Highly atom-economical, catalyst-free, and solvent-free phosphorylation of chalcogenides

Article abstract of DOI:10.1039/c9ob01921a

Silica gel promoted, catalyst-free and solvent-free S-P, Se-P and Te-P bond formations are described. A variety of disulfides coupled with diarylphosphine oxides provide the corresponding phosphinothioates in excellent yields. For the first time, diselenides and ditellurides reacted with dialkyl phosphites under catalyst-free conditions to provide the corresponding phosphoroselenoates and phosphorotelluroates, respectively, in good to excellent yields.

Full text of DOI:10.1039/c9ob01921a

Organic &
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Highly atom-economical, catalyst-free, and
solvent-free phosphorylation of chalcogenides†‡
Cite this: Org. Biomol. Chem., 2019,
17, 9757
Rakhee Choudhary,§ Pratibha Singh,§ Rekha Bai,§ Mahesh C. Sharma and
Satpal Singh Badsara
*
Silica gel promoted, catalyst-free and solvent-free S–P, Se–P and Te–P bond formations are described. A
variety of disulfides coupled with diarylphosphine oxides provide the corresponding phosphinothioates in
excellent yields. For the first time, diselenides and ditellurides reacted with dialkyl phosphites under cata-
lyst-free conditions to provide the corresponding phosphoroselenoates and phosphorotelluroates,
respectively, in good to excellent yields.
Received 2nd September 2019,
Accepted 25th October 2019
DOI: 10.1039/c9ob01921a
rsc.li/obc
synthesis of thiophosphinates via coupling between phosphine
oxides and thiols using a platinum electrode and n-BuNBF4 as
Introduction
Organic frameworks possessing both sulphur and phosphorus the reaction medium. Nguyen and co-workers8d have used
moieties play an important role in organic synthesis, pharma- N-heterocyclic carbenes for S–P bond formation between disul-
ceuticals, materials and medicinal chemistry and fides and phosphine oxides. Although significant progress has
agrochemicals.1,2 These molecules exhibit a variety of biologi- been made for such S–P bond formations, these procedures
cal activities and have been used as enzyme inhibitors, insecti-
cides, pesticides, fungicides, anticholinesterases, as potential
HIV-I and ACHE inhibitors.3 Similarly, selenophosphonates are
versatile intermediates in the synthesis of natural products and
complex frameworks.4 The Michaelis–Arbuzov reaction between
P(OR)3 and RSO2Cl5 and nulceophilic substitution by employing
RSX or R2P(O)X6 have been the traditional methods for the
preparation of phosphinothioates. Toxicity and moisture sensi-
tivity are the major drawbacks of these methods.
Recently, this area has received much attention and various
synthetic protocols have been developed for the synthesis of
phosphinothioates using a variety of sulphur and phosphorus
surrogates by employing different catalytic systems (Scheme 1,
Path a).7,8 Pan and co-workers8a have reported a KI/tert-butyl
peroxybenzoate (TBPB) catalysed synthesis of thiophosphi-
nates via the S–P bond formation between phosphine oxides
and thiols. Li, Zhang and co-workers8b have developed visible
light mediated S–P bond formation between phosphine oxides
and thiols using Rose Bengal as the photocatalyst. Very
recently, the Zheng group8c has reported an electrochemical
MFOS Laboratory, Department of Chemistry, Centre of Advanced Study,
University of Rajasthan, JLN Marg, Jaipur, Rajasthan, 302004, India.
E-mail: badsarass4@uniraj.ac.in, sattubhu2005@gmail.com
†This work is dedicated to Professor Chin-Fa Lee (National Chung Hsing
University, Taichung, Taiwan) for his contribution to Chalcogenides Chemistry.
‡Electronic supplementary information (ESI) available. See DOI: 10.1039/
c9ob01921a
§These authors contributed equally.
Scheme 1 Phosphorylation of chalcogenides.
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require transition metal catalysis, use of strong oxidants, high (1a) was superior to thiophenol (1a′) for P–S bond formation
temperature or use of toxic and smelly substrates. with diphenyl phosphine oxide (2a) on silica gel, providing the
Meanwhile, selenophosphonates and tellurophosphonates corresponding phosphinothioate 3a in quantitative yield.
have been synthesized via the coupling of phosphites with dis- After optimization of the reaction conditions, the substrate
elenides and ditellurides, respectively, using transition scope was studied. For this, a variety of dilsulfides 1a–1g were
metals,9a–c AIBN,9d NaN3/PhI(OAc)2, 9e calix[4]arene9f etc. as the employed for S–P bond formations with different phosphine
catalytic systems (Scheme 1, Path b). Due to the above dis- oxides (2a–c) on silica gel under the optimized reaction con-
cussed versatile applications of phosphochalcogenoates, the ditions (Table 2). Aryl disulphides possessing both electron
development of a facile, economical and sustainable procedure withdrawing groups (1b–d and g–h) and electron donating
for the synthesis of these frameworks via S–P, Se–P, and Te–P groups (1e–f) reacted well with phosphine oxides 2a–c to
bond formations is highly desirable. We herein disclose a provide the corresponding phosphinothioates 3b–r in 75–99%
green, atom economical and general procedure for chalcogen– yields. o-Substituted disulphide 1g also reacted smoothly with
phosphorus bond formation under catalyst-free and solvent- phosphine oxide to provide phosphinothioate 3m in 79%
free conditions at ambient temperature (Scheme 1, Path c).
