SO3H
a) ( )
i) C6H5NSO3
ii) HCl
Br2/ dioxan -5oC
H2SO4
O CO2H
O NO2 O
b) ( )
i) AcONO2
ii) Pyridine heat200oC
HNO3
O COCH3
OO CH2
CH3
c ( ) d) ( )
Ac2O,SnCl4
i) BunLiii) CH3CH2I
Wolffkishner
red.
O CH3
O CHO O CH2OH
K2Cr2O7/H2SO4
NaBH4
H2/Ni-CO
A ) a: )); b: )x) c: )); d: )x)
List (I) List (II)
1)
2)
3)
1)
2)
O CH3
H2/Ni-Co
O CH2OH
NaBH4
O CHOi) DMF, POCl3
ii) aq. Na2 CO3O
i) BunLiii) CH3I
Cu-Cr2O3/C250oC
O CH3
H2/Ni-Co
O CH2OH
NaBH4
O CHOi) DMF, POCl3
ii) aq. Na2 CO3O
i) BunLiii) CH3I
Cu-Cr2O3/C250oC
O CH3
O CHOO
i) DMF, POCl3
ii) aq. Na2 CO3
Cu-Cr2O3/C250oC
i) BunLiii) CH3I
O CH3
O CH2OHO CHO
O CH3
O CHOO
i) DMF, POCl3
ii) aq. Na2 CO3
Cu-Cr2O3/C250oC
H2/Ni-Co
NaBH4
H2/Ni-Co
Cu-Cr2O3/C250oC
QIII: Link systemics from list )I) to one systemic in list )II):
[SMQ,s]
III-Thiophene: (Prerequisite SD1)
III-Thiophene: (Prerequisite SD1)Ninth: From Fig.1 the student can
summarize all the reactions of thiophene in the following
diagram (Fig. 9). [Z=S]
The above diagram represents the reactivity of (thiophene nucleus), and gives the linear separated chemical relations between thiophene, and thiophene compounds.
290C, 21 atm.
CH3COCl/SnCl4
C6 H6 , 0oC
NO2BF4
CH3CH = CH2S
S
S
SS
CH3CH3
CH3CH3
S
O
O
O
i) DMF, POCl3
ii) aq. NaOAcLi/NH3, CH3OH
S
S SO3H S COCH3
S Pri
S
ii)I2
i)(CH3)3B
i)Et3BLiii)I2
S CH3
S Et
SCH2O/HCl
CH2Cl
Bun Li
CHO
NO2
Br
Br2/AcOH
ether
Benzyne
C6H5NSO3
S/700oC
Rany NiMaleic anhydride
Tenth: The student can illustrate the chemical relations in (Fig. 10) systemically by modifying (SD1 to SD6) [Z = S ]
SD6SD6
S
S290C, 21 atm.
CH3COCl/SnCl4
C6 H6 ,
NO2BF4
CH3 CH=CH2
S
S
SS+
red
S
O
O
O
i) DMF, POCl3
ii) aq. NaOAc
Li/NH3, CH3OH
Maleicahydride
S
S SO3H
S NO2
S Pri
S ii) I2
I) (CH3)3B2
i)Et3B
Li
ii)I2
S CH3
S Et
S
CH2O/HCl
CH2Cl
CHO
ether
Br2/AcOH
C6H5NSO3
Benzyne
S, 200
Cu / Quinoline
heatCO2H
?
?
?
(4)(6)
(5)
(3)
Br
COCH3
Bnu Li
? (2)
?(1)
reductionoxidation
Red.
The above systemic diagram (SD 6) shows; (i) The known chemical relations between thiophene and its compounds, (ii) The unknown chemical relations between thiophene compounds (1-6).
Fig. 10
Eleventh: After the next stage of the study of thiophene compounds [ G = R, X, CH2OH, CHO, RCO, COOH ] . The student can modify (SD6 to SD7) Fig.11 by addition of chemical relations (1-6).
In the (SD7) all chemical relations between thiophene compounds were clarified.
- At this stage of teaching the unite we can ask the Students to answer the following
Systemic Assessmet-4
SD 7SD 7 Fig.11
ASSESSMENT – IVON SD7
ASSESSMENT – IVON SD7
QI) Draw systemic diagrams illustrating the chemical relations between compounds of each of the following sets:[SSnQ,s]
S COOH S S CHO
1) , , (Clockwise)
S S Br S SO3H
2) , ,
S S COOH S COCH3
3) , ,
SS COOH S CHO
4) , , ,
S CH2Cl
A I – 1
S COOH
S
S CHO
K2Cr2O7/ H2SO4
Cu-Quinoline ii) NaoAc
i) DMF POCl3
QII) Complete the following systemic diagram:
O CH3
..........
