Synthesis of Short-Chain Alkenyl Ethers from Primary and Bio-sourced Alcohols via the Nickel-Catalyzed Hydroalkoxylation Reaction of Butadiene and Derivatives

Article abstract of DOI:10.1002/adsc.201500721

Hydroalkoxylation of butadiene has been performed in the presence of nickel precatalysts associated with chelating diphosphine ligands. High butadiene conversions and selectivities forming alkyl butenyl ethers were obtained with low catalyst loading. Reactions were performed with a wide scope of primary alcohols including benzylic alcohol derivatives and bio-sourced alcohols. In the same way, the scope of dienes that can be reacted according to this reaction has been also studied. Substituted butadiene derivatives have shown a lower reactivity compared to butadiene. Isoprene formed OC5 alkenyl ethers with a high regioselectivity for one branched isomeric form.

Full text of DOI:10.1002/adsc.201500721

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DOI: 10.1002/adsc.201500721
Synthesis of Short-Chain Alkenyl Ethers from Primary and Bio-
sourced Alcohols via the Nickel-Catalyzed Hydroalkoxylation Re-
action of Butadiene and Derivatives
Alexis Mifleur,a HØl›ne Ledru,a Adrien Lopes,a Isabelle Suisse,a,*
AndrØ Mortreux,a and Mathieu Sauthiera,*
a
Univ. Lille, CNRS, Centrale Lille, ENSCL, Univ. Artois, UMR 8181 - UCCS - UnitØ de Catalyse et Chimie du Solide,
F-59000 Lille, France.
Fax: (+33) 3 20 33 63 01; e-mail: mathieu.sauthier@univ-lille1.fr or isabelle.suisse@ensc-lille.fr
Received: July 30, 2015; Revised: September 28, 2015; Published online: December 9, 2015
Supporting information for this article is available on the WWW under http://dx.doi.org/10.1002/adsc.201500721.
Abstract: Hydroalkoxylation of butadiene has been reaction has been also studied. Substituted butadiene
performed in the presence of nickel precatalysts as- derivatives have shown a lower reactivity compared
sociated with chelating diphosphine ligands. High bu- to butadiene. Isoprene formed OC5 alkenyl ethers
tadiene conversions and selectivities forming alkyl with a high regioselectivity for one branched isomer-
butenyl ethers were obtained with low catalyst load- ic form.
ing. Reactions were performed with a wide scope of
primary alcohols including benzylic alcohol deriva-
tives and bio-sourced alcohols. In the same way, the Keywords: butadiene; ether; hydroalkoxylation;
scope of dienes that can be reacted according to this nickel; polyol
Introduction
vents. Several methods are described to obtain allyl
or butenyl ethers. The oldest and undoubtedly most
Allyl ethers or derivatives such as but-2-enyl ethers used is the Williamson reaction, which involves an al-
are found in many naturally occurring biologically cohol and an alkyl halide in the presence of a base.
active molecules, which are frequently involved in or- Nevertheless, this synthetic pathway is not ideal for
ganic synthesis. For example, allyl ethers are classical- several reasons. Side reactions such as halide elimina-
ly used as protecting groups for alcohols,[1] especially tion are occurring and an excess of alkylating reagent
in carbohydrates chemistry due to their stability is thus often needed. Besides this chemoselectivity
under the conditions required for glycoside forma- issue, this transformation provides a stoichiometric
tion[2,3] or electrophiles in allylic alkylation reactions[4] amount of salts as waste that needs to be removed
(Scheme 1). Butenyl ethers can also be used as mono- using costly processes.
mers in UV-induced cationic photopolymerization
This reaction thus doesn’t fill the criteria of the
with commercial applications in the fields of coatings, green chemistry concepts due to the lack of atom
inks and adhesives.[5] Allyl or butenyl ethers derived economy.[6] Consequently, new convenient methods
from polyols with a short C3 or C4 chain are also oriented toward the synthesis of ethers with high
potent hydrotropes that can find applications as sol- atom economy and low salt formation are needed.
With this objective in mind, the catalytic hydroalkoxy-
lation reaction of unsaturated double or triple bonds
by alcohols permits the formation of ethers without
any waste.
Reactions between an alcohol and an alkene in the
presence of Brønsted acids[7] or organometallic com-
plexes[8] as catalysts have been reported for the intra-
or intermolecular formation of alkyl ethers. Likewise,
Scheme 1. Applications of allyl ethers as protecting groups
or reactants.
the use of alkynes[9] or allenes[10] gave enol ethers or
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Synthesis of Short-Chain Alkenyl Ethers
alkyl allyl ethers respectively, compounds known as tion metals.[20] In this context, nickel based catalysts
useful intermediates in organic synthesis.[11] Regarding have been evaluated, mainly in order to draw a com-
dienes, studies mainly focused on the telomerization parison with palladium equivalents. Mixtures of bu-
reaction which corresponds to the metal catalyzed tenyl or octadienyl ethers along with dimers were ob-
linear dimerization of butadiene with simultaneous tained with varying selectivities depending on the
addition of an alcohol to form octadienyl ethers.[12] nature of the monophosphine used, but no satisfying
Classical palladium precursors with phosphine[13] or selectivity for butenyl ethers was obtained.[21] In our
carbene[14] ligands provided very efficient catalytic group, we recently disclosed the nickel-catalyzed hy-
systems causing this reaction to now be included in an droalkoxylation of butadiene with primary alcohols to
industrial process for the production of 1-octene.[15] form selectively OC4 ethers (1 and 2) using specifical-
Amphiphilic compounds were also obtained by graft- ly the bidentate diphenylphosphinobutane (dppb)
ing hydrocarbon C8 chains on agro-based polyol sub- ligand associated with a nickel precatalyst.[22] We wish
strates thus yielding 100% agro-based molecules if now to report our progress on the optimization of this
considering the bio-ethanol to butadiene synthetic reaction as well as the extension of the scope to
pathway.[16] The simple addition of an alcohol on one a wider variety of alcohols including biomass issued
double bond of a butadiene unit (a hydroalkoxylation alcohols and substituted dienes.
reaction) has received little attention, due to the lack
of efficient catalytic process in terms of activity and
selectivity. This approach would advantageously open Results and Discussion
an access to shorter amphiphiles and thus comple-
ment the scope of products already accessible from In our preliminary work, the hydroalkoxylation of bu-
polyols and 1,3-butadiene according to the telomeri- tadiene was performed in the presence of Ni(acac)2
zation reaction. Indeed, the hydroalkoxylation reac- precursor and the dppb (diphenylphosphinobutane
tion using butadiene and alcohols affords both linear L1, Scheme 3) ligand with NaBH4 as reducing agent
1 (cis and trans) and branched 2 butenyl ethers for the in situ generation of the Ni(0) species. Al-
(OC4), but in many cases, octadienyl ethers 3–4 though largely used in the literature, this method re-
(OC8) and C8 dimers are also obtained as side prod- quires a fine control of the reaction conditions to
ucts (Scheme 2). The first selective synthesis of OC4 avoid the possible formation of nickel nanoparti-
ethers via metal-catalyzed hydroalkoxylation was re- cules.[23] Ni(cod)2/dppb catalytic systems were there-
ported with ethanol and 1,3-butadiene in the presence fore used in order to outline the best catalytic condi-
of a high loading of rhodium trichloride.[17] Smutny tions for the ethoxylation reaction of butadiene (BD).
et al. showed that p-allyl palladium catalysts allowed In a typical experiment, the catalyst was prepared by
the addition of phenol to butadiene, however with stirring a solution of the nickel precursor and the
low yields and large amounts of by-products (ortho-, ligand in ethanol for 5 min in a Schlenk tube under
para-butenylphenol).[18] Interesting butadiene conver- nitrogen. Liquid butadiene (BD/Ni=125–2500) was
sion and methylbutenyl ether selectivities were ob- then added at À158C and the mixture was heated to
tained with bis(p-allylpalladium) dichloride precur- the desired temperature. The results are reported in
sors in high methanol dilution conditions.[19] Due to Table 1. After 17 h, using 0.8 mol% catalyst, a 93%
the high cost of palladium, several groups have also butadiene conversion was attained with 95% selectiv-
been interested in the telomerization or hydroalkoxy- ity towards butenyl ethers (Entry 1).[22] The same re-
lation reactions catalyzed by more abundant transi- action stopped after two hours showed a similar
result. Nevertheless, the reaction mixture was cloudy
in both experiments, probably due to the limited solu-
bility of the ligand and catalyst in ethanol. We thus
performed the reaction using toluene as a co-solvent
(3 mL, entry 2) in order to obtain a clear solution.
