Simple and advantageneous stereoselective synthesis of (Z)-allyl phosphonates starting from Baylis-Hillman adducts

Article abstract of DOI:10.1080/00397911.2011.561396

(Chemical Equation Presented) Baylis-Hillman adducts 3-hydroxyl-2-methylene alkanoates have been converted in one pot into the corresponding (Z)-allyl phosphonates by treatment with FeCl₃ and trialkyl phosphites in toluene under reflux. The pro

Full text of DOI:10.1080/00397911.2011.561396

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Simple and Advantageneous
Stereoselective Synthesis of (Z)-
Allyl Phosphonates Starting from
Baylis–Hillman Adducts
Biswanath Das a , Nisith Bhunia a & Kongara Damodar a
a Organic Chemistry Division I, Indian Institute of Chemical
Technology, Hyderabad, India
Accepted author version posted online: 27 Dec 2011.Published
online: 29 May 2012.
To cite this article: Biswanath Das , Nisith Bhunia & Kongara Damodar (2012): Simple and
Advantageneous Stereoselective Synthesis of (Z)-Allyl Phosphonates Starting from Baylis–Hillman
Adducts, Synthetic Communications: An International Journal for Rapid Communication of Synthetic
Organic Chemistry, 42:17, 2479-2489
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Synthetic Communications1, 42: 2479–2489, 2012
Copyright # Taylor & Francis Group, LLC
ISSN: 0039-7911 print=1532-2432 online
DOI: 10.1080/00397911.2011.561396
SIMPLE AND ADVANTAGENEOUS STEREOSELECTIVE
SYNTHESIS OF (Z)-ALLYL PHOSPHONATES STARTING
FROM BAYLIS–HILLMAN ADDUCTS
Biswanath Das, Nisith Bhunia, and Kongara Damodar
Organic Chemistry Division I, Indian Institute of Chemical Technology,
Hyderabad, India
GRAPHICAL ABSTRACT
Abstract Baylis–Hillman adducts 3-hydroxyl-2-methylene alkanoates have been converted
in one pot into the corresponding (Z)-allyl phosphonates by treatment with FeCl3 and
trialkyl phosphites in toluene under reflux. The products are formed in excellent yields
(88–98%) within 1–1.5 h. The process is highly convenient and efficient, cost-effective,
and remarkably stereoselective.
Keywords Arbuzov reaction; Baylis–Hillman adduct; FeCl3; trialkyl phosphite; (Z)-allyl
phosphonates
INTRODUCTION
Baylis–Hillman adducts are important precursors for the stereoselective
synthesis of various multifunctional molecules.[1] They have been widely employed
for the preparation of several natural products, their analogs, and other bioactive
compounds.[1,2] However, their utility for the preparation of allyl phosphonates is
limited.[3] Allyl phosphonates are important bioactive compounds. They exhibit inter-
esting antimicrobial and antimalarial properties.[4] They are also useful precursors for
the synthesis of various valuable organic compounds.[5]
Received December 1, 2010.
Part 204 in the series, ‘‘Studies on novel synthetic methodologies.’’
Address correspondence to Biswanath Das, Organic Chemistry Division I, Indian Institute of
Chemical Technology, Hyderabad 500007, India. E-mail: biswanathdas@yahoo.com
2479

2480
B. DAS, N. BHUNIA, AND K. DAMODAR
In an earlier method,[3a] allyl phosphonates were prepared by thermal Arbuzov
rearrangement of allyl phosphites derived from Baylis–Hillman adducts by treatment
with diethyl phosphorochloride in the presence of Et3N. The intermediates, allyl
phophites, were separated. Subsequently, these compounds underwent rearrange-
ment by heating for 1–4 h at 70–100 ꢀC. The allyl phosphonates containing ester
moiety (yields: 61–81%) were formed with stereoselectivity of 95:5 for (Z)=(E) iso-
mers. In another method,[3b] Baylis–Hillman adducts were not directly converted into
allyl phosphonates but they were initially converted into activated Baylis–Hillman
acetates, which on treatment with trialkyl phosphites at 80 ꢀC afforded the corre-
sponding allyl phosphonates. The products containg ester group (yields: 87–95%)
possessed 93–68% (Z) and 7–32% (E) selectivity. Herein, we report an efficient advan-
tageous method for the preparation of (Z)-allyl phosphonates starting directly from
Baylis–Hillman adducts.
RESULTS AND DISCUSSION
In continuation of our work[6] on the applications of Baylis–Hillman reaction,
we have observed that the adduct, 3-hydroxy-2-methylene-alkanoates (1), when
treated with FeCl3 and trialkyl phosphites in toluene under reflux, were directly
converted into the corresponding (Z)-allyl phosphonates (Scheme 1).
