Highly regioselective isomerization-hydroformylation of internal olefins catalyzed by rhodium/tetraphosphine complexes

Article abstract of DOI:10.1002/adsc.201100139

A new class of substituted tetraphosphine ligands has been applied in the rhodium-catalyzed regioselective isomerization-hydroformylation of internal olefins. The rhodium/tetraphosphine ligand system is highly effective for the isomerization and hydroformylation of 2-alkenes to form linear aldehydes. Greater than 95% linear selectivity and up to 94% yield of the total aldehydes were obtained for 2-pentene, 2-hexene and 2-octene. The catalyst system also showed high to moderate linear selectivity for the isomerization and hydroformylation of 3-hexene, 3-octene and 4-octene but with slow reaction rates. Copyright

Full text of DOI:10.1002/adsc.201100139

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DOI: 10.1002/adsc.201100139
Highly Regioselective Isomerization–Hydroformylation of Inter-
nal Olefins Catalyzed by Rhodium/Tetraphosphine Complexes
Chaoxian Cai,a Shichao Yu,b Guodu Liu,c Xiaowei Zhang,a and Xumu Zhanga,*
a
Department of Chemistry and Chemical Biology & Medicinal Chemistry, Rutgers, The State University of New Jersey,
Piscataway, NJ 08854, USA
Fax : (+1)-732-445-6312; e-mail: xumu@rci.rutgers.edu
Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, Peopleꢀs Republic of China
College of Science, Northwest Agriculture & Forestry University, Yangling, Shaanxi 712100, Peopleꢀs Republic of China
b
c
Received: February 24, 2011; Revised: June 27, 2011; Published online: October 6, 2011
Abstract: A new class of substituted tetraphosphine
ligands has been applied in the rhodium-catalyzed
regioselective isomerization–hydroformylation of
internal olefins. The rhodium/tetraphosphine ligand
system is highly effective for the isomerization and
hydroformylation of 2-alkenes to form linear alde-
hydes. Greater than 95% linear selectivity and up
to 94% yield of the total aldehydes were obtained
for 2-pentene, 2-hexene and 2-octene. The catalyst
system also showed high to moderate linear selec-
tivity for the isomerization and hydroformylation of
3-hexene, 3-octene and 4-octene but with slow reac-
tion rates.
and consists of ca. 11% 1-butene/isobutene and 42%
trans- and cis-2-butene.[4] While it is a well established
process for the hydroformylation of terminal olefins,
the development of the regioselective hydroformyla-
tion of internal olefins to form linear aldehydes in a
commercially acceptable reaction rate is quite chal-
lenging. Over the last decade, only a few catalysts
have been reported to show high regioselectivity with
a decent reaction rate for the hydroformylation of in-
ternal olefins. These catalyst include van Leeuwenꢀs
Xantphos derivatives [linear to branch ratio (n:i)=9.5
for 2-octene],[5] Bellerꢀs Naphos-type ligands (n:i=
10.1 for 2-octene and up to 99:1 with its sulfonated
derivatives in a biphasic system),[6] Bçrnerꢀs acyl
phosphite ligands (n:i=2.2 for a mixture of octene
isomers),[7] and the bulky phosphite ligands of UCC[8]
(n:i=19 and 17 for 2-hexene and 2-octene, respec-
tively) and DuPont/DSM (n:i=35 for 2-hexene).[9]
Our group has previously reported the develop-
ment of tetraphosphoramidite ligands for highly
Keywords: hydroformylation; isomerization; regio-
selectivity; rhodium; tetraphosphine
Hydroformylation of alkenes is one of the most im- linear selective hydroformylation of 2-olefins.[10] The
portant homogenous catalytic processes to produce al- Rh/tetraphosphoramidite catalyst system proved to be
dehydes and alcohols, which are versatile intermedi- highly regioselective for the hydroformylation of 2-
ates and building blocks for pharmaceuticals, agro- hexene and 2-octene with linear selectivity up to
chemicals, commodity and fine chemicals.[1] The reac- 99.5%. Recently, we have reported the development
tion was discovered by Otto Roelen in 1938 as oxy- of robust tetraphosphine ligands as another efficient
genated products were produced in the cobalt- ligand sytem for the highly linear selective hydrofor-
catalyzed Fischer–Tropsch process.[2] Ever since this mylation of terminal olefins.[11] This type of ligand is
discovery, the reaction has been under intensive stud- effective for the hydroformylation at high tempera-
ies for its industrial importance.[3] Many catalyst sys- tures, affording greater than 97% linear selectivity for
tems have been developed over the years. Currently, the hydroformylation of 1-octene and 1-hexene at
most commercial hydroformylation processes use 1408C. Herein, we would like to report our continued
highly reactive rhodium catalysts modified with work on this type of ligand for the regioselective iso-
monophosphorus ligands or bisphosphorus ligands to merization–hydroformylation of some interesting in-
address the issue of regioselectivity and stereoselec- ternal olefins.