The butadiene/nickel ratio was increased up to 1250
with satisfactory conversions and selectivities (En-
tries 2–3). At higher BD/Ni ratios, the level of conver-
sion was extremely limited (21% conv. after 2 h,
Entry 4). EtOH/toluene (v/v) ratios were varied from
10:3 to 1:12. As the quantity of ethanol decreased,
lower conversions of butadiene were obtained within
the reaction time. In addition, the selectivity in buten-
yl ethers decreased, showing that the excess of etha-
nol favors the hydroalkoxylation process over the di-
merization of 1,3-butadiene (Entries 3; 5–7). The in-
Scheme 2. Hydroalkoxylation, telomerization and dimeriza-
tion of butadiene.
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Alexis Mifleur et al.
Scheme 3. Hydroethoxylation of butadiene: influence of the ligand.
fluence of the ligand/Ni ratio was also studied. At low allowed a 33% conversion with a 24% OC4 selectivi-
ratios (0.5, 0.75 and 1), the conversion was rather low ty. The results indicate the importance of the chela-
between 26 and 51% (Entries 8–10). The best results tion cycle size on this reaction. Other diphosphines
in terms of activity (78% conv.) and selectivities that are able to form seven membered chelation
(95% and 84% respectively) were obtained with 1.5 cycles with the metal were tested. Among them, com-
and 2 L/Ni ratios (Entries 3 and 11 respectively). mercial diphosphines with the same skeleton as dppb,
Using higher ratios was detrimental to the activity but with alkyl groups on the phosphorous atoms such
and selectivity. This limitation can be explained by as iPr (L5), cyclohexyl (L7) and tBu (L8) were evalu-
the strongly favored formation of the less reactive ated. iPr substituents led to moderate conversion and
nickel complex Ni(dppb)2 in the presence of an excess selectivities whereas more hindered Cy and tBu sub-
of the diphosphine. As expected, upon decreasing the stituents led to inactive catalysts. Concerning the im-
temperature, the reaction was much slower with only portance of the diphosphine backbone, the di(amino-
13 and 18% conversions after 2 h at 60 and 708C re- phosphine) L14 gave moderate results in terms of
spectively (Entries 13–14). Further increase of the conversion (77%) and selectivity (44%) while the
temperature up to 908C did not lead to a notable im- binap ligand L12 affords the OC4 ethers with a 99%
provement of the activity.
selectivity albeit with a lower butadiene conversion
The catalytic activity and selectivity obtained (44%).[25] The best results were obtained using the L9
during this reaction depend particularly on the nature (dppmb) ligand leading to 65% conversion as well as
of the ligand associated to the Ni(0) precursor. Mono- total selectivity to the OC4 ethers. In comparison
phosphines lead to the selective linear dimerization of with the dppb ligand, the presence of a rigid aromatic
1,3-butadiene.[24] Diphosphines L1–L15 were evaluat- skeleton appears to be favorable in terms of selectivi-
ed for the hydroethoxylation reaction of butadiene. ty.
Among those, linear diphosphines L1–L8 with various
We were then interested in the evolution of the
substituents on the phosphorus atoms and L15 pos- product distribution during the reaction period. A
sessing an amino group, aryl (L9, L12, L13) or ferro- glass reactor with a sampling release at the bottom of
cenic L10, cyclic L6, L11 and di(aminophosphine) the Schlenk tube has been used to take the samples
L14 ligands were tested (Scheme 3). Unexpected re- without any loss of butadiene. Using this procedure,
sults were observed with dppe L2 and dppp L3 which aliquot samples of the reaction mixture were taken
did not give any conversion, whereas the dpppen L4 and analyzed by GC for 24 h. Figure 1 presents the
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Synthesis of Short-Chain Alkenyl Ethers
Table 1. Hydroethoxylation of butadiene: variation of experimental conditions.[a]
Entry
BD/Ni;
L/Ni
Solvent
( mL/mL)
Time (h)
Conv. (%)[b]
Sel. OC4
(1a/2a) (%)[b]
1
125; 1.5
125; 1.5
1250; 1.5
2500; 1.5
1250; 1.5
1250; 1.5
1250; 1.5
1250; 0.5
1250; 0.75
1250; 1
EtOH
(10)
EtOH/toluene
(10:3)
EtOH/toluene
(10:3)
EtOH/toluene
(10:3)
EtOH/toluene
(6.5:6.5)
EtOH/toluene
(1:3)
EtOH/toluene
(1:12)
EtOH/toluene
(10:3)
EtOH/toluene
(10:3)
EtOH/toluene
(10:3)
EtOH/toluene
(10:3)
EtOH/toluene
(10:3)
EtOH/toluene
(10:3)
EtOH/toluene
(10:3)
17
3
93
82
78
21
25
32
8
95
(24/76)
79
(27/73)
95
(20/80)
98
(47/53)
78
(16/84)
28
(24/76)
5
(43/57)
88
(16/84)
90
(16/84)
91
(18/82)
84
(18/82)
94
(17/83)
85
(85/15)
93
2
3
2
4
2
5
2
6
72
2
7
8
2
26
41
51
78
48
13
18
9
2
10
11
12
13[c]
14[d]
2
1250; 2
2
1250; 3
2
1250; 1.5
1250; 1.5
2
2
(85/15)
[a]
BD=butadiene=1.5 mL (17.2 mmol); T=808C.
Conversions and selectivities were determined by GC analysis.
608C.
708C.
[b]
[c]
[d]
composition of the mixture as a function of time
using L1 (dppb) as ligand. As expected, the curves in-
dicate that the reaction occurs very efficiently with
64% yield into OC4 products after 1 hour and 78%
after 2 h. After 3 h, there is no more evolution of the
products distribution and a maximum value of 85%
OC4 is obtained with approximatively 5% of OC8
telomers and C8 dimers.
The linear/branched ratio remained almost stable
during the reaction course at around 80:20; this indi-
cates that no isomerization of the products takes
place. As the curve depicting the conversion of buta-
diene as a function of time for the first hours is
almost linear, the slope of the curve can be easily cal-
culated. With these reaction conditions, the turn over
frequency (TOF) of the nickel catalyst was found to
be approximately 800 hÀ1. The same calculation per-
Figure 1. Time-dependent reaction progress of the hydro-
ethoxylation of butadiene. Conditions: butadiene=1.5 mL
(17.2 mmol); BD/Ni(cod)2/dppb=1250:1:1.5; EtOH/tolu-
ene=10/3 mL/mL; T=808C.
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Alexis Mifleur et al.
Table 2. Hydroalkoxylation of butadiene using various primary alcohols[a]
Entry
alcohol
ROH
Ligand
Conv. (%)[b]
Sel.[b] OC4
(%)
2:1
ratio
yield[c] (%)
1
2
L1
L9
91
99
71
96
50:50
50:50
45
67
3
4
L1
L9
99
76
95
100
67:33
80:20
84
58
5
6
L1
L9
50
70
90
95
47:53
68:32
45
67
7
8
L1
L9
76
99
100
100
50:50
84:16
46
62
9
10
L1
L9
86
99
90
100
83:17
79:21
32
36
11
L1
69
96
82:18
nd
12
13
L1
L9
24
33
78
94
83:17
86:14
nd
nd
14
15
16
L1
L9
L9
4
0
99
68
–
100
33:67
–
80:20
nd
–
80
17
L9
91
95
50:50
49
[a]
Butadiene=0.5 mL (5.7 mmol); BD/Ni(cod)2/ligand: 125/1/1.5; ROH/BD=3; toluene=1 mL; T=808C; t=17 h.
Determined by GC analysis.
isolated yield.
[b]
[c]
formed from butadiene hydroethoxylation reaction at primary alcohols, in particular benzyl alcohol deriva-
608C gave a TOF of 112 hÀ1 (Entry 13, Table 1, tives and primary bio-sourced alcohols. The use of
OC4=18% after 2 h).
benzyl alcohol and its substituted derivatives allowed
In our previous publication, we showed that pri- the isolation and the spectroscopic characterization of
mary alcohols such as methanol or benzyl alcohol the corresponding ethers unambiguously.
could be used for this reaction whereas secondary or
Hydroalkoxylation of these alcohols was performed
tertiary alcohols such as iPrOH or tBuOH failed to in the presence of nickel catalysts coordinated by the
react. We next decided to extend our study to other two most efficient phosphines, dppb L1 and dppmb
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Synthesis of Short-Chain Alkenyl Ethers
Table 3. Hydroalkoxylation of butadiene with bio-sourced
alcohols
L9. The reaction conditions were beforehand opti-
mized with benzyl alcohol and we found that
a PhCH2OH/BD ratio of 3 was the optimal value to
obtain simultaneously satisfying conversions and OC4
selectivities. The reactions were performed for 17 h in
order to attain maximum conversions and isolated
yields. Results are reported in Table 2.