I
=
Initially, the reaction of the adduct, 1a (R Ph, R ¼ Me), with triethyl
phosphite [P(OEt)3] was monitored using various metal chlorides and solvents
(Scheme 2), Table 1). Considering the reaction time and yield, FeCl3 was found to
be the most effective in toluene. The activity of InCl3 was next to that of FeCl3. A
similar sequence was also observed in the preparation of allyl chlorides from Baylis–
Hillman adducts using different metal chlorides.[6a] The reaction with other metal
halides required longer reaction times, and the yields were also less. The activity of
FeCl3 in tetrahydrofuran (THF) was also diminished. The products were formed
within 1–1.5 h in good yields (88–98%).
I
=
The reaction of 1a (R Ph, R ¼ Me) was also carried out with different phos-
phites (Table 2). P(OEt)3 was identified as the best phosphorylating agent, though
P(OMe)3 was also highly effective. However, the other phosphites were not useful
to prepare the allyl phosphonates from the Baylis–Hillman adducts.
Finally, a series of allyl phosphonates was prepared from different Baylis–
Hillman adducts containing ester moiety and P(OEt)3 using FeCl3 in toluene under
Scheme 1. Synthesis of (Z)-allyl phosphonates from Baylis–Hillman adducts.

(Z)-ALLYL PHOSPHONATES
2481
Scheme 2. Synthesis of (Z)-allyl phosphonates from Baylis–Hillman adducts using triethyl phosphite.
reflux (Table 3). FeCl3 is easily available and less expensive, and thus the process is
cost-effective. The adducts were derived from aromatic, heteroaromatic, and
aliphatic aldehydes, and the ester groups were ꢁCOOMe, -COOEt, and -COOtBu.
The products were formed within 1–1.5 h, and the yields were excellent (88–98%).
The presence of electron-donating or electron-withdrawing groups in the aromatic
ring of the adducts did not affect the conversion. Various functional groups such
as halogen, nitro, ether, and nitrile remained unchanged.
The present method is highly stereoselective, only the (Z)-allyl phosphonates
were obtained exclusively from the adducts derived from aromatic, aliphatic, and
heteroaromatic aldehydes. The structures of the products were established by
comparison of their spectral data (IR, 1H NMR, 13C NMR, and HRMS) with those
reported for the known or related compounds.[3]
The treatment of the Baylis–Hillman adducts (1) with FeCl3 is known to
produce the corresponding (Z)-allyl chlorides.[6a] The mechanism of the conversion
involves the activation of the hydroxyl group of adducts by the Lewis acid FeCl3
to produce the intermediate 4. Chloride ion then attacks this intermediate to afford
the allyl chloride via a general transition state 5. The configuration of allyl chloride
Table 1. Synthesis of (Z)-allyl phosphonates from Baylis–Hillman adduct,
1a, using different Lewis acids (Scheme 2)a
Entry
Lewis acid
Solvent
Time (h)
Yield (%)b
1
2
CeCl3 ꢂ 7H2O
CeCl3 ꢂ 7H2O
ZrCl4
Toluene
THF
6
10
10
20
10
20
10
20
10
20
1
36
51
42
54
48
57
35
62
79
85
95
77
95
3
Toluene
Toluene
Toluene
Toluene
Toluene
Toluene
Toluene
Toluene
Toluene
THF
4
ZrCl4
VCl3
5
6
VCl3
ZnCl2
7
8
ZnCl2
InCl3
9
10
11
12
13
InCl3
FeCl3
FeCl3
FeCl3
6
Toluene
4
aReaction conditions: Baylis–Hillman adduct, 1a (1 mmol), triethyl phos-
phite (1.2 mmol), Lewis acid (0.35 mmol), and toluene (10 ml) under reflux.
bYields of isolated pure compound after column chromatography.

2482
B. DAS, N. BHUNIA, AND K. DAMODAR
Table 2. Synthesis of (Z)-allyl phosphonates from Baylis–Hillman adduct,
a
=
1a (R Ph), using different phosphite reagents under reflux (Scheme 1)
Entry
Phosphite reagent
Yield (%)b
1
2
3
4
5
6
P(OEt)3
HP(O)(OEt)2
P(OMe)3
95
Trace
90
HP(O)(OMe)2
P(OPh)3
HP(O)(OPh)2
Trace
30
Trace
aReaction conditions: Baylis–Hillman adduct, 1a (1 mmol), trialkyl=
triphenyl phosphite (1.2 mmol), FeCl3 (0.35 mmol), and toluene (10 ml);
the reaction mixture was stirred for 1 h under reflux.
bYields of isolated pure compound after column chromatography.
can possibly be rationalized by considering the transition-state models A and B
(Fig. 1). Model A is more favored than B, and (Z)-products are formed predomi-
nantly. The reaction was initially conducted at room temperature but under the reflux
condition the reaction times are decreased and the yields and selectivity are increased.
