An effect of application of chiral aluminium alkoxides and amides as adducts to zirconium catalyzed carbo- and cycloalumination of olefins

Article abstract of DOI:10.1016/j.jorganchem.2003.09.055

This paper is dedicated to a study of properties of the following novel optically active organoaluminium compounds (OACs): (1S,2S)-l,7,7-trimethyl-2-[(dialkylalumina)oxy]-bicyclo[2.2.1]heptanes and (1S)-N-(dialkylalumina)-6,7-dimethoxy-1-methyl-1,2,3,4 -tetrahydroisoquinolines. The synthesis of the chiral OACs was carried out in the reaction of either natural camphor or salsolidine with both AlEt₃ and i-Bu₂AlH. The main goal of the research was to investigate the stereodifferentiating activity of the chiral OACs in the olefin carbo- and cycloalumination reactions, catalyzed by Cp₂ZrCl₂.

Full text of DOI:10.1016/j.jorganchem.2003.09.055

Journal of Organometallic Chemistry 689 (2004) 444–453
www.elsevier.com/locate/jorganchem
An effect of application of chiral aluminium alkoxides and amides
as adducts to zirconium catalyzed carbo-
and cycloalumination of olefins
a,
Leonard M. Khalilov , Ludmila V. Parfenova , Svetlana V. Pechatkina ,
a
a
*
a
b
a
Askhat G. Ibragimov , Jean P. Genet , Usein M. Dzhemilev , Irina P. Beletskaya
c
a
Institute of Petrochemistry and Catalysis, Bashkortostan Republic Academy of Science and Ufa Scientific Centre of RAS,
Prospect Oktyabrya, 141, Ufa 450075, Russian Federation
b
Ecole Nationale Superieure de Chimie de Paris, France
c
Department of Chemistry, Moscow State University, V-234, Moscow, GSP 199889, Russian Federation
Received 10 February 2003; accepted 10 September 2003
Abstract
This paper is dedicated to a study of properties of the following novel optically active organoaluminium compounds (OACs):
1S,2S)-l,7,7-trimethyl-2-[(dialkylalumina)oxy]-bicyclo[2.2.1]heptanes and (1S)-N-(dialkylalumina)-6,7-dimethoxy-1-methyl-1,2,3,4-
(
tetrahydroisoquinolines. The synthesis of the chiral OACs was carried out in the reaction of either natural camphor or salsolidine
with both AlEt3 and i-Bu2AlH. The main goal of the research was to investigate the stereodifferentiating activity of the chiral OACs
in the olefin carbo- and cycloalumination reactions, catalyzed by Cp2ZrCl2.
Ó 2003 Elsevier B.V. All rights reserved.
Keywords: Chiral organoaluminium compounds; Cycloalumination; Carboalumination; Camphor; Salsolidine; Optically active shift reagents
1
. Introduction
())DIOP [4] were used as chiral ligands. The reaction
provides the optical yield of only 2–27% for the chiral
high OACs.
Unlike the application of chiral aluminium alkoxy-
hydrides and amides in the reactions of asymmetric re-
duction of carbonyl compounds [1–3], the information
regarding utilization of chiral aluminium alkioxides and
amides in stereodifferentiating catalytic reactions with
olefins is limited. One of the rare examples is presented
in [4]. A description of the reaction of hydroalumination
of 1,1- disubstituted alkenes in the presence of Ni-con-
taning complex catalysts activated by chiral ligands is
given as follows (see Scheme 1).
It was supposed that introduction of chiral ligands could
provide optically active products in the olefin carbo- and
cycloaluminationreactionswhichwereinvestigatedin[5,6].
These reactions were selected for the research of optical
activity of amides and alkoxides due to significant experi-
ence gained by the authors during the study of applications
and mechanisms of these reactions [11a–11d]. This paper
describes an effect of introduction of chiral alkylaluminium
alkoxides and amides as catalytic and stoichiometric ad-
ducts on the reactions (Scheme 2). The reactions of
i-Bu2AlH with a-methylstyrene and of Et3Al with either
a-methylstyrene or nonene-1 were selected as the model
carbo-andcycloaluminationreactions. Itwasassumedthat
both chiral alkylaluminium alkoxides and amides would be
involved in the catalytic Zr-complexes on the both reaction
pathways and provide stereochemical results.
Within the reaction, the ())-N-methylsalicylidene-
amine,
())-N,N-dimethylmenthylamine
(DMMA),
+)-N,N-dimethylbornylamine (DMBA), (+)-(R)-N,N-di-
(
methyl-l-phenylethylamine (DMPEA), (+)-(S,S)-2,3-di-
methoxy-l,4-bis-(N,N-dimethylaminebutane) (DDB) and
*
Corresponding author. Tel.: +7-3472-313-527; fax: +7-3472-312-
50.
E-mail address: lmk@anrb.ru (L.M. Khalilov).
The chiral OACs have been obtained, respectively, by
the reaction of (1S)-camphor ((1S)-1,7,7-trimethylbicy-
7
0
022-328X/$ - see front matter Ó 2003 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2003.09.055

L.M. Khalilov et al. / Journal of Organometallic Chemistry 689 (2004) 444–453
445
addition of i-Bu2AlH to (1S)-camphor (Scheme 3). This
fact was confirmed by correspondence of chemical shift
R
R
Ni] L*
0 h, 20˚C
C H
.
[
+
L*. AlBui
L*.
*
3
HC CH2
R'
Al
of C-7 signal in 13C NMR spectra of dimer complex 1 to
3
4
R'
3
that shift of the standard exo-camphor alcohol [7a,7b].
This kind of addition is typical for the camphor reduc-
tion using metal hydrides [1,8a–8g]. The endo-addition
assumes high stereoselectivity of the camphor reduction;
therefore, the reaction results in the formation of S-chiral
centre at C-2-atom with enantiomeric excess of 98%.