The reactions were successful with benzylic alcohol
and its derivatives regardless of the nature and posi-
tion of the substituents on the aromatic cycle. Conver-
sions of 69–99% and high to total selectivity to the
OC4 ethers were obtained in all cases (Entries 1–11,
Table 2). As previously observed with ethanol, the
branched isomer was the major product.
We then examined the possibility to perform this
reaction with cinnamyl and 3-phenylpropargyl alco-
hols (Entries 12–15) but in these two cases, the con-
version dropped drastically with no conversion in the
case of propargylic alcohol using L9 (dppmb,
Entry 15). Finally two heteroaromatic primary alco-
hols were evaluated in the presence of L9 ligand with
interesting results in terms of conversions and OC4
selectivities (Entries 16 and 17, Table 2). We then fo-
cused our attention particularly on bio-sourced alco-
hols. Furfuryl and tetrahydrofurfuryl alcohols are ob-
tained from the reduction of furfural. The furfural
itself is produced from the hydrolysis and dehydration
of agricultural wastes. Hydrogenolysis of sorbitol or
xylitol, originating respectively from glucose, affords
the production of ethane-1,2-diol or propane-1,3-diol.
On the other hand, butane-1,4-diol can be obtained
by fermentation of biomass sugars. Glycerol carbon-
ate and solketal were synthesized according to de-
scribed procedures from glycerol which is available in
large amounts as a by-product of biodiesel produc-
Entry alcohol
Conv. Sel. 1+2 (%) Sel. 3[c] (%)
(%)[c] (2/1 ratio)[c]
1[a]
2[a]
100
92
98 (67:33)
46 (50:50)
51 (50:50)
–
–
79[a]
–
–
3
4
100[b] 98 (71:29)
0[a,b]
– –
–
5[b]
6[b]
7[b]
81
90
93
83 (55:45)
83 (52:48)
85 (63:37)
13
13
11
8[b]
54
52 (nd)
12
[a]
Butadiene=1.5 mL (17.2 mmol); BD/Ni(cod)2/dppb=
125:1:1.5; ROH/BD=3; toluene=3 mL; T=808C; t=
17 h.
Butadiene=1.5 mL (17.2 mmol); BD/Ni(cod)2/dppmb=
125:1:1.5; ROH/BD=1.7; THF=2.5 mL; T=808C; t=
17 h.
[b]
[c]
Determined by GC analysis.
tion.[26] We performed catalytic reactions in the pres- tivities (conversions=54–93%, OC4 selectivities=
ence of dppb L1 or dppmb L9 based nickel catalysts. 52–83%, Entries 5–8). As two hydroxyl functions are
Only the best results for each alcohol in terms of ac- present, diethers were also found in the reaction mix-
tivity and chemoselectivity into OC4 ethers are re- ture. In the case of propane-1,2-diol, the secondary
ported in Table 3. In the first set of experiments, we hydroxyl moiety was almost unreactive as we already
used the initial catalytic conditions: Ni(cod)2/ligand in observed in the case of 2-propanol or tert-butanol hy-
toluene as the solvent. It appeared that furfuryl alco- droalkoxylation.[22] The monoether produced from the
hol, tetrahydrofurfuryl alcohol and solketal could be etherification of the primary hydroxyl group was the
converted into the corresponding OC4 ethers with sole reaction product.
satisfying selectivities (79 to 100% conversions, En-
The scope of the reaction was then further studied
tries 1–3, Table 3) whereas in the case of glycerol car- with butadiene derivatives such as isoprene, pipery-
bonate, no reaction occurred (Entry 4). In the case of lene, 1-phenylbuta-1,3-diene and hexa-2,4-diene as
the diols that are more hydrophilic, conversions were well as myrcene (Table 4). In comparison to buta-
always very limited regardless of the ligand (48% diene, a larger number of possible isomeric alkenyl
conversion for butane-1,3-diol and <10% for ethane- ethers can be obtained due to the substituents on the
1,2-diol and 1,2- or 1,3-propanediol).
dienes. In the case of the ethoxylation of isoprene,
While performing these catalytic reactions, we ob- five isomers are potentially accessible depending on
served that these diols were not entirely soluble in the regioselectivity of the reaction (Scheme 4).
toluene. We then used THF as the solvent in which
The reaction of isoprene with ethanol and metha-
the diols were much more soluble. With these condi- nol, at 658C, afforded the corresponding OC5 ethers
tions, the alcohols could be converted into OC4 with 86% and 80% of isoprene conversion respec-
ethers with moderate to high conversions and selec- tively after 17 h (Entries 1 and 2, Table 4). Among the
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Table 4. Hydroalkoxylation of substituted dienes with vari-
ous alcohols.[a]
Entry Diene
ROH
T
Conv. Yield
(8C) (%) OC5
(%)[b]
Scheme 5. Major products obtained from the reaction be-
tween benzylic alcohol and substituted butadiene deriva-
tives.
1
2
3
MeOH 65
EtOH 65
EtOH 80
86
80
86
86 (nd)[c]
80 (nd)
82 (nd)
4
BzOH 65
80
80 (73)
(Table 4, Entry 5) whereas the benzyl alcohol led to
65% conversion at 658C (Entry 6). Selectivities to
OC5 ethers were also disappointing with no OC5
ethyl ethers and only 37% of OC5 in the case of
benzyl alcohol. Even then, a major product was ob-
served and isolated from the reaction mixture with
19% yield (see experimental part). A similar result
was obtained with 1-phenyl-buta-1,3-diene which led
to a poor product yield in the hydroalkoxylation reac-
tion (16% selectivity, entry 7). Hexa-2,4-diene and
ethyl sorbate also proved to be unsuitable for hydro-
alkoxylation with no diene conversion: the substitu-
tion of the two double bonds led to bulky substrates,
which are much less reactive. Finally, we used myr-
cene which can be extracted from plants. Although
the reactivity of this natural diene was very limited,
ethyl and benzyl ethers could be formed.
5
6
EtOH 80
BzOH 65
43
55
0 (0)
37 (19)
7
8
BzOH 65
BzOH 80
81
0
16 (16)
–
9
BzOH 80
0
–
10
11
12
Myrcene
EtOH 80
BzOH 65
BzOH 80
24
0
29
13 (nd)
–
29 (10)
[a]
Diene=17.2 mmol;
diene/Ni(cod)2/dppmb=125:1:1.5;
ROH/diene=3; toluene=3 mL; t=17 h.
Determined by GC analysis, isolated yield of major
isomer in parentheses; please see Scheme 5 for the struc-
tures.
[b]
[c]
not determined.
Conclusions
We have developed an efficient and selective synthe-
sis of alkyl butenyl ethers from butadiene and pri-
mary alcohols using simple and readily accessible
nickel catalysts. To access high selectivities, the choice
of ligand associated to the nickel precursor is crucial
and diphosphines with two phosphorous atoms
bridged with four carbons led to superior catalytic ef-
ficiency. From this observation, the use of the dppmb
ligand is a good alternative to the dppb ligand for the
synthesis of OC4 ethers, giving rise to better selectivi-
ties. With this optimized catalytic system, OC4 ethers
were synthesized from a large range of primary alco-
hols under mild conditions. Agro-based alcohols and
Scheme 4. Hydroalkoxylation of isoprene with ethanol.
OC5 ethers formed, a major product was always ob- diols were efficiently converted according to this reac-
served (ca 80% selectivity), but as seen previously in tion thus showing the interest of the synthetic meth-
the case of butadiene, the isoprenyl methyl and ethyl odology in the context of the valorization of polyols.
ethers could not be isolated due to their high volatili- The reaction was then extended to substituted dienes,
ty. The products obtained from the reaction with but they were less reactive. Further studies are in
benzyl alcohol allowed isolation of the main isomer progress to investigate the mechanistic details of this
via silica gel column chromatography, and the product reaction by NMR spectroscopic analyses, together
was further fully characterized by NMR (Scheme 5). with X-Ray characterizations of some nickel inter-
As in the case of butadiene, the major product is the mediates, and results will be reported in due time.
branched isomer at the less substituted position.