tivity.
The structures of our new tetraphosphine ligands
Low-cost olefin feedstocks with mixtures of both are depicted in Figure 1. The ligands were prepared
internal and terminal alkenes are preferred starting by following our previously disclosed procedures.[11]
materials in the large-scale hydroformylation process. The ligands are based on a biphenyl backbone, and
For example, Raffinate II is an economical feedstock, have four equivalent phosphorus groups, which can
which is one effluent from the steam cracking process greatly enhance the local phosphorus concentration
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Figure 1. Tetraphosphine ligands.
Scheme 2. Isomerization and hydroformylation of an inter-
nal olefin.
near the coordinating center. As illustrated in
Scheme 1, the tetraphosphine ligands are able to bind
to Rh bidentately through a dynamic multiple chelat-
ing mode with each phosphine group coming from the tion parameters, such as ligand to Rh ratio (L/Rh),
different aromatic rings. In this bidentate Rh com- temperature and CO/H2 pressure, were tested for
plex, the existing free phosphorus atoms can effective- their influences on the regioselectivity. Under the
ly increase the local phosphorus concentration around conditions listed in Table 1, as we expected, the cata-
the metal center and enhance the chelating ability. lyst smoothly converted 2-hexene to the correspond-
When a phosphine in the bidentate Rh complex disso- ing aldehydes with the linear aldehyde as the main
ciates from the metal, any one of the two equivalent product. The pressure effect was significant (en-
phosphines from the same aromatic ring can coordi- tries 1–4). As the CO/H2 pressure increased from 2.5/
nate to Rh and form the bidentate complex again. 2.5 to 20/20, the linear to branch ratio decreased from
Such a kind of multidentarity can stabilize the biden- 36.5 to 8.6, and the turnover number (TON) slightly
tate Rh complex and promote the catalyst longevity decreased from 330 to 280. The temperature effect
at elevated temperatures.
was also compared (entries 1, 5 and 7) under other-
The hydroformylation of an internal olefin is de- wise the same conditions. The highest linear selectivi-
picted in Scheme 2. To obtain a highly linear selective
terminal aldehyde, the double bond of an internal
olefin must migrate to the end. This sets two kinetic Table 1. Optimization of the reaction conditions for the hy-
droformylation of 2-hexene with ligand 6.[a]
requirements: (i) the isomerization of an internal
olefin must be faster than its hydroformylation, and
(ii) the hydroformylation of a terminal olefin must be
faster than that of the corresponding internal olefins.
Otherwise, branched aldehydes will be produced.
Therefore, having catalysts that can differentiate
these reaction rates are crucial for obtaining high
turnover numbers of linear aldehydes from internal
olefins. Such requirements make necessary a finely
tuning of catalyst and reaction conditions to maximize
the linear selectivity.