The intermediate (Z)-allyl chlorides could not be isolated as these active compounds
spontaneously undergo the Arbuzov reaction with trialkyl phosphites and form the
(Z)-allyl phosphonates (Scheme 3). However, when the (Z)-allyl chlorides prepared
Table 3. FeCl3-catalyzed synthesis of (Z)-allyl phosphonates from Baylis–Hillman adducts
with triethylphosphite (Scheme 1)a
Entry
Rb
Productc
Time (h)
Yieldd (%)
1
2
C6H5
4-MeC6H4
3a
3b
3c
3d
3e
3f
1
1
95
97
98
93
94
97
93
94
96
92
92
90
89
88
94
91
90
3
4-CH3)2CHC6H4
4-ClC6H4
4-BrC6H4
1
4
1
5
1
6
4-FC6H4
4-CNC6H4
1
7
3g
3h
3i
1
8
4-MeO C6H4
4-NO2C6H4
2-NO2C6H4
2-Napthyl
1.25
0.5
1
9
10
11
12
13
14
15
16
17
3j
3k
3l
1.25
1
2-Furyl
(CH3)2CHCH2
CH3(CH2)3CH2
C6H5, (RI ¼ Et)
C6H5, (RI ¼ tBu)
C6H5, (RII ¼ Me)
3m
3n
3o
3p
3q
1.5
1.5
1
1
1.5
aReaction conditions: Baylis–Hillman adduct, 1 (1 mmol), triethyl phosphate (1.2 mmol),
FeCl3 (0.35 mmol), and toluene (10 ml); the reaction mixture was stirred under reflux.
bR1 ¼ Me and RII ¼ Et in each entity otherwise stated.
cThe products were characterized from their IR, 1H NMR, 13C NMR, and HRMS spectra.
dYields of isolated pure compound after column chromatography.

(Z)-ALLYL PHOSPHONATES
2483
Figure 1.
Scheme 3. Transition-state analysis for the rationalization of the observed stereoselectivity in the reaction
leading to the Z-allyl chloride and Z-allyl phosphonates.
by the reaction of the Baylis–Hillman adducts with FeCl3[6a] were separately treated
with trialkyl phosphites under the present reaction conditions, the (Z)-allyl phospho-
nates were obtained. In absence of FeCl3, the reaction did not proceed, and in the
presence of catalytic amount of FeCl3, only a minor amount of the product was
obtained. Even with the less of one third equivalent of FeCl3 compared to the amount
of the adduct, the yields of the products were reasonably less. It has been clearly
shown in the mechanism that for the conversion of each mole of an adduct one-third
equivalent of FeCl3 is required (Scheme 3). Thus, for an efficient preparation of
(Z)-allyl phosphonates, 0.35 equivalent of FeCl3 compared to the amount of the
adducts has been used.
CONCLUSION
In conclusion, we have developed a simple and efficient method for the
synthesis of (Z)-allyl phosphonates from the Baylis–Hillman adducts by treatment
with FeCl3 and trialkyl phosphates. The direct conversion of the adducts, convenient
experimental procedure, application of less expensive reagents, impressive yields, and
excellent stereoselectivity are the advantages of the present method.

2484
B. DAS, N. BHUNIA, AND K. DAMODAR
EXPERIMENTAL
Anhydrous FeCl3 (0.35 mmol) and trialkyl phosphite 2 (1.2 mmol) were added
to a stirring solution of 3-hydroxy-2-methylene alkanoate 1 (1 mmol) in toluene
(10 ml). The mixture was heated under reflux for 1–1.5 h. The reaction was monitored
by thin-layer chromatography (TLC). After completion, the solvent was removed
under vaccum, and water (10 ml) was added. The mixture was extracted with EtOAc
(3 ꢃ 10 ml). The extract was washed with water (3 ꢃ 10 ml), dried over anhydrous
Na2SO4, and concentrated. The residue was subjected to column chromatography
(silica gel, hexane=EtOAc, 4:1) to obtained pure (Z)-allyl phosphonates, 3.
The spectral (IR, 1H and 13C NMR, and MS) and analytical data of all
compounds are given.