It has been shown that at the room temperature in 1:1
molar ratio at c ¼ 26 g 100 mlꢀ1, the formation of alk-
oxide results in the dimer form (1). By applying the
cryoscopic method, it was detected that the alkoxide
indeed has the dimer structure (Table 1). The dilution of
the reaction mixture to c ¼ 1 g 100 mlꢀ reduces the
molecular weight of the dimer due to the shift of the
equilibrium to the monomer (2) with simultaneous de-
crease of [a]D (see Table 1). This decrease happens be-
cause the number of the chiral centres goes down from 6
for the dimer to 3 for the monomer.
-
4
8
Scheme 1.
clo[2.2.1]heptane-2) and (1S)-salsolidine (hydrochloride
1S)-6,7-dimethoxy-l-methyl-1,2,3,4-tetrahydroisoquin-
(
oline) with either i-Bu2AlH or Et3Al, and their struc-
tures have been investigated. They have been obtained
also in situ for the olefin carbo- and cycloalumination
reaction. This approach provided results in the investi-
gation of the stereodifferentiating activity of the chiral
OACs in the olefin carbo- and cycloalumination reac-
tions, catalyzed by Cp2ZrCl2.
1
2
. Results and discussion
2
.1. Structure of chiral alkylaluminium alkoxides and
It was supposed that the molecular weight and [a]D
of the aluminium alkoxide would not change in O-
containing solvents, for example in 1,4-dioxane. As it is
shown in Table 2, a dilution of the solution of alu-
minium alkoxide 2 in 1,4-dioxane insignificantly varies
the molecular weight which is between theoretical
amides obtained in reactions of (1S)-camphor and (1S)-
salsolidine with either i-Bu AlH or Et Al
2
3
Let us first discuss the reaction of (1S)-camphor with
i-Bu2AlH in benzene. The reaction proceeds via endo-
a. AlEt3
R'
b. AlEt3
HAlBui
2
R
(
R O) AlR''
(R O) AlR''
3-n
[
Zr]
1
n
3-n
1
n
a. R=Ph, R'=CH3;
b. R=n-C H , R'=H
[Zr]
(
R ) AlR''
(R ) AlR''
2 n 3-n
2
n
3-n
7
15
R
*
R'
R
R1=
R3
R'
*
R'' Al
2
Al
Et
CH O
3
R = H or Et
R2=
3
N
CH O
3
Scheme 2.
i
Bu
H
Al
O
Bui
i
Bui
Bui
Bu
O
Al
O
C H
10
6
6
H
HAlBui
Al
+
2
i
Bu
O
1
7
H
[
α]D24= - 42.8˚
2
Scheme 3.

446
L.M. Khalilov et al. / Journal of Organometallic Chemistry 689 (2004) 444–453
Table 1
formation of the complex with polar molecules of the
solvent.
Let us proceed with the discussion of the reaction of
Change in molecular weight and optical rotation angle of molecular
complex (1S,2S)-1,7,7-trimethyl-2-[(diisobutylalumina)oxy]bicyclo[2.2.1]
heptane (2) vs. its concentration in benzene
(1S)-camphor with Et3Al. This reaction provides com-
plex 5, which was proposed in [9] according to Scheme 5.
2
0b
Concentration Molecular
(g 100 ml
Dimer concen-
tration (1) (%)
[a]
D
ꢀ1
ꢀ1
)
weight (g mol )
The structure of the complex 5 has been confirmed by
the authors using 13C NMR spectroscopy. The signal
a
2
6.4
5.5
596 ꢂ 16
100.0
74.2
52.6
36.6
26.7
8.6
+(26.9 ꢂ 0.7)
+(14.6 ꢂ 0.6)
+(10.2 ꢂ 1.1)
+(6.5 ꢂ 1.1)
+(4.4 ꢂ 0.9)
+(1.4 ꢂ 0.3)
ꢀ1
1
516 ꢂ 10
452 ꢂ 15
404 ꢂ 17
375 ꢂ 15
322 ꢂ 10
that appears at 216.0 ppm and belongs to the carbonyl
carbon atom in complex 5 is significantly broadened
compared to that signal of initial (1S)-camphor. More-
over, the resonance line of the neighbor quaternary
carbon atom at 59.2 ppm is shifted to the low field by 2
ppm and also broadened. The value of [a]D of (1S)-
camphor increases from )42 to )8 °C due to the com-
plex formation. Treatment of the complex with 10%
HC1 recovers the (1S)-camphor. Dilution of the com-
plex solution in benzene makes the molecular weight
decrease as presented in Table 3. Probably, the decrease
occurs because of the complex decomposition into mo-
nomeric camphor.
9
5
3
1
.1
.3
.2
.1
a
Theoretical molecular weight of dimer (1) – 592.9 g mol
a] [(1S)-camphor] ¼ )42.8° (c ¼ 8 g 100 mlꢀ1, C2H5OH).
20
.
b
[
D
Table 2
Change in molecular weight and optical rotation angle of molecular
complex (1S,2S)-1,7,7-trimethyl-2-[(diisobutylalumina)oxy]bicyclo[2.2.1]
heptane (2) vs. its concentration in 1,4-dioxane
21
Concentration
(g 100 ml
Molecular weight
ꢀ1
[a]
D
ꢀ1
)
(g mol
)
a
3
2
1
4.2
0.1
1.8
517 ꢂ 10
491 ꢂ 9
+(14.6 ꢂ 0.4)
+(11.7 ꢂ 0.5)
+(9.8 ꢂ 0.4)
Table 3
Change in molecular weight of complex 5 vs. its concentration in
benzene
504 ꢂ 10
a
Theoretical molecular weight of solvate [(2) ꢁ C4H8O2] – 384.6 g
ꢀ
1
ꢀ1
.
mol and [(1) ꢁ C4H8O2] – 681.0 g mol
ꢀ1
ꢀ1
Molecular weight (g mol )
a
Concentration of 5 (g 100 ml
)
1
1
1
4.2
3.8
1.5
253 ꢂ 5
238 ꢂ 5
227 ꢂ 4
213 ꢂ 4
204 ꢂ 4
195 ꢂ 4
ꢀ1
weights of solvates (2) ꢁ C4H8O2 (384 g mol 1) and
ꢀ
ꢀ
1
(
1) ꢁ C4H8O2 (593 g mol ). This fact could be explained
9
.6
8.0
.0
by the equilibrium between complexes 3 and 4 as il-
lustrated in Scheme 4. The value of [a]D decreases in-
significantly from +14.6 to +9.8 °C due to the
6
a
Theoretical molecular weight of complex 5, 268.4 g mol
.