Table 2 Catalyst-free S–P bond formation between disulfides 1 and
diarylphosphine oxides 2a,b
Results and discussion
We began our investigation using thiophenol (1a′) and diphe-
nyl phosphine oxide (2a) as the model substrates and then
allowed them to react in an aqueous medium at room temp-
erature for 24 h, which provided the S–P coupled product
phosphinothioate 3a in trace amounts (Table 1, entry 1).
Increasing the reaction temperature provided somewhat better
results (entry 2). Neat conditions could not offer better results
at both ambient temperature and 80 °C (entries 3 & 4). Based
on our previous experience,10 we then performed this S–P
coupling reaction using silica gel at room temperature, which
showed the best results, providing 3a in 96% yield. To find the
alternative to thiophenol, we then screened various reaction
conditions for S–P bond formation using diphenyl disulphide
1a as a sulphur surrogate with diphenyl phosphine oxide (2a)
(entries 7–12). It was concluded that the diphenyl disulfide
Table 1 Optimization of the reaction conditionsa
Sulphur
surrogate
Temp.
(°C)
Time
(h)
Yield of
Entry
Solvent
3ab (%)
1
2
3
4
5
6
7
8
1a′
1a′
1a′
1a′
1a′
1a′
1a
1a
1a
1a
1a
H2O
H2O
—
—
Silica gel
Silica gel
—
RT
80
RT
80
RT
80
RT
80
RT
80
RT
80
24
24
24
24
24
24
24
24
6
Trace
30
Trace
Trace
96
70
75
70
99
72
90
—
9
Silica gel
Silica gel
H2O
10
11
12
6
12
12
1a
H2O
80
a Reaction conditions for entries 1–6: Thiophenol 1a′ (1.0 mmol) and
diphenyl phosphine oxide 2a (0.5 mmol) were reacted in water or silica
gel. For entries 7–12: diphenyl disulfide 1a (0.5 mmol) and diphenyl a Reaction conditions: Diphenyl disulfide 1 (0.5 mmol) and phosphine
phosphine oxide 2a (0.5 mmol) were reacted in solvent or silica gel. oxide 2 (0.5 mmol) were reacted in silica gel at room temperature for
b Isolated yields are based on 2a.
6 h. b Isolated yields are based on phosphine oxide 2.
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yield. Interestingly, alkyl disulphides 1i–j were also coupled
with phosphine oxides 2a–c under the optimized reaction con-
ditions to afford phosphinothioates 3s–v in 46–52% isolated
yields.
Next, we turned our attention to expand this interesting
method for the synthesis of phosphoroselenoates 5 via Se–P
bond formation (Table 3). Accordingly, a variety of diselenides
4 were treated with dialkyl phosphites 2′ under the optimized
reaction conditions to provide the resulting phosphoroseleno-
ates 5 in 78–94% yields. Notably, diselenides possessing elec-
tron donating groups (4b–d) as well as an electron withdrawing
group (4e) reacted well with the different dialkyl phosphites 2′
to afford phosphoroselenoates 5. Dipropyl diselenide (4f) also
reacted well with diethyl phosphite (2′a) to provide the desired
phosphoroselenoate 5l in 78% yield.
Scheme 2 Synthesis of phosphorotelluroate 7 and gram-scale synth-
eses of 3a & 5a.
Notably, we have also utilized this interesting method for
the preparation of phosphorotelluroates via the Te–P coupling
between diphenyl ditelluride (6) and dialkyl phosphites 2′a–b
(Scheme 2, Path a). The corresponding phosphorotelluroates
7a & 7b were obtained in 80% and 78% yields respectively.
Also, to establish the synthetic utility of this facile S–P and Se–
P bond formation, we also performed gram-scale experiments
(Scheme 2, Path b). We carried out the reaction of 10.0 mmol
of diphenyldisulfide (1a) with 10.0 mmol of diphenyl phos-
phine oxide (2a) using silica gel at room temperature for 6 h,
providing the resulting phosphinothioate 3a in 98% yield.
Similarly, the reaction between diphenyldiselenide (4a) and
diethyl phopshite (2′a) on a 10.0 mmol scale using silica gel at
room temperature for 6 h provided the corresponding phos-
phoroselenoate 5a in 85% yield.