Compound 3a: (Z)-Methyl-2-((diethoxyphosphoryl)-methyl)-
3-phenylacrylate
1
IR tmax (neat): 1717, 1633, 1442, 1268 cmꢁ1; H NMR (200 MHz, CDCl3) d
ppm 7.81 (1H, d, J ¼ 6.0 Hz), 7.60 (2H, d, J ¼ 8.0 Hz), 7.46 (1H, d, J ¼ 6.0 Hz),
7.46–7.31 (3H, m), 4.14–4.01 (4H, q, J ¼ 7.0 Hz), 3.85 (3H, s), 3.23 (2H, d, J ¼
22.0 Hz), 1.22 (6H, t, J ¼ 7.0 Hz); 13C NMR (50 MHz, CDCl3) d ppm 168.3, 141.4
(d, J ¼ 11.0 Hz), 134.7, 129.5, 129.0, 128.6, 123.6 (d, J ¼ 11.5 Hz), 62.2 (d, J ¼ 6.5 Hz),
52.1, 26.0 (d, J ¼ 140.0 Hz), 16.2 (d, J ¼ 6.0 Hz); 31P NMR (161.9 MHz, CDCl3) d
ppm 27.05; ESIMS: m=z 313 [M þ H]þ, 335 [M þ Na]þ; HRMS (ESI): m=z
335.1025 [M þ Na]þ (calculated for C15H21O5PNa: 335.1024).
Compound 3b: (Z)-Methyl-2-((diethoxyphosphoryl)methyl)-3-
ptolylacrylate
1
IR tmax (neat): 1714, 1631, 1438, 1269 cmꢁ1; H NMR (200 MHz, CDCl3) d
ppm 7.72 (1H, d, J ¼ 6.0 Hz), 7.49 (2H, d, J ¼ 8.0 Hz), 7.19 (2H, d, J ¼ 8.0 Hz),
4.15–4.02 (4H, m), 3.82 (3H, s), 3.19 (2H, d, J ¼ 22.0 Hz), 2.40 (3H, s), 1.27 (6H,
t, J ¼ 7.0 Hz); 13C NMR (50 MHz, CDCl3) d ppm 168.4, 142.0 (d, J ¼ 11.0 Hz),
139.1, 132.0, 129.9, 129.0, 123.1 (d, J ¼ 11.5 Hz), 62.0 (d, J ¼ 6.5 Hz), 52.1, 22.0,
26.1 (d, J ¼ 140.0 Hz), 16.2 (d, J ¼ 6.0 Hz); 31P NMR (161.9 MHz, CDCl3) d ppm
27.10; ESIMS: m=z 327 [M þ H]þ, 349 [M þ Na]þ; HRMS (ESI): m=z 327.1369
[M þ H]þ (calculated for C16H24O5P: m=z 327.1361).
Compound 3c: (Z)-Methyl-2-((diethoxyphosphoryl)methyl)-3-
(4-isopropylphenyl)acrylate
1
IR tmax (neat): 1716, 1631, 1438, 1270 cmꢁ1; H NMR (200 MHz, CDCl3) d
ppm 7.72 (1H, d, J ¼ 6.0 Hz), 7.52 (2H, d, J ¼ 8.0 Hz), 7.23 (2H, d, J ¼ 8.0 Hz),
4.11–4.02 (4H, m), 3.82 (3H, s), 3.20 (2H, d, J ¼ 22.0 Hz), 2.91 (1H, m), 1.31–1.20
(12H, m); 13C NMR (50 MHz, CDCl3) d ppm 168.3, 150.5, 141.7 (d, J ¼ 11.0 Hz),
132.2, 129.9, 126.5, 122.4 (d, J ¼ 11.5 Hz), 62.0 (d, J ¼ 6.5 Hz), 52.0, 33.9, 26.0 (d,
J ¼ 140.0 Hz), 24.0, 16.3 (d, J ¼ 6.0 Hz); 31P NMR (161.9 MHz, CDCl3) d ppm
27.15; ESIMS: m=z 355 [M þ H]þ, 374 [M þ Na]þ; HRMS (ESI): m=z 355.1665
[M þ H]þ (calculated for C15H28O5P: m=z 355.1674).

(Z)-ALLYL PHOSPHONATES
2485
Compound 3d: (Z)-Methyl-3-(4-chlorophenyl)-
2-((diethoxyphosphoryl) methyl)acrylate
1
IR tmax (neat): 1719, 1634, 1439, 1269 cmꢁ1; H NMR (200 MHz, CDCl3) d
ppm 77.71 (1H, d, J ¼ 6.0 Hz), 7.57 (2H, d, J ¼ 8.0 Hz), 7.36 (2H, d, J ¼ 8.0 Hz),
4.15–4.01 (4H, m), 3.82 (3H, s), 3.13 (2H, d, J ¼ 22.0 Hz), 1.28 (6H, t, J ¼ 7.0 Hz);
13C NMR (50 MHz, CDCl3) d ppm 168.2, 140.2 (d, J ¼ 11.0 Hz), 135.1, 133.5,
131.1, 129.5, 124.8 (d, J ¼ 11.5 Hz), 62.2 (d, J ¼ 6.5 Hz), 52.5, 26.2 (d, J ¼ 140.0 Hz),
16.6 (d, J ¼ 6.0 Hz); 31P NMR (161.9 MHz, CDCl3) d ppm 26.08; ESIMS: m=z 347
[M þ H]þ, 369 [M þ Na]þ; HRMS (ESI): m=z 347.0831 [M þ H]þ (calculated for
C16H21ClO5P m=z 347.0815).
