Simple and efficient synthesis of closo-rhoda- and closo-iridacarboranes with π-ligands based on cyclic dienes

Full text of DOI:10.1023/A:1013023626971

«
1
702
Russian Chemical Bulletin, International Edition, Vol. 50, No. 9, pp. 1702—1704, September, 2001
Simple and efficient synthesis of closo-rhoda- and closo-iridacarboranes
with π-ligands based on cyclic dienes
T. V. Zinevich, A. V. Safronov, E. V. Vorontsov, P. V. Petrovskii, and I. T. Chizhevsky
A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences,
8 ul. Vavilova, 119991 Moscow, Russian Federation.
Fax: (095) 135 5085. E-mail: chizbor@ineos.ac.ru
2
1
2
Closo- and exo-nido-rhodacarboranes with cyclic
1-R -2-R -3,1,2-RhC B H (7a—d) (see Table 1). Un-
2 9 9
3
π-hydrocarbon ligands based on dienes, for example, of
der these conditions, η -allylic complexes 6a—c were
obtained along with less common complexes 7a—c (see,
for example, 7a ). In all cases, the mixtures obtained
were readily separated into individual compounds by
column chromatography on silica gel. The reactions of
salts 1b or 1c with [(η -COD)RhCl] in the presence of
COD proceeded selectively to form either exclusively
compound 7a (the yield was 67%) or a mixture of
complexes 6c and 7c in a ratio of ∼1 : 6, respectively. In
addition, the reaction of 6d with [(η -COD)IrCl] in
the presence of COD afforded η -allylalkene complex
3
3,2
the η -allyl or η -allylalkene type, exhibit high cata-
lytic activity in homogeneous catalysis.1,2 Data on
closo-iridacarboranes containing η-enyl/dienyl ligands
are lacking in the literature. Known procedures for the
preparation of rhodium closo-complexes of this type,3
which contain no heteroatomic susbtitutents in the
carborane fragments, generally involve many steps and
often require isolation and purification of intermediates
at each stage, which sometimes leads to a noticeable
decrease in the yields of the target products. In this
connection, the development of a simple, efficient, and
versatile procedure for the synthesis of these compounds
assumes great importance.
6
,4
4
2
4
2
3
,2
Scheme 1
The procedure proposed in the present study allows
one to substantially simplify the synthesis of closo-rhoda-
H
–
1
,2
3
R1
carboranes containing η -cycloalkene, η -cycloallyl,
or η3 -cycloallylalkene ligands and to prepare these
compounds in high or moderate yields by one-step
reactions with the use of available reagents. It also
opens up the way to the synthesis of structurally similar
closo-iridacarborane complexes. This method is based
on the reactions of Ê salts of nido-dicarbaundecaborates
,2
[
(1,5-R32COD)MCl]2
K+
R2
C H /EtOH
6
6
1
2
[
nido-7-R -8-R —C B H ]– (1, R1 and R2 = H, Alk,
2 9 10
4
1a—c
or ArAlk) with the [(η -diene)RhCl]2 dimers under
specific conditions, which have been used previously for
the preparation of the known exo-nido-bis(phos-
phine)rhodacarboranes.5
5 R3
3
8
4
7
R3
2
6
The reactions of compounds 1a—d (see Scheme 1;
R3
1
R3
R1 = Me, R = Ph for 1d)) or [nido-7,9-C B H ] Ê
2
–
+
M
M
2
9
12