Scheme 3 Plausible mechanism for the synthesis of phosphinothioate 3.
The plausible mechanism for this catalyst-free and solvent-
free phosphorylation of chalcogenides was established with
the help of a control experiment (Scheme 3, Path a). When the
reaction between 1a and 2a was carried out in the presence of
5.0 equivalents of TEMPO (2,2,6,6-tetramethylpiperidine
1-oxyl) on silica gel at room temperature for 6 h, the desired
product 3a was not detected and instead compound 8 was
obtained. On the basis of the control experiment, a plausible
mechanism for the synthesis of phosphinothioate 3 via a
radical pathway is depicted in Scheme 3, Path b.
Table 3 Catalyst-free Se–P bond formation between diselenide 4 and
dialkyl phosphites 2’a,b
Experimental
General information
All chemicals were procured from commercial suppliers and
used without further purification. NMR spectra were recorded
on a Jeol resonance-400 instrument using CDCl3 as solvent.
Chemical shifts are reported in parts per million (ppm) and
referenced to the residual solvent resonance. The coupling con-
stant (J) is reported in hertz (Hz). Standard abbreviations indi-
cating multiplicity were used as follows: s = singlet, d = doublet,
t = triplet, dd = double doublet, q = quartet, and m = multiplet.
General procedure for 3a (Table 1)
Thiophenol 1a′ (1.0 mmol, 0.110 g) or diphenyl disulphide 1a
(0.5 mmol, 0.109 g) and diphenyl phosphine oxide 2a
(0.5 mmol, 0.101 g) were mixed in an open flask. A solvent
(1.0 mL) or silica gel (1.0 g, 60–120 mesh) was then added to
a Reaction conditions: Diselenide 4 (0.5 mmol) and dialkyl phosphites
2′ (0.5 mmol) were reacted in silica gel at room temperature for 6 h.
b Isolated yields are based on dialkyl phosphites 2′.
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this reaction mixture. After completion of the reaction, the (d, JC–P = 2.0 Hz), 135.6 (d, JC–P = 2.0 Hz), 136.5 (d, JC–P = 3.0
solvent was removed and the residue thus obtained was puri- Hz); 31P (162 MHz, CDCl3): δ 42.2.
fied via column chromatography (silica gel, 30% EtOAc in
hexanes) to afford the corresponding product 3a.
S-(p-Tolyl) diphenylphosphinothioate (3e)8d
S-Phenyl diphenylphosphinothioate (3a)8a
The title compound was prepared following the general pro-
1
cedure for 3 (Table 2), using bis(4-methylphenyl)disulfide 1e
Yield: 0.153 g, 99%; M.P.: 78 °C; H NMR (400 MHz, CDCl3):
δ 7.17–7.23 (m, 3H), 7.40–7.50 (m, 8H), 7.81–7.88 (m, 4H); 13C
(0.5 mmol, 0.123 g) and diphenylphosphine oxide 2a
NMR (100 MHz, CDCl3): δ 126.1 (d, JC–P = 5.0 Hz), 128.5 (d,
(0.5 mmol, 0.101 g), providing 3e as a white solid. Yield:
1
0.152 g, 94%; M.P.: 92 °C; H NMR (400 MHz, CDCl3): δ 2.25
JC–P = 13.0 Hz), 128.9 (d, JC–P = 2.0 Hz), 129.1, 131.6 (d, JC–P
=
(s, 3H), 6.99 (d, J = 8.0 Hz, 2H), 7.30 (dd, J = 1.6 & 8.0 Hz, 2H),
7.40–7.51 (m, 6H), 7.80–7.85 (m, 4H); 13C NMR (100 MHz,
CDCl3): δ 21.2, 122.3 (d, JC–P = 5.0 Hz), 128.5 (d, JC–P = 13.0 Hz),
130.0, 131.7 (d, JC–P = 10.0 Hz), 132.3 (d, JC–P = 3.0 Hz), 132.7, (d,
JC–P = 106.0 Hz), 135.4 (d, JC–P = 3.0 Hz), 139.2 (d, JC–P = 3.0 Hz).
10.0 Hz), 132.3 (d, JC–P = 3.0 Hz), 132.5 (d, JC–P = 107.0 Hz),
135.4 (d, JC–P = 4.0 Hz).
General procedure for 3 (Table 2)
Disulphide 1 (0.5 mmol) and phosphine oxide 2 (0.5 mmol)
were mixed in an open flask and then silica gel (1.0 g,
60–120 mesh) was added to this reaction mixture. The reaction
mixture was kept in open air at room temperature for 6 h. After
completion of the reaction, the residue was purified via
column chromatography (silica gel, 30% EtOAc in hexanes) to
afford the corresponding products 3.