Compound 3e: (Z)-Methyl-3-(4-bromophenyl)-
2-((diethoxyphosphoryl)methyl)acrylate
1
IR tmax (neat): 1717, 1633, 1438, 1272 cmꢁ1; H NMR (200 MHz, CDCl3) d
ppm 7.69 (1H, d, J ¼ 6.0 Hz), 7.02 (2H, d, J ¼ 8.0 Hz), 7.49 (1H, d, J ¼ 8.0 Hz),
4.12–4.02 (4H, m), 3.83 (3H, s), 3.12 (2H, d, J ¼ 22.0 Hz), 1.26 (6H, t, J ¼ 7.0 Hz);
13C NMR (50 MHz, CDCl3) d 167.5, 140.2 (d, J ¼ 11.0 Hz), 133.7, 131.2, 131.0,
124.1 (d, J ¼ 11.5 Hz), 123.1, 62.2 (d, J ¼ 6.5 Hz), 52.1, 26.0 (d, J ¼ 140.0 Hz), 16.2
(d, J ¼ 6.0 Hz); 31P NMR (161.9 MHz, CDCl3) d ppm 26.07; ESIMS: m=z 391
[M þ H]þ, 413 [M þ Na]þ; HRMS (ESI): m=z 391.0297 [M þ H]þ (calculated for
C16H21BrO5P m=z 391.0309).
Compound 3f: (Z)-Methyl-2-((diethoxyphosphoryl)methyl)-3-
(4-fluorophenyl)acrylate
IR tmax (neat): 1717, 1601, 1501, 1439, 1268 cmꢁ1 1H NMR (200 MHz,
;
CDCl3) d ppm 77.72 (1H, d, J ¼ 6.0 Hz), 7.62–7.60 (2H, m), 7.09 (2H, t, J ¼ 8.0 Hz),
4.12–4.01 (4H, m), 3.81 (3H, s), 3.12 (2H, d, J ¼ 22.0 Hz), 1.25 (6, t, J ¼ 7.0 Hz); 13
NMR (50 MHz, CDCl3) d ppm 168.2, 163.1 (d, J ¼ 280.0 Hz), 140.2 (d, J ¼
11.0 Hz), 131.1 (d, J ¼ 10.0 Hz), 130.8, 123.3 (d, J ¼ 11.5 Hz), 115.5 (d, J ¼ 18.0 Hz),
61.7 (d, J ¼ 6.5 Hz), 52.0, 26.0 (d, J ¼ 140.0 Hz), 16.1 (d, J ¼ 6.0 Hz); 31P NMR
(161.9 MHz, CDCl3) d ppm 26.06; ESIMS: m=z 331 [M þ H]þ, 353 [M þ Na]þ;
HRMS (ESI): m=z 353.0938 [M þ Na]þ (calculated for C16H20FO5PNa m=z
353.0930).
C
Compound 3g: (Z)-Methyl-3-(4-cyanophenyl)-
2-((diethoxyphosphoryl)methyl)acrylate
1
IR tmax (neat): 1717, 1635, 1437, 1267 cmꢁ1; H NMR (200 MHz, CDCl3) d
ppm 7.80–7.68 (5H, m), 4.18–4.02 (14H, m), 3.86 (3H, s), 3.10 (2H, d, J ¼ 22.0 Hz),
7.81 (1H, d, J ¼ 6.0 Hz), 1.29 (6H, t, J ¼ 7.0 Hz); 13C NMR (50 MHz, CDCl3) d ppm
167.5, 139.2 (d, J ¼ 11.0 Hz), 132.2, 130.0, 127.0 (d, J ¼ 11.5 Hz), 118.2, 112.4, 62.2
(d, J ¼ 6.5 Hz), 52.2, 26.1 (d, J ¼ 140.0 Hz), 16.1 (d, J ¼ 6.0 Hz); 31P NMR
(161.9 MHz, CDCl3) d ppm 26.09; ESIMS: m=z 338 [M þ H]þ, 360 [M þ Na]þ;
HRMS (ESI): m=z 360.0976 [M þ Na]þ (calculated for C16H20NO5PNa m=z
360.0976).