Our previous studies on the hydroformylation of 1-
hexene and 1-octene showed that ligand 6 afforded
the best linear selectivity.[11] In our continued studies
on the hydroformylation of internal olefins, 2-hexene
was used as the model substrate and ligand 6 was
tested first. The catalyst complex was prepared in situ
Entry L/Rh T [oC] CO/H2 [atm] t [h] n:i[b] TON[c]
1
2
3
4
5
6
7
8
9
4
4
4
4
4
4
4
2
6
140
140
140
140
120
120
100
120
120
2.5/2.5
5/5
1
1
1
1
1
4
1
1
1
36.5 3.3ꢂ102
26.1 3.2ꢂ102
19.4 3.1ꢂ102
10/10
20/20
2.5/2.5
2.5/2.5
2.5/2.5
2.5/2.5
2.5/2.5
8.6
2.8ꢂ102
43.9 3.1ꢂ102
36.0 8.9ꢂ102
76.2 2.3ꢂ102
41.9 1.9ꢂ102
53.0 2.6ꢂ102
[a]
S/C=1000, RhACHTNUGRTENUNG(acac)(CO)2 =1.0 mM, toluene as solvent,
decane as internal standard. Results determined by GC,
average of 3 repeated runs.
Linear to branch ratio.
by mixing the ligand and RhACHTNUGRTENUNG(acac)(CO)2 in toluene.
Even that we did not intend to fully optimize the re-
action conditions at this stage, several important reac-
[b]
[c]
Turnover number.
Scheme 1. Multiple chelating ability of a tetraphosphine ligand due to enhanced local phosphorus concentration.
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Highly Regioselective Isomerization–Hydroformylation of Internal Olefins
Table 2. Hydroformylation of 2-hexene with various substi-
tuted tetraphosphine ligands.[a]
ty was obtained at 1008C with an n:i ratio of 76.2 and
a TON of 230. Moreover, the catalyst was highly se-
lective for the linear aldehyde formation even at
1408C (entry 1, n:i=36.5). This is quite desirable
since for a long chain olefin, it often requires high
temperatures to isolate the product by distillation.
The reaction at 1208C (entry 5) afforded an n:i ratio
of 43.9 and a TON of 310, a slight improvement in
linear selectivity and a slight decrease in TON com-
pared to those at 1408C (entry 1). The effect of L/Rh
ratio is compared in entries 5, 8 and 9. As the L/Rh
ratio increased from 2 to 4 to 6, the n:i ratio improved
from 41.9 to 43.9 to 53.0, and the TON varied from
190 to 310 to 260, respectively. This indicates that a
sufficient amount of ligand is required to stabilize the
catalyst, but an over-presence of ligand will compete
with the binding site for olefin and therefore slow
down the reaction. A fairly good set of reaction con-
ditions is using L/Rh=4, 1208C and CO/H2 =2.5/2.5
atm (entry 5). Under these conditions, the catalyst has
good stability, and after 4 h, a total aldehyde yield of
89% (TON=890) was obtained with an n:i ratio of
36.0 (entry 6).
Entry
Ligand
n:i[b]
Linear[c]
TON[d]
1
2
3
4
5
6
7
8
9
1
2
3
4
5
6
27.2
16.0
56.4
27.5
25.3
36.0
1.6
96.5
94.1
98.3
96.5
96.2
97.3
61.5
16.7
23.1
7.7ꢂ102
7.3ꢂ102
8.9ꢂ102
8.5ꢂ102
9.4ꢂ102
8.9ꢂ102
6.9ꢂ102
6.8ꢂ102
7.1ꢂ102
bisbi[e]
Ph2PBn[f]
0.2
0.3
bisbi+Ph2PBn[g]
[a]
S/C=1000, RhACTHNUTGRNE(UNG acac)(CO)2 =1.0 mM, L/Rh=4, 1208C,
CO/H2 =2.5/2.5 atm, time=4 h, toluene as solvent,
decane as internal standard. Results determined by GC,
average of 3 repeated runs.