S-(4-Methoxyphenyl) diphenylphosphinothioate (3f)8a
The title compound was prepared following the general pro-
cedure for 3 (Table 2), using bis(4-methoxyphenyl)disulphide
1f (0.5 mmol, 0.139 g) and diphenylphosphine oxide 2a
(0.5 mmol, 0.101 g), providing 3f as a colourless liquid. Yield:
1
S-(4-Bromophenyl) diphenylphosphinothioate (3b)7g
0.149 g, 88%; H NMR (400 MHz, CDCl3): δ 3.71 (s, 3H), 6.72
(d, J = 8.8 Hz, 2H), 7.32 (d, J = 8.4 Hz, 2H), 7.42–7.49 (m, 6H),
7.81–7.86 (m, 4H), 7.85 (d, J = 7.2 Hz, 2H); 13C NMR (100 MHz,
The title compound was prepared following the general pro-
cedure for 3 (Table 2), using bis(4-bromophenyl)disulphide 1b
(0.5 mmol, 0.188 g) and diphenylphosphine oxide 2a
(0.5 mmol, 0.101 g), providing 3b as a white solid. Yield:
CDCl3): δ 55.3,114.8, 115.9 (d, JC–P = 5.0 Hz), 128.5 (d, JC–P
=
13.0 Hz), 131.6 (d, JC–P = 11.0 Hz), 132.2 (d, JC–P = 3.0 Hz),
132.6 (d, JC–P = 105.0 Hz), 137.1 (d, JC–P = 4.0 Hz), 160.4.
1
0.182 g, 94%; M.P.: 88 °C; H NMR (400 MHz, CDCl3): δ 7.31
(s, 4H), 7.41–7.46 (m, 4H), 7.48–7.52 (m, 2H), 7.80–7.86 (m,
4H); 13C NMR (100 MHz, CDCl3): δ 123.7 (d, JC–P = 2.0 Hz),
125.3 (d, JC–P = 5.0 Hz), 128.6 (d, JC–P = 13.0 Hz), 131.5 (d,
S-Phenyl di-p-tolylphosphinothioate (3g)
The title compound was prepared following the general pro-
cedure for 3 (Table 2), using diphenyldisulfide 1a (0.5 mmol,
0.109 g) and di(p-tolyl)phosphine oxide 2b (0.5 mmol,
0.115 g), providing 3g as a colourless liquid. Yield: 0.168 g,
JC–P = 10 Hz), 132.1 (d, JC–P = 104 Hz), 132.2, 132.4 (d, JC–P
3.0 Hz), 136.6 (d, JC–P = 3.0 Hz).
=
S-(3-Chlorophenyl) diphenylphosphinothioate (3c)8c
1
99%; H NMR (400 MHz, CDCl3): δ 2.33 (s, 6 H), 7.14–7.21 (m,
The title compound was prepared following the general pro-
cedure for 3 (Table 2), using bis(3-chlorophenyl)disulphide 1c
(0.5 mmol, 0.153 g) and diphenylphosphine oxide 2a
(0.5 mmol, 0.101 g), providing 3c as a white solid. Yield:
0.153 g, 89%; M.P.: 80 °C; 1H NMR (400 MHz, CDCl3): δ 7.09 (t,
J = 8.4 Hz, 1H), 7.18 (dd, J = 0.8 & 8.4 Hz, 1H), 7.36–7.49 (m,
8H), 7.78–7.84 (m, 4H); 13C NMR (100 MHz, CDCl3): δ 128.1 (d,
JC–P = 5.0 Hz), 128.6 (d, JC–P = 14.0 Hz), 129.1, 130.0, 131.5 (d,
7H), 7.42 (s, 1H), 7.44 (d, J = 1.2 Hz, 1H), 7.68 (d, J = 8.4 Hz,
2H), 7.71 (d, J = 8.0 Hz, 2H); 13C NMR (100 MHz, CDCl3): δ
21.5, 126.5 (d, JC–P = 5.0 Hz), 128.7, 129.0, 129.1 (d, JC–P = 13.0
Hz), 129.3 (d, JC–P = 109.0 Hz), 131.5 (d, JC–P = 11.0 Hz), 135.1
(d, JC–P = 3.0 Hz), 142.7 (d, JC–P = 2.0 Hz); 31P (162 MHz,
CDCl3): δ 42.7; HRMS (ESI) exact mass calcd for C20H19OPS +
H (M + H), 339.0972; found: 339.0967.