2486
B. DAS, N. BHUNIA, AND K. DAMODAR
Compound 3h: (Z)-Methyl-2-((diethoxyphosphoryl)methyl)-3-
(4-methoxyphenyl)acrylate
IR tmax (neat): 1713, 1605, 1512, 1439, 1257 cmꢁ1 1H NMR (200 MHz,
;
CDCl3) d ppm 7.72 (1H, d, J ¼ 6.0 Hz), 7.59 (2H, d, J ¼ 8.0 Hz), 6.92 (2H, d,
J ¼ 8.0 Hz), 4.12–4.04 (4H, m), 3.82 (6H, s), 3.21 (2H, d, J ¼ 22.0 Hz), 1.28 (6H, t,
J ¼ 7.0 Hz); 13C NMR (50 MHz, CDCl3) d ppm 167.8, 151.0, 128.0 (d, J ¼ 11.0 Hz),
127.3, 127.0, 119.0 (d, J ¼ 11.5 Hz), 116.5, 62.2, 62.0 (d, J ¼ 6.5 Hz), 52.2, 26.0 (d,
J ¼ 140.0 Hz), 16.0 (d, J ¼ 6.0 Hz); 31P NMR (161.9 MHz, CDCl3) d ppm 27.17;
ESIMS: m=z 334 [M þ H]þ, 356 [M þ Na]þ; HRMS (ESI): m=z 343.1323 [M þ H]þ
(calculated for C16H24O6P m=z 343.1310).
Compound 3i: (Z)-Methyl-2-((diethoxyphosphoryl
methyl)-3-(4-nitrophenyl)acrylate
IR tmax (neat): 1721, 1637, 1520, 1346, 1238 cmꢁ1 1H NMR (200 MHz,
;
CDCl3) d ppm 8.19 (1H, d, J ¼ 8.0 Hz), 7.40 (2H, d, J ¼ 8.0 Hz), 6.99 (1H, d,
J ¼ 6.0 Hz), 4.20–4.02 (4H, m), 3.64 (3H, s), 2.99 (2H, d, J ¼ 22.0 Hz), 1.34 (6H, t,
J ¼ 7.0 Hz); 13C NMR (50 MHz, CDCl3) d ppm 167.3, 138.8, 137.0 (d, J ¼ 10.0 Hz),
129.0, 128.0 (d, J ¼ 11.5 Hz), 123.9, 123.0, 62.5 (d, J ¼ 6.5 Hz), 52.0, 32.0 (d, J ¼
140.0 Hz), 22.0, 16.7 (d, J ¼ 6.0 Hz); 31P NMR (161.9 MHz, CDCl3) d ppm 26.03;
ESIMS: m=z 358 [M þ H]þ, 380 [M þ Na]þ; HRMS (ESI): m=z 380.0882 [M þ Na]þ
(calculated for C15H20NO7PNa m=z 380.0875).
Compound 3j: (Z)-Methyl-2-((diethoxyphosphoryl)methyl)-3-
(2-nitrophenyl)acrylate
1
IR tmax (neat): 1719, 1641, 1526, 1384 cmꢁ1; H NMR (200 MHz, CDCl3) d
ppm 8.20 (1H, d, J ¼ 8.0 Hz), 8.04 (1H, d, J ¼ 6.0 Hz), 7.78–7.69 (2H, m), 7.55
(1H, t, J ¼ 8.0 Hz), 4.09–3.96 (4H, m), 3.88 (3H, s), 2.91 (2H, d, J ¼ 22.0 Hz), 1.22
(6H, t, J ¼ 7.0 Hz); 13C NMR (50 MHz, CDCl3) d ppm 167.7, 147.5, 139.1 (d, J ¼
10.0 Hz), 138.7, 134.8, 131.0, 129.9, 125.4 (d, J ¼ 11.0 Hz), 125.2, 62.0 (d, J ¼ 6.5 Hz),
52.4, 25.4 (d, J ¼ 140.0 Hz), 16.0 (d, J ¼ 6.0 Hz); 31P NMR (161.9 MHz, CDCl3) d
ppm 26.25; ESIMS: m=z 358 [M þ H]þ, 380 [M þ Na]þ; HRMS (ESI): m=z
380.0882 [M þ Na]þ (calculated for C15H20NO7PNa m=z 380.0875).