Linear to branch ratio.
Percentage of linear aldehyde in all aldehydes.
Turnover number.
2,2’-Bis-[(diphenylphosphino)methyl]-1,1’-biphenyl.
When bisbi/Rh ratio is varied from 2 to 4 to 8, the n:i
ratios are 1.4, 1.6 and 1.6, respectively.
[b]
[c]
[d]
[e]
[f]
BenzylACHTNUGTRENNUNG
[g]
Wilkinsonꢀs dissociation mechanism is generally ac-
cepted for the rhodium-catalyzed hydroformylation of
alkenes, where the regioselectivity arises from the for-
mation of linear and branched metal-alkyl com- screened for the hydroformylation of 2-hexene
_
plexes.[12] For the bidentate ligand (LL) catalyst (Table 2). We are pleased to find that in all cases, the
system, the 16-electron square-planar intermediate tetraphosphine ligands afforded >90% linear alde-
_
HRh(CO)ACHTUNGTRENNUNG(LL) was proposed to be the regioselective hyde. Ligand 1 is the tetraphosphine without any sub-
catalyst species.[1] One of the reasons for the eroded stituent on the phenyl group. With this ligand, a TON
regioselectivity at high temperature and under high of 770 was obtained with an n:i ratio of 27.2 (entry 1).
syngas pressure is the formation of unselective cata- The n:i ratio dropped to 16.0 when an electron-donat-
lytic species, due to the dissociation of phosphorus li- ing group was attached to the phenyl (ligand 2,
gands from the rhodium complex (Scheme 3). Our re- entry 2). The highest linear selectivity was obtained
sults in Table 1 are consistent with these propositions. with ligand 3 that bears a CF3 group at the para posi-
Under high CO pressure, the bidentate ligand in the tion (n:i=56.4, entry 3). However, if the CF3 group is
metal complex can be partially or completely dis- attached at the meta positions, very small or no im-
placed by CO, resulting in unselective catalyst species provement was observed for the linear selectivity (en-
and decreased linear selectivity. The tetraphosphine tries 4 and 5) compared to ligand 1. Similarly, ligand 6
ligands in Figure 1 are able to stabilize the catalyst that bears two strong electron-withdrawing fluoro
complex effectively; therefore, high linear selectivity groups at the meta positions afforded an n:i ratio of
was obtained at high operating temperatures and with 36.0, a small improvement in the linear selectivity
only moderate ligand to rhodium ratios.
(entry 6). Regarding the catalytic activity, all ligands
After a good set of reaction conditions was identi- that bear electron-withdrawing groups (entries 3–6)
fied, the ligands in Figure 1 bearing various electron- showed improved turnover numbers compared to
donating or electron-withdrawing groups were ligand 1. This observation is consistent with the find-
ings reported by van Leeuwen et al. on the hydrofor-
mylation of 1-octene using an electronically modified
thixantphos ligands.[5d] It is generally reasoned that an
electron-withdrawing phosphorus ligand can weaken
the p back bonding of rhodium to the carbonyl group
and therefore facilitate its dissociation from the rhodi-
um center and enhance the alkene coordination, re-
sulting in an increase in reaction rate. Conversely, a
ligand attached with a more electron-donating group
will lower the hydroformylation speed. Indeed, this
_
Scheme 3. Rhodium/ligand (LL) complexes and ligand dis-
sociation under the influence of CO in hydroformylation.