JC–P = 10.0 Hz), 132.0 (d, JC–P = 105.0 Hz), 132.5 133.4 (d, JC–P
3.0 Hz), 134.4 (d, JC–p = 1.0 Hz), 134.8 (d, JC–P = 4.0 Hz).
=
S-(4-Bromophenyl) di-p-tolylphosphinothioate (3h)
The title compound was prepared following the general pro-
cedure for 3 (Table 2), using bis(4-bromophenyl) disulfide 1b
S-(4-Chlorophenyl) diphenylphosphinothioate (3d)8a
The title compound was prepared following the general pro- (0.5 mmol, 0.188 g) and di(p-tolyl)phosphine oxide 2b
cedure for 3 (Table 2), using bis(4-chloro phenyl)disulfide 1d (0.5 mmol, 0.115 g), providing 3h as a colourless liquid. Yield:
1
(0.5 mmol, 0.143 g) and diphenylphosphine oxide 2a 0.179 g, 86%; H NMR (400 MHz, CDCl3): δ 2.38 (s, 6 H), 7.24
(0.5 mmol, 0.101 g), providing 3d as a white solid. Yield: (d, J = 8.0 Hz, 2H), 7.25 (d, J = 8.0 Hz, 2H), 7.32 (s, 4H), 7.69 (d,
1
0.163 g, 95%; M.P.: 82 °C; H NMR (400 MHz, CDCl3): δ 7.17 J = 8.0 Hz, 2H), 7.72 (d, J = 8.0 Hz, 2H); 13C NMR (100 MHz,
(dd, J = 1.6 & 6.8 Hz, 2H), 7.37 (dd, J = 1.6 & 8.4 Hz, 2H), CDCl3): δ 21.7, 123.6, 126.0, 129.1 (d, JC–P = 109.0 Hz), 129.4 (d,
7.43–7.47 (m, 4H), 7.47–7.53 (m, 2H), 7.81–7.86 (m, 4H); 13C JC–P = 14.0 Hz), 131.6 (d, JC–P = 11.0 Hz), 132.2, 136.6 (d, JC–P
=
NMR (100 MHz, CDCl3): δ 124.7, 128.7 (d, JC–P = 13.0 Hz), 3.0 Hz), 143.1, (d, JC–P = 3.0 Hz); HRMS (ESI) exact mass calcd
129.4, 131.6 (d, JC–P = 11 Hz), 132.2 (d, JC–P = 104.0 Hz), 132.5 for C20H18BrOPS + H (M + H), 417.0078; found: 417.0073.
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S-(4-Chlorophenyl) di-p-tolylphosphinothioate (3i)
JC–P = 4.0 Hz), 138.1 (d, JC–P = 14.0 Hz); HRMS (ESI) exact mass
calcd for C22H23OPS + H (M + H), 367.1285; found: 367.1275.
The title compound was prepared following the general pro-
cedure for 3 (Table 2), using bis(4-chlorophenyl)disulfide 1d
(0.5 mmol, 0.143 g) and di(p-tolyl) phosphine oxide 2b
(0.5 mmol, 0.115 g), providing 3i as a white solid. Yield:
S-(2-Bromophenyl) bis(3,5-dimethylphenyl)phosphinothioate (3m)
The title compound was prepared following the general pro-
cedure for 3 (Table 2), using bis(2-bromophenyl)disulfide 1g
(0.5 mmol, 0.188 g) and bis(3,5-dimethylphenyl)phosphine
oxide 2c (0.5 mmol, 0.129 g), providing 3m as a white solid.
1
0.163 g, 88%; M.P.: 98 °C; H NMR (400 MHz, CDCl3): δ 2.38
(s, 6H), 7.16 (d, J = 8.4 Hz, 2H), 7.24 (d, J = 8.4 Hz, 2H), 7.25 (d,
J = 8.0 Hz, 2H), 7.38 (dd, J = 1.2 & 8.4 Hz, 2H), 7.69 (d, J = 8.0
Hz, 2H), 7.72 (d, J = 8.0 Hz, 2H); 13C NMR (100 MHz, CDCl3): δ
21.7, 125.3 (d, JC–P = 4.0 Hz), 129.1 (d, JC–P = 109.0 Hz), 129.3,
129.5, 131.6 (d, JC–P = 11.0 Hz), 135.3 (d, JC–P = 2.0 Hz), 136.4
(d, JC–P = 4.0 Hz), 143.1 (d, JC–P = 3.0 Hz); HRMS (ESI) exact
mass calcd for C20H18ClOPS + H (M + H), 373.0583; found:
373.0584.
1
Yield: 0.176 g, 79%; M.P.: 84 °C; H NMR (400 MHz, CDCl3):
δ 2.27 (s, 12H), 6.99 (t, J = 7.6 Hz, 1H), 7.07 (s, 2H), 7.14 (t, J =
7.6 Hz, 1H), 7.41 (d, J = 8.0 Hz, 1H), 7.45 (d, J = 13.2 Hz, 4H),
7.91 (d, J = 7.6 Hz, 1H); 13C NMR (100 MHz, CDCl3): δ 21.3,
127.9, 128.3 (d, JC–P = 5.0 Hz), 129.2 (d, JC–P = 10.0 Hz), 129.4
(d, JC–P = 4.0 Hz), 129.9, 131.9 (d, JC–P = 106.0 Hz), 133.3, 134.3
(d, JC–P = 3.0 Hz), 136.7 (d, JC–P = 4.0 Hz), 138.3 (d, JC–P
=
14.0 Hz); HRMS (ESI) exact mass calcd for C22H22BrOPS + Na
(M + Na), 467.0210; found: 469.0201.