Scheme 4.
Scheme 5.

L.M. Khalilov et al. / Journal of Organometallic Chemistry 689 (2004) 444–453
447
i
Me
MeO
MeO
Me
Bu
Al
Bu i
3
-
HAlBui
2
MeO
MeO
NH * HCl
N
i
H
i
9
ClAlBu ,
Al
Bu
2
11
1
Bu
-
2H2
i
[
α] 21 = - 25.80
D
Scheme 6.
Let us describe the interaction of (1S)-salsolidine with
i-Bu AlH. Both in benzene and 1.4-dioxane, (1S)-sal-
solidine completely reacts with i-Bu2AlH at mole ratio
contains only one 1S chiral center. Probably, formation
of oligomeric complexes neutralizes the stereodifferen-
tiating effect, and, consequently, degrades optical ac-
tivity of the complexes.
The dilution with 1,4-dioxane similarly affects the
molecular weight and value of [a]D for complexes 7–9
(Table 5).
2
1
:3 and forms (1S)-N-(diisobutylalumina)-6,7-dime-
thoxy-1-methyl-1,2,3,4-tetrahydroisoquinoline (6) with
9
0
5–98% yield (Scheme 6). At 20 °C, the reaction runs for
.5–1.5 h.
Unlike for the alkylaluminium alkoxides, dilution of
Let us finally discuss the reaction of (1S)-salsolidine
the reaction mixture with benzene makes the molecular
weight of the complex 6 increase as shown in Table 4.
This increase occurs probably due to formation of dimer
with Et Al in benzene. The reaction runs at 20 °C for 0.5
3
h and provides (1S)-N-(diethylalumina)-6,7-dimethoxy-
1-methyl-1,2,3,4-tetrahydroisoquinoline (9) with 95–98%
yield. (1S)-Salsolidine completely reacts with fivefold
excess of Et3Al, whereas the reaction with i-Bu2AlH
flows at 1:3 mole ratio. The excessive Et3Al is supposed
to be consumed for coordination with methoxy groups
of salsolidine as shown in Scheme 8.
(
7
7), trimer (8) and other oligomeric complexes (Scheme
). Discussions concerning their structure and formation
mechanism are presented in [10a–10l].
The dilution also make the value of [a]D reduce,
which demonstrates low rotating ability of chiral olig-
omeric complexes (Table 4). For example, the complex 6
The dilution of the reaction mixture increases the-
molecular weight of complex 9 (Table 6) due to forma-
Table 4
Change in molecular weight and optical rotation angle of complexes 6–
8
vs. their concentration in benzene
Table 5
Change in molecular weight and optical rotation angle of complexes 6–
2
D
0
Concentration Molecular weight
ꢀ1
(g mol )
[a]
8
vs. their concentration in 1,4-dioxane
ꢀ1
(g 100 ml
)
2
D
0
Concentration Molecular weight
ꢀ1
(g mol )
[a]
1
3.4
541 ꢂ 10
664 ꢂ 13
762 ꢂ 15
887 ꢂ 17
1051 ꢂ 21
+(13.7 ꢂ 0.6)
+(10.7 ꢂ 1.0)
+(7.6 ꢂ 1.1)
+(6.5 ꢂ 1.2)
+(5.3 ꢂ 1.3)
ꢀ1
(
g 100 ml
)
8
4
2
1
.1
.9
.9
.7
14.0
10.5
7.9
870 ꢂ 19
1119 ꢂ 20
1297 ꢂ 22
+(20.1 ꢂ 2.0)
+(19.0 ꢂ 0.4)
+(15.0 ꢂ 0.6)
i
Bu
i
i
i
Me
Bu
Bu
Al
Bu
MeO
MeO
Me
Al
C H
6
6
MeO
MeO
N
H
Al
N
N
Al
i
OMe
OMe
Bu
i
Bu
i
Me
Bu
6
i
Bu
7
OMe
MeO
Me
C H
6 6
i
i
Bu
Bu
Me Bui
N
i
Al
N
Al
N
Bu
MeO
MeO
OMe
OMe
Al
i
Me
Bu i
Bu
8
Scheme 7.

448
L.M. Khalilov et al. / Journal of Organometallic Chemistry 689 (2004) 444–453
AlEt3
Me
MeO
MeO
Me
Et
Et
Et
5
-
AlEt3
MeO
MeO
Al
NH * HCl
N
ClAlEt2,
Al
Et
Et
-
2EtH
AlEt3
9
C H
6
6
AlEt3
Et
Et
Me
AlEt3
MeO
MeO
Al
N
N
OMe
Al
OMe
Me
AlEt3
Et
Et
AlEt3
10
Scheme 8.
Table 6
Change in molecular weight and optical rotation angle of complexes 9
and 10 vs. their concentration in benzene
2.2. An effect of application of synthesized alkylaluminium
chiral alkoxides and amides as adducts to carbo- and
cycloalumination of olefins
2
0
Concentration
(g 100 ml
Molecular weight
ꢀ1
[a]
D
ꢀ1
a
)
(g mol )
The stereodifferentiating effect of application of syn-
thesized above chiral alkylaluminium alkoxides and
amides as catalytic and stoichiometric adducts was
studied in reactions of a-methylstyrene carboalumina-
tion with either i-Bu2AlH or Et3Al, and in reactions of
nonene-1 carbo- and cycloalumination with Et3Al using
Cp2ZrCl2 catalyst.
2
0.6
1.0
752 ꢂ 10
790 ꢂ 23
835 ꢂ 16
846 ꢂ 10
945 ꢂ 5
+(12.1 ꢂ 0.2)
+(9.5 ꢂ 0.4)
+(8.7 ꢂ 0.7)
+(5.5 ꢂ 0.5)
+(2.6 ꢂ 0.6)
ꢀ1
1
8
7
3
.3
.2
.5
a
Theoretical molecular weight of complex 9, 748.1 g mol
.