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Table 3. Isomerization–hydroformylation of various internal
olefins using ligand 3.[a]
was observed for ligand 2 (entry 2), which has the
lowest turnover number (TON=730) in this series of
ligands. The highest TON was obtained with ligand 5,
which bears two CF3 group at the meta positions
(entry 5). For comparison, the bisphosphine ligand
(bisbi) was prepared[13] and applied in the hydrofor-
mylation of 2-hexene under the same conditions
(entry 7). Clearly, the tetraphosphine ligands have
better performance than bisbi with respect to both
catalyst activity and regioselectivity. Matsumoto and
Tamura have reported that there is a synergistic effect
by applying a mixture of mono- and bisphosphine li-
gands in Rh-catalyzed hydroformylation of terminal
Entry Substrate
Aldehyde dis- Conv. Iso.
tribution [%][b] [%][c] [%][d]
a
b
g+d
1[e]
2
>99 <1 0
85
63
6
88
98
7
2
5
0
13
3[f]
84
98
16
4
olefins.[14] For this reason, benzyl
ACTHNUTRGNEUNG(diphenyl)phosphine
(Ph2PBn) and a 1:2 mixture of bisbi and Ph2PBn were
also tested for the hydroformylation of 2-hexene as
control reactions (entries 8 and 9), which afforded n:i
ratios of 0.2 and 0.3, respectively. Therefore, the high
regioselectivity afforded by the tetraphosphorus li-
gands is indeed arising from the enhanced stabiliza-
tion effect for the selective catalyst intermediate, not
from a potential synergistic effect of monodentate
and bidentate coordination modes.
4[g]
92
4
4
5
6
7
40
47
66
33 27
29 24
18 16
55
59
60
48
46
42
[a]
S/C=1000, RhACTHNUTGRNE(UNG acac)(CO)2 =1.0 mM, L/Rh=4, 1258C,
Finally, ligand 3 was applied in the isomerization–
hydroformylation of a series of olefins with varied
chain lengths (Table 3). The reactions were screened
under the following conditions: S/C=1000, L/Rh=4,
1258C, CO/H2 =5/5 atm, toluene as solvent. In all
cases, the isomerization and hydroformylation are two
dominant reactions, and no or only very small quanti-
ties of hydrogenation products were observed. The re-
sults showed that ligand 3 is highly selective for the
linear hydroformylation of C5 to C8 internal olefins
with the double bonds at the b positions. For 2-pen-
tene (entry 1), after 2 h at 1258C, >99% selectivity to
the linear aldehyde was observed with 85% of starting
materials converted to either aldehyde or 1-pentene
(6%). For 2-octene (entry 3), 98% selectivity to the
CO/H2 =5/5 atm, time=2 h, toluene as solvent, decane
as internal standard. Numbers are calculated from aver-
ages of 2 repeated runs.
Percent of a, b, g or d aldehyde of all aldehydes, deter-
mined by GC or proton NMR.
Conversion of substrate, determined by GC. The sub-
strate was almost exclusively converted to aldehydes and
isomers.
Percent of total isomers converted from substrate, deter-
mined by GC.
[b]
[c]
[d]
[e]
A mixture of 20% cis-2-pentene and 80% trans-2-pent-
AHCTUNGTERGeNNUN ne.
A mixture of 24% cis-2-octene and 76% trans-2-octene.
Reaction time=12 h.