S-(p-Tolyl) di-p-tolylphosphinothioate (3j)8c
The title compound was prepared following the general pro-
cedure for 3 (Table 2), using bis(4-methylphenyl)disulfide 1e
(0.5 mmol, 0.123 g) using di(p-tolyl)phosphine oxide 2b
(0.5 mmol, 0.115 g), providing 3j as a colourless liquid. Yield:
S-(3-Bromophenyl) bis(3,5-dimethylphenyl)phosphinothioate
(3n)
The title compound was prepared following the general pro-
cedure for 3 (Table 2), using bis(3-bromophenyl)disulfide 1h
(0.5 mmol, 0.188 g) and bis(3,5-dimethylphenyl)phosphine
oxide 2c (0.5 mmol, 0.129 g), providing 3n as a colourless
1
0.169 g, 96%; H NMR (400 MHz, CDCl3): δ 2.23 (s, 3H), 2.35
(s, 6H), 6.99 (d, J = 8.0 Hz, 2H), 7.21 (d, J = 8.0 Hz, 2H), 7.22 (d,
J = 8.0 Hz, 2H), 7.32 (dd, J = 1.2 & 8.0 Hz, 2H), 7.70 (d, J =
8.0 Hz, 2H), 7.73 (d, J = 8.4 Hz, 2H); 13C NMR (100 MHz,
1
liquid. Yield: 0.191 g, 86%; H NMR (400 MHz, CDCl3): δ 2.31,
CDCl3): δ 21.1, 21.6, 122.7 (d, JC–P = 5.0 Hz), 129.2 (d, JC–P
=
(s, 12H), 7.06 (t, J = 8.0 Hz, 1H), 7.12 (s, 2H), 7.34 (d, J =
8.0 Hz, 1H), 7.39–7.44 (m, 5H), 7.48 (d, J = 1.6 Hz, 1H); 13C
NMR (100 MHz, CDCl3): δ 21.3, 122.3 (d, JC–P = 1.0 Hz),
128.8 (d, JC–P = 5.0 Hz), 129.1, (d, JC–P = 10.0 Hz), 130.2, 131.8
13 Hz), 129.5 (d, JC–P = 109.0 Hz), 129.9, (d, JC–P = 2.0 Hz),
131.6 (d, JC–P = 10.0 Hz), 135.2, (d, JC–P = 3.0 Hz), 138.9
(d, JC–P = 3.0 Hz), 142.7 (d, JC–P = 3.0 Hz).
(d, JC–P = 105.0 Hz), 131.9 (d, JC–P = 1.0 Hz), 134.0 (d, JC–P
=
3.0 Hz), 134.2 (d, JC–P = 3.0 Hz), 137.7 (d, J = 4.0 Hz), 138.4
S-(4-Methoxyphenyl) di-p-tolylphosphinothioate (3k)
C–P
(d, JC–P
= 14.0 Hz); HRMS (ESI) exact mass calcd for
The title compound was prepared following the general pro-
cedure for 3 (Table 2), using bis(4-methoxyphenyl)disulfide 1f
(0.5 mmol, 0.139 g) using di(p-tolyl)phosphine oxide 2b
(0.5 mmol, 0.115 g), providing 3k as a colourless liquid. Yield:
C22H22BrOPS + H (M + H), 445.0391; found: 445.0372.
S-(4-Bromophenyl) bis(3,5-dimethylphenyl)phosphinothioate (3o)
The title compound was prepared following the general pro-
cedure for 3 (Table 2), using bis(4-bromophenyl)disulfide 1b
(0.5 mmol, 0.188 g) and bis(3,5-dimethylphenyl)phosphine
oxide 2c (0.5 mmol, 0.129 g), providing 3o as a white solid.
1
0.164 g, 89%; H NMR (400 MHz, CDCl3): δ 2.35 (s, 6H), 3.71
(s, 3H), 6.71 (d, J = 8.8 Hz, 2H), 7.211 (d, J = 8.0 Hz, 2H), 7.219
(d, J = 8.0 Hz, 2H), 7.32 (dd, J = 1.6 & 8.8 Hz, 2H), 7.67 (d, J =
8.0 Hz, 2H), 7.70 (d, J = 8.0 Hz, 2H); 13C NMR (100 MHz,
CDCl3): δ 21.6, 53.3, 114.8, 116.5 (d, JC–P = 5.0 Hz), 129.2 (d,
JC–P = 13.0 Hz), 129.6, (d, JC–P = 109.0 Hz), 131.6 (d, JC–P = 10
Hz), 136.9 (d, JC–P = 3.0 Hz), 142.7 (d, JC–P = 3.0 Hz), 160.3 (d,
JC–P = 1.0 Hz); HRMS (ESI) exact mass calcd for C21H21O2PS +
H (M + H), 369.1078; found: 369.1077.
