Cadmium(II) Chloride-Catalyzed Dehydrative C?P Coupling of Propargyl Alcohols with Diarylphosphine Oxides to Afford Allenylphosphine Oxides

Article abstract of DOI:10.1002/adsc.201700957

The cadmium(II) chloride-catalyzed dehydrative C?P cross-coupling reaction of propargyl alcohols with diarylphosphine oxides is reported. Several propargyl alcohols including those bearing the sterically demanding tert-butyl group at the triple bond terminus can be used as good substrates in the reaction to produce the corresponding allenylphosphine oxides in good to high yields in acetonitrile at 100 °C. The reaction can also be easily scaled up to a gram-scale synthesis. A mechanism study indicates that the reaction may proceed through a process of propargylic substitution to generate phosphonite intermediates followed by [2,3] sigmatropic rearrangement to produce the allenyl products, rather than through a common allenylative substitution resulting from P-nucleophilicity. (Figure presented.).

Full text of DOI:10.1002/adsc.201700957

Title: Cadmium(II) Chloride-Catalyzed Dehydrative C-P Coupling
of Propargyl Alcohols with Diarylphosphine Oxides to Afford
Allenylphosphine Oxides
Authors: Jianlin Yang, Ming Zhang, Kang Qiu, Lize Wang, Jingjing Yu,
Zefeng Xia, Ruwei Shen, and Li-Biao Han
This manuscript has been accepted after peer review and appears as an
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To be cited as: Adv. Synth. Catal. 10.1002/adsc.201700957
Link to VoR: http://dx.doi.org/10.1002/adsc.201700957

10.1002/adsc.201700957
Advanced Synthesis & Catalysis
UPDATE
DOI: 10.1002/adsc.201((will be filled in by the editorial staff))
Cadmium(II) Chloride-Catalyzed Dehydrative C-P Coupling of
Propargyl Alcohols with Diarylphosphine Oxides to Afford
Allenylphosphine Oxides
Jianlin Yang,a Ming Zhang,a Kang Qiu,a Lize Wang,b Jingjing Yu,b Zefeng Xia,b Ruwei
Shen,*a,b Li-Biao Hanc
aState Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech
University, Nanjing 210009, China. E-mail: shenrw@njtech.edu.cn
bCollege of Oversea Education, Nanjing Tech University, Nanjing 210009, China
cNational Institute of Advanced Industrial Science & Technology (AIST), Tsukuba, Ibaraki, 305-8565, Japan.
Received: ((will be filled in by the editorial staff))
Supporting information for this article is available on the WWW under http://dx.doi.org/10.1002/adsc.201######.((Please
delete if not appropriate))
compounds is through the Horner-Mark [2,3]-
rearrangement reaction which was developed in
1960s.[6] However, this method requires the use of
moisture-sensitive and highly toxic phosphorus
halides, and often suffers from low yields, harsh
conditions and limited scope. These drawbacks thus
stimulate the search for new alternative mild methods.
Stawinski[7] and our group[8] have developed several
effective catalytic transformations of P(O)H
compounds with propargylic compounds such as
propargylic halides, acetates and epoxides to afford
allenylphosphoryl compounds in high yields with
high selectivity.
On the other hand, the catalytic dehydrative
coupling reaction of a C-OH bond with a Nu-H bond
has recently emerged as a powerful tool to construct
new C-C and C-heteroatom bonds.[9-11] The
methodology is synthetically appealing as it employs
readily available and low-cost alcohols without the
need for wasteful prefunctionalization and principally
generates water as the sole byproduct. Accordingly, a
more direct and ideal method for the synthesis of
phosphoryl allenes would be a catalytic dehydrative
C-P coupling of propargyl alcohols with the stable
and readily available P(O)H compounds. In this
aspect, Nishibayashi first demonstrated in a study the
Ru-catalyzed dehydrative propargylic substitution of
propargyl alcohols with Ph2P(O)H to provide
propargyl phosphine oxides (Scheme 1a).[12]
Mechanistically, the reaction takes place as a result of
the nucleophilic attack of the phosphorus atom to the
C3 atom of the Ru-allenylidene intermediate.[12b] The
resultant propargyl phosphine oxides could undergo a
facile alkyne-allene isomerization under their
conditions to generate phosphoryl allenes for further
transformations.[12c,12d] The direct synthesis of
phosphoryl allenes via a dehydrative C-P coupling
protocol has been realized very recently by the
groups of Zhao and Yang independently, using
Cu(OTf)2 and AgOTf as the catalysts (Scheme 1b).[13]
Abstract: The cadmium(II) chloride-catalyzed dehydrative
C-P cross-coupling reaction of propargyl alcohols with
diarylphosphine oxides is reported. Several propargyl
alcohols including those bearing the sterically demanding
tert-butyl group at the triple bond terminus can be used as
good substrates in the reaction to produce the
corresponding allenylphosphine oxides in good to high
o
yields in acetonitrile at 100 C. The reaction can also be
easily scaled up to a gram-scale synthesis. A mechanism
study indicates that the reaction may proceed through a
process of propargylic substitution to generate phosphonite
intermediates followed by [2,3] sigmatropic rearrangement
to produce the allenyl products, rather than through a
common allenylative substitution resulting from P-
nucleophilicity.
Keywords: allenylphosphoryl compound; dehydration;
organophosphorus; propargyl alcohol; selectivity
Introduction
Organophosphorus compounds are of fundamental
importance in organic synthesis and catalysis, and
also have wide utility in biology, agrochemistry and
material science.[1] Phosphoryl allenes are amongst a
special class of P-functionalized unsaturated
compounds that have received significant attention in
recent years.[2-5] Indeed, the properties arising from
the unique allenic structure and the phosphorus
functionality render them valuable intermediates in
many synthetic applications, such as the formation of
highly functionalized olefins via selective additions
with electrophiles or nucleophiles,[2] chiral
organophosphorus compounds via transition metal-
catalyzed asymmetric additions,[3] and other
structurally sophisticated phosphorus compounds via
Diels–Alder or other related cyclizations.[4,5]
traditional and universal preparation of these
A
1
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10.1002/adsc.201700957
Advanced Synthesis & Catalysis
Scheme 1. Transition metal-catalyzed dehydrative C-P cross coupling reactions of propargyl alcohols with P(O)H
compounds.
Both the reactions were believed to proceed via the
attack of the phosphorus atom to the C3 atom of the
allenic carbon cation (in resonance with the
corresponding propargylic carbon cation) to form the
C-P bond based on the P-nucleophility of the P(O)H
compounds. Thus, low yields were often observed for
substrates bearing R1 as the sterically hindered group.
As our recent advance in this area,[7] here we report
a CdCl2-catalyzed dehydrative coupling of propargyl
alcohols with P(O)H compounds (Scheme 1c). A
remarkable feature of this reaction is the good
compatibility of propargyl alcohols that bear
sterically demanding substituents at the triple bond
terminus (C3) as substrates to produce the allenyl
products in high yields. More intriguingly, a
mechanism study reveals that the reaction may
proceed as a process of propargylic substitution of
propargyl alcohols by R2P(O)H based on their O-
nucleophilicity to form phosphonite intermediates
followed by [2,3] sigmatropic rearrangement to
produce the allenyl products, rather than as the
common allenylative substitution resulting from P-
nucleophilicity.[7,12,13] To our knowledge, such a
distinct reactivity is seldom demonstrated.