Piperylene was also evaluated but this diene ap-
pears to be less reactive than isoprene with only 43%
conversion for the ethoxylation reaction at 808C
116
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FULL PAPERS
Synthesis of Short-Chain Alkenyl Ethers
0.096 mmol) and the ligand (0.143 mmol) in 3 mL toluene or
Experimental Section
2.5 mL THF in a glass reactor closed by a Rotafloꢁ stop-
cock. Under nitrogen atmosphere, the tube was cooled at
À158C and degassed polyol derivative was added
(29.1 mmol, 1.5 equiv). A precise amount of butadiene
(1.5 mL, 17.2 mmol) was then condensed at low temperature
and transferred in the reaction mixture via a cannula. The
glass reactor was closed and heated to 808C for 17 h. After
reaction, the mixture was cooled and vented before GC
analyses with heptane as internal standard. The compounds
were isolated by flash chromatography column.
General procedure for the catalytic hydroalkoxylation of
1,3-dienes with alcohols: The catalytic solution is prepared
in a glove box by mixing Ni(cod)2 (38.2 mg, 0.14 mmol) and
the ligand (0.21 mmol) in 3 mL toluene or 2.5 mL THF in
a glass reactor closed by a Rotafloꢁ stopcock. Under nitro-
gen atmosphere, purified and degassed alcohol was added
General methods: Hydroalkoxylation reactions were carried
out under nitrogen. Furthermore, the glass reactor closed
with a Rotafloꢁ stopcock was filled in a glove box under
argon with catalyst and solvents. Other reactants were
added out of the gloves box with Schlenk tube techniques.
Chemicals were purchased from Aldrich, Alfa Aesar, Acros,
Linde Gas France and Strem. Benzyl alcohol was distilled
over CaH2 before use. Benzyl alcohol derivatives, 4-pyridi-
nemethanol, 2-thiophenemethanol, cinnamyl alcohol, 3-phe-
nylpropargyl alcohol, butadiene and its derivatives were
used without further purification. Ethanol and methanol
were distilled over magnesium turnings. Toluene and tetra-
hydrofuran were obtained from
a solvent purification
system MBraun SPS-800. Furfuryl alcohol, tetrahydrofurfur-
yl alcohol and diols were distilled over CaSO4 and NaHCO3.
Analytical thin layer chromatography (TLC) was carried
out using commercial silica gel plates (Merck 60 F254),
spots were determined with UV light. Conversions were de-
termined by gas chromatography on a Shimadzu 2010 appa-
ratus equipped with an Equity-5 column (30 m, i.d.=
0.32 mm). The isolated yields were determined after flash
chromatography on Revelerisꢁ Flash Chromatography
equipped with ELSD and UV (254 nm, 280 nm) detectors.
(51.9 mmol,
3 equiv). A precise amount of 1,3-diene
(17.2 mmol) was then added to the mixture. The glass reac-
tor was closed and heated to 808C for 17 h. After reaction,
the mixture was cooled and vented before GC analyses with
heptane as internal standard. The compounds were isolated
by flash chromatography column.
1
The compounds were characterized by H NMR, 13C NMR
Characterization of butenyl ethers
1
and HRMS. H (300 MHz) and 13C (75 MHz) NMR spectra
(Butenyloxymethyl)benzene: The products were synthesized
according to the general procedure for the catalytic hydroal-
koxylation of 1,3-butadiene with benzyl alcohol and deriva-
tives. The crude mixture gave 67% yield of the branched/
linear (Z/E) isomers as colorless liquid after flash column
chromatography on silica gel with petroleum ether/ethyl
1
were recorded using a Bruker AC 300 spectrometer. H and
13C NMR chemical shifts are reported to the center of the
solvent resonance [CDCl3: 7.27 (1H), 77.0 (13C) ppm].
General procedures
1
acetate: 92:8 eluent (Rf =0.8). H NMR (300 MHz, CDCl3),
General procedure for the catalytic hydroalkoxylation of 1,3-
butadiene with ethanol: The catalytic solution is prepared in
a glove box by mixing Ni(cod)2 (3.8 mg, 0.014 mmol) and
the ligand (0.021 mmol) in 3 mL toluene in a glass reactor
closed by a Rotafloꢁ stopcock. Under nitrogen atmosphere,
the tube was cooled at À158C and dry and degassed EtOH
was added (10 mL). A precise amount of butadiene (1.5 mL,
17.2 mmol) was then condensed at low temperature and
transferred into the reaction mixture via a cannula. The
glass reactor was closed and heated to 808C for 2 h. After
reaction, the mixture was cooled and vented before GC
analyses with heptane as internal standard.
General procedure for the catalytic hydroalkoxylation of
1,3-butadiene with benzyl alcohol and derivatives: The cata-
lytic solution is prepared in a glove box by mixing Ni(cod)2
(12.6 mg, 0.046 mmol) and the ligand (0.069 mmol) in 1 mL
toluene or a glass reactor closed by a Rotafloꢁ stopcock.
Under nitrogen atmosphere, the tube was cooled at À158C
and the degassed benzyl alcohol derivative was added
(51.6 mmol, 3 equiv). A precise amount of butadiene
(1.5 mL, 17.2 mmol) was then condensed at low temperature
and transferred into the reaction mixture via a cannula. The
glass reactor was closed and heated to 808C for 17 h. After
reaction, the mixture was cooled and vented before GC
analyses with heptane as internal standard. The compounds
were isolated by flash chromatography column.
mixture isomers: d 7.28–7.43 (m, 5H), 5.86 (ddd, J=17.3,
10.2, 7.2 Hz, 1H), 5.62–5.82 (m, 2H), 5.20–5.31 (m, 2H),
4.63 (d, J=12.1 Hz, 1H), 4.57 (s, 1H), 4.55 (s, 1H), 4.45 (d,
J=11.7 Hz, 1H), 4.02 (dq, J=5.8, 1.3 Hz, 1H), 3.95–3.99 (m,
2H), 3.93–3.97 (m, 2H), 1.78 (dd, J=6.0, 1.1 Hz, 3H), 1.70
(dd, J=5.8, 0.8 Hz, 3H), 1.35 (d, J=6.4 Hz, 3H). 13C NMR
(75 MHz, CDCl3), mixture isomers: d 13.0, 17.6, 21.2, 65.3,
69.8, 70.7, 71.8, 71.9, 76.1, 115.9, 127.2, 127.47, 127.6, 127.6,
128.2, 129.3, 138.4, 138.7, 140.1. HRMS (EI) m/z [M+H]+:
calcd for C11H15O: 163.1118; found: 163.1109.
1-(Butenyloxy)methyl-3-methoxybenzene: The products
were synthesized according to the general procedure for cat-
alytic hydroalkoxylation of 1,3-butadiene with benzyl alco-
hol and derivatives. The crude mixture gave 84% yield of
the branched/linear (Z/E) isomers as colorless liquid after
flash column chromatography on silica gel with petroleum
ether/ethyl acetate: 92:8 eluent (Rf =0.8). 1H NMR
(300 MHz, CDCl3), mixture isomers: d 7.28 (t, J=8.0 Hz,
1H), 6.92–6.99 (m, 2H), 6.81–6.89 (m, 1H), 5.83 (ddd, J=
17.3, 10.2, 7.3 Hz, 1H), 5.60–5.77 (m, 2H), 5.15–5.32 (m,
2H), 4.59 (d, J=12.1 Hz, 1H), 4.53 (s, 1H), 4.51 (s, 1H),
4.41 (d, J=12.2 Hz, 1H), 4.13 (d, J=6.0 Hz, 1H), 3.96 (qd,
J=6.0, 0.8 Hz, 1H), 3.83 (s, 3H), 1.76 (dq, J=6.0, 1.1 Hz,
3H), 1.69 (d, J=6.0 Hz, 3H), 1.33 (d, J=6.4 Hz, 3H).
13C NMR (75 MHz, CDCl3), mixture isomers: d 17.65, 21.26,
55.01, 69.69, 71.65, 76.08, 112.86, 13.10, 115.94, 119.73,
119.84, 127.50, 129.21, 129.44, 127.50, 129.21, 129.44, 140.12,
140.39, 159.65. HRMS (EI) m/z [M+H]+: calcd for
C12H17O2: 193.1223; found: 193.1223.
General procedure for the catalytic hydroalkoxylation of
1,3-butadiene with bio-sourced alcohols: The catalytic solu-
tion is prepared in a glove box by mixing Ni(cod)2 (26.3 mg,
Adv. Synth. Catal. 2016, 358, 110 – 121
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asc.wiley-vch.de
117

FULL PAPERS
Alexis Mifleur et al.