1
Yield: 0.196 g, 88%; M.P.: 106 °C; H NMR (400 MHz, CDCl3):
δ 2.30 (s, 12H), 7.10 (s, 2H), 7.27–7.32 (m, 4H), 7.38 (s, 2H),
7.42 (s, 2H); 13C NMR (100 MHz, CDCl3): δ 21.3, 123.6 (d, JC–P
=
2.0 Hz), 125.9 (d, JC–P = 5.0 Hz), 129.1 (d, JC–P = 11.0 Hz), 131.9
(d, JC–P = 105.0 Hz), 132.2, 134.2 (d, JC–P = 3.0 Hz), 136.7 (d,
JC–P = 3.0 Hz), 138.3 (d, JC–P = 13.0 Hz); HRMS (ESI) exact mass
calcd for C22H22BrOPS + H (M + H), 445.0391; found:
445.0383.
S-Phenyl bis(3,5-dimethylphenyl)phosphinothioate (3l)
The title compound was prepared following the general pro-
cedure for 3 (Table 2), using diphenyldisulfide 1a (0.5 mmol,
S-(3-Chlorophenyl) bis(3,5-dimethylphenyl)phosphinothioate (3p)
0.109 g) and bis(3,5-dimethylphenyl)phosphine oxide 2c The title compound was prepared following the general pro-
(0.5 mmol, 0.129 g), providing 3l as a white solid. Yield: cedure for 3 (Table 2), using bis(3-chlorophenyl)disulfide 1c
1
0.157 g, 86%; M.P.: 94 °C; H NMR (400 MHz, CDCl3): δ 2.28 (0.5 mmol, 0.143 g) and bis(3,5-dimethylphenyl)phosphine
(s, 12H), 7.08 (s, 2H), 7.15–7.21 (m, 3H), 7.41 (s, 2H), 7.43–7.44 oxide 2c (0.5 mmol, 0.129 g), providing 3p as a colourless
1
(m, 4H); 13C NMR (100 MHz, CDCl3): δ 21.2, 126.5 (d, JC–P
=
liquid. Yield: 0.166 g, 83%; H NMR (400 MHz, CDCl3): δ 2.33
5.0 Hz), 128.7 (d, JC–P = 1.0 Hz), 129.0 (d, JC–P = 3.0 Hz), 129.1, (s, 12H), 7.12–7.16 (m, 3H), 7.22 (dd, J = 1.2 & 8.0 Hz, 1H), 7.38
132.2 (d, JC–P = 105.0 Hz), 133.9 (d, JC–P = 3.0 Hz), 135.3 (d, (dd, J = 1.6 & 8.0, 2H), 7.41 (s, 2H), 7.45 (s, 2H); 13C NMR
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(100 MHz, CDCl3): δ 21.3, 128.6 (d, JC–P = 5.0 Hz), 129.1 (d, HRMS (ESI) exact mass calcd for C21H21OPS + H (M + H),
JC–P = 10.0 Hz), 129.9, 131.9 (d, JC–P = 105.0 Hz), 133.5 (d, JC–P
=
353.1129; found: 353.1128.
4 Hz), 138.4 (d, JC–P = 14.0 Hz); HRMS (ESI) exact mass calcd
for C22H22ClOPS + H (M + H), 401.0896; found: 401.0882.
S-Benzyl bis(3,5-dimethylphenyl)phosphinothioate (3u)
The title compound was prepared following the general pro-
cedure for 3 (Table 2), using dibenzyldisulfide 1i (0.5 mmol,
S-(p-Tolyl) bis(3,5-dimethylphenyl)phosphinothioate (3q)8c
The title compound was prepared following the general pro- 0.123 g) and bis(3,5 dimethylphenyl)phosphine oxide 2c
cedure for 3 (Table 2), using bis(4-methylphenyl)disulfide 1e (0.5 mmol, 0.129 g), providing 3u as a colourless liquid. Yield:
1
(0.5 mmol, 0.123 g) and bis(3,5-dimethylphenyl)phosphine 0.087 g, 46%; H NMR (400 MHz, CDCl3): δ 2.32 (s, 12H), 4.00
oxide 2c (0.5 mmol, 0.129 g), providing 3q as a white solid. (d, J = 9.2 Hz, 2H), 7.13 (s, 2H), 7.19–7.22 (m, 5H), 7.44 (s, 2H),
1
Yield: 0.190 g, 99%; M.P.: 120 °C; H NMR (400 MHz, CDCl3): 7.47 (s, 2H); 31P (162 MHz, CDCl3): δ 44.7; HRMS (ESI) exact
δ 2.25 (s, 3H), 2.31 (s, 12H), 7.01 (d, J = 8.0 Hz, 2H), 7.11 (s, mass calcd for C23H25OPS + H (M + H), 381.1442; found:
2H), 7.31–7.33 (m, 2H), 7.42 (s, 2H), 7.45 (s, 2H); 13C NMR 381.1440.