Our study began with examination on the reaction of
3-tert-butyl-1-phenylprop-2-yn-1-ol (1a) as the
alcohol partner and Ph2P(O)H (2a) as the nucleophile
using zinc salts as catalysts. We initially questioned
whether the steric hindrance of the big t-Bu
substituent at C3 in 1a would trigger the occurring of
the C-P bond formation event at C1. Unfortunately,
initial experiments showed that ZnCl2 and Zn(OTf)2
were both ineffective to promote the reaction (Table
1, entries 1 and 2). To our surprise, when CdCl2, a
similar group 12 inorganic metallic salt, was used, the
reaction afforded allenyl product 3a in 62% yield
(Table 1, entry 3). The reaction demonstrated
excellent regioselectivity as the 31P NMR
spectroscopy of the crude product shows only one
new peak at 29.2 ppm assigned to be 3a. With these
encouraging results, we then examined the catalytic
activity of two other commercially available Cd salts.
The reaction catalyzed by CdI2 proceeded more
quickly but the yield was low due to the formation of
some unidentified byproducts of large polarity (Table
1, entry 4). However, Cd(OAc)2 was proved
ineffective (Table 1, entry 5). Using CdCl2 as the
catalyst, the solvent effect was investigated (Table 1,
entries 6-11). The results show that the solvent also
Results and Discussion
2
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10.1002/adsc.201700957
Advanced Synthesis & Catalysis
Table 1. Effect of the catalysts and solvents on the
dehydrative C-P coupling reaction of 1a and 2a.[a]
Table 2. CdCl2-catalyzed C-P coupling of propargyl
alcohols with diarylphosphine oxides. [a]
run
M
solvent
time (h)
3a, yield (%)b
1
2
ZnCl2
Zn(OTf)2
CdCl2
DCE
DCE
12
12
12
4
trace
trace
62
36
0
3
DCE
4
CdI2
DCE
5
Cd(OAc)2
CdCl2
DCE
12
12
12
12
12
12
12
16
24
6
toluene
THF
trace
0
7
CdCl2
8
CdCl2
Dioxane
MeCN
DMF
0
9
CdCl2
CdCl2
85
0
10
11
12
13
CdCl2
DMSO
MeCN
MeCN
0
[c]
CdCl2
80
58
[d]
CdCl2
[a]Conditions: 1a (0.24 mmol), 2a (0.2 mmol), [M] (10
mol%), solvent (2 mL).
[b]Isolated yields.
[c] 5 mol% of the catalyst was used.
[d] 1 mol% of the catalyst was used.
has a significant influence on the outcome of the
reaction. The best result was obtained when MeCN
was used as the solvent; A very clean transformation
was observed and 3a was obtained in 85% yield
(Table 1, entry 9). However, all the other solvents we
checked gave negative results. For example, the
reaction performed in toluene generated a very
complex mixture and only a trace amount of the
product was detected (Table 1, entry 6). When the
reaction was performed in THF or dioxane, propargyl
alcohol 1a decomposed and 3a was not formed
(Table 1, entries 7 and 8). When DMF or DMSO was
used as the solvent, no reaction took place (Table 1,
entries 10 and 11). Furthermore, we also checked the
effect of the catalyst loading on the reaction. When
the reaction was conducted in the presence of 5 mol%
of CdCl2, the reaction gave rise to the product 3a in
80% yield in 16 h (Table 1, entry 12). Further
decrease in the catalyst loading to 1 mol% led to a
reduced yield to 58% in 24 h (Table 1, entry 13).
Table 2 shows the results of the CdCl2-catalyzed
dehydrative C-P coupling reactions of a variety of
propargyl alcohols with diarylphosphine oxides under
the optimal conditions. Thus, propargyl alcohols 1
bearing haloaryl substituents reacted cleanly with 2a,
producing the corresponding allenyl products 3b-3f
highly selectively. The yields (3b-3d) were generally
[a]Conditions: 1 (0.24 mmol), 2 (0.2 mmol), CdCl2 (10
mol%) in MeCN (2 mL). Isolated yields are given.
[b]Combined yields of a mixture of the allenyl and
propargyl products.
[c] 3g/3g’ = 4/1.
[d] 3h/3h’ = 2/1.
[e] 3m/3m’ = 1.5/1.
[f] ca. 40−60% of 2a recovered.
3
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10.1002/adsc.201700957
Advanced Synthesis & Catalysis
high for substrates bearing para-substituted phenyl
groups, while substrates with ortho-substituted
phenyl groups gave moderate yields (3e and 3f). The
reactions of 3-butyl-1-arylprop-2-yn-1-ols with 2a
also took place smoothly to selectively produce the
allenyl products 3i-3l in good to high yields.
However, the use of alcohols bearing electron-rich
phenyl groups at C1 afforded mixtures of allenyl and
propargyl products likely due to electronic effect. For
example, the reaction of 1-(4-methoxyphenyl)-4,4-
dimethylpent-2-yn-1-ol (1g) with 2a produced a
mixture of 3g and 3g’ with a ratio of 4/1. Mixture of
products were also obtained from the reactions of 1-
(2-methoxyphenyl)-4,4-dimethylpent-2-yn-1-ol (1h)
and 1-(3,5-dimethylphenyl)hept-2-yn-1-ol (1m) with
2a. On the other hand, the use of 1,1-disubstituted
propynols also resulted in the formation of the allenyl
products 3n-3q, but in low yields due to the
methods by its effectiveness for both substrates 1a
and 1i bearing different sterically demanding groups
at the C3 position (t-Bu vs n-Bu). However,
significant loss of product yields was observed in
reactions of 1a and 2a promoted by the Cu and Ag
catalysts. This obvious difference led us to the
assumption that the present reaction should proceed
via a different mechanism from the Cu or Ag
catalysis.
decomposition
of
the
propargyl
alcohols.
Furthermore, 1-phenylprop-2-yn-1-ols bearing
a
phenyl or cyclopropanyl substituent at C3 both
successfully gave the expected products 3r and 3t in
good yields. However, no reaction took place when
undec-6-yn-5-ol (1s) was employed because of its
low reactivity. The present reaction could be applied
to other diarylphosphine oxides.[14] Typical substrates
bearing electron-donating and electron-withdrawing
substitutes on the phenyl rings were all proved as
good substrates to provide the expected products 3u,
3v, 3w and 3y in high yields, but 2e bearing two o-
tolyl groups gave 3x in a low yield due to the steric
effect. The obtained products were characterized by
1H, 13C and 31P NMR, HRMS, and the sturcture of 3y
was further confirmed by X-ray crystallography.[15]
The present reaction can be easily scaled up for a
gram-scale synthesis (Scheme 2). For example, the
reaction of 1c and 2a performed on a 4.5 mmol scale
in 10 mL of MeCN afforded 1.546 g of 3c (88%)
using 10 mol% of the catalyst. When 5 mol% of the
catalyst was employed, the reaction still took place
smoothly and 1.524 g of 3c was obtained.
Figure 1. The steric effect: a comparison on the
performance of Cd, Cu and Ag catalysts for the
dehydrative C-P coupling reactions of 1a/2a and 1i/2a.