..........
..........
....................
O
i) ...........ii) ..........
CH2OH
O CHO
)1)
)5)
)2))4)
)3)
A
O CH3 O
H2/ Ni-Co
)1)
)5))2))4) Cu- Cr2O3 /C
NaBH4
250oC
)3)
ii) CH3I
CH2OH
i) DMF, POCl3
ii) aq. Na2CO3 O CHOO
i) BunLi
SUMMARY: In the linear classical approach we
teach heterocycles as separate chemical reactions of the rings , also the relationships between heterocyclic derivatives are ambiguous infront of our students; however in SATL-HE the students are able to do the the following chemical transformations:
1- Heterocycles to another heterocycles in a direct pathway:
Het. AnotherHet.
Z Z
O SThiourea
O S
SH2
RNH2/
hvN
R
CH2Cl2/
baseNH
N
N
2,3-Pyridyne
O
aq N2H4
130oCNH
NN
N
Examples:
S
2- Three-membered to four-membered heterocycles via
aliphatic compounds and vis versa:Aliphatic
Compound
Z
Z
To ToO
O
Ph3P H2CO/
H+e.g:
Aliphatic Compound
Z
ZX
ToTo
To
O
NH
O
NR
Ph CO3H
RN3,
e.g:
3- Heterocyclic derivative to another hetercyclic derivative:X
G
X
YHet. Het.
Example:
Z Br
H2SO4
Z SO3H
H2SO4
Z COCH3
)Z = O, S)
4- Aliphatic compound to another aliphatic compound
via heterocycle:Aliphatic
compoundAliphatic
compoundToTo
X
OH Cl
OHO
NH3
OH NH2
SR
S S R
Red.ii) BR3
i) Bun-Li
RanyNi
5- Heterocycles to homocycles:X
Het. HO
S
Benzynee.g.
O
O
CH3CH3
OH
OHCH3
KOH
O O R
RR RC C
R = (Si (CH3)3)
6- Design synthesis of any target heterocyclic system via
Retro-Synthesitic Analysis[RSA]: Synthesis of [IMIDES]
R.S.A. Decomposition
Synthesis
N
O
O
Ar
N
O
O
Ar
: Al Cl3
+
O Al Cl3
N
O
Ar
+
O
N
O
Ar
Al Cl3/
O Al Cl3
N
O
Ar
+
N
O
O
Ar
Al Cl3
+
ClH
Conclusion:
After the experimentation of SATLHC in Egypt we reached to the following conclusions:
1) SATLHC improved the students ability to view (HC) from a more global perspective.
2) SATLHC helps the students to develop their own mental framework at higher-level cognitive processes (application, analysis, and synthesis).
3) SATLHC increases students ability & enthusiasm to learn HC in a greater context.
5) SATLHC increases the ability of students to think systemically.
6) SATLHC enhances the students mental skills towards building
target heterocyclic systems via Retro-Synthetic Analysis.
4)SATLHC help students to view the pattern of pure and applied heterocyclic
- chemistry rather than synthesis and reactions of heterocycles.
References:)1) Taagepera, M.; Noori, S.; J. Chem. Educ. 2000, 77, 1224.
)2) Fahmy, A. F. M.; Lagowsik. J. J.; J. Chem. Educ. 2003, 80, )9), 1078.
)3) Fahmy, A. F. M., El-Shahaat, M. F., and Saied, A., International Workshop on SATLC, Cairo, Egypt, April )2003).
)4) Fahmy, A.F.M., Lagowski, J.J.; Systemic Approach in Teaching and Learning Aliphatic Chemistry; Modern Arab Establishment for printing, publishing; Cairo, Egypt )2000).
)5) Fahmy A. F. M., El-Hashash M., Systemic Approach in Teaching and Learning Heterocyclic Chemistry. Science Education Center, Cairo, Egypt )1999).
)6) Fahmy, A. F. M.; Hamza M. S. A; Medien, H. A. A.; Hanna, W. G., M. Abedel-Sabour; and Lagowski; J. J.; Chinese J. Chem. Edu., 23 )12) 2002, 12, 17th IEEC, Beijing August (2002).
(7 )Systemic assessment as a new tool for assessing students learning In Chemistryusing SATL methods: Systemic true false [STFQs] and systemic sequencing [SSQs] question types. A.F.M. Fahmy and J. J. Lagowski
AJCE. 2, )2)66-78)2012).
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