Compound 3k: (Z)-Methyl-2-((diethoxyphosphoryl)methyl)-3-
(2-naphthyl)acrylate
1
IR tmax (neat): 1719, 1630, 1445, 1256 cmꢁ1; H NMR (200 MHz, CDCl3) d
ppm 8.19 (1H, d, J ¼ 6.0 Hz), 7.90–7.72 (4H, m), 7.54–7.38 (3H, m), 4.17–4.03
(4H, m), 3.86 (3H, s), 3.28 (2H, d, J ¼ 140.0 Hz), 1.30 (6H, t, J ¼ 7.0 Hz); 13C
NMR (50 MHz, CDCl3) d ppm 168.2, 141.8 (d, J ¼ 11.0 Hz), 133.8, 129.0, 128.4,
128.1, 127.3, 126.2, 126.0, 123 (d, J ¼ 11.5 Hz), 62.2 (d, J ¼ 6.5 Hz), 51.8, 26.3 (d,
J ¼ 140.0 Hz), 22.0, 16.1 (d, J ¼ 6.0 Hz); 31P NMR (161.9 MHz, CDCl3) d ppm
27.2; ESIMS: m=z 363 [M þ H]þ, 385 [M þ Na]þ; HRMS (ESI): m=z 385.1183
[M þ Na]þ (calculated for C19H23O5PNa m=z 385.1180).

(Z)-ALLYL PHOSPHONATES
2487
Compound 3l: (Z)-Methyl-2-((diethoxyphosphoryl)methyl)-3-
(furan-2-yl)acrylate
1
IR tmax (neat): 1718, 1646, 1440, 1260 cmꢁ1; H NMR (200 MHz, CDCl3) d
ppm 7.58 (1H, m), 7.48 (1H, d, J ¼ 6.0 Hz), 6.74 (1H, m), 6.50 (1H, m), 4.10–3.99
(4H, m), 3.81 (3H, s), 3.42 (2H, t, J ¼ 22.0 Hz), 1.21 (6H, t, J ¼ 7.0 Hz); 13C NMR
(50 MHz, CDCl3) d ppm 167.8, 144.7, 127.9 (d, J ¼ 10.0 Hz), 127.0, 119.1 (d,
J ¼ 11.0 Hz), 116.5, 112.0, 61.1 (d, J ¼ 6.0 Hz), 51.8, 25.8 (d, J ¼ 140.0 Hz), 16.0 (d,
J ¼ 6.5 Hz); 31P NMR (161.9 MHz, CDCl3) d ppm 27.35; ESIMS: m=z 303 [M þ H]þ,
325 [M þ Na]þ; HRMS (ESI): m=z 325.0814 [M þ Na]þ (calculated for C13H19O6
PNa m=z 325.0816).
Compound 3m: (Z)-Methyl-2-((diethoxyphosphoryl)methyl)-5-
methylhex-2-enoate
1
IR tmax (neat): 1718, 1646, 1440, 1260 cmꢁ1; H NMR (200 MHz, CDCl3) d
ppm 6.91 (1H, dd, J ¼ 7.0, 5.0 Hz), 4.12–4.01 (4H, m), 3.79 (3H, s), 2.94 (2H, d,
J ¼ 22.0 Hz), 2.20–2.14 (2H, m), 1.77 (1H, m), 1.30 (6H, d, J ¼ 8.0 Hz), 0.95 (6H,
t, J ¼ 8.0 Hz); 13C NMR (50 MHz, CDCl3) d ppm 167.2, 145.2 (d, J ¼ 11.0 Hz),
123.5 (d, J ¼ 11.5 Hz), 61.5 (d, J ¼ 6.5 Hz), 52.0, 38.0, 27.9, 24.5 (d, J ¼ 140.0 Hz),
22.1, 15.7 (d, J ¼ 6.0 Hz); 31P NMR (161.9 MHz, CDCl3) d ppm 27.64; ESIMS:
m=z 293 [M þ H]þ, 315 [M þ Na]þ; HRMS (ESI): m=z 293.1511 [M þ H]þ (calcu-
lated for C13H26O5P m=z 293.1517).
Compound 3n: (Z)-Methyl-2-((diethoxyphosphoryl)methyl)oct-2-
enoate
1
IR tmax (neat): 1719, 1646, 1440, 1282 cmꢁ1; H NMR (200 MHz, CDCl3) d
ppm 6.69 (1H, dd, J ¼ 7.0, 5.0 Hz), 4.11–4.01 (4H, m), 3.53 (3H, s), 2.91 (2H, d,
J ¼ 22.0 Hz), 2.30–2.22 (2H, m), 1.51–1.40 (2H, m), 1.38–1.22 (10H, m), 0.90 (3H,
t, J ¼ 7.0 Hz); 13C NMR (50 MHz, CDCl3) d ppm 167.3, 146.5 (d, J ¼ 11.0 Hz),
122.5 (d, J ¼ 11.5 Hz), 62.0 (d, J ¼ 6.5 Hz), 52.0, 31.2, 29.2, 28.0, 25.2 (d, J ¼
140.0 Hz), 22.5, 16.1 (d, J ¼ 6.0 Hz), 14.0); 31P NMR (161.9 MHz, CDCl3) d ppm
27.72; ESIMS: m=z 307 [M þ H]þ, 329 [M þ Na]þ; HRMS (ESI): m=z 307.1667
[M þ H]þ (calculated for C14H28O5P m=z 307.1674).