4
R1
(
2) with the dimers [(η -diene)RhCl]2 (diene is
R1
dicyclopentadiene (DCPD), 2-(hydroxymethyl)norborna-
diene (HMNBD), 2-(2-hydroxyprop-2-yl)norbornadiene
R2
+
R2
(
HPNBD), cycloocta-1,5-diene (COD), or 1,5-dimethyl-
4
cycloocta-1,5-diene (DMCOD)) or [(η -COD)IrCl] in
the C H —EtOH mixture (4 : 1) (0.5—12 h) afforded
closo-3,3,3-(η1,2-C10H13)-1-R -2-R -3,1,2-RhC B H
(
(
R
2
6
6
1
2
2
9
9
3a,b, R = R2 = H (a) or Me (b)); closo-3,3-
1
6a—d
7a—e
3
,2
3
1
2
η
-C H -2-CR )-1-R -2-R -3,1,2-RhC B H (4a—d,
= R = R3 = H (a); R = R2 =Me, R = H (b);
1
2
1
2
3
7
7
2
2
9
3
9
1
a: R = R = H
6a, 7a: M = Rh; R = R = Me, R = H
6b, 7b: M = Rh;
1
2
1
1b: R1 = R2 = Me
1
2
3
1
2
3
1
2
1
2
R = R = R =Me (c); R = Me, R = Ph, R = H (d))
or closo-2,2-(η3,2-C H -2-CH )-2,1,7-RhC B H (5);
1c: R , R = o-(CH2)2C6H4
R , R = o-(CH2)2C6H4, R3 = H
1
2
3
6c, 7c: M = Rh; R = R = R = Me
2
7
7
2
2
9
11
1
3
6
7d: M = Rh; R = R = R = H
d: M = Ir; R = R = Me, R = H
3
3
1
2
or closo-3-(η -1,5-R —C H )-1-R -2-R -3,1,2-
1
2
3
2
8
11
MC B H (6a—d) and closo-3,3-(η3,2-1,5-R3 —C H )-
7e: M = Ir; R = R = Me, R = H
1
2
3
2
9
9
2
8
9
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1620—1623, September, 2001.
066-5285/01/5009-1702 $25.00 ©ꢀ2001 Plenum Publishing Corporation
1

Closo-(η-dienyl)rhodacarboranes
Russ.Chem.Bull., Int.Ed., Vol. 50, No. 9, September, 2001 1703
7
Table 1. Reagents and the yields of the products in the reac-
in CH Cl
performed previously afforded exclusively
2
2
4
tions of salts 1a—d and 2 with [(η -diene)ÌCl]
3
2
η -cycloallylic complex 6a.
Complexes 3a,b and 6b,c are feachered by the pres-
ence of the agostic C—H...Rh interaction. In complexes
6c and 6b, these interactions involve respectively one or
two competing aliphatic CH2 groups of the η -cyclo-
octenyl ligand, which are located in the α positions with
respect to the allylic fragment. Correspondingly, the
signals for the hydrogen atoms involved in the C—H...Rh
bond are observed in the 1H NMR spectra of com-
4
τ/ha
Starting
salt
[(η -diene)ÌCl]2
Product
Yield
(%)
L
M
3
1
1
à
b
DCPD
HMNBD
COD
Rh
Rh
Rh
Rh
Rh
Rh
Rh
0.5
1.0
12.0
2.5
2.0
4.0
3a8
4a9
7d
3b8
4b9
4c10
79
89
44
90
75
71
35
24
84
40
81
5
DCPD
HMNBD
HPNBD
COD
pounds 6c and 6b as multiplets at δH 0.08 and –0.24
with the intensities of one and two protons, respectively
6a3
,7
12.0
1
1
a6
(Table 2). The 2D EXSY H- H NMR spectrum (22 °C)
of complex 6b, which was fluctional in solution, re-
vealed evidences of the exchange between the terminal
and central protons of the allylic group, between the
terminal protons of the allylic group and the adjacent
aliphatic exo-protons, and between the endo-protons
involved in the C—H...Rh bond and the aliphatic
endo-protons at positions 5 or 7 of the ligand. All these
data are indicative of the 1,2-migration of the allylic
fragment in complex 6b with respect to the carbon
sceleton of the ligand.
7
Ir
0.25
6d
7e
6c
7c
6b
0
.5
DMCOD
COD
Rh
Rh
1.0
1
c
d
3.0
29
31
34
7
b
b
1
2
HMNBD
HMNBD
Rh
Rh
5.0
4.0
4d
5
43
a
b
τ is the reaction time.