It was established that the reactionof a-methylstyrene
with i-Bu2AlH in the presence of Cp2ZrCl2 has two
pathways and significantly depends on the reaction
conditions (Scheme 9). First of all, at room temperature
the reaction provides a mixture of hydroalumination
(11) and carboalumination (13) products at 8:9 mole
tion of dimeric derivative 10, which is analogous to the
complex 7; the value of [a]D decreases with the dilution.
Therefore, the formation of dimeric structures also
neutralizes the stereodifferentiating effect and degrades
optical activity of these complexes.
Scheme 9.

L.M. Khalilov et al. / Journal of Organometallic Chemistry 689 (2004) 444–453
449
Table 7
Influence of chiral OACs 1, 2 and 6–8 concentration on enantiomeric excess of oxidation and hydrolysis products 12 and 14 in carboalumination
reaction of a-methylstyrene by i-Bu2AlH
2
D
2
OAC*
Ratio i-Bu
(
2
AlH:camphor
salsolidine):olefin:Cp ZrCl
Yield of (12) (%)
Yield of (14) (%)
[a] (14) (CHCl
3
)
ee (14) (%)
2
2
–
10:0:10:0.5
11:1:10:0.5
8
2
9
14
0
0
14
6.8 ꢂ 1.2
1
–2
–8
15:5:10:0.5
7
0
10
0
12.6 ꢂ 2.2
–
24
–
1
1
0:10:10:0.5
3:1:10:0.5
30
27
0.9 ꢂ 0.1
2
6
25:5:10:0.5
0:10:10:0.5
91
0
1
0
–
–
–
–
3
ratio and common yield of 17%. The thermal reaction at
0 °C raises the yield of the same products at 1:1 mole
ratio to only 27%. The structure of compounds 11 and
3 was established by applying 13C and 1H NMR
spectroscopy to the products of their oxidation and
hydrolysis – alcohols 12 and 14, respectively. Second, an
addition of chiral alkylaluminium alkoxides 1 and 2 to
the reaction mixture does not change the common yield
of hydro- and carboalumination products, but also rel-
atively increase the yield of carboalumination product
ways. However, an increase of chiral complex 7 con-
centration to a ratio 25:5:10:0.5 of i-Bu2AlH:(1S)-
salsolidine:olefin:Cp2ZrCl2 gives a predomination of
hydroalumination products to 91%. At mole ratio i-
Bu2AlH:(1S)-camphor of 1:1 or i-Bu2AlH:(1S)-salsoli-
din of 3:1, the hydro- and carboalumination reactions
appear to be completely blocked. Moreover, an intro-
duction of optically active alkoxide 1 or amide 6 as
chiral activators increases the optical yield of organ-
oaluminium compound 13. These results testify that the
chiral alkoxides and amides indeed take part in the
generation of a catalytic system.
6
1
1
3 (Table 7). For example, at mole ratio i-Bu2AlH:(1S)-
camphor:olefin:Cp2ZrCl2 of 11:1:10:0.5 the ratio of hy-
dro- to carbo- is 1:7. Furthermore, the introduction of
alkylaluminium amides 6–8 quickens the reaction and
increases the common yield of products on both path-
The reaction of a-methylstyrene with triethylalumin-
ium in the presence of Cp ZrCl provides OAC 15
as a carboalumination product with low yield of 7%
2
2
Scheme 10.
Scheme 11.

450
L.M. Khalilov et al. / Journal of Organometallic Chemistry 689 (2004) 444–453
Table 8
Influence of chiral OACs 5, 9 and 10 concentration on enantiomeric excess of alcohols 20 and 22
2
D
2
OAC*
Ratio AlEt
(
3
:camphor
salsolidine):olefin:Cp ZrCl
Yield of (18) (%) Yield of (20) (%) Yield of (22) (%) [a] (22) (CHCl
3
)
ee (22) (%)
2 2
–
10:0:10:0.5
1:1:10:0.5
5
24
0
29
84
11
0
0
5
1
1.2 ꢂ 0.3
5
15:5:10:0.5
42
0
37
0
19
0
2.5 ꢂ 0.5
–
13
–
1
1
0:10:10:0.5
3:1:10:0.5
59
18
3
0.7 ꢂ 0.1
3
9
and 10
25:5:10:0.5
0:10:10:0.5
4
0
0
0
0
0
–
–
–
–
3
(
1
Scheme 10). Oxidation and hydrolysis of the compound
5 gives tertial alcohol 16. Introduction of complex 5 at
3. Experimental section
mole ratio 15:5:10:0.5 of AlEt3:camphor:olefin:Cp2ZrCl2
does not change the yield of compound 16. On the other
hand, application of amides 9 and 10 at mole ratio
3.1. General
All operations were carried out under argon using
Schlenk techniques. Solvents were dried by refluxing
over LiAlH or i-Bu AlH and were freshly distilled prior
2
5:5:10:0.5 of AlEt : salsolidine:olefin:Cp ZrCl de-
3 2 2
creases the yield of the carboalumination product to 3%.