[f]
[g]
linear aldehyde was obtained with 84% starting mate- a mixture of 66% linear, 18% b-branched and 16% g-
rials converted to either aldehydes or isomers (16%). and d-branched aldehydes was observed. As listed in
After a prolonged reaction time (12 h at 1258C, Table 3, from 2-pentene to 3-hexene to 4-octene, the
entry 4), the conversion was improved to 98% with increase of steric hindrance at the double bond result-
92% linear aldehyde, and the total branched alde- ed in a decrease of hydroformylation rate, an increase
hydes increased from 2% to 8%. Olefins with double in the amount of branched aldehydes, and a large in-
bonds at the g positions were also tested (entries 2 crease of olefin isomers. Interestingly, a much better
and 5). For 3-hexene, the catalyst is linear selective, conversion to the aldehydes and linear selectivity was
affording 88% linear aldehyde, 7% b-branched alde- obtained for trans-4-octene when it was compared to
hyde and 5% g-branched aldehyde (entry 2). For 3- 3-octene (entries 5 and 7). This appears surprising
octene, a mixture of 40% linear, 33% b-branched and since the double bond of 4-octene is one more bond
27% g- and d-branched aldehydes was observed away from the terminal carbon than 3-octene. But
(entry 5). The hydroformylation of internal olefins considering the fact that the migration of the double
with double bonds at the d positions was studied bond in 3-octene can occur in both directions, the mi-
using 4-octene as the model substrate (entries 6 and gration from the g position to the d position is a ther-
7). The reaction of trans-4-octene showed better re- modynamically favourable process, and the double
sults than cis-4-octene. For cis-4-octene, a mixture of bond migration toward the inside direction actually
47% linear, 29% b-branched and 24% g- and d- slows down the hydroformylation process. However,
branched aldehydes was observed; for trans-4-octene, for 4-octene, the double bond can equally migrate in
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Adv. Synth. Catal. 2011, 353, 2665 – 2670

Highly Regioselective Isomerization–Hydroformylation of Internal Olefins
gioselectivity. The Rh/tetraphosphine catalyst system
is highly effective for the isomerization- hydroformy-
lation of 2-alkenes to form linear aldehydes. Greater
than 95% linear selectivity and up to 94% yield of
the total aldehydes were obtained for 2-pentene, 2-
hexene and 2-octene. The catalyst system also showed
high to moderate linear selectivity for the isomeriza-
tion–hydroformylation of 3-hexene, 3-octene and 4-
Scheme 4. Isomerization mechanism of an internal olefin:
3
À
(1) Rh H addition and b-H elimination pathway, (2) h -allyl octene but with slower reaction rates. Further ligand
coordination and reductive elimination pathway. The open
box represents a vacant coordination site of Rh.
improvements, applications and mechanism studies
are now under investigation and will be reported in
due course.
both directions from the middle position to the termi-
nal positions; therefore, 4-octene has twice the chance Experimental Section
of isomerizing to 1-octene, resulting in a higher yield
of linear aldehyde.
General Procedure for the Regioselective
For an internal olefin, there exist two common Isomerization–Hydroformylation of Internal Olefins
mechanisms for the double bond migration from an
internal position to the terminal, either through an
An 8-mL vial with a magnetic stirring bar was charged with
ligand 3 (8 mmol, 6.3 mg) and RhACHTNUGRTNE(NUG acac)(CO)2 (2 mmol,
À
Rh H addition and b-H elimination pathway or
0.2 mL of 10 mM solution in toluene). The mixture was
stirred for 5 min; 2-hexene (2 mmol, 0.24 mL) was then
added, followed by decane (0.1 mL) as internal standard
and toluene (1.46 mL). The reaction mixture was transferred
to an autoclave. The autoclave was purged with nitrogen
three times and subsequently charged with CO (5 atm) and
H2 (5 atm). The autoclave was then heated to 1208C and the
pressure was set to 10 atm. After required time, the auto-
clave was cooled in ice/water, and the pressure was carefully
released in a well-ventilated hood. The reaction mixture was
through reductive elimination of a Rh
AHCTUNGTRENNUNG
plex to shift the double bond to the end
(Scheme 4).[15] Under our reaction conditions, both
mechanisms appear possible. Compared to a terminal
olefin, the double bond of an internal olefin needs to
migrate one or more times in order to form the linear
aldehyde. For example, it requires three consecutive
double bond migrations for 4-octene to produce the
linear aldehyde. During this consecutive isomerization
process, each Rh/alkene intermediate complex has a
chance to start its own hydroformylation catalytic
cycle. As a result, branched aldehydes will be pro-
duced.[12] Our results indicate that for a b internal
olefin (2-pentene, 2-hexene, or 2-octene), the hydro-
formylation rate of the branched Rh/alkene complex
is slow enough compared to the rate of isomerization
and the rate of terminal alkene hydroformylation so
that linear aldehyde is formed as the main product.