(100 MHz, CDCl3): δ 21.1, 21.3, 122.7 (d, JC–P = 5.0 Hz), 129.2
(d, JC–P = 10.0 Hz), 129.9, 132.5 (d, JC–P = 105.0 Hz), 133.9 (d,
S-Cyclohexyl di-p-tolylphosphinothioate (3v)
JC–P = 3.0 Hz), 135.4 (d, JC–P = 4.0 Hz), 138.2 (d, JC–P = 14.0 Hz), The title compound was prepared following the general pro-
139.0.
cedure for 3 (Table 2), using dicyclohexyl disulfide 1j
(0.5 mmol, 0.115 g) and di(p-tolyl)phosphine oxide 2c
(0.5 mmol, 0.115 g), providing 3v as a colourless liquid. Yield:
0.079 g, 61%; H NMR (400 MHz, CDCl3): δ 1.25–1.32 (m, 3H),
S-(4-Methoxyphenyl) bis(3,5-dimethylphenyl)phosphinothioate
(3r)
1
The title compound was prepared following the general pro- 1.46–1.51 (m, 3H), 1.64–1.66 (m, 2H), 1.91–1.95 (m, 2H), 2.38
cedure for 3 (Table 2), using bis(4-methoxyphenyl)disulfide 1f (s, 6H), 3.22–3.30 (m, 1H), 7.25 (d, J = 8.0 Hz, 2H), 7.26 (d, J =
(0.5 mmol, 0.139 g) and bis(3,5-dimethylphenyl)phosphine 7.2 Hz, 2H), 7.71–7.76 (m, 4H); 13C NMR (100 MHz, CDCl3):
oxide 2c (0.5 mmol, 0.129 g), providing 3r as a white solid. δ 21.6, 25.3, 25.8, 35.6 (d, JC–P = 3.0 Hz), 44.3, 129.3 (d, JC–P
=
1
Yield: 0.174 g, 88%; M.P.: 132 °C; H NMR (400 MHz, CDCl3): 14.0 Hz), 129.9 (d, JC–P = 105.0 Hz), 131.5 (d, JC–P = 11.0 Hz),
δ 2.29 (s, 12H), 3.70 (s, 3H), 6.71 (d, J = 8.8 Hz, 2H), 7.08 (s, 142.6 (d, JC–P = 3.0 Hz); HRMS (ESI) exact mass calcd for
2H), 7.30–7.32 (m, 2H), 7.39 (s, 2H), 7.43 (s, 2H); 13C NMR C20H25OPS + H (M + H), 345.1442; found: 345.1868.
(100 MHz, CDCl3): δ 21.2, 55.2, 114.7, 116.4 (d, JC–P = 5.0 Hz),
General procedure for 5 (Table 3)
129.1 (d, JC–P = 10.0 Hz), 132.3 (d, JC–P = 104.0 Hz), 133.9 (d,
JC–P = 3.0 Hz), 137.0 (d, JC–P = 3.0 Hz), 138.1 (d, JC–P = 14 Hz); Diselenides
4
(0.5 mmol) and dialkylphosphonate 2′
HRMS (ESI) exact mass calcd for C23H25O2PS + H (M + H), (0.5 mmol) were mixed in an open flask and then silica gel
397.1391; found: 397.1386.
(1.0 g, 60–120 mesh) was added to this reaction mixture. The
reaction mixture was kept in open air at room temperature for
12 h. After completion of the reaction, the residue was purified
S-Benzyl diphenylphosphinothioate (3s)8a
The title compound was prepared following the general pro- via column chromatography (silica gel, 20% EtOAc in hexanes)
cedure for 3 (Table 2), using dibenzyldisulfide 1i (0.5 mmol, to afford the corresponding products 5.
0.123 g) and diphenylphosphine oxide 2a (0.5 mmol, 0.101 g),
O,O-Diethyl Se-phenyl phosphoroselenoate (5a)9c
providing 3s as a colourless liquid. Yield: 0.084 g, 52%; 1H
NMR (400 MHz, CDCl3): δ 4.02 (d, J = 9.2 Hz, 2H), 7.19–7.21 The title compound was prepared following the general pro-
(m, 5H), 7.43–7.47 (m, 4H), 7.51 (dd, J = 1.6 & 7.2 Hz, 2H), cedure for 5 (Table 3), using diphenyldiselenide 4a (0.5 mmol,
7.83–7.89 (m, 4H); 13C NMR (100 MHz, CDCl3): δ 33.2, 127.4, 0.156 g) and diethylphosphite 2′a (0.5 mmol, 0.069 g), provid-
128.6 (d, JC–P = 3.0