The reaction of AlEt with nonene-l using Cp ZrCl
4
2
to use. Commercial 91.8% AlEt and 74% i-Bu AlH
3
3
2
2
2
1
13
as catalyst gives mainly the cycloalumination product
1. Presence of complex 5 or amides 9 and 10 in the
were used. The NMR spectra H and C were recorded
1
2
at 25 °C on spectrometers JEOL FX-90Q (90 MHz H,
22.5 MHz C) and BRUKER AM-300 (300 MHz H,
1
3
1
reaction mixture leads to carbo- and hydroalumination
products 17 and 19 (Scheme 11). The structure of
compounds 17, 19 and 21 was confirmed by identifying
corresponding products of oxidation and hydrolysis 18,
1
3
75 MHz C). The samples were prepared in standard
tubes of 5-mm diameter. D6-benzene and d-chloro-
phorm were used as internal standard. Chemical shifts
of signals of carbon and hydrogen atoms are given in d-
scale (ppm) with respect to TMS. Optical rotation an-
gles [a]D were determined on polarimeter P-400 (France)
with halogen tube with sodium filter as a radiation
source with k ¼ 589.3 nm. The measurements of [a]D
were performed in a sectional cylindrical glass cell of 53
mm length. The cell was filled with a solution through a
glass inlet using syringe under argon. Enantiomeric
excess of products was determined using tris[3-(hepta-
fluorbutiryl)-l-campharato]europium (III) as a shift-
reagent. Addition of the 10 mol% shift-reagent results in
a low field shift and a diastereomeric decay of signals
that belong to carbon atoms at hydroxy-group of
products of OACs oxidation and hydrolysis (14, 20 and
22). The amount of enantiomeric alcohols in the mixture
was determined using signal intensity of protons in
HCOH-groups. The cryoscopic studies were carried out
in a lengthened conic glass cell with three inlets: for
argon, for mixer and for Beckman thermometer. The
accuracy of melting point detection is 0.005 °C. The
hydrolysis products of reaction mixture were analyzed
on chromatograph ‘‘Chrom-5’’ (flame-ionizating detec-
tor, column 2 m ꢃ 3 mm 15% ‘‘Peg-6000’’ or 5% ‘‘SE-
30’’ on Chromaton N-AW, 50–190 °C). The yields of the
alkylaluminium alkoxides or amides were calculated
relative to amount of the initial camphor or salsolidine.
The yields of hydro-, carbo- and cycloalumination
products were calculated relative to amount of the initial
2
0 and 22. The dependence of product yields upon mole
ratios of reagents is presented in Table 8. Addition of
camphor increases the yield of hydro- and carboalumi-
nation products. However, at mole ratio 1:1 of
AlEt3:camphor the reaction becomes inhibited. These
facts can have the following explanation. The OACs
that contain oxygen or nitrogen coordinate with the
central atom of the catalyst and produce relatively stable
complexes, which become active in hydro- and carboa-
lumination reactions. Growth of concentration of chiral
OACs formed from either (1S)-camphor or (1S)-salsol-
idine increases the enanthiomeric excess of 20 and 22
only to 13%. Moreover, the chiral OACs obtained from
(
1S)-camphor provide more effective sterodifferentiating
than that obtained from salsolidine (Tables 7 and 8).
This effect is probably a result of the structure of the
aluminium complexes and the number of active chiral
centers in them.
The investigation of optically active alkylaluminium
amides and alkoxides allows the authors to formulate
the following conclusion. The introduction of oxygen
and nitrogen containing chiral OACs into hydro-, car-
bo- and cycloalumination reactions of a-olefins using
Cp ZrCl catalyst could indeed provide optically active
2
2
products. The stereodifferentiating effect of those for-
mation is caused by coordination of chiral alkylalu-
minium alkoxides and amides with the central atom of
the catalyst.

L.M. Khalilov et al. / Journal of Organometallic Chemistry 689 (2004) 444–453
451
olefin. Individual optically active alcohols and hydro-
carbons were isolated by preparative gas-liquid chro-
matography (Carlo Erba, column 4 m ꢃ 5 mm, 15%
i-Bu2AlH (15 mmol). (1S)-6,7-Dimethoxy-1-methyl-1,2,
3,4-tetrahydroisoquinoline hydrochloride ((1S)-salsoli-
2
1
ꢀ1
dine) (1.219 g, 5 mmol, [a] ¼ )25.8° (c ¼ 2 g 100 ml
,
D
‘
‘SE-30’’ on Chromaton N-AW). Purity of the com-
C2H5OH)) was added by small portions, and reaction
mixture was stirred for 1 h at r.t. Complex 6 was obtained
with 96% yield. 13C NMR (C D ) d 19.51 (q, C ), 23.22
pounds was controlled by H and 13C NMR method.
1
6
6
10
3
2
.2. Synthesis of dimer complex (1S,2S)-1,7,7-trimethyl-
-[(diisobutylalumina)oxy]-bicyclo[2.2.1]heptane (1)
(br. t, C ), 26.21 (d C ), 28.62 (q C ), 37.98 (t, C ), 51.38
13 14 15 3
(t, C ), 55.67 (q, C ,C ), 71.01 (d, C ), 113.11 (d, C , C ),
2 11 12 1 5 8
125.90 (s, C4), 130.91 (s, C9), 149.11 (s, C6, C7).
The reaction mixture was treated with 10% HCl. The
A glass reactor of 50 ml was fixed on a magnetic
stirrer under argon, filled with 12 ml benzene and 2.5 ml
4% i-Bu2AlH (13 mmol). (1S)-1,7,7-trimethyl-bicy-
clo[2.2.1]heptane-2-on ((1S)-camphor) (0.705 g, 13
solvent was evaporated, and the dry residue was ex-
tracted by ethyl alcohol. The extract was filtered and
evaporated. (1S)-6,7-Dimethoxy-1-methyl-1,2,3,4-tetra-
7
2
4
ꢀ1
19
mmol, [a] ¼ )42.8° (c ¼ 8 g 100 ml , C H OH)) was
hydroisoquinoline ([a] ¼ )22.4 ꢂ 2. 6° (c ¼ 2:8 g 100
D
2
5
D
ml , C H OH)) was formed. H and C NMR spectra
were identical with those of authentic sample [7a].
ꢀ
1
1
13
added by a small portions to the mixture. The mixture
was stirred for 1 h at r.t. Dimer (1S, 2S)-1,7,7-trimethyl-
2
5
2
obtained with 95–98% yield. H NMR (C6D6) 0.79 (s,
-[(diisobutylalumina)oxy]bicyclo[2.2.1]heptane (1) was
1
3.5. Synthesis of (1S)-2-(diethylalumina)-6,7-dime-
thoxy-1-methyl-1,2,3,4-tetrahydroisoquinoline (9)
6
4
H, CH3), 0.97 (s, 3H, Me), 1.11 (m, 1H, CH), 2.12 (m,
H, CH2), 4.29 (m, 1H, CHO), 0.45 (d, 4H, AlCH2,
3
3
JHH ¼ 6.8 Hz), 1.24 (d, 12H, AlCH2CHCH3, JHH ¼ 5.6
A glass reactor of 50 ml was fixed on a magnetic
stirrer under argon, filled with 12 ml benzene and 1.8 ml
91.8% AlEt (15 mmol). (1S)-Salsolidine hydrochloride
13
Hz), 1.98–2.25 (m, 1H, AlCH CH). C NMR (C D ) d
2
6
6
1
C ), 26.28 (d, C ), 27.37 (t, C ), 28.88 (q, C ), 35.43 (t,
3.64 (q, C ), 20.63 (q, C ), 21.19 (q, C ), 24.10 (br. t,
1
0
8
9
3
(0.731 g, 3 mmol) was added by small portions to the
reaction mixture, which was stirred for 1 h at r.t.