1
immediately analyzed by GC and H NMR to determine the
conversion and regioselectivity.
Acknowledgements
We thank the National Institutes of Health (GM58832) and
Dow Chemical Co. for financial support. The Bruker
400 MHz NMR spectrometer used in these studies was pur-
For a g internal olefin (3-hexene or 3-octene), the chased with a grant from the National Center for Research
Resources (NCRR) (No. 1S10RR023698-01A1), a component
of NIH.
outcome is affected by the steric hindrance of the sub-
strate. For 3-hexene, the time of two consecutive iso-
merizations is still shorter than that of branched hy-
droformylation, resulting in the linear aldehyde as the
main product; however, much worse regioselectivity
was observed for 3-octene, which has increased steric
hindrance and a less accessible double bond com-
pared to 3-hexene. For a d internal olefin (cis- or
trans-4-octene), our results indicate that the time
spent on three consecutive isomerizations is not much
shorter than that of branched hydroformylation, re-
sulting in a lot of branched aldehydes and olefin iso-
mers.
References
[1] For recent reviews and monographs, see: a) Rhodium
Catalyzed Hydroformylation, (Eds.: C. Claver,
P. W. N. M. van Leeuwen), Kluwer Academic Publish-
ers, Dordrecht, The Netherlands, 2000; b) F. Ungvary,
Coord. Chem. Rev. 2005, 249, 2946; c) M. L. Clarke,
Curr. Org. Chem. 2005, 9, 701; d) M. Dieguez, O.
Pamies, C. Claver, Tetrahedron: Asymmetry 2004, 15,
2113; e) B. Breit, W. Seiche, Synthesis 2001, 1.
In summary, we have shown that by using the mul-
tiple chelating capability of our tetraphosphine li-
gands, the hydroformylation of some industrially im-
portant internal olefins can be achieved with high re-
[2] O. Roelen, Ger. Offen. 849,548, 1938.
[3] a) R. Jennerjahn, I. Piras, R. Jackstell, R. Franke, K.-D.
Wiese, M. Beller, Chem. Eur. J. 2009, 15, 6383; b) C. U.
Gruenanger, B. Breit, Angew. Chem. 2010, 122, 979;
Adv. Synth. Catal. 2011, 353, 2665 – 2670
ꢁ 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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Chaoxian Cai et al.
COMMUNICATIONS
Angew. Chem. Int. Ed. 2010, 49, 967; c) G. Makado, T.
Morimoto, Y. Sugimoto, K. Tsutsumi, N. Kagawa, K.
Kakiuchi, Adv. Synth. Catal. 2010, 352, 299; d) A. A.
Dabbawala, R. V. Jasra, H. C. Bajaj, Catal. Commun.
2010, 11, 616; e) A. G. Panda, M. D. Bhor, S. S. Ekbote,
B. M. Bhanage, Catal. Lett. 2009, 131, 649; f) W. Liu,
M. Yuan, H. Fu, H. Chen, R. Li, X. Li, Chem. Lett.
2009, 38, 596; g) P. E. Goudriaan, M. Kuil, X.-B. Jiang,
P. W. N. M. van Leeuwen, J. N. H. Reek, Dalton Trans.
2009, 1801; h) S. Simaan, I. Marek, J. Am. Chem. Soc.
2010, 132, 4066; i) T. Spangenberg, B. Breit, A. Mann,
Org. Lett. 2009, 11, 261; j) A. D. Worthy, M. M.
Gagnon, M. T. Dombrowski, K. L. Tan, Org. Lett. 2009,
11, 2764.
[7] D. Selent, D. Hess, K.-D. Wiese, C. Kunze, A. Bçrner,
Angew. Chem. 2001, 113, 1739; Angew. Chem. Int. Ed.
2001, 40, 1696.