A 1 : 1 mixture of diastereomers.
The compositions and the structures of the new
closo-rhodacarborane complexes were confirmed by the
data from elemental analysis and the 1H, 13C{ H}, and
11B/11B{ H} NMR spectra (see Table 2) (the assign-
7
e in 40% yield. It should be noted that protonation of
4
1
[
closo-3,3-(η -COD)-1,2-Me -3,1,2-RhC B H ]PPN
2 2 9 9
3
4
1
with TFA or the reaction of 1b with [(η -COD)RhCl]
2
1
Table 2. Data of elemental analysis and the H NMR spectra (CDCl , 400.13 MHz) of complexes 4d, 6b—d, and 7b—e
3
Com-
poundCalculated
Found
Molecular
δ (J/Hz)a
(
%)
formula
C
H
B
4
d
47.31
7.43
6.03
6.04
—
Ñ Í B Rh Mixture of A and B diastereomers: 7.63—7.13 (two d + m, 10 Í, Ph , Ph ,
17 26 9 A B
4
J = 8.1); 5.36 (s, 1 Í, ÍAsyn(8)); 5.21 (s, 1 Í, ÍBsyn(8));
4
4
3
3
2
.97 (m, 1 Í, Í (5)); 4.75 (m, 1 Í, Í (5)); 4.27 (m, 1 Í, Í (3));
A B B
.12 (m, 1 Í, Í (3)); 4.02 (s, 1 Í, Í anti(8)); 4.09 (s, 1 Í, ÍBanti(8));
A
A
.68 (m, 2 Í, Í (4), Í (4)); 3.62 (m, 2 Í, Í (6), Í (6));
A
B
A
B
.40 (m, 1 Í, Í (1)); 3.33 (m, 1 Í, Í (1)); 2.46 (s, 3 Í, Ìå—B);
A
B
.07 (s, 3 Í, Ìå—A); 1.81 (dm, 1 Í, Í (7α) or H (7β)),
B
B
JAB = 10.2); 1.79 (m, 2 Í, Í (7α), H (7β)); 1.68 (dt, 1 Í, Í (7β)
A
A
B
or H (7α)), J
= 10.2, J = 1.6)
B
AB
t
6
6
6
b
48.52
8.41
6.80
6.72
—
Ñ Í B Rh 7.15 (m, 2 Í, m-Ñ H ); 6.98 (m, 2 Í, o-Ñ H ); 5.86 (q*, 2 Í, Í(1),
18 30 9 6 4 6 4
4
Í(3), J ≈ 8.4); 4.43 (t, 1 Í, Í(2), J = 7.6); 3.87 (d, 2 Í, ÑÍ H C H ,
A B 6 4
JAB = 16.8); 3.78 (d, 2 Í, ÑÍ H C H , J = 16.8); 2.03 (m, 2 Í,
A
B
6
4
AB
Íexo(4), Íexo(8)); 1.53 (m, 3 Í, Íexo(5), Íexo(6), Hexo(7)); 1.24 (m, 2 Í,
Íendo(5), Íendo(7)); 1.08 (m, 1 Í, Íendo(6)); –0.24 (m, 2 Í, Íendo/agost(4),
Íendo/agost(8))
c
41.98
1.99
7.99
7.99
24.39 Ñ Í B Rh 5.18 (q*, 1 Í, Í(3), JH(3),H(4) = JH(3),H(2) ≈ 8.9); 4.62 (d, 1 Í, Í(2),
24.29
14 32 9
4
J = 8.0); 2.48 (ddd, 1 Í, Íexo(4), JAB = 15.0, JH(4exo),H(3) = 8.9,
JH(4exo),H(5) = 2.4); 2.26, 2.18, 2.15 (all s, 3 H each, Ñ(1)—Ìå, 2 Ìåcarb);
2
.16 (m, 1 Í, Íexo(8)); 2.06 (m, 1 Í, Íendo(4)); 1.90 (m, 2 Í, Í(5),
Í(7)); 1.77 (m, 1 Í, Í(7)); 1.45 (m, 2 Í, Í(6)); 1.03 (d, 3 Í, C(5)—Ìå,
Jgem = 6.8); 0.08 (m, 1 Í, Íendo/agost(8))
5.31 (m, 1 Í, Í(2)); 5.20 (q*, 2 Í, Í(1), Í(3), J ≈ 8.4); 2.34 (m, 2 Í,
Íexo(4), Íexo(8)); 2.24 (s, 6 Í, Ìå); 1.72 (m, 5 Í, Í(5), Íexo(6), Í(7));
d b,c
31.03
1.20
6.25
6.06
20.97 Ñ Í B Ir
21.06
1
2
28 9
3
1
.26 (br.d, 1 Í, Íendo(6), Jgem = 12.0); 0.82 (m, 2 Í, Íendo/agost(?)(4),
Íendo/agost(?)(8))d
(
to be continued)

1
704
Russ.Chem.Bull., Int.Ed., Vol. 50, No. 9, September, 2001
Zinevich et al.
Table 2 (continued)
Com-
poundCalculated
Found
Molecular
δ (J/Hz)a
(
%)
formula
C
H
B
7
7
b e
48.31
8.63
6.30
6.30
—
Ñ Í B Rh 7.27 (m, 2 Í, m-C H ); 7.12 (d, 1 Í, o-C H , J = 6.8); 7.03 (d, 1 Í,
18 28 9 6 4 6 4
4
o-C H , J = 6.8); 5.85 (q*, 1 Í, Í(1), J ≈ 8.0); 5.65 (t*, 1 Í, Í(6),
6 4
J ≈ 7.6); 4.16 (t, 1 Í, Í(2), J = 7.6); 3.83, 3.70, 3.60, 3.22 (all d,
1
2
H each, ÑÍ C H , J
.73 (m, 3 Í, Í(5), Í(7)); 2.50, 2.30 (both m, 1 H each, Í(4)); 2.18, 1.77
= 18.0); 3.32 (q*, 1 Í, Í(3), J ≈ 7.6);
2
6
4
ÀÂ
(
both m, 1 H each, Í(8))
ñ c
42.96
2.20
7.89
7.53
—
Ñ Í B Rh 5.54 (q*, 1 Í, Í(1), J ≈ 7.2); 5.41 (t*, 1 Í, Í(6), J ≈ 6.9); 4.32 (d, 1 Í,
1
4
30 9
4
Í(2), J = 8.1); 3.69 (q*, 1 Í, Í(5), J ≈ 8.1); 3.47 (m, 1 Í, H(4));
.22 (m, 1 Í, H(7)); 2.86 (dd, 1 Í, H(4), JAB = 14.3, JÍ(4),Í(5)
JÍ(4),Í(3) = 8.6); 2.42, 1.80 (both m, 1 H each, Í(8)); 2.22, 2.00 (both s,
H each, Mecarb); 1.90 (s, 3 Í, Ñ(3)—Me); 1.03 (d, 3 Í, Ñ(7)—Me,
Jgem = 6.9)
3
=
3
7
7
d e
34.93
6.57
6.43
28.48 Ñ Í B Rh 6.02 (q*, 1 Í, Í(1), J ≈ 8.0); 5.37 (t*, 1 Í, Í(6), J ≈ 7.2); 4.64 (q*, 1 Í,
28.41
10 22 9
3
5.08
Í(3), J ≈ 7.6); 4.49 (t, 1 Í, Í(2), J = 7.6); 3.74 (q*, 1 Í, H(5), J ≈ 8.4);
.49, 3.04 (both br.s, 1 H each, Hcarb); 3.24 (m, 1 Í, H(4)); 2.54 (dd, 1 Í,
H(4), JÀÂ = 16.6, JÍ(4),Í(5) = JÍ(4),Í(3) = 7.2); 2.45, 2.11 (both m,
H each, Í(8))
3
1
e
—
—
—
—
5.57 (q*, 1 Í, Í(3), J ≈ 7.6); 4.96 (t*, 1 Í, Í(6), J ≈ 6.7); 4.15 (t, 1 Í,
Í(2), J = 7.3); 3.85 (q*, 1 H, H(1), J ≈ 6.6); 3.65 (m, 1 Í, Í(8));
2
3
2
1
.38 (m, 2 Í, Í(7), H(8)); 2.82 (dd, 1H, H(5), JAB = 14.9, J = 7.2);
.67 (m, 1H, H(5)); 2.54 (s, 3 Í, Ìå); 2.48 (q*, 1 Í, Í(4));
.95 (c, 3 Í, Ìå); 1.80 (m, 1 Í, Í(4))
a
b
c
Quadruplet-like (q*) and triplet-like (t*) multiplet signals.
1
The H NMR spectrum was recorded at –93 °C.
1
The H NMR spectrum was measured in CD Cl .
2
2
d
e
The participation of the H atom in the formation of the C—H...Ir bond was not unambiguously confirmed.
The assignment of the signals was made by comparing with the H NMR spectra of compounds 7a, 7c, and 7å.
1
6
1
13
ment of the signals in the H and C NMR spectra was
3. D. M. Speckman, C. B. Knobler, and M. F. Hawthorne,
Organometallics, 1985, 4, 426.
1
1
13
1
1
made using the correlation H- H and C{ H}- H NMR
spectra).
4
5
6
7
. I. T. Chizhevsky, A. I. Yanovsky, and Yu. T. Struchkov,
J. Organomet. Chem., 1997, 536—537, 51.
. J. A. Long, T. B. Marder, P. E. Behnken, and M. F.
Hawthorne, J. Am. Chem. Soc., 1984, 106, 2979.
We thank O. L. Tok (the A. N. Nesmeyanov Insti-
tute of Organoelement Compounds of the Russian Acad-
emy of Sciences) for measuring the 2D 1H- H NMR
spectra of complexes 6c and 7c.
This work was financially supported by the Russian
Foundation for Basic Research (Project No. 00-03-
. J. C. Jeffery, F. G. J. Stone, and I. Topaloglu, Polyhedron,
1
1
993, 12, 319.
. A. R. Kudinov, R. T. Bogoudinov, P. V. Petrovskii, and
M. I. Rybinskaya, Izv. Akad. Nauk, Ser. Khim., 1999, 3, 592
[Russ. Chem. Bull., 1999, 3, 586 (Engl. Transl.)].
3
2824).
8. I. T. Chizhevskii, T. V. Zinevich, P. V. Petrovskii, V. A.
Antonovich, and L. I. Zakharkin, Metalloorg. Khim., 1991,
4
, 1416 [Organomet. Chem. USSR, 1991, 4, 706 (Engl.
References
Transl.)].
9
. L. I. Zakharkin, I. T. Chizhevsky, G. G. Zhigareva, P. V.
Petrovskii, A. V. Polyakov, A. I. Yanovsky, and Yu. T.
Struchkov, J. Organomet. Chem., 1988, 358, 449.
1
2
. F. Teixidor, R. Núñez, M. A. Flores, A. Demonceau, and
C. Viñas, J. Organomet. Chem., 2000, 614—615, 48.
. A. Felekidis, M. Goblet-Stachow, J. F. Liégeois, B. Pirotte,
J. Delarge, A. Demonceau, M. Fontaine, A. F. Noels, I. T.
Chizhevsky, T. V. Zinevich, V. I. Bregadze, F. M. Dolgushin,
A. I. Yanovsky, and Yu. T. Struchkov, J. Organomet. Chem.,
1
0. M. M. Il´in, T. V. Zinevich, I. V. Pisareva, I. T. Chizhevskii,
and V. A. Davankov, Izv. Akad. Nauk, Ser. Khim., 2000, 4,
7
59 [Russ. Chem. Bull., Int. Ed., 2000, 4, 759].
1
997, 536—537, 405.
Received July 31, 2001