Complex 9 was formed with 95% yield. 13C NMR
(C6D6) d 19.51 (q, C10), 23.22 (br. t, C13), 26.21 (d, C14),
28.62 (q, C15), 37.98 (t, C3), 51.38 (t, C2), 55.67 (q,
C11,C12), 71.01 (d, C1), 113.11 (d, C5, C8), 125.90 (s, C4),
130.91 (s, C ), 149.11 (s, C , C ).
1
1
12
5
13
C6), 42.55 (t, C3), 45.62 (d, C4), 47.03 (s, C7), 50.12 (s,
C1), 83.95 (d, C2).
Further, the reaction mixture was treated with 10%
solution of HCl. The solvent was removed and the dry
residue was extracted by ethyl alcohol. The extract was
filtered and evaporated. (1S, 2S)-1,7,7-Trimethyl-bicy-
9
6
7
21
clo[2.2.1]heptan-2-ol (isoborneol) ([a] ¼ )33.5° (c ¼ 4
The reaction mixture was treated with 10% HCl. The
solvent was removed and the dry residue was extracted
by ethyl alcohol. The extract was filtered and evapo-
rated. (1S)-6,7-Dimethoxy-1-methyl-1,2,3,4-terahydro-
isoquinoline was obtained [7a].
D
ꢀ
1
1
13
g 100 ml , C H OH)) was obtained. H and C NMR
2
5
spectra were identical with those of authentic sample
7a,7b].
[
3
.3. Reaction of (1S)-Camphor with AlEt
3
2
3.6. Reaction of a-methylstyrene with (i-Bu) AlH in the
A glass reactor of 50 ml was fixed on a magnetic stirrer
under argon, filled with 12 ml benzene and 1.6 ml 91.8%
presence of (1S,2S)-1,7,7-trimethyl-2-[(diisobutylalu-
mina)oxy]bicyclo[2.2.1]heptane (2)
AlEt (13 mmol). Small portions of (1S)-camphor (0.705
3
g, 13 mmol) were added to the reaction mixture, which
was stirred for 1 h at r.t. Complex 5 was obtained. 13C
NMR (CDCl3) d 0.48 (t, C11), 9.25 (q, C10), 10.36 (q, C12),
A glass reactor of 50 ml was fixed on a magnetic
stirrer under argon, filled with 12 ml benzene, 2.1 ml
74% i-Bu2AlH (11 mmol) and 0.054 g (1S)-camphor (1
mmol). The mixture was stirred for 30 min. Then
Cp2ZrCl2 (0.146 g, 0.5 mmol) and a-methylstyrene
(1.182 g, 10 mmol) were added. The mixture was stirred
for 24 h, blown by dry oxygen and treated with 10% HCl
at 0 °C. The products were extracted by hexane; the
upper layer was dried over CaCl2. Yields of alcohols 12
and 14 were determined by GLC. H and 13C NMR
spectra of 2-phenylpropan-1-ol (12) were identical with
those of authentic sample [7a].
1
4
8.88 (q, C8), 19.60 (q, C9), 26.88 (t, C5), 30.20 (t, C6),
3.33 (d, C4), 43.53 (t, C3), 47.23 (s, C7), 59.20 (br. s, C1).
The reaction mixture was treated with 10% HCl and
the product was extracted by benzene. The extract was
filtered and evaporated. (1S)-Camphor was observed.
1H and 13C NMR spectra were identical with those of
authentic sample [7a,7c,7d].
1
3.4. Synthesis of (1S)-2-(diisobutylalumina)-6,7-dime-
thoxy-1-methyl-1,2,3,4-tetrahydroisoquinoline (6)
1
5-Methyl-2-phenylhexane-2-ol (14). H NMR (CDCl3)
3
d 0.91 (d, 6H, CH , J
2H, CH ); 1.59 (s, 3H, CH ); 1.67–2.09 (m, 3H, CH,
2 3
¼ 6.35 Hz); 0.80–1.35 (m,
3
H–H
A glass reactor of 50 ml was fixed on a magnetic stirrer
under argon, filled with 12 ml benzene and 2.9 ml 74%
CH C H ); 2.44 (s, 1H, OH); 7.10–7.34 (m, 5H, C H ).
5
2
6
6
5

452
L.M. Khalilov et al. / Journal of Organometallic Chemistry 689 (2004) 444–453
1
3
C NMR (CDCl3) d 22.61 (d, C6, C7), 28.33 (s, C5), 30.15
s, C1), 32.88 (s, C3), 41.98 (s, C4), 74.69 (s, C2), 124.83 (d,
g of (1S)-salsolidine hydrochloride (1 mmol) and 1.9 ml
of AlEt3 (91.8%) (15 mmol), and the reaction mixture
was stirred for 30 min. Then 0.146 g of Cp2ZrCl2 (0.5
mmol), 1.182 g of a-methylstyrene (10 mmol) were ad-
ded. The reaction mixture was stirred for 24 h, blown by
dry oxygen and decomposed by 10% solution of HCl at
(
C9), 126.46 (d, C11), 128.08 (d, C10). 147.9 (s, C8).
The experiment was repeated with the addition of 5
mmol of (1S)-camphor (0.771 g); 15 mmol of (i-Bu)2AlH
(
2.9 ml) are required for this amount.
0
°C in order to obtain alcohol 16. The products were
3
presence of (1S)-2-(diisobutylalumina)-6,7-dimethoxy-1-
.7. Reaction of a-methylstyrene with (i-Bu) AlH in the
extracted by hexane, the upper layer was dried over
CaCl2. Yields of carboalumination products were de-
termined by GLC.