[8] E. Billig, A. G. Abatjoglou, D. R. Bryant, (UCC), U.S.
Patent 4,769,498, 1988.
[9] P. M. Burke, J. M. Garner, K. A. Kreutzer, A. J. J. M.
Teunissen, C. S. Snijder, C. B. Hansen, (DSM/Du Pont),
PCT Int. Patent WO 97/33854, 1997.
[10] a) Y. Yan, X. Zhang, X. Zhang, J. Am. Chem. Soc.
2006, 128, 16058; b) S. Yu, Y. Chie, Z. Guan, X. Zhang,
Org. Lett. 2008, 10, 3469.
[11] S. Yu, X. Zhang, Y. Yan, C. Cai, L. Dai, X. Zhang,
Chem. Eur. J. 2010, 16, 4938.
[12] a) C. K. Brown, G. Wilkinson, J. Chem. Soc. A 1970,
2753; b) D. Evans, J. A. Osborn, G. Wilkinson, J. Chem.
Soc. A 1968, 3133; c) D. Evans, G. Yagupsky, G. Wil-
kinson, J. Chem. Soc. A 1968, 2660.
[4] P. Kumar, W. Vermeiren, J.-P. Dath, W. F. Hoelderich,
Energy Fuels 2006, 20, 481.
[5] a) L. A. van der Veen, P. C. J. Kamer, P. W. N. M. van
Leeuwen, Angew. Chem. 1999, 111, 349; Angew. Chem.
Int. Ed. 1999, 38, 336; b) L. A. van der Veen, P. C. J.
Kamer, P. W. N. M. van Leeuwen, Organometallics
1999, 18, 4765; c) S. C. van der Slot, J. Duran, J. Luten,
P. C. J. Kamer, P. W. N. M. van Leeuwen, Organometal-
lics 2002, 21, 3873; d) L. A. van der Veen, M. D. K.
Boele, F. R. Bregman, P. C. J. Kamer, P. W. N. M. van
Leeuwen, K. Goubitz, J. Fraanje, H. Schenk, C. Bo, J.
Am. Chem. Soc. 1998, 120, 11616.
[6] a) H. Klein, R. Jackstell, K.-D. Wiese, C. Borgmann,
M. Beller, Angew. Chem. 2001, 113, 3505; Angew.
Chem. Int. Ed. 2001, 40, 3408; b) H. Klein, R. Jackstell,
C. Borgmann, M. Beller, Chem. Commun. 2005, 2283;
c) R. Jackstell, H. Klein, M. Beller, K.-D. Wiese, D.
Rçttger, Eur. J. Org. Chem. 2001, 3871.
[13] a) T. J. Devon, G. W. Phillips, T. A. Puckette, J. L. Stavi-
noha, J. J. Vanderbilt, U.S. Patent 4,694,109, 1987;
b) W. A. Herrmann, C. W. Kohlpaintner, E. Herdtweck,
P. Kiprof, Inorg. Chem. 1991, 30, 4271; c) C. P. Casey,
G. T. Whiteker, M. G. Melville, L. M. Lori, J. A.
Gavney Jr, D. R. Powell, J. Am. Chem. Soc. 1992, 114,
5535; d) W. A. Herrmann, R. Schmid, C. W. Kohlpaint-
ner, T. Priermeier, Organometallics 1995, 14, 1961;
e) C. P. Casey, E. L. Paulsen, E. W. Beuttenmueller,
B. R. Proft, L. M. Petrovich, B. A. Matter, D. R.
Powell, J. Am. Chem. Soc. 1997, 119, 11817.
[14] a) M. Matsumoto, M. Tamura, J. Mol. Catal. 1982, 16,
209; b) M. Matsumoto, M. Tamura, J. Mol. Catal. 1982,
16, 195.
[15] M. Arthurs, M. Sloan, M. G. B. Drew, S. M. Nelson, J.
Chem. Soc. Dalton Trans. 1975, 1794.
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