Methyl 4-(Butenyloxy)methylbenzoate: The products
were synthesized according to the general procedure for the
catalytic hydroalkoxylation of 1,3-butadiene with benzyl al-
cohol and derivatives. The crude mixture gave 67% yield of
the branched/linear (Z/E) isomers as colorless liquid after
flash column chromatography on silica gel with petroleum
ether/ethyl acetate: 92:8 eluent (Rf =0.8). 1H NMR
(300 MHz, CDCl3), branched isomer: d 7.99 (d, J=8.3 Hz,
2H), 7.40 (d, J=8.5 Hz, 2H), 5.78 (ddd, J=17.3, 10.2,
7.3 Hz, 1H), 5.21 (dq, J=12.1, 0.9 Hz, 1H), 5.17 (dq, J=5.1,
0.9 Hz, 1H), 4.61 (d, J=12.8 Hz, 1H), 4.43 (d, J=12.8 Hz,
1H), 3.92 (dq, J=6.4, 0.8 Hz, 1H), 3.90 (s, 3H), 1.30 (d, J=
6.4 Hz, 3H). Linear isomer: d 8.00 (d, J=8.3 Hz, 2H), 7.39
(d, J=8.1 Hz, 2H), 5.55–5.85 (m, 2H), 5.20 (m, J=12.2,
1.2 Hz, 2H), 5.16 (m, J=5.8, 2.1 Hz, 2H), 4.54 (s, 2H), 4.52
(s, 2H), 3.89 (s, 3H), 1.71 (dd, J=6.1, 1.2 Hz, 3H), 1.63 (dd,
J=6.0, 0.8 Hz, 3H). 13C NMR (75 MHz, CDCl3), branched
isomer: d 144.14, 139.85, 129.07, 127.02, 116.22, 76.61, 69.25,
51.88, 21.22. Linear isomer: d 166.78, 143.77, 129.75, 129.14,
127.08, 126.99, 116.19, 71.06, 51.85, 17.62. HRMS (EI) m/z
[M+H]+: calcd for C13H17O3: 221.1172; found: 221.1173.
1-(Butenyloxy)methyl-3-chlorobenzene: The products
were synthesized according to the general procedure for cat-
alytic hydroakoxylation of 1,3-butadiene with benzyl alcohol
and derivatives. The crude mixture gave 62% yield of the
branched/linear (Z/E) isomers as colorless liquid after flash
column chromatography on silica gel with petroleum ether/
ethyl acetate 95:5 eluent (Rf =0.8). 1H NMR (300 MHz,
CDCl3), mixture isomers: d 7.22–7.33 (m, 3H), 5.85 (ddd,
J=17.5, 10.4, 7.3 Hz, 1H), 5.62–5.78 (m, 2H), 5.20–5.33 (m,
2H), 4.59 (d, J=12.2 Hz, 1H), 4.53 (s, 2H), 4.51 (s, 2H),
4.41 (d, J=12.2 Hz, 1H), 4.16 (d, J=6.0 Hz, 2H), 3.90–4.06
(m, 3H), 1.80 (dq, J=6.0, 1.1 Hz, 3H), 1.72 (dd, J=6.0,
0.8 Hz, 3H), 1.37 (d, J=6.4 Hz, 3H). 13C NMR (75 MHz,
CDCl3), mixture isomers: d 120.08, 17.56, 21.14, 65.43, 68.93,
70.91, 76.41, 16.07, 125.26, 125.37, 127.23, 127.31, 127.35,
127.42, 129.36, 129.51, 134.04, 139.80, 140.57, 140.89.
1-(Butenyloxy)methyl-2-chlorobenzene: The products
were synthesized according to the general procedure for the
catalytic hydroalkoxylation of 1,3-butadiene with benzyl al-
cohol and derivatives. The crude mixture gave 36% yield of
the branched/linear (Z/E) isomers as colorless liquid after
flash column chromatography on silica gel with petroleum
ether/ethyl acetate: 95:5 eluent (Rf =0.8). 1H NMR
(300 MHz, CDCl3), mixture isomers: d 7.50–7.63 (m, 1H),
7.17–7.41 (m, 3H), 5.86 (ddd, J=17.3, 10.2, 7.2 Hz, 1H),
5.63–5.80 (m, 2H), 5.17–5.35 (m, 2H), 4.77 (s, 2H), 4.67 (d,
J=13.2 Hz, 1H), 4.63 (s, 2H), 4.57 (d, J=13.2 Hz, 1H), 4.20
(d, J=5.7 Hz, 1H), 4.02 (s, 3H), 1.77 (d, J=6.2 Hz, 3H),
1.70 (s, 3H), 1.37 (d, J=6.4 Hz, 3H). 13C NMR (75 MHz,
CDCl3), mixture isomers: d 17.67, 21.22, 65.91, 67.05, 68.72,
69.67, 71.32, 76.88, 116.01, 126.57, 128.24, 128.79, 129.02,
129.05, 129.14, 132.62, 136.54, 139.94. HRMS (EI) m/z [M+
H]+: calcd for C11H14OCl: 197.0728; found: 197.0729.
5.60–5.90 (m, 2H), 5.18–5.30 (m, 2H), 4.56 (d, J=13.4 Hz,
1H), 4.48 (s, 2H), 4.46 (s, 2H), 4.34 (d, J=11.7 Hz, 1H),
4.12 (ddt, J=6.0, 1.9, 0.9 Hz, 2H), 3.99 (ddt, J=6.0, 2.3,
1.1 Hz, 2H), 2.34 (s, 6H), 1.76 (dtd, J=6.0, 1.2, 1.2, 1.1 Hz,
3H), 1.69 (dtd, J=6.0, 1.1, 1.1, 0.8 Hz, 3H), 1.33 (d, J=
6.4 Hz, 3H). 13C NMR (75 MHz, CDCl3), mixture isomers: d
13.18, 17.76, 21.02, 21.20, 21.32, 21.37, 65.39, 67.10, 70.01,
70.92, 71.99, 72.12, 76.21, 100.50, 116.00, 124.61, 125.52,
125.61, 125.63, 125.78, 126.93, 127.51, 127.59, 127.89, 129.01,
129.10, 129.14, 129.58, 130.00, 136.15, 137.83, 138.20, 138.23,
140.28. HRMS (EI) m/z [M+Na]+: calcd for C13H17ONa:
212.1172; found: 212.1184.
2-(Butenyloxymethyl)thiophene: The products were syn-
thesized according to the general procedure for catalytic hy-
droalkoxylation of 1,3-butadiene with benzyl alcohol and
derivatives. The crude mixture gave 80% yield of the
branched/linear (Z/E) isomers as colorless liquid after flash
column chromatography on silica gel with petroleum ether/
ethyl acetate: 95:5 eluent (Rf =0.8). 1H NMR (300 MHz,
CDCl3), mixture isomers: d 7.24–7.34 (m, 1H), 6.94–7.07 (m,
2H), 5.81 (ddd, J=17.4, 10.1, 7.3 Hz, 1H), 5.73 (s, 2H),
5.17–5.32 (m, 2H), 4.72 (td, J=12.2, 0.7 Hz, 1H), 4.56–4.71
(m, 2H), 4.10–4.15 (m, 2H), 3.91–4.06 (m, 1H), 1.75 (dq, J=
6.2, 1.1 Hz, 3H), 1.66–1.71 (m, 3H), 1.31 (d, J=6.4 Hz, 3H).
13C NMR (75 MHz, CDCl3), mixture isomers: d 12.92, 17.69,
21.27, 64.38, 66.08, 66.28, 70.41, 75.76, 116.31, 125.37, 125.85,
126.47, 127.26, 129.85, 139.84, 141.66.
4-(Butenyloxymethyl)pyridine: The products were synthe-
sized according to the general procedure for catalytic hydro-
alkoxylation of 1,3-butadiene with benzyl alcohol and deriv-
atives. The crude mixture gave 49% yield of the branched/
linear (Z/E) isomers as colorless liquid after flash column
chromatography on silica gel with petroleum ether/diethyl
1
ether: 20:80 eluent (Rf =0.4). H NMR (300 MHz, CDCl3),
mixture isomers: d 8.50 (dt, J=4.3, 1.7 Hz, 2H), 7.20 (d, J=
6.0 Hz, 2H), 5.63–5.79 (m, 2H), 5.50–5.63 (m, 1H), 5.09–
5.21 (m, 1H), 4.43 (dd, J=50.9, 13.6 Hz, 2H), 4.45 (s, 2H),
4.45 (s, 2H), 4.07 (d, J=6.6 Hz, 1H), 3.94 (dt, J=6.2,
0.8 Hz, 2H), 3.86 (dquin, J=0.6, 6.4 Hz, 1H), 1.68 (dd, J=
6.1, 1.0 Hz, 3H), 1.61 (dd, J=6.1, 0.7 Hz, 3H), 1.27 (d, J=
6.4 Hz, 3H). 13C NMR (75 MHz, CDCl3), mixture isomers: d
13.04, 17.61, 21.11, 30.14, 65.78, 68.03, 69.81, 71.28, 16.88,
116.46, 121.58, 121.63, 121.91, 126.05, 126.82, 128.44, 130.03,
139.44, 147.53, 147.88, 149.55, 151.08.
2-(Butenyloxy)methylfuran: The products were synthe-
sized according to the general procedure for catalytic hydro-
alkoxylation of 1,3-butadiene with benzyl alcohol and deriv-
atives. The crude mixture gave 75% yield of the branched/
linear (Z/E) isomers as yellow oil after flash column chro-
matography on silica gel with petroleum ether/diethyl ether:
1
60:40 eluent (Rf =0.8). H NMR (300 MHz, CDCl3), mixture
isomers: d 7.31–7.5 (m, 2H), 6.20–6.28 (m, 4H), 5.45–5.75
(m, 3H), 5.09–5.19 (m, 2H), 4.39–4.44 (m, 1H), 4.38 (s, 1H),
4.36 (s, 1H), 4.23–4.29 (m, 1H), 4.01 (d, J=6.0 Hz 1H),
3.80–3.92 (m, 2H), 1.56–1.68 (m, 3H), 1.19 (d, J=6.0, 3H).
13C NMR (75 MHz, CDCl3), mixture isomers: d 17.6, 21.17,
25.41, 25.51, 28.09, 28.21, 66.54, 68.17, 70.82, 70.92, 77.37,
78.03, 115.58, 115.61, 140.30.
2-(Butenyloxy)methyltetrahydrofuran: The products were
synthesized according to the general procedure for catalytic
hydroalkoxylation of 1,3-butadiene with benzyl alcohol and
derivatives. The crude mixture gave 13% yield of the
1-(Butenyloxymethyl)-3,5-dimethylbenzene: The products
were synthesized according to the general procedure for cat-
alytic hydroalkoxylation of 1,3-butadiene with benzyl alco-
hol derivatives. The crude mixture gave 10% yield of the
branched/linear (Z/E) isomers as colorless liquid after flash
column chromatography on silica gel with petroleum ether/
diethyl ether: 80:20 eluent (Rf =0.9). 1H NMR (300 MHz,
CDCl3), mixture isomers: d 7.00 (br. s, 2H), 6.95 (s, 1H),
118
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Adv. Synth. Catal. 2016, 358, 110 – 121

FULL PAPERS
Synthesis of Short-Chain Alkenyl Ethers
branched/linear (Z/E) isomers as yellow oil after flash
lation of 1,3-butadiene with bio-sourced derivatives. The
crude mixture gave 10% yield of the branched/linear (Z/E)
isomers as colorless liquid by flash column chromatography
on silica gel with petroleum ether/diethyl ether: 1:1 eluent
column chromatography on silica gel with petroleum ether/
1
diethyl ether: 60:40 eluent (Rf =0.64). H NMR (300 MHz,
CDCl3), mixture isomers: d 5.78–5.65 (m, 1H), 5.58–5.53 (m,
1H), 5.17–5.07 (m, 2H), 4.06–3.94 (m, 1H), 3.88–3.79 (m,
2H), 3.76–3.69 (m, 1H), 3.48–3.36 (m, 1H), 3.32–3.26 (m,
1H), 2.05–1.97 (m, 1H), 1.95–1.79 (m, 3H), 1.69–1.52 (m,
2H), 1.23 (dt, J=6.4, 1.3 Hz). 13C NMR (75 MHz, CDCl3),
mixture isomers: d 17.6, 21.17, 25.41, 25.51, 28.09, 28.21,
66.54, 68.17, 70.82, 70.92, 77.37, 78.03, 115.58, 115.61, 140.30.
1
(Rf =0.9). H NMR (300 MHz, CDCl3), mixture isomers: d
5.61–5.77 (m, 2H), 5.47–5.60 (m, 1H), 5.02–5.19 (m, 2H),
3.97–4.03 (m, 1H), 3.86 (dd, J=6.0, 0.8 Hz, 2H), 3.78 (quin,
J=6.5 Hz, 1H), 3.42–3.56 (m, 3H), 3.31–3.42 (m, 1H), 1.75–
1.88 (m, 2H), 1.68 (dd, J=6.2, 1.1 Hz, 3H), 1.61–1.66 (m,
1H), 1.20 (d, J=6.4 Hz, 3H). 13C NMR (75 MHz, CDCl3),
mixture isomers: d 13.03, 17.64, 21.13, 30.11, 30.24, 30.35,
65.15, 67.04, 67.20, 71.49, 76.76, 115.26, 127.03, 127.42,
127.66, 129.03, 140.44, 140.48. HRMS (EI) m/z [M+H]+:
calcd for C11H21O2: 185.1536; found: 185.1531.
4-(Butenoxymethyl)-2,2-dimethyl-1,3-dioxolane:
The
products were synthesized according to the general proce-
dure for catalytic hydroalkoxylation of 1,3-butadiene with
bio-sourced derivatives. The crude mixture gave 61% yield
of the branched/linear (Z/E) isomers as colorless liquid after
flash column chromatography on silica gel with petroleum
ether/diethyl ether: 1:1 eluent (Rf =0.3). 1H NMR
(300 MHz, CDCl3), mixture isomers: d 5.56–5.73 (m, 1H),
5.41–5.56 (m, 1H), 5.02–5.16 (m, 2H), 4.12–4.25 (m, 1H),
4.03 (d, J=7.0 Hz, 1H), 3.98 (dd, J=8.3, 6.4 Hz, 1H), 3.86–
3.92 (m, 2H), 3.73–3.84 (m, 2H), 3.60–3.72 (m, 2H), 3.20–
3.54 (m, 2H), 1.62–1.69 (m, 3H), 1.57–1.62 (m, 3H), 1.33–
1.38 (m, 6H), 1.29 (s, 6H), 1.18 (d, J=6.2 Hz, 3H).
13C NMR (75 MHz, CDCl3), mixture isomers: d 12.9, 17.5,
21.0, 21.0, 25.2, 25.2, 66.6, 67.0, 69.1, 69.2, 70.7, 70.9, 72.0,
74.6, 74.7, 74.7, 77.6, 109.1, 109.1, 109.0, 115.8, 115.8, 126.5,
127.2, 127.8, 129.5, 139.9. HRMS (EI) m/z [M+H]+: calcd
for C11H19O3: 187.1329; found: 187.1328.
4-(Butenoxy)butanol: The products were synthesized ac-
cording to the general procedure for catalytic hydroakoxyla-
tion of 1,3-butadiene with bio-sourced derivatives. The
crude mixture gave 53% yield of the branched/linear (Z/E)
isomers as colorless liquid after flash column chromatogra-
phy on silica gel with petroleum ether/diethyl ether: 1:1
1
eluent (Rf =0.3). H NMR (300 MHz, CDCl3), mixture iso-
mers: d 5.60–5.76 (m, 1H), 5.45–5.60 (m, 1H), 5.01–5.19 (m,
2H), 4.00 (d, J=6.4 Hz, 2H), 3.86 (d, J=6.2 Hz, 2H), 3.79
(quin, J=6.6 Hz, H), 3.58 (d, J=4.3 Hz, 2H), 3.37–3.51 (m,
2H), 3.22–3.35 (m, 2H), 2.94 (br. s. , 1H), 2.86 (br. s, 1H),
1.66 (dd, J=6.2, 0.9 Hz, 3H), 1.54–1.64 (m, 4H), 1.20 (d, J=
6.4 Hz, 3H). 13C NMR (75 MHz, CDCl3), mixture isomers: d
13.40, 17.99, 21.45, 27.03, 27.21, 30.41, 30.52, 62.81, 62.84,
66.41, 68.51, 70.32, 71.87, 77.39, 116.03, 127.01 127.73,
128.18, 129.77, 140.50. HRMS (EI) m/z [M+H]+: calcd for
C8H17O2: 145.1223; found: 145.1222.
2-(Butenyloxy)ethanol: The products were synthesized ac-
cording to general procedure for catalytic hydroalkoxylation
of 1,3-butadiene with bio-sourced derivatives. The crude
mixture gave 38% yield of the branched/linear (Z/E) iso-
mers as colorless liquid after flash column chromatography
on silica gel with petroleum ether/diethyl ether: 1:1 eluent
Characterization of alkenyl ethers
1
(Rf =0.3). H NMR (300 MHz, CDCl3), mixture isomers: d
(((3-Methylbut-3-en-2-yl)oxy)methyl)benzene: The products
were synthesized according to the general procedure for cat-
alytic hydroalkoxylation of 1,3-dienes with alcohols at 658C.
The crude mixture gave 73% yield of the branched major
isomer as colorless liquid after flash column chromatogra-
phy on silica gel with petroleum ether/ethyl acetate: 98:2
eluent (Rf =0.9). 1H NMR (300 MHz, CDCl3): d 7.35–7.36
(m, 5H), 4.94–4.96 (m, 2H), 4.48 (d, J=11.8 Hz, 1H), 4.27
(d, J=11.8 Hz, 1H), 3.91–3.97 (q, J=6.4 Hz, 1H), 1.72 (s,
3H), 1.30 (d, J=6.4 Hz, 3H). 13C NMR (75 MHz, CDCl3): d
16.6, 20.2, 69.8, 78.7, 112.6, 127.4, 127.7, 128.4, 138.8, 146.0.
HRMS (EI) m/z [M+H]+: calcd for C12H17O: 177.1274;
found: 177.1274.
5.58–5.78 (m, 1H), 5.43–5.58 (m, 1H), 5.01–5.18 (m, 1H),
3.97–4.07 (m, 1H), 3.88 (ddd, J=3.8, 2.4, 1.1 Hz, 1H), 3.74–
3.85 (m, 1H), 3.64 (br. s. , 2H), 3.42–3.55 (m, 2H), 3.31–3.40
(m, 2H), 2.89 (br. s. , 1H), 1.61–1.68 (m, 3H), 1.57–1.61 (m,
3H), 1.19 (dd, J=6.4, 3.8 Hz, 3H). 13C NMR (75 MHz,
CDCl3), mixture isomers: d 12.91, 17.47, 20.95, 61.46, 61.60,
66.16, 69.27, 70.93, 71.62, 77.17, 115.75, 126.46, 127.28,
127.79, 129.56, 138.88. HRMS (EI) m/z [M+H]+: calcd for
C6H13O2: 117.0910; found: 117.0919.
3-(Butenoxy)propanol: The products were synthesized ac-
cording to the general procedure for catalytic hydroalkoxy-
lation of 1,3-butadiene with bio-sourced derivatives. The
crude mixture gave 89% yield of the branched/linear (Z/E)
isomers as colorless liquid after flash column chromatogra-
phy on silica gel with petroleum ether/diethyl ether: 1:1
((Pent-3-en-2-yloxy)methyl)benzene: The products were
synthesized according to the general procedure for catalytic
hydroalkoxylation of 1,3-dienes with alcohols at 658C. The
crude mixture gave 19% yield of the linear isomers with Z/
E configuration as colorless liquid after flash column chro-
matography on silica gel with petroleum ether/ethyl acetate:
1
eluent (Rf =0.3). H NMR (300 MHz, CDCl3), mixture iso-
mers: d 5.54–5.71 (m, 1H), 5.38–5.53 (m, 1H), 4.97–5.14 (m,
2H), 3.96 (d, J=6.4 Hz, 1H), 3.78–3.86 (m, 2H), 3.63 (br. s,
2H), 3.48 (t, J=6.0 Hz, 1H), 3.16 (br. s., 1H), 1.66–1.79 (m,
2H), 1.62 (dd, J=6.2, 0.9 Hz, 3H), 1.58 (dd, J=7.5, 0.8 Hz,
3H), 1.15 (dd, J=6.4, 2.6 Hz, 3H). 13C NMR (75 MHz,
CDCl3), mixture isomers: d 12.87, 17.45, 20.99, 31.96, 32.02,
60.70, 61.03, 66.05, 68.16, 71.48, 77.02, 115.59, 126.47, 127.18,
127.65, 129.23, 139.85. HRMS (EI) m/z [M+H]+: calcd for
C7H15O2: 131.1067; found: 131.1075.
1
95:5 eluent (Rf =0.76). H NMR (300 MHz, CDCl3): d 7.28–
7.20 (m, 5H), 5.62–5.55 (m, 1H), 5.41–5.38 (m, 1H), 4.50 (d,
J=12.0 Hz, 1H), 4.31 (d, J=12.0 Hz, 1H), 3.82 (q, J=
6.2 Hz, 1H), 1.67 (dd, J=1.6, 6.4 Hz 3H), 1.58 (dd, J=2.0,
6.8 Hz, 3H), 1.21 (d, J=6.2 Hz, 3H), 1.20 (d, J=6.4 Hz,
3H). 13C NMR (75 MHz, CDCl3): d 18.0, 22.0, 70.0, 76.1,
127.6, 127.9, 128.0, 128.6, 133.3, 133.6, 139.4.
1,3-Di(butenoxy)propane: The products were synthesized
according to the general procedure for catalytic hydroakoxy-
(3-(Benzyloxy)but-1-en-1-yl)benzene: The products were
synthesized according to the general procedure for catalytic
Adv. Synth. Catal. 2016, 358, 110 – 121
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FULL PAPERS
Alexis Mifleur et al.
hydroalkoxylation of 1,3-dienes with alcohols at 658C. The
crude mixture gave 16% yield of the branched isomer as
colorless liquid after flash column chromatography on silica
gel with petroleum ether/ethyl acetate: 95:5 eluent (Rf =
0.44). 1H NMR (300 MHz, CDCl3): d 7.34–7.13 (m, 10H),
6.46 (d, J=15.9 Hz, 1H), 6.08 (dd, J=7.5, 15.9 Hz, 1H),
4.54 (d, J=12.0, 1H), 4.36 (d, J=12.0, 1H), 4.07–3.98 (m,
1H, 1.30 (d, J=6.1 Hz, 3H). 13C NMR (75 MHz, CDCl3): d
21.8, 70.1, 75.9, 126.6, 127.5, 127.8, 128.4, 128.7, 128.7, 131.5,
131.8.
[6] a) P. T. Anastas, J. C. Warner, Green Chemistry -
Theory and Practice, Oxford University Press, 1998;
b) P. T. Anastas, I. T. Horvµth, Chem. Rev. 2007, 107,
2167–2168; c) P. T. Anastas, Handbook of Green
Chemistry, Wiley-VCH, 2009.
[7] a) S. Radhakrishnan, G. Thoelen, J. Franken, J. De-
gr›ve, C. E. A. Kirschhock, J. A. Martens, ChemCat-
Chem 2013, 5, 576–581; b) D. C. Rosenfeld, S. Shekhar,
A. Takemiya, M. Utsunomiya, J. F. Hartwig, Org. Lett.
2006, 8, 4179–4182; c) Z. Li, J. Zhang, C. Brouwer, C.-
G. Yang, N. W. Reich, C. He, Org. Lett. 2006, 8, 4175–
4178; d) L. Coulombel, E. DuÇach, Green Chem. 2004,
6, 499–501; e) P. J. Linares-Palomino, S. Salido, J. Altar-
ejos, A. Sµnchez, Tetrahedron Lett. 2003, 44, 6651–6655.
[8] a) K. M. Gligorich, M. J. Schultz, M. S. Sigman, J. Am.
Chem. Soc. 2006, 128, 2794–2795; b) H. Qian, X. Han,
R. A. Widenhoefer, J. Am. Chem. Soc. 2004, 126, 9536–
9537; c) C.-G. Yang, N. W. Reich, Z. Shi, C. He, Org.
Lett. 2005, 7, 4553–4556; d) J. G. Taylor, N. Whittall,
K. K. Hii, Chem. Commun. 2005, 5103–5105; e) M. J.-L.
Tschan, C. M. Thomas, H. Strub, J.-F. Carpentier, Adv.
Synth. Catal. 2009, 351, 2496–2504; f) D. H. Camacho,
I. Nakamura, S. Saito, Y. Yamamoto, Angew. Chem.
1999, 111, 3576–3578; Angew. Chem. Int. Ed. 1999, 38,
3365–3367.
(((7-Methyl-3-methyleneoct-6-en-2-yl)oxy)methyl)ben-
zene: The products were synthesized according to the gener-
al procedure for catalytic hydroalkoxylation of 1,3-dienes
with alcohols at 808C. The crude mixture gave 10% yield of
the branched isomer as colorless liquid after flash column
chromatography on silica gel with petroleum ether/ethyl
1
acetate: 95:5 eluent (Rf =0.47). H NMR (300 MHz, CDCl3):
d 7.26–7.38 (m, 5H), 5.49–5.59 (m, 1H), 5.43 (td, J=1.2,
6.7 Hz, 1H), 5.10–5.19 (m, 3H), 4.47–4.54 (m, 2H), 4.34 (s,
2H), 4.30 (s, 2H), 4.01–4.07 (m,1H), 3.92–3.98 (m,2H),
2.03–2.24 (m, 4H), 1.56–1.78 (m, 9H), 1.31 (d, J=6.4 Hz,
3H). 13C NMR (75 MHz, CDCl3): d 17.1, 20.6, 25.7, 26.5,
30.3, 39.66, 66.6, 69.9, 71.4, 74.6, 76.6, 110.8, 124.2, 127.3,
127.5, 127.6, 127.7, 127.8, 128.3, 150.1. HRMS (EI) m/z [M+
H]+: calcd for C17H25O: 245.1900; found: 245.1899.
[9] a) M. Kondo, T. Kochi, F. Kakiuchi, J. Am. Chem. Soc.
2011, 133, 32–34; For a review, see: b) N. Huguet,
A. M. Echavarren, Top. Organomet. Chem. 2013, 43,
291–324; c) A. Zhanko, M. E. Maier, Chem. Eur. J.
2014, 20, 1918–1930.
Acknowledgements
[10] Z. Zhang, R. A. Widenhoefer, Org. Lett. 2008, 10,
2079–2081.
[11] a) T. Shimasaki, Y. Konno, M. Tobisu, N. Chatani, Org.
Lett. 2009, 11, 4890–4892; b) D. K. Whelligan, D. W.
Thomson, D. Taylor, S. Hoelder, J. Org. Chem. 2010,
75, 11–15.
We are grateful to the Region Nord-Pas de Calais for A. Mi-
fleurꢀs fellowship. Chevreul institute (FR 2638), Minist›re de
lꢀEnseignement SupØrieur et de la Recherche, Institut Univer-
sitaire de France, RØgion Nord – Pas de Calais and FEDER
are acknowledged for supporting and funding this work.
[12] a) S. Takahashi, T. Shibano, N. Hagihara, Tetrahedron
Lett. 1967, 8, 2451–2453; b) A. Behr, M. Becker, T.
Beckmann, L. Johnen, J. Leschinski, S. Reyer, Angew.
Chem. 2009, 121, 3652–3669; Angew. Chem. Int. Ed.
2009, 48, 3598–3614.
[13] a) F. Benvenuti, C. Carlini, M. Lami, M. Marchionna,
R. Patrini, A. M. R. Galletti, G. Sbrana, J. Mol. Catal.
A 1999, 144, 27–40; b) M. J.-L. Tschan, E. J. García-
Suµrez, Z. Freixa, H. Launay, H. Hagen, J. Benet-Buch-
holz, P. W. N. M. van Leeuwen, J. Am. Chem. Soc. 2010,
132, 6463–6473.
[14] a) N. D. Clement, L. Routaboul, A. Grotevendt, R.
Jackstell, M. Beller, Chem. Eur. J. 2008, 14, 7408–7420;
b) J. Mesnager, P. Lammel, E. Jeanneau, C. Pinel,
Appl. Catal. A 2009, 368, 22–28; c) A. Grotevendt, R.
Jackstell, D. Michalik, M. Gomez, M. Beller, ChemSus-
Chem 2009, 2, 63–70.
[15] a) R. Mülhaupt, Macromol. Chem. Phys. 2003, 204,
289–327; b) M. Zintl, B. Rieger, Angew. Chem. 2007,
119, 337–339; Angew. Chem. Int. Ed. 2007, 46, 333–335;
c) C. L. Edwards, US 20050038305, 2005; d) C. L. Ed-
wards, US 20050037940, 2005.
References
[1] a) T. W. Greene, P. G. M. Wuts, Protective Groups in
Organic Synthesis, 3rd ed., John Wiley & Sons, 1999,
p. 67–74; b) F. GuibØ, Tetrahedron 1997, 53, 13509–
13556; c) P. A. Gent, R. Gigg, R. Conant, J. Chem. Soc.
Perkin Trans. 1 1972, 1535–1542.
[2] A. Liptak, A. Borbµs, I. Bajza, in: Comprehensive Gly-
coscience: From Chemistry to Systems Biology, Vol.
1 (Ed.: J. P. Kamerling), Elsevier, 2007, pp 222–225.
[3] a) G.-J. Boons, S. Isles, Tetrahedron Lett. 1994, 35,
3593–3596; b) P. A. Gent, R. Gic, J. Chem. Soc. Chem.
Commun. 1974, 277–278; c) M. Sauthier, A. Mortreux,
I. Suisse, in: Carbohydrate Chemistry, Vol. 40 (Eds.: A.
P. Rauter, T. Lindhorst, Y. Queneau), Royal Society of
Chemistry, 2014, pp 73–98.
[4] a) A. CommerÅon, M. Bourgain, M. Delaumeny, J. F.
Normant, J. Villieras, Tetrahedron Lett. 1975, 16, 3837–
3840; b) A. Eleutario, T. Cuvigny, M. Julia, J. Organo-
met. Chem. 1988, 339, 199–212; c) H. Kiuchi, D. Taka-
hashi, K. Funaki, T. Sato, S. Oi, Org. Lett. 2012, 14,
4502–4505.
[16] a) I. Pennequin, J. Meyer, I. Suisse, A. Mortreux, J.
Mol. Catal. A 1997, 120, 139–142; b) S. Bigot, J. Lai, I.
Suisse, M. Sauthier, A. Mortreux, Y. Castanet, Appl.
Catal. A 2010, 382, 181–189; c) C. Damez, B. Estrine,
[5] J. V. Crivello, B. Yang, J. Polym. Sci. Part A 1995, 33,
1381–1389.
120
asc.wiley-vch.de
ꢀ 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Adv. Synth. Catal. 2016, 358, 110 – 121

FULL PAPERS
Synthesis of Short-Chain Alkenyl Ethers
A. Bessmertnykh, S. Bouquillon, F. HØnin, J. Mol.
Catal. A 2006, 244, 93–98; d) B. Estrine, S. Bouquillon,
F. HØnin, J. Muzart, Eur. J. Org. Chem. 2004, 13, 2914–
2922; e) B. Estrine, S. Bouquillon, F. HØnin, J. Muzart,
Green Chem. 2005, 7, 219–223; f) C. Hadad, C. Damez,
S. Bouquillon, B. Estrine, F. HØnin, J. Muzart, I.
Pezron, L. Komunjer, Carbohydr. Res. 2006, 341, 1938–
1944; g) S. Bouquillon, C. R. Chimie 2011, 14, 716–725;
for a review concerning bio-butadiene: h) E. V. Mak-
shina, M. Dusselier, W. Janssens, J. Degr›ve, P. A.
Jacobs, B. F. Sels, Chem. Soc. Rev. 2014, 43, 7917–7953.
[17] K. C. Dewhirst, J. Org. Chem. 1967, 32, 1297–1300.
[18] E. J. Smutny, J. Am. Chem. Soc. 1967, 89, 6793–6794.
[19] R. Patrini, M. Lami, M. Marchionna, F. Benvenuti,
A. M. Raspolli Galletti, G. Sbrana, J. Mol. Catal. A
1998, 129, 179–189.
[22] S. Bigot, M. S. I. El Alami, A. Mifleur, Y. Castanet, I.
Suisse, A. Mortreux, M. Sauthier, Chem. Eur. J. 2013,
19, 9785–9788.
[23] V. P. Ananikov, K. A. Gayduk, Z. A. Starikova, I. P. Be-
letskaya, Organometallics 2010, 29, 5098–5102.
[24] a) P. W. Jolly, in: Comprehensive Organometallic
Chemistry, Vol. 8 (Eds.: G. Wilkinson, F. G. A. Stone,
E. W. Abel), Pergamon, pp 671–712; b) P. Denis, A.
Mortreux, F. Petit, G. Buono, G. Peiffer, J. Org. Chem.
1984, 49, 5274–5276.
[25] It has been previously reported that the L12 (Binap)
ligand leads to no activity for the ethoxylation reaction
of butadiene. This result was obtained with the
Ni(acac)2/NaBH4 combination as metal precursor.
However, with the present reaction conditions using
low valent Ni(cod)2 precursor, a moderate conversion
of butadiene could be obtained (44%).
[20] V. Rodriguez-Ruiz, R. Carlino, S. Bezzenine-LafollØe,
R. Gil, D. Prim, E. Schulz, J. Hannedouche, Dalton
Trans. 2015, 44, 12029–12059.
[21] a) D. Commerenc, Y. Chauvin, Bull. Soc. Chim. Fr.
1974, 3–4, 652–656; b) F. J. Weigert, W. C. Drinkard, J.
Org. Chem. 1973, 38, 335–337.
[26] a) M. Besson, P. Gallezot, C. Pinel, Chem. Rev. 2014,
114, 1827–1870; b) P. Lanzafame, G. Centi, S. Perathon-
er, Chem. Soc. Rev. 2014, 43, 7562–57580.
Adv. Synth. Catal. 2016, 358, 110 – 121
ꢀ 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
asc.wiley-vch.de
121