2
methyl-1,2,3,4- tetrahydroisoquinoline (6)
The experiment was repeated with the addition of 5
mmol of hydrochloride (1S)-salsolidine (1.219 g); 25
mmol of AlEt3 (3.14 ml) are required for this amount.
A glass reactor of 50 ml was fixed on a magnetic stirrer
under argon, filled with 9 ml of benzene, 0.244 g of (1S)-
salsolidine (1 mmol) and 2.5 ml of (i-Bu) AlH (13
2
mmoles) and mixed for 30 min. Then, Cp ZrCl (0.146 g,
2
3.10. Reaction of nonene-1 with AlEt in the presence of
3
2
0
.5 mmol) and a-methylstyrene (1.182 g, 10 mmol) were
adducts of complex 5
added to the reaction mixture. The reaction mixture was
stirred for 24 h, blown by dry oxygen and decomposed
by 10% solution of HCl at 0 °C. The products were ex-
tracted by hexane; the upper layer was dried over CaCl2.
Yields of alcohols 12 and 14 were determined by GLC.
The experiment was repeated with the addition of 5
mmol of (1S)-salsolidine (1.210 g); 26 mmol of (i-
A glass reactor of 50 ml was fixed on a magnetic
stirrer under argon, filled with 6 ml of benzene, 0.154 g
of camphor (1 mmol) and 1.4 ml of AlEt3 (91.8%) (11
mmol), and the reaction mixture was stirred for 30 min.
Then, 0.146 g of Cp ZrCl (0.5 mmol) and 1.262 g of
nonene-1 (10 mmol) were added. The reaction mixture
was stirred for 24 h, blown by dry oxygen and decom-
posed by 10% solution of HCl at 0 °C. The products
were extracted by hexane; the upper layer was dried over
CaCl2. Yields of the products of carboalumination were
determined by GLC. Nonan-1-ol (18) [7a], 2-ethyl-
nonan-l-ol (20) and 7-heptylbutan-l,4-diol (22) were
2
2
Bu) AlH (5 ml) are required for this amount. Yields are
2
listed in Table 7.
3.8. Reaction of a-methylstyrene with AlEt
presence of adducts of Complex (5)
3
in the
A glass reactor of 50 ml was fixed on a magnetic stirrer
under argon, filled with 6 ml of benzene, 0.542 g of
camphor (1 mmol) and 1.4 ml of AlEt (91.8%) (11
formed.
1
2-Ethylnonan-1-ol (20). H NMR (CDCl ) d 0.82–
0.96 (m, 6H, CH ); 1.10-1.65 (m, 14H, CH ); 1.93–2.18
3
3
3
2
mmol), and the reaction mixture was stirred for 30 min.
Then Cp2ZrCl2 (0.146 g, 0.5 mmol) and a-methylstyrene
(m, 1H, CH); 3.51-3.99 (m, 2H, CH2OH); 4.66 (m, 1H,
OH). 13C NMR (CDCl3) d 11.10 (t, C4), 14.09 (q, C11),
22.67 (t, C10), 23.32 (t, C3), 26.90 (t, C6), 28.52 (t, C8),
29.43 (t, C7), 31.84 (t, C9), 32.49 (t, C5), 39.38 (d, C2),
(
1.182 g, 10 mmol) were added to the reaction mixture.
The reaction mixture was stirred for 24 h, blown by dry
oxygen and decomposed by 10% solution of HCl at 0 °C
in order to obtain alcohol 16. The products were extracted
65.98 (t, C1).
7-Heptylbutan-1 4-diol (22). H NMR (CDCl ) d
1
3
3
by hexane; the upper layer was dried over CaCl . Yields of
2
0.74 (t, 3H, CH , J
3
¼ 5.61 Hz); 1.10–1.25 (m, 10H,
H–H
carboalumination products were determined by GLC.
The experiment was repeated with the addition of 5
mmol of the camphor (0.771 g); 15 mmol of AlEt3 (1.9
CH ); 1.35–2.00 (m, 5H, CH, CH ); 3.49–3.65 (m, 4H,
2
2
CH2OH); 4.15 (m, 2H, OH). 13C NMR (CDCl3) d 14.09
(q, C11), 22.67 (t, C10), 27.01 (t, C6), 29.30 (t, C8), 29.89
(t, C7), 31.84 (t, C3, C9), 35.74 (t, C5), 39.38 (d, C2),
60.71 (t, C4), 65.98 (t, C1).
ml) are required for this amount.
1
2
-Phenylpentan-2-ol (16). H NMR (CDCl3) d 0.80
3
(
1
2
t, 3, CH3, JH-H ¼ 6.3 Hz,); 1.20-1.35 (m, 2H, CH2);
The experiment was repeated with the addition of 5
mmol of camphor (0.771 g); 15 mmol of AlEt (1.9 ml)
are required for this amount.
3
.50 (s, 3H, CH ); 1.75 (t, 2H, CH C J
3
¼ 6.3 Hz);
2
H-H
3
13
.55 (s, 1H, OH); 7.18-7.40 (m, 5H, C H ). C NMR
6
5
(
CDCl ) d 14.48 (q, C ), 17.34 (q, C ), 30.15 (t, C ),
3 5 1 4
4
1
6.60 (t, C3), 74.82 (s, C2), 124.83 (d, C7), 126.52 (d, C9),
28.15 (d, C8), 148.11 (s, C6).