In order to gain more insight into the mechanism,
some competition experiments were then conducted
and noted as follows. 1) The reaction of 1a, 1i and 2a
with equal molar amount was performed under the
catalytic conditions. Analysis of the crude reaction
mixture by 31P NMR shows that 3a and 3i were
formed in a ratio of 1/0.99 in a combined yield of 95%
(Scheme 3, eq. 1). This result indicates that the steric
effect at C3 has no influence on the reaction. [16] 2) In
comparison, the reaction is sensitive to steric effect of
the substitute at C1. Thus, the treatment of an equal
molar amount of 1d, 1e and 2a with the catalyst
resulted in the formation of 3d and 3e in a ratio of
2.10/1 (Scheme 3, eq. 2). When mixed substrates (1j
and 1k) bearing the small fluorine atom were
examined, 3j and 3k were formed in a ratio of 1.15/1
(Scheme 3, eq. 3). 3) Another noteworthy observation
arose from the competition reaction of 1a, 2c and 2d
that gave a mixture of products in favor of the
formation of 3v (3v/3w = 2.09/1, Scheme 3, eq. 4).
This result suggests that Ar2P(O)H bearing electron-
withdrawing groups reacts preferentially to form the
product, contradicting the level of their nucleophilic
ability. 4) The reaction of an equal molar amount of
1a, 2a and 2e led to the formation of 3a
predominately (Scheme 3, eq. 5). This result is
expectable considering the steric effect of the P(O)H
compounds.
Scheme 2. The gram-scale synthesis of 3c.
Figure 1 shows a comparison on the performance
of the Cd catalyst with the known Cu and Ag
catalysts on the reactions of 1a or 1i with 2a. Clearly,
the present reaction is distinguished from the known
4
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10.1002/adsc.201700957
Advanced Synthesis & Catalysis
Scheme 3. Competition experiments for a mechanism study (for details, see the Supporting Information).
Based on these observations, we proposed a
possible mechanism as shown in Scheme 4. The
coordination of CdCl2 to alcohol 1 may activate and
enable the cleavage of the C-O bond to generate the
carbon cation B and [Cd(OH)Cl2] anion C.[17]
Ar2P(O)H 2 is in equilibrium with its tautomer 2’
(Scheme 3a),[18] and may react with C to form
[Cd(OPAr2)Cl2] anion D. The reaction of B and D
then produces a propargyl phosphonite intermediate
E, which undergoes the classical [2,3]-rearrangement
to give the allenyl product 3 (Scheme 4b). It is
noteworthy that the introduction of electron-
withdrawing groups in 2 generally leads to a shift in
equilibrium towards 2’ and increases the acidity of 2’
(Scheme 4a), thus enhancing its reactivity to the
reaction with C.[18a] This fact accounts for the
preferred formation of 3v in the competition reaction
Scheme 4. (a) Tautomeric equilibrium between 2 and 2’;
of 1a, 2c and 2d (Scheme 3, eq. 4). On other hand,
(b) The proposed mechanism.
the differentitation of the intermediates B due to the
electronic effect of the substitutes at C1 should have
an important influence on the selectivity of the
Conclusion
reaction as experimentally observed from the
reactions of 1g, 1h and 1m. The reasons for this
unexpected result are unclear at present and need
further study.
In conclusion, we have disclosed a CdCl2-
catalyzed dehydrative C-P cross-coupling reaction of
5
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10.1002/adsc.201700957
Advanced Synthesis & Catalysis
131.3 (d, JP-C = 7.4 Hz), 131.2 (d, JP-C = 9.6 Hz), 128.7,
128.3 (d, JP-C = 13.0 Hz), 128.0 (d, JP-C = 12.0 Hz), 127.6
propargyl alcohols with P(O)H compounds. A
remarkable advantage of the reaction is the good
applicability of propargyl alcohols that bear sterically
demanding substituents at the triple bond terminus to
provide products in high yields. The reaction may
involve a process of propargylic substitution in favor
of a distinct and high level of O-nucleophilic
selectivity to form phosphonite intermediates
followed by [2,3] rearrangement to selectively give
the allenyl products. Further investigation into the
reaction scope and detailed mechanism will be
pursued.
(d, JP-C = 2.4 Hz), 112.5 (d, JP-C = 93.8 Hz), 96.6 (d, JP-C
=
14.1 Hz), 37.5 (d, JP-C = 4.8 Hz), 30.8 (d, JP-C = 3.1 Hz).
31P NMR (CDCl3, 162 MHz): δ = 29.0. HRMS (ESI-TOF):
m/z = 407.1305, calcd for C25H25ClOP [MH+] 407.1332.
(1-(4-Fluorophenyl)-4,4-dimethylpenta-1,2-dien-3-yl)
diphenylphosphine oxide (3c). 76.2 mg (yield 96%),
prepared from 49.5 mg of 1c (0.24 mmol) and 40.4 mg of
1
2a (0.2 mmol) in 2 mL MeCN. H NMR (CDCl3, 400
MHz): δ = 7.81–7.76 (m, 2H), 7.64–7.59 (m, 2H), 7.55–
7.51 (m, 1H), 7.48–7.43 (m, 2H), 7.32–7.27 (m, 1H), 7.24–
7.19 (m, 2H), 6.97–6.90 (m, 4H), 6.02 (d, J = 11.2 Hz, 1H),
1.35 (s, 9H). 13C NMR (CDCl3, 100 MHz): δ = 208.9 (dd,
JP-C = 6.9 Hz, JF-C = 2.2 Hz), 162.0 (dd, JF-C = 245.9 Hz,
JP-C = 1.7 Hz), 133.8 (d, JP-C = 106.3 Hz), 133.3 (d, JP-C
=
103.4 Hz), 131.6 (d, JP-C = 2.6 Hz), 131.4 (d, JP-C = 9.4 Hz),
131.26 (d, JP-C = 9.4 Hz), 131.23 (d, JP-C = 3.2 Hz), 128.6
(dd, JF-C = 6.5 Hz, JP-C = 2.6 Hz), 128.2 (d, JP-C = 13.0 Hz),
Experimental Section
127.84 (d, JF-C = 7.8 Hz, JP-C = 2.2 Hz), 127.78 (d, JP-C
=
9.3 Hz), 115.4 (d, JP-C = 22.7 Hz), 112.1 (d, JP-C = 94.0 Hz),
96.5 (d, JP-C = 14.3 Hz), 37.4 (d, JP-C = 5.5 Hz), 30.7 (d, JP-
C = 4.1 Hz). 31P NMR (CDCl3, 162 MHz): δ = 29.3. HRMS
(ESI-TOF): m/z = 391.1632, calcd for C25H25FOP [MH+]
391.1627.
General Information
Unless otherwise specified, all reactions were performed
under dry N2 atmosphere. Anhydrous solvents were
distilled prior to use: THF, dioxane and toluene were
distilled from sodium using benzophenone as the indicator;
MeCN, DCE, DMF and DMSO were distilled from CaH2.
Propargyl alcohols 1a-1t were prepared following a
procedure reported by Hailes.[19] A typical procedure was
given in the Supporting Information (Page 8 in SI).
(1-(4-Bromophenyl)-4,4-dimethylpenta-1,2-dien-3-yl)
diphenylphosphine oxide (3d). 86.3 mg (yield 96%),
prepared from 64.1 mg of 1d (0.24 mmol) and 40.4 mg of
1
2a (0.2 mmol) in 2 mL MeCN. H NMR (CDCl3, 400
MHz): δ = 7.79–7.73 (m, 2H), 7.62–7.57 (m, 2H), 7.54–
7.43 (m, 3H), 7.34–7.27 (m, 3H), 7.24–7.20 (m, 2H), 6.84
(d, J = 8.0 Hz, 2H), 5.97 (d, J = 11.2 Hz, 1H), 1.33 (s, 9H).
13C NMR (CDCl3, 100 MHz): δ = 208.9 (d, JP-C = 7.1 Hz),
133.7 (d, JP-C = 105.5 Hz), 133.3 (d, JP-C = 103.1 Hz),
131.8 (d, JP-C = 7.3 Hz), 131.65 (d, JP-C = 2.5 Hz), 131.58
Diarylphosphine oxides
2
were purchased from
commercial sources or prepared following known method.
[8a]
Flash chromatography was performed on silica gel
using petroleum ether and EtOAc as eluent. 1H, 13C and 31
NMR spectra were recorded on a 400 MHz spectrometer.
Chemical shifts (ppm) were recorded with
P
(d, JP-C = 1.7 Hz), 131.4 (d, JP-C = 9.4 Hz), 131.3 (d, JP-C
=
2.8 Hz), 131.2 (d, JP-C = 9.5 Hz), 128.2 (d, JP-C = 12.6 Hz),
127.9 (d, JP-C = 8.3 Hz), 127.8 (d, JP-C = 1.4 Hz), 120.9 (d,
tetramethylsilane (TMS) as the internal reference standard.
Chemical shifts are expressed in ppm and J values are
given in Hz. HRMS analysis of the products was obtained
from the Analytical Center of State Key Laboratory of
Materials-Oriented Chemical Engineering at Nanjing Tech
University.
JP-C = 1.7 Hz), 112.5 (d, JP-C = 93.6 Hz), 96.5 (d, JP-C
=
14.0 Hz), 37.5 (d, JP-C = 5.0 Hz), 30.8 (d, JP-C = 3.9 Hz).
31P NMR (CDCl3, 162 MHz): δ = 29.1. HRMS (ESI-TOF):
m/z = 451.0798, calcd for C25H25BrOP [MH+] 451.0826.
(1-(2-Bromophenyl)-4,4-dimethylpenta-1,2-dien-3-yl)
diphenylphosphine oxide (3e). 74.0 mg (yield 78%),
prepared from 80.1 mg of 1e (0.3 mmol) and 41.5 mg of 2a
(0.21 mmol) in 2 mL MeCN. 1H NMR (CDCl3, 400 MHz):
δ = 7.81–7.76 (m, 2H), 7.60–7.40 (m, 6H), 7.29–7.25 (m,
1H), 7.20–7.14 (m, 3H), 7.08 (d, J = 7.2 Hz, 1H), 7.03–
6.99 (m, 1H), 6.47 (d, J = 11.2 Hz, 1H), 1.34 (s, 9H). 13C
NMR (CDCl3, 100 MHz): δ = 209.3 (d, JP-C = 7.4 Hz),
133.5 (d, JP-C = 106.7 Hz), 133.1 (d, JP-C = 102.4 Hz),
132.8, 132.4 (d, JP-C = 7.7 Hz), 131.7 (d, JP-C = 3.3 Hz),
131.4 (d, JP-C = 9.4 Hz), 131.25 (d, JP-C = 9.5 Hz), 131.24
General
Procedure
for
the
CdCl2-Catalyzed
Dehydrative Reaction of Propargyl Alcohols with
Diarylphosphine Oxides
An oven-dried Schlenk tube containing a Teflon-coated
stir bar was charged with anhydrous CdCl2 (3.7 mg,
10 mol %). The Schlenk tube was sealed and then
evacuated and backfilled with N2 (3 cycles). 0.5 mL of
MeCN was injected with vigrous stirring. Then
1
(0.24 mmol) and 2 (0.2 mmol) dissolved in 1.5 mL of
(d, JP-C = 2.0 Hz), 128.5 (d, JP-C = 1.5 Hz), 128.3 (d, JP-C
=
MeCN was added. The Schlenk tube was sealed and
o
12.9 Hz), 127.8 (d, JP-C = 10.7 Hz), 127.7, 127.2, 122.0 (d,
immersed in an oil bath which was heated to 100 C. After
JP-C = 3.9 Hz), 112.0 (d, JP-C = 93.7 Hz), 96.5 (d, JP-C
=
the reaction was complete (monitored by TLC, 12 h),
removal of the solvent under vacuum left a slurry residue,
which was purified by flash chromatography on silica
(petroleum ether/ethyl acetate 3/1 to 1/1) to afford the
product 3. Note: the residual waste containing the
hazardous cadmium salts should be disposed properly.
(4,4-Dimethyl-1-phenylpenta-1,2-dien-3-yl)diphenyl
phosphine oxide (3a).[13a] 63.2 mg (yield 85%), prepared
from 45.1 mg of 1a (0.24 mmol) and 40.4 mg of 2a (0.2
13.9 Hz), 37.4 (d, JP-C = 5.2 Hz), 30.8 (d, JP-C = 3.4 Hz).
31P NMR (CDCl3, 162 MHz): δ = 29.2; 31P NMR (CDCl3,
162 MHz): δ = 29.2. HRMS (ESI-TOF): m/z = 451.0820,
calcd for C25H25BrOP [MH+] 451.0826.
(1-(2-Chlorophenyl)-4,4-dimethylpenta-1,2-dien-3-yl)
diphenylphosphine oxide (3f). 52.8 mg (yield 63%),
prepared from 53.3 mg of 1f (0.24 mmol) and 40.4 mg of
1
2a (0.2 mmol) in 2 mL MeCN. H NMR (CDCl3, 400
1
MHz): δ = 7.82–7.77 (m, 2H), 7.61–7.52 (m, 3H), 7.49–
7.45 (m, 2H), 7.29–7.06 (m, 7H), 6.46 (d, J = 11.2 Hz, 1H),
1.34 (s, 9H). 13C NMR (CDCl3, 100 MHz): δ = 209.4 (d,
mmol) in 2 mL MeCN. H NMR (CDCl3, 400 MHz): δ =
7.78–7.73 (m, 2H), 7.66–7.60 (m, 2H), 7.52–7.48 (m, 1H),
7.45–7.40 (m, 2H), 7.30–7.15 (m, 6H), 7.00 (d, J = 8.0 Hz,
2H), 6.02 (d, J = 11.2 Hz, 1H), 1.34 (s, 9H). 31P NMR
(CDCl3, 162 MHz): δ = 29.2.
JP-C = 8.0 Hz), 133.7 (d, JP-C = 107.0 Hz), 133.3 (d, JP-C
=
103.0 Hz), 131.8 (d, JP-C = 3.0 Hz), 131.7 (d, JP-C = 3.0 Hz),
131.5 (d, JP-C = 9.0 Hz), 131.32 (d, JP-C = 10.0 Hz), 131.28
(1-(4-Chlorophenyl)-4,4-dimethylpenta-1,2-dien-3-yl)
diphenylphosphine oxide (3b). 74.6 mg (yield 92%),
prepared from 53.3 mg of 1b (0.24 mmol) and 40.4 mg of
(d, JP-C = 3.0 Hz), 130.7 (d, JP-C = 7.0 Hz), 129.6 (d, JP-C
=
1.0 Hz), 128.34 (d, JP-C = 4.0 Hz), 128.32 (d, JP-C = 12.0
Hz) , 127.8 (d, JP-C = 12.0 Hz), 127.7 (d, JP-C = 2.0 Hz),
126.7 (d, JP-C = 2.0 Hz), 112.1 (d, JP-C = 93.0 Hz), 93.9 (d,
JP-C = 14.0 Hz), 37.4 (d, JP-C = 4.0 Hz), 30.8 (d, JP-C = 3.0
Hz). 31P NMR (CDCl3, 162 MHz): δ = 29.1. HRMS (ESI-
TOF): m/z = 407.1337, calcd for C25H25ClOP [MH+]
407.1332
1
2a (0.2 mmol) in 2 mL MeCN. H NMR (CDCl3, 400
MHz): δ = 7.79–7.74 (m, 2H), 7.63–7.58 (m, 2H), 7.52–
7.49 (m, 1H), 7.49–7.42 (m, 2H), 7.31–7.27 (m, 1H), 7.23–
7.17 (m, 4H), 6.90 (d, J = 8.0 Hz, 2H), 5.98 (d, J = 10.8 Hz,
1H), 1.33 (s, 9H). 13C NMR (CDCl3, 100 MHz): δ = 209.0
(d, JP-C = 7.5 Hz), 133.8 (d, JP-C = 105.7 Hz), 133.3 (d, JP-C
= 102.5 Hz), 132.9 (d, JP-C = 2.4 Hz), 131.7 (d, JP-C = 2.1
Hz), 131.5 (d, JP-C = 9.5 Hz), 131.4 (d, JP-C = 3.2 Hz),
Diphenyl(1-phenylhepta-1,2-dien-3-yl)phosphine oxide
(3i). [13a] 30.5 mg (yield 82%), prepared from 25.6 mg of 1i
6
This article is protected by copyright. All rights reserved.

10.1002/adsc.201700957
Advanced Synthesis & Catalysis
(0.13 mmol) and 20.2 mg of 2a (0.1 mmol) in 1 mL MeCN. HRMS (ESI-TOF): m/z = 449.2027, calcd for C31H30OP
1H NMR (CDCl3, 400 MHz): δ = 7.78–7.69 (m, 4H), 7.51–
7.38 (m, 3H), 7.35–7.32 (m, 2H), 7.27–7.24 (m, 2H), 7.21–
7.17 (m, 1H), 7.09 (d, J = 8.0 Hz, 2H), 6.11 (dt, J1 = 11.2
Hz, J2 = 3.2 Hz, 1H), 2.49–2.33 (m, 2H), 1.60–1.52 (m,
2H), 1.37–1.29 (m, 2H), 0.84 (t, J = 7.4 Hz, 3H). 31P NMR
(CDCl3, 162 MHz): δ = 29.5.
[MH+] 449.2034.
(1,1-Diphenylhepta-1,2-dien-3-yl)diphenylphosphine
oxide (3o). 18.2 mg (yield 20%), prepared from 63.4 mg of
1o (0.24 mmol) and 40.4 mg of 2a (0.2 mmol) in 2 mL
1
MeCN; 24.3 mg of 2a recovered. H NMR (CDCl3, 400
MHz): δ = 7.66–7.61 (m, 4H), 7.46–7.42 (m, 2H), 7.34–
7.26 (m, 10H), 6.99–6.97 (m, 4H), 2.47–2.41 (m, 2H),
1.67–1.59 (m, 2H), 1.35–1.31 (m, 2H), 0.83 (t, J = 7.4 Hz,
3H). 13C NMR (CDCl3, 100 MHz): δ = 208.8 (d, JP-C = 5.9
Hz), 135.3 (d, JP-C = 6.8 Hz), 131.79 (d, JP-C = 103.2 Hz),
131.76 (d, JP-C = 2.5 Hz), 131.5 (d, JP-C = 9.3 Hz), 128.4,
128.2 (d, JP-C = 12.0 Hz), 128.1 (d, JP-C = 2.5 Hz), 127.7,
112.7 (d, JP-C = 14.6 Hz), 102.0 (d, JP-C = 98.4 Hz), 30.6 (d,
JP-C = 5.9 Hz), 28.1 (d, JP-C = 7.4 Hz), 22.4, 13.8. 31P NMR
(CDCl3, 162 MHz): δ = 29.9. HRMS (ESI-TOF): m/z =
449.2038, calcd for C31H30OP [MH+] 449.2034.
(1-(4-Fluorophenyl)hepta-1,2-dien-3-yl)diphenyl
phosphine oxide (3j). 67.3 mg (yield 86%), prepared from
49.5 mg of 1j (0.24 mmol) and 40.4 mg of 2a (0.2 mmol)
1
in 2 mL MeCN. H NMR (CDCl3, 400 MHz): δ = 7.79–
7.74 (m, 2H), 7.71–7.65 (m, 2H), 7.52–7.50 (m, 1H), 7.46–
7.39 (m, 3H), 7.35–7.32 (m, 2H), 7.05–7.02 (m, 2H), 6.97–
6.92 (m, 2H), 6.09 (dt, J1 = 10.8 Hz, J2 = 3.2 Hz, 1H),
2.50–2.29 (m, 2H), 1.60–1.48 (m, 2H), 1.38–1.31 (m, 2H),
0.84 (t, J = 7.4 Hz, 3H). 13C NMR (CDCl3, 100 MHz): δ =
208.9 (dd, JP-C = 6.4 Hz, JF-C = 1.9 Hz), 162.1 (dd, JF-C
=
245.6 Hz, JP-C = 1.3 Hz), 131.71 (d, JP-C = 104.7 Hz),
131.9 (d, JP-C = 3.3 Hz), 131.8 (d, JP-C = 2.8 Hz), 131.6 (d,
(1-Cyclohexylidene-3,3-dimethylbut-1-en-2-yl)diphenyl
phosphine oxide (3p). 32.5 mg (yield 43%), prepared
from 43.2 mg of 1p (0.24 mmol) and 40.4 mg of 2a (0.2
mmol) in 2 mL MeCN; 12.8 mg of 2a recovered. 1H NMR
(CDCl3, 400 MHz): δ = 7.69–7.64 (m, 4H), 7.48–7.38 (m,
JP-C = 10.3 Hz), 131.4 (d, JP-C = 10.4 Hz), 131.3 (d, JP-C
=
104.7 Hz), 128.5 (dd, JF-C = 6.5 Hz, JP-C = 2.3 Hz), 128.3
(d, JP-C = 12.2 Hz), 128.1 (d, JP-C = 13.0 Hz), 128.0 (d, JF-C
= 7.9 Hz, JP-C = 2.0 Hz), 115.5 (d, JP-C = 21.8 Hz), 103.3 (d, 6H), 1.99–1.91 (m, 2H), 1.76–1.88 (m, 2H), 1.42–1.24 (m,
JP-C = 97.7 Hz), 96.4 (d, JP-C = 14.2 Hz), 30.4 (d, JP-C = 5.6
Hz), 27.8 (d, JP-C = 5.5 Hz), 22.3, 13.7. 31P NMR (CDCl3,
162 MHz): δ = 29.5. HRMS (ESI-TOF): m/z = 391.1616,
calcd for C25H25FOP [MH+] 391.1627.
4H), 1.20 (s, 9H), 1.09–1.00 (m, 2H). 13C NMR (CDCl3,
100 MHz): δ = 203.8 (d, JP-C = 8.8 Hz), 134.7 (d, JP-C
=
102.0 Hz), 131.4 (d, JP-C = 9.0 Hz), 131.0 (d, JP-C = 2.5 Hz),
127.9 (d, JP-C = 11.2 Hz), 105.2 (d, JP-C = 100.3 Hz), 104.5
(1-(2-Fluorophenyl)hepta-1,2-dien-3-yl)diphenyl
phosphine oxide (3k). 65.0 mg (yield 83%), prepared
from 49.4 mg of 1k (0.24 mmol) and 40.4 mg of 2a (0.2
(d, JP-C = 13.6 Hz), 36.2 (d, JP-C = 7.2 Hz), 30.8 (d, JP-C =
3.5 Hz), 30.1 (d, JP-C = 6.3 Hz), 26.3 (d, JP-C = 3.4 Hz),
25.4. 31P NMR (CDCl3, 162 MHz): δ = 31.6. HRMS (ESI-
TOF): m/z = 387.1860, calcd for C24H29OPNa [MNa+]
387.1854.
1
mmol) in 2 mL MeCN. H NMR (CDCl3, 400 MHz): δ =
7.78–7.68 (m, 4H), 7.50–7.46 (m, 1H), 7.42–7.38 (m, 3H),
7.35–7.30 (m, 2H), 7.17–7.08 (m, 2H), 7.04–6.93 (m, 2H),
(1-Cyclohexylidenehex-1-en-2-yl)diphenylphosphine
6.26 (dt, J1 = 11.2 Hz, J2 = 3.4 Hz, 1H), 2.48–2.29 (m, 2H), oxide (3q). 29.4 mg (yield 39%), prepared from 43.2 mg
1.59–1.52 (m, 2H), 1.38–1.29 (m, 2H), 0.83 (t, J = 7.4 Hz,
of 1q (0.24 mmol) and 40.4 mg of 2a (0.2 mmol) in 2 mL
MeCN; 16.2 mg of 2a recovered.. H NMR (CDCl3, 400
3H). 13C NMR (CDCl3, 100 MHz): δ = 209.6 (dd, JP-C
6.0 Hz, JF-C = 1.4 Hz), 159.4 (dd, JF-C = 248.6 Hz, JP-C
=
=
1
MHz): δ = 7.73–7.68 (m, 4H), 7.50–7.41 (m, 6H), 2.24–
2.19 (m, 2H), 2.01–1.93 (m, 2H), 1.85–1.80 (m, 2H), 1.47–
1.41 (m, 4H), 1.34–1.28 (m, 4H), 1.06–0.98 (m, 2H), 0.84
(t, J = 7.2 Hz, 3H). 13C NMR (CDCl3, 100 MHz): δ =
204.0 (d, JP-C = 7.6 Hz), 137.6 (d, JP-C = 102.8 Hz), 131.6
3.3 Hz), 131.86 (d, JP-C = 3.5 Hz), 131.80 (d, JP-C = 105.1
Hz), 131.74 (d, JP-C = 2.5 Hz), 131.53 (d, JP-C = 9.8 Hz),
131.42 (d, JP-C = 10.5 Hz), 131.40 (d, JP-C = 104.0 Hz),
128.7 (dd, JF-C = 8.0 Hz, JP-C = 1.5 Hz), 128.3 (d, JP-C
=
10.2 Hz), 128.13 (d, JP-C = 11.1 Hz), 128.12, 124.1 (d, JP-C
(d, JP-C = 8.7 Hz), 131.4 (d, JP-C = 2.5 Hz), 128.2 (d, JP-C =
= 3.2 Hz), 120.3 (d, JF-C = 12.1 Hz, JP-C = 7.2 Hz), 115.5 (d, 12.1 Hz), 104.8 (d, JP-C = 14.6 Hz), 96.3 (d, JP-C = 103.3
JP-C = 21.2 Hz), 102.8 (d, JP-C = 97.5 Hz), 96.0 (dd, JP-C
=
Hz), 30.4 (d, JP-C = 5.7 Hz), 30.1 (d, JP-C = 5.5 Hz), 27.2 (d,
JP-C = 7.9 Hz), 26.4 (d, JP-C = 3.3 Hz), 25.5, 22.1, 13.9. 31P
NMR (CDCl3, 162 MHz): δ = 32.1. HRMS (ESI-TOF):
m/z = 365.2016, calcd for C24H30OP [MH+] 365.2034.
(1,3-Diphenylpropa-1,2-dien-1-yl)diphenylphosphine
oxide (3r). [13a] 54.9 mg (yield 70%), prepared from 62.5
mg of 1r (0.3 mmol) and 40.4 mg of 2a (0.2 mmol) in 2
mL MeCN. 1H NMR (CDCl3, 400 MHz): δ = 7.80–7.72 (m,
4H), 7.68 (d, J = 8.0 Hz, 2H), 7.48–7.44 (m, 1H), 7.39–
7.21 (m, 11H), 7.12 (d, J = 7.6 Hz, 2H), 6.29 (d, J = 10.8
Hz, 1H). 31P NMR (CDCl3, 162 MHz): δ = 29.6.
13.8 Hz, JF-C = 5.8 Hz), 30.4 (d, JP-C = 5.0 Hz), 27.7 (d, JP-
= 6.3 Hz), 22.3, 13.7. 31P NMR (CDCl3, 162 MHz): δ =
C29.6. HRMS (ESI-TOF): m/z = 391.1618, calcd for
C25H25FOP [MH+] 391.1627.
Diphenyl(1-(4-(trifluoromethyl)phenyl)hepta-1,2-dien-
3-yl)phosphine oxide (3l). 64.3 mg (yield 73%), prepared
from 76.8 mg of 1l (0.3 mmol) and 40.4 mg of 2a (0.2
1
mmol) in 2 mL MeCN. H NMR (CDCl3, 400 MHz): δ =
7.79–7.66 (m, 4H), 7.54–7.40 (m, 6H), 7.52–7.50 (m, 1H),
7.36–7.31 (m, 2H), 7.16 (d, J = 8.4 Hz, 2H), 6.13 (dt, J1 =
9.2 Hz, J2 = 3.2 Hz, 1H), 2.52–2.32 (m, 2H), 1.59–1.50 (m,
2H), 1.37–1.32 (m, 2H), 0.84 (t, J = 7.4 Hz, 3H). 13C NMR
(CDCl3, 100 MHz): δ = 209.3 (d, JP-C = 6.4 Hz), 136.7 (d,
(1-Cyclopropyl-3-phenylpropa-1,2-dien-1-yl)diphenyl
phosphine oxide (3t). 83.4 mg (yield 78%), prepared from
61.9 mg of 1s (0.36 mmol) and 60.6 mg of 2a (0.3 mmol)
1
JP-C = 5.8 Hz), 132.08 (d, JP-C = 3.4 Hz), 131.93 (d, JP-C
=
in 3 mL MeCN. H NMR (CDCl3, 400 MHz): δ = 7.81–
2.7 Hz), 131.65 (d, JP-C = 105.0 Hz), 131.55 (d, JP-C = 9.2
Hz), 131.37 (d, JP-C = 9.3 Hz), 131.24 (d, JP-C = 103.4 Hz),
128.4 (d, JP-C = 12.0 Hz), 128.3 (d, JP-C = 12.21Hz), 126.7
(d, JP-C = 1.8 Hz), 126.0 (d, JF-C = 225.2 Hz), 125.5 (d, JP-C
= 2.9 Hz), 104.3 (d, JP-C = 96.7 Hz), 96.4 (d, JP-C = 13.0
Hz), 30.5 (d, JP-C = 5.2 Hz), 27.8 (d, JP-C = 5.9 Hz), 22.3,
13.7. 31P NMR (CDCl3, 162 MHz): δ = 29.6. HRMS (ESI-
TOF): m/z = 441.1591, calcd for C26H25F3OP [MH+]
441.1595.
(4,4-Dimethyl-1,1-diphenylpenta-1,2-dien-3-yl)diphenyl
phosphine oxide (3n). 16.4 mg (yield 18%), prepared
from 63.4 mg of 1n (0.24 mmol) and 40.4 mg of 2a (0.2
mmol) in 2 mL MeCN; 23.1 mg of 2a recovered. 1H NMR
(CDCl3, 400 MHz): δ = 7.61–7.56 (m, 4H), 7.40–7.36 (m,
2H), 7.28–7.25 (m, 10H), 6.97–6.94 (m, 4H), 1.35 (s, 9H).
13C NMR (CDCl3, 100 MHz): δ = 208.1 (d, JP-C = 7.5 Hz),
135.3 (d, JP-C = 7.0 Hz), 133.7 (d, JP-C = 103.4 Hz), 133.4
(d, JP-C = 8.2 Hz), 131.4 (d, JP-C = 9.7 Hz), 128.3, 128.0 (d,
JP-C = 14.1 Hz), 127.9, 127.6, 112.0 (d, JP-C = 14.8 Hz),
110.6 (d, JP-C = 93.5 Hz), 38.0 (d, JP-C = 5.9 Hz), 30.9 (d,
JP-C = 4.4 Hz). 31P NMR (CDCl3, 162 MHz): δ = 29.0.
7.73 (m, 4H), 7.51–7.48 (m, 1H), 7.43–7.32 (m, 5H), 7.27–
7.17 (m, 3H), 7.06 (d, J = 8.0 Hz, 2H), 6.16 (dd, J1 = 10.8
Hz, J2 = 1.6 Hz, 1H), 1.65–1.57 (m, 1H), 0.86–0.81 (m,
2H), 0.62–0.60 (m, 2H). 13C NMR (CDCl3, 100 MHz): δ =
207.2 (d, JP-C = 7.2 Hz), 132.6, 132.3 (d, JP-C = 6.7 Hz),
131.83 (d, JP-C = 2.7 Hz), 131.73 (d, JP-C = 4.2 Hz), 131.70
(d, JP-C = 103.9 Hz), 131.65 (d, JP-C = 10.2 Hz), 131.5 (d,
JP-C = 9.8 Hz), 128.6 (d, JP-C = 1.5 Hz), 128.2 (d, JP-C = 6.8
Hz), 128.1 (d, JP-C = 7.3 Hz), 127.5 (d, JP-C = 1.3 Hz),
126.6 (d, JP-C = 2.6 Hz), 107.4 (d, JP-C = 99.6 Hz), 99.0 (d,
JP-C = 13.3 Hz), 9.0 (d, JP-C = 18.4 Hz), 9.03, 8.9 (d, JP-C
=
1.5 Hz). 31P NMR (CDCl3, 162 MHz): δ = 29.8. HRMS
(ESI-TOF): m/z = 357.1395, calcd for C24H22OP [MH+]
357.1408.
(4,4-Dimethyl-1-phenylpenta-1,2-dien-3-yl)di-p-tolyl
phosphine oxide (3u). 65.4 mg (yield 82%), prepared
from 45.1 mg of 1a (0.24 mmol) and 45.9 mg of 2b (0.2
mmol) in 2 mL MeCN. 1H NMR (CDCl3, 400 MHz): δ =
7.62 (dd, J1 = 12.0 Hz, J2 = 8.0 Hz, 2H), 7.50 (dd, J1 = 12.0
Hz, J2 = 8.0 Hz, 2H), 7.22–7.16 (m, 5H), 7.01–7.98 (m,
4H), 6.00 (d, J = 11.2 Hz, 1H), 2.38 (s, 3H), 2.21 (s, 3H),
1.33 (s, 9H). 13C NMR (CDCl3, 100 MHz): δ = 208.9 (d,
7
This article is protected by copyright. All rights reserved.

10.1002/adsc.201700957
Advanced Synthesis & Catalysis
JP-C = 7.8 Hz), 141.8 (d, JP-C = 3.1 Hz), 141.5 (d, JP-C = 2.6
Hz), 133.0 (d, JP-C = 7.7 Hz), 131.5 (d, JP-C = 9.0 Hz),
131.3 (d, JP-C = 9.5 Hz), 130.8 (d, JP-C = 108.0 Hz), 130.0
(d, JP-C = 105.8 Hz), 128.8 (d, JP-C = 12.2 Hz), 128.5 (d, J
= 12.9 Hz), 128.4 (d, JP-C = 1.6 Hz), 127.1 (d, JP-C = 1.7
Hz), 126.5 (d, JP-C = 2.0 Hz), 112.0 (d, JP-C = 94.7 Hz),
97.3 (d, JP-C = 13.7 Hz), 37.3 (d, JP-C = 5.7 Hz), 30.8 (d, JP-
= 4.3 Hz), 21.4 (d, JP-C = 18.1 Hz). 31P NMR (CDCl3,
C162 MHz): δ = 29.5. HRMS (ESI-TOF): m/z = 401.2058,
calcd for C27H30OP [MH+] 401.2034.
104.0 Hz), 135.3 (d, JP-C = 101.5 Hz), 134.8 (d, JP-C = 15.7
Hz), 134.5 (d, JP-C = 16.1 Hz), 132.0 (d, JP-C = 3.1 Hz),
131.9 (d, JP-C = 8.2 Hz), 131.6 (d, JP-C = 2.5 Hz), 131.3 (d,
JP-C = 10.2 Hz), 131.1 (d, JP-C =10.6 Hz), 129.7 (d, JP-C
=
13.1 Hz), 129.5 (d, JP-C = 8.4 Hz), 129.4 (d, JP-C = 13.9 Hz),
129.2 (d, JP-C = 8.8 Hz), 128.7, 127.7 (d, JP-C = 1.4 Hz),
126.4 (d, JP-C = 2.2 Hz), 111.2 (d, J = 96.5Hz), 98.2 (d, JP-C
= 14.4 Hz), 37.5 (d, J = 6.3 Hz), 30.7 (d, JP-C = 4.0 Hz). 31
P
NMR (CDCl3, 162 MHz): δ = 27.3. HRMS (ESI-TOF):
m/z = 441.0935, calcd for C25H24Cl2OP [MH+] 441.0942.
(4,4-Dimethyl-1-phenylpenta-1,2-dien-3-yl)bis(4-fluoro
phenyl)phosphine oxide (3v). 64.3 mg (yield 79%),
prepared from 45.1 mg of 1a (0.24 mmol) and 47.0 mg of
1
Acknowledgements
2c (0.2 mmol) in 2 mL MeCN. H NMR (CDCl3, 400
MHz): δ = 7.77–7.71 (m, 2H), 7.63–7.57 (m, 2H), 7.27–
7.20 (m, 3H), 7.16–7.11 (m, 2H), 7.00 (d, J = 8.0 Hz, 2H),
6.92-6.87 (m, 2H), 6.05 (d, J = 11.6 Hz, 1H), 1.33 (s, 9 H).