Compound 3o: (Z)-Ethyl-2-((diethoxyphosphoryl)methyl)-3-
phenylacrylate
1
IR tmax (neat): 1717, 1633, 1442, 1268 cmꢁ1; H NMR (200 MHz, CDCl3) d
ppm 7.75 (1H, d, J ¼ 6.0 Hz), 7.58 (2H, d, J ¼ 8.0 Hz), 7.40–7.29 (3H, m), 4.29
(2H, q, J ¼ 7.0 Hz), 4.12–4.09 (4H, m), 3.20 (2H, d, J ¼ 22.0 Hz), 1.38 (3H, t,
J ¼ 7.0 Hz), 1.32 (3H, t, J ¼ 7.0 Hz), 1.25 (3H, t, J ¼ 7.0 Hz); 13C NMR (50 MHz,
CDCl3) d ppm 167.5, 141.1 (d, J ¼ 11.0 Hz), 134.5, 129.5, 129.0, 128.5, 124.1 (d,
J ¼ 11.5 Hz), 62.0 (d, J ¼ 6.5 Hz), 61.2, 26.1 (d, J ¼ 140.0 Hz), 16.1 (d, J ¼ 6.0 Hz),
14.1; 31P NMR (161.9 MHz, CDCl3) d ppm 27.04; ESIMS: m=z 327 [M þ H]þ, 349
[M þ Na]þ; HRMS (ESI): m=z 327.1356 [M þ H]þ (calculated for C16H24O5P m=z
327.1361).

2488
B. DAS, N. BHUNIA, AND K. DAMODAR
Compound 3p: (Z)-tert-Butyl-2-((diethoxyphosphoryl)methyl)-3-
phenylacrylate
1
IR tmax (neat): 1717, 1630, 1439, 1271 cmꢁ1; H NMR (200 MHz, CDCl3) d
ppm 7.64 (1H, d, J ¼ 6.0 Hz), 7.56 (2H, d, J ¼ 8.0 Hz), 7.40–7.29 (3H, m), 4.12–4.01
(4H, m), 3.13 (2H, d, J ¼ 22.0 Hz), 1.58 (9H, s), 1.30 (6H, t, J ¼ 8.0 Hz); 13C NMR
(50 MHz, CDCl3) d ppm 166.9, 140.6 (d, J ¼ 11.0 Hz), 135.2, 129.1, 129.0, 128.9,
125.5, 81.0, 62.0 (d, J ¼ 6.5 Hz), 28.1, 26.0 (d, J ¼ 140.0 Hz), 16.4; 31P NMR
(161.9 MHz, CDCl3) d ppm 27.03; ESIMS: m=z 355 [M þ H]þ, 377 [M þ Na]þ;
HRMS (ESI): m=z 377.1496 [M þ H]þ (calculated for C18H27O5PNa m=z 377.1493).
Compound 3q: (Z)-Methyl-2-((dimethoxyphosphoryl)methyl)-3-
phenylacrylate
1
IR tmax (neat): 1719, 1646, 1440, 1282 cmꢁ1; H NMR (200 MHz, CDCl3) d
ppm 7.76 (1H, d, J ¼ 6.0 Hz), 7.51 (2H, d, J ¼ 8.0 Hz), 7.41–7.28 (3H, m), 3.82 (3H,
S), 3.68 (6H, d, J ¼ 10.0 Hz), 3.15 (2H, d, J ¼ 22.0 Hz); 13C NMR (50 MHz, CDCl3)
d ppm 168.1, 142.0 (d, J ¼ 6.0 Hz), 134.9, 129.5, 129.1,129.0, 123.4 (d, J ¼ 6.5 Hz),
52.5 (d, J ¼ 6.5 Hz), 52.1, 26.2 (d, J ¼ 140.0 Hz); 31P NMR (161.9 MHz, CDCl3) d
ppm 27.12; ESIMS: m=z 285 [M þ H]þ, 307 [M þ Na]þ; HRMS (ESI): m=z
307.0713 [M þ Na]þ (calculated for C13H17O5PNa m=z 307.0711).
ACKNOWLEDGMENT
The authors thank the Council of Scientific and Industrial Research, New
Delhi, for financial assistance.
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