3
3.11. Reaction of nonene-1 with AlEt in the presence of
adducts of chiral OACs (9) and (10)
3.9. Reaction of a-methylstyrene with AlEt
presence of adducts of chiral OACs (9), (10)
3
in the
A glass reactor of 50 ml was fixed on a magnetic
stirrer under argon, filled with 6 ml of benzene, 0.244 g
of hydrochloride (1S)-salsolidine (1 mmol) and 1.9 ml of
A glass reactor of 50 ml was fixed on a magnetic
stirrer under argon and filled with 6 ml of benzene, 0.243
AlEt (91.8%) (15 mmol), and the reaction mixture was
3
stirred for 30 min. Then, 0.146 g of Cp ZrCl (0.5 mmol)
2
2

L.M. Khalilov et al. / Journal of Organometallic Chemistry 689 (2004) 444–453
[8] (a) E.C. Ashby, J.R. Boone, J. Org. Chem. 41 (1976) 2890;
453
and 1.262 g of nonene-1 (10 mmol) were added. The
reaction mixture was stirred for 24 h, blown by dry
oxygen and decomposed by 10% of HCl solution at 0
(
b) E.C. Ashby, S.A. Noding, A.B. Goel, J. Org. Chem. 45 (1980)
1
028;
c) H.C. Brown, V. Varma, J. Org. Chem. 39 (1974) 1631;
(
(
°
C. The products were extracted by hexane; the upper
d) S. Krishnamurthy, H. Brown, J. Am. Chem. Soc. 98 (1976)
layer was dried over CaCl2. Ratio of products was de-
termined by GLC. Nonan-1-ol (18) [7a], 2-ethylnonan-l-
ol (20) and 7-heptylbutan-1,4-diol (22) were formed.
The experiment was repeated with the addition of 5
mmol of hydrochloride salsolidine (1.21 g); 25 mmol of
AlEt3 (3.14 ml) is required for this amount.
3383;
(e) H.C. Brown, S. Krishnamurthy, Nung Min Yoon, J. Org.
Chem. 41 (1976) 1778;
(
f) H. John, S. Akiyama, F.J. Cedar, M.J. Bennet, R.M. Tuggu, J.
Am. Chem. Soc. 96 (1974) 274;
g) W. Hans, F. Ben, Tetrahedron 32 (1976) 2831.
[9] G.A. Tolstikov, V.P. UrÕev, Organoaluminium synthesis, Nauka,
979.
10] (a) T.R.R. McDonald, W.S. McDonald, Proc. Chem. Soc. (1963)
82;
(
1
[
3
Acknowledgements
(
(
b) O.T. Beachley, G.E. Coates, G. Kohnstam, J. Chem. Soc.
1965) 3248;
The authors thank INTAS Fund for the financial
support (Project No. 99-3-1541). The authors are also
grateful to Dr. Evgueni V. Parfenov for revising English
text of the paper and providing valuable comments.
(c) J.L. Atwood, G.D. Stuky, J. Am. Chem. Soc. 92 (1970)
285;
(
d) K. Gosling, G.M. McLaughlin, G.A. Sim, J.D. Smith, Chem.
Commun. (1970) 1617;
e) M. Cesari, G. Perego, G. Del Piero, S. Cucinella, E. Cernia, J.
Organomet. Chem. 78 (1974) 203;
f) G. Perego, G. Del Piero, M. Cesari, A. Zazatta, G. Dozzi, J.
Organomet. Chem. 87 (1975) 53;
g) G. Del Piero, M. Cesari, G. Dozzi, A. Mazzei, J. Organomet.
(
(
References
(
[
1] A. Xajos, Komplexe Hydride und inke Anwendung inder Organ-
ischen Chemie, Veb Deutscher Verlag der Wissenschaften, Berlin,
Chem. 129 (1977) 281;
(h) K.M. Waggoner, P.P. Power, J. Am. Chem. Soc. 113 (1991)
3385;
1966, 624 p.
[
2] V.A. Pavlov, T.V. Simonova, E.P. Klabunovskii, Bull. Acad. Sci.
USSR, Div. Chem. Sci. 36 (1987) 770.
(i) D.M. Choquette, M.J. Timm, J.L. Hobbs, T.M. Nicholson,
M.M. Olmstead, R.P. Planalp, Inorg. Chem. 32 (1993) 2600;
(j) C. Schnitter, S.D. Waezsada, H.W. Roesky, M. Teichert, I.
Uson, E. Parisini, Organometallics 16 (1997) 1197;
(k) C.J. Harlah, S.G. Bott, A.R. Barron, J. Chem. Soc., Dalton
Trans. (1997) 637;
[
[
3] K. Maruoka, H. Yamamoto, Angew. Chem. 97 (1988) 3967.
4] G. Giacomelli, L. Bertero, L. Lardicci, Tetrahedron Lett. 22
(1981) 883.
[
[
5] U.M. Dzhemilev, A.G. Ibragimov, O.S. Vostrikova, G.A. Tolsti-
kov, Bull. Acad. Sci. USSR, Div. Chem. Sci. 34 (1985) 43.
(l) J.E. Park, B.-J. Bae, Y. Kim, J.T. Park, I.-H. Suh,
Organometallics 18 (1999) 1059.
6] U.M. Dzhemilev, A.G. Ibragimov, A.P. Zolotarev, R.R. Musluk-
hov, G.A. Tolstikov, Bull. Acad. Sci. USSR, Div. Chem. Sci. 38
[11] (a) U.M. Dzhemilev, A.G. Ibragimov, Russ. Chem. Rev. 69 (2)
(2000) 121;
(1989) 194.
[
7] (a) Integrated Spectral Data Base System for Organic Com-
pounds, National Institute of Materials and Chemical Research
Tsukuba, Ibaraki 305-8565, Japan. Available from www.aist.-
go.jp/RIODB/SDBS
(b)
L.M. Khalilov, L.V. Parfenova, S.V. Rusakov, A.G.
Ibragimov, U.M. Dzhemilev, Russ. Chem. Bull., Int. Ed. 49
(2000) 2051;
(c) S.V. Rusakov, L.M. Khalilov, L.V. Parfenova, A.G. Ibragi-
mov, O.A. Ponomarev, U.M. Dzhemilev, Russ. Chem. Bull., Int.
Ed. 50 (2001) 2336;
(
b) M.L. Sierra, J.P. Oliver, J.V. Srini, R. Kumar, Organomet-
allics 11 (1992) 206;
c) D.G. Morris, M. Murray, J. Chem. Soc. Perkin Trans. (1976)
579;
d) Shinichi Ueji, Tetrahedron Lett. 21 (1980) 475.
(
(d)
A.V. Balaev, L.V. Parfenova, I.M. Gubaidullin, S.V.
1
Rusakov, S.I. Spivak, L.M. Khalilov, U.M. Dzhemilev, Dokl.
Phys. Chem. 381 (2001) 279.
(