Due to the coupling of F-C and P-C, the 13C NMR spectra
show very complex peaks not easily interprepted. Typical
signals belong to the allenyl unit: δ = 209.1 (d, JP-C = 7.9
Hz), 111.9 (d, JP-C = 96.4 Hz), 97.7 (d, JP-C = 14.3 Hz)).
Signals belong to the t-Bu group: δ = 37.5 (d, JP-C = 6.2
Hz), 30.7 (d, JP-C = 4.1 Hz). A full list of the 13C NMR data:
13C NMR (CDCl3, 100 MHz): δ = 209.18, 209.10, 166.14,
166.11, 165.90, 165.86, 163.63, 163.60, 163.39, 163.34,
133.96, 133.88, 133.86, 133.75, 133.67, 133.65, 133.56,
132.39, 132.32, 130.23, 130.20, 129.89, 129.85, 129.15,
129.11, 128.83, 128.79, 128.62, 128.60, 128.44, 127.63,
127.61, 127.00, 126.41, 126.39, 115.77, 115.63, 115.55,
115.42, 115.38, 115.25, 115.17, 115.04, 112.37, 111.41,
97.78, 97.63, 37.49, 37.43, 30.76, 30.72. 31P NMR (CDCl3,
162 MHz): δ = 27.8. HRMS (ESI-TOF): m/z = 409.1511,
calcd for C25H24F2OP [MH+] 409.1533.
Financial support from the NSFC (21302095), Jiangsu
Provincial NSFC (BK20130924) and Nanjing Tech University is
acknowledged. L. W., J. Y. and Z. X. thank the support from the
Training Program of Innovation and Entrepreneurship for
Undergraduates (201736006A) at NJTech.
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(4,4-dimethyl-1-phenylpenta-1,2-dien-3-yl)bis(4-
methoxyphenyl)phosphine oxide (3w). 73.3 mg (yield
83%), prepared from 47.0 mg of 1a (0.25 mmol) and 53.9
1
mg of 2d (0.21 mmol) in 2 mL MeCN. H NMR (CDCl3,
400 MHz): δ = 7.66 (dd, J1 = 11.6 Hz, J2 = 8.8 Hz, 2H),
7.52 (dd, J1 = 11.6 Hz, J2 = 8.8 Hz, 2H), 7.24–7.14 (m, 3H),
7.00 (d, J = 7.6 Hz, 2H), 6.92 (dd, J1 = 8.8 Hz, J2 = 2.4 Hz,
2H), 6.68 (dd, J1 = 8.8 Hz, J2 = 2.4 Hz, 2H), 5.99 (d, J =
11.6 Hz, 1H), 1.33 (s, 9 H). 13C NMR (CDCl3, 100 MHz):
δ = 209.0 (d, JP-C = 7.7 Hz), 162.1 (d, JP-C = 3.2 Hz), 161.8
(d, JP-C = 2.9 Hz), 133.3 (d, JP-C = 11.0 Hz), 133.1 (d, JP-C
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=11.2 Hz), 132.9 (d, JP-C = 7.0 Hz), 128.4, 127.1 (d, JP-C
=
1.5 Hz), 126.4 (d, JP-C = 2.3 Hz), 125.3 (d, JP-C = 112.7 Hz),
124.7 (d, JP-C = 110.2 Hz), 113.6 (d, JP-C = 13.0 Hz), 113.3
(d, JP-C = 12.8 Hz), 112.3 (d, JP-C = 95.6 Hz), 97.1 (d, J =
13.5 Hz), 55.1 (d, J = 11.7 Hz), 37.2 (d, JP-C = 5.6 Hz),
30.7 (d, JP-C = 3.4 Hz). 31P NMR (CDCl3, 162 MHz): δ =
29.8. HRMS (ESI-TOF): m/z = 433.1960, calcd for
C27H30O3P [MH+] 433.1933.
(4,4-Dimethyl-1-phenylpenta-1,2-dien-3-yl)di-o-tolyl
phosphine oxide (3x). 22.3 mg (yield 28%), prepared from
45.1 mg of 1a (0.24 mmol) and 46.0 mg of 2e (0.2 mmol)
1
in 2 mL MeCN. H NMR (CDCl3, 400 MHz): δ = 7.77 (d,
J = 8.0 Hz, 2H), 7.62–7.57 (m, 1H), 7.42–7.05 (m, 10H),
5.31 (d, J = 11.2 Hz, 1H), 2.63 (s, 3H), 2.50 (s, 3H), 0.74
(s, 9H). 13C NMR (CDCl3, 100 MHz): δ = 208.4 (d, JP-C
=
6.7 Hz), 143.2 (d, JP-C = 8.5 Hz), 142.8 (d, JP-C = 8.0 Hz),
132.8 (d, JP-C = 6.2 Hz), 132.4 (d, JP-C = 3.4 Hz), 132.2 (d,
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JP-C = 3.1 Hz), 131.9 (d, JP-C = 10.2 Hz), 131.55 (d, JP-C
=
101.5 Hz), 131.77 (d, JP-C = 11.5 Hz), 131.53 (d, JP-C = 2.9
Hz), 131.46 (d, JP-C = 101.7 Hz), 131.2 (d, JP-C = 3.2 Hz),
128.2, 127.1 (d, J = 1.4 Hz), 126.5 (d, JP-C = 12.1 Hz),
124.9 (d, JP-C = 13.6 Hz), 124.4 (d, JP-C = 13.0 Hz), 110.4
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(d, JP-C = 92.7 Hz), 97.1 (d, JP-C = 14.2 Hz), 37.3 (d, JP-C
=
5.1 Hz), 31.0 (d, JP-C = 2.7 Hz), 21.9 (d, JP-C = 4.6 Hz),
21.8 (d, JP-C = 4.6 Hz). 31P NMR (CDCl3, 162 MHz): δ =
36.7. HRMS (ESI-TOF): m/z = 401.2059, calcd for
C27H30OP [MH+] 401.2034.
bis(3-Chlorophenyl)(4,4-dimethyl-1-phenylpenta-1,2-
dien-3-yl)phosphine oxide (3y). 61.2 mg (yield 71%),
prepared from 45.1 mg of 1a (0.24 mmol) and 54.0 mg of
2f (0.2 mmol) in 2 mL MeCN. 1H NMR (CDCl3, 400
MHz): δ = 7.77–7.73 (m, 1H), 7.64–7.56 (m, 2H), 7.51–
7.37 (m, 3H), 7.29–7.13 (m, 5H), 7.03 (d, J = 8.0 Hz, 1H),
6.11 (d, J = 11.8 Hz, 1H), 1.34 (s, 3H). 13C NMR (CDCl3,
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=
8
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10.1002/adsc.201700957
Advanced Synthesis & Catalysis
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9
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Advanced Synthesis & Catalysis
UPDATE
Cadmium(II) Chloride-Catalyzed Dehydrative C-P
Coupling of Propargyl Alcohols with
Diarylphosphine Oxides to Afford
Allenylphosphine Oxides
Adv. Synth. Catal. Year, Volume, Page – Page
Jianlin Yang, Ming Zhang, Kang Qiu, Lize Wang,
Jingjing Yu, Zefeng Xia, Ruwei Shen,* Li-Biao
Han
10
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