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Ligand-Property Control in the Nickel(0)ButadieneP-Ligand Catalytic System Dominance of УStericФ Factors in the Control of Oligomer Distribution.

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Ligand-Property Control in the Nickel(o)/Butadiene/
P-Ligand Catalytic System: Dominance of “Steric”
Factors in the Control of Oligomer Distribution[**]
[%I
By Paul Heimbach, Joachim Kluth, Hartmut Schenkluhn,
and Bruno Weimann“]
40.0
The control of isomeric distribution in the cyclooligomerization of butadiene on nickel-ligand catalysts can be attributed to several mutually independent ligand-association
processes“! This finding permits the study of the control of
individual association processes by ligand properties and
hence comparison of the results obtained with various model
complexes. We illustrate such an analysis in the present report of control of the degree of oligomerization (details of the
control of cyclodimer distribution will be found in [’I).
Table I . Experimental data on ligand-property control in the nickel(o)/P-ligand/
butadiene ( I : 1 : 170) catalytic system, [Nil,,= 34 mmol/l (40 mmol/l at - 78 “C):
7 = 6 0 ” C , r=48 h. butadiene conversion >95%, see [la] for experimental procedure. c-DIM = cyclodimer. c-TRIM = cyclotrimer; Z = 100 x c-TRIM/(c-DIM +
c-TRIM)
PrBu(iPr),
P(iPr),
P(nPr),
PEt,
PPhEt,
PPhMel
P(PhCHI),
PPh,Et
PPh,
PPh,(OEt)
PPh(O-nBu),
PPh(OEt),
PPhl(0Ph)
PfO-nBu),
P(0-iPr),
P( OMe ) 1
PPh(OPh)2
P(0-0-Tol)~[b]
P(O-o-Biph)?[c]
P(OPh),
2.0
3.1
4.9
5.6
7.9
9.2
10.3
10.6
12.9
15.5
17.3
18.3
18.5
19.5
19.8
23.4
23.7
28.0
28.9
29.2
167
45.8
160
68.8
139
73.9
132
64.5
136
85.3
122
66.8
74.0
160
140
84 I
145
85.0
133
88.8
118
56.6
116
50.8
139
87.8
11248.6
130
70.2
107
38.0
129
89.8
141
97.6
152
97.7
128
87.4
49.6
23.6
12.9
29.0
12.6
23.5
23.2
13.1
14.8
5.9
40.5
40.4
121
49.1
22.1
59.8
52
26
15
31
13
26
24
13
15
11.1
11
I .4
1.5
12.2
2
2
6
42
44
12
SO
24
59
12
46
32
18
22
17
34
7
14
12
14
37
41
9
51
15
63
14
2
5
II
20.0
6
[O]>
160.
Fig. 1. Surface representation of the amount of cyclododecatriene in the butadiene cyclooligomers as function of “electronic” x and “steric” 8 ligand parameters
Zc,,,
=946.8 - 0.67 x - 12.9688+0.454- 10- f?
S = 5.47; MR = 0.9606; u (estimated)= 4.5; extent of control 25% “electronic”,
75% “steric”.
75% of the overall control induced by the chosen P-ligands is
“steric” in character. Thus both small and large cone angles
8 of the P-ligands favor cyclotrimerization of butadiene.
According to studies on ligand concentration control maps
of 11. representative P-ligand~~’.~],
an octadienediyl(1igand)nickel(Ir) complex is responsible for control of the degree of oligomerization at a [L]o/[Ni]oratio of unity at constant nickel concentration of 34 mmol/l. Depending upon
the ligand, the n,u-bisallyl form (1) (L = tricyclohexylphosphane“”]) or the n,m-bisallyl form (2) (L = triphenylphosphane[6b1,tri(2-biphenylyl) phosphite[‘”) is preferentially
formed. Only the T , U form can associate with a further substrate molecule and react to form butadiene trimers.
(a1 Remainder: unknown and open-chain butadiene oligomers. (bJ Tol= tolyl.
[c] Biph = biphenylyl.
Trimers
Su
In order to obtain quantitative information about the (ligand-property dependent) control of the degree of oligomerization (see Table 1) at constant [L],/[Ni], ratio of unity, the
amount of trimer was examined by multilinear regression
analysis[31.The ligand properties were characterized by the
“steric” parameter 8 and the “electronic” parameter x [ ~ ]Fig.
ure 1 reproduces the correlation found. Each ligand L,(O,,x,)
is characterized by a point in the xy plane; the amount of
trimer Z is plotted in the z direction. According to this analysis the influence of the “steric” parameter 6 predominates:
[‘I
Prof. Dr. P. Heimbach [ ‘1, DiplLChem. 1. Kluth. Dr. H. Schenkluhn [ * 1
Universital Essen-Gesamthochschule
Fachbereich 8-Chemie. Organische Chemie I
Postfach 6843. D-4300 Essen 1 (Germany)
and Max-Planck-lnstitut fur Kohlenforschung, D-4330 Miilheim/Ruhr
(Germany)
Dr. B Wcimann
Max-Planck-Institut fur Kohlenforschung, D-4330 Mulheim/Ruhr (Germany)
[ ’ ] To whom correspondence should be addressed.
[**I Control of Metal-Catalyzed Reactions. Part 10.-Part 9 P. Heimbach, J.
Kluth, H . Schenkluhn in B. Pullman: Catalysis in Chemistry and Biochemistry:
Theory and Experiment. Vol 12. D. Reidel. Dordrecht 1979. p. 227
Angew. Chem. Int Ed. Engl 19 (1980) No. 7
Dimers
= Butadiene, L = P-Ligand,
m = 0 or 1
Increasing donor character (decreasing x value) or bulkiness of the P-ligand (8>150”) favors formation of (1). Thus
trimer formation should increase with such ligands. Moreover, it should also be considered that for steric reasons association of the substrate to form (1) is all the easier the smaller
the cone angle of the P-ligand (8<140”); association should
be more difficult at large angles.
There are accordingly two opposing effects to be expected
for the control of the degree of cyclooligomerization, in
agreement with the minimum found in the proportion of
steric control. The electronic ligand effect, however, is uniform and probably essentially reflects the n,u/n,n-equilibrium of the precursor complexes (thermodynamic selectivity).
Received: September 13, 1979;
supplemented: February 4. 1980 [Z 51 1 a I€]
German version: Angew. Chem. 92, 567 (1980)
[l] a) F. Brille. J. Kluth, H. Schenkluhn, J. Mol. Catal. 5, 27 (1979); b) F. Brille.
P.Hermbach, J. Klurh, H. Schenkluhn, Angew. Chem. 91,428 (1979): Angew.
Chem. Int. Ed. Engl. /R. 400 (1979); c) A. Sisak, H. Schenkluhn, P. Hermbach, Acta Chim. Acad. Sci. Hung. 103, 377 (1980); d) P. Hermbach. H.
Schenkluhn, Top. Curr. Chem. 92.45 (1980).
0 Verlag Chemie, GmbH, 6940 Weinherm, 1980
0570-0833/80/0707-0569
S 02 50/0
569
121 P. Heimbach. J. Kluth, H . Schenkluhn. B. Weimann. Angew. Chem. Y2. 569
(1980): Angew Chem. In1 Ed. Engl. 10. 570 (1980)
[3] H. Schenkluhn, W.Scheidr. B. Weimonn. M. Zuhre.r. Angew Chem. Y I , 429
(1979); Angew. Chem. In1 Ed. Engl. I X . 401 (1979): quality criteria for the
optimum polynomial quotient S’/d (S’: variance of fit; 2. variance of experimental values). the multicorrelation coefficient M R . and a Chi’ test.
[4] C. A. Tolman. Chem. Rev. 77. 313 (1977): the “electronic” parameter x, of the
ligand L, is determined by IR spectroscopy ria the induced shlft of the
u < o ( A l )band of the L,Ni(CO), complex, and the ”steric” paramter A, as the
Corresponding apical angle.
151 J. El.m>wr. P Heimhuch, J. Kluih, A. Sisok. H . Srhenkllrhn. to be published.
161 a ) B. Barnert, B Bussemerer. P. Heimbuch. P. W. Jolly. C. Kruger. 1. Tkarchenko, G. Wilke. Tetrahedron Lett. 1972. 1457; b) B. Bussemeier. P. W. Jully. G. Wilke. J Am. Chem. Soc. Y6. 4726 (1974): c) B. Bussemeier. Dissertation. Universitat Bochum 1973
Under the conditions given in Table 1 the dimers vinylcyclohexene (VCH) and 1,5-cyclooctadiene (COD) predominate; Figure 1 shows the result of multilinear regression analysis[*]. (For a definition of the “electronic” and
“steric” parameters y, and 6,see r i . 3 1 . ) A purely “electronic”
effect is found for the amount of COD in the control region
3
0
I
.,20
0
0’
1’
n
50
Ligand-Property Control in the Nickel(o)/Butadiene/
P-Ligand Catalytic System: “Electronic” Factors
in the Control of Cyclodimer Distribution[’*’
1L
t
5’
e l
6’
By Paul Heimbach, Joachim Kluth, Hartmui Schenkluhn,
and Bruno Weimann[*l
0
XIcrn-lI
In the cyclooligomerization of butadiene on nickel-ligand
catalysts the ligand-property control of the degree of oligomerization at a [L],/[Ni],, ratio of unity is primarily of a “steric” nature and can be interpreted by corresponding association processes[’]. We now report an analysis of the ligandproperty control of cyclodimer distribution.
20
10
30
Fig. I . Dimer distribution in the cyclooligomerization of butadiene on nickel-ligand catalysts as function of the “electronic” ligand parameter x. (See Table I
for numbers of experiments.)
2‘,,,L=79.3-5.43x+0.206x’ (without nos. 9 and 13)
S= 5.41; MR=0.95X9; u (estimated)=4.0 extent of control: 100% “electronic”
( S . MR, u. see [I]).
Table 1. Experimental data on ligand-property control in the system nickel(ii)/P-ligand/butadiene= 1 . I . 170. [Ni],,=34 mmol/l. T=60“C, t = 4 8 h, butadiene conversion
>95%; see IS] for experimental procedure. VCH = vinylcyclohexene. C O D = 1.5-cyclooctadiene; Z = I00 x COD/(VCH + COD). The cyclodimer divinylcyclobutane.
which IS likewise formed, rearranges during the catalytic process to COD and VCH and can no longer be detected after 48 hl? The values in parentheses were not considered in the regression analysis
~~___
No.
L,
X
lcm
‘I
A
VCH
“‘I
IV la1
COD
r%][a]
ZC”,
Zd,
(~m.~x)l)lM
[NIIu
[bl
~
PtBu(iPr),
P(iPr),
P(nPr),
PEt,
PPhEt,
PPhMe’
P(PhCHI)?
PPh’Et
PPh,
PPhl(OEt)
P P h ( 0 nBu)l
PPh(0Et)’
PPh2(OPh)
P( 0 - n B u)
P(O-rPr),
P(0Meh
PPh(OPh)l
P(0-o-Tol), [L]
P(O-u-Biph), [dl
P(OPh),
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
2.0
31
4.9
5.6
7.9
9.2
10.3
10.6
12.9
I5 5
17.3
18 3
18.5
19.5
19.8
23.4
23.7
28.0
28.9
29.2
32 I
33.5
28.4
35.2
53.9
54.2
55.1
53.5
24.4
51.9
48.4
41.1
20 I
47 6
46.7
40.4
24.5
7.8
25
8.5
I67
160
139
132
136
I22
160
I40
145
133
118
I I6
I39
112
130
107
129
141
152
128
[a] Remainder: unknown and open-chain butadiene dimers. [b] I‘,,,,,
Biph= biphenylyl.
(maximum overall reaction rate)
[‘I Prof. Dr. P. Heimbach [ ‘ I , DiplLChem. J . Kluth, Dr. H. Schenkluhn [ ‘ I
Universitkt Essen-Gesamthochschule..
Fachbereich 8-Chemie. Organische Chemie I
Postfach 8643. D-4300 Essen I (Germany)
and Max-Planck-lnstitut fur Kohlenforschung, D-4330 Mulheim/Ruhr
(Germany)
[+I
[**I
Dr. B. Weimann
Max-Planck-Institut fur Kohlenforschung, D-4330 Miilheim/Ruhr (Germany)
To whom correspondence should be addressed
Control of Metal-Catalyzed ReacLions. Part I I --Part 10: 111
570
61.6
56.6
56.4
55.6
44.8
33.6
42. I
44.7
74.4
44.2
48.1
45.8
75.7
49 0
43.3
53 9
72.7
91.6
96.7
90.6
0 Verlag Chernie. GmbH, 6Y40 Wemheim, 1980
IS
66
63
67
61
45
38
43
45
(75)
46
50
53
(79)
51
48
57
74
92
97
91
69
64
58
55
49
47
45
45
(44)
45
47
49
(49)
52
53
65
66
89
94
96
defined for the conversion range of 0--95M
nd
nd
nd
nd
nd
nd
nd
0.57i0.01
0.89 t 0.08
0.95 t 0.06
nd
nd
3.30t0 2
nd
0.59?0.01
nd
nd
5 17t0.9
7 49 t 0.2
4.03t0.5
[c] Tol=tolyl [d]
given. The correlative relation can be represented by a simple parabola (the ligands PPh, and PPhzOPh are exceptions).
Octadienediyl(Iigand)nickel(11) complexes are assumed as
crucial catalytic intermediates for the control of the dimer
As expected, the pronounced steric indistribution (see
fluence of the P-ligands found in trimer formation is no longer operative in the control of dimer formation. If the ratio of
cyclodimers COD and VCH were determined solely by the
.rr,o/.rr,.rr-equilibrium of the complexes (1) and (2) (thermo-
057(i-0X.j~/X#/o707-o57(~ S 02 5 0 / 0
Angew. Chem. I n t . Ed. Engf. 19 (1980) No. 7
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nickell, factors, distributions, dominance, catalytic, property, oligomer, system, уstericф, ligand, control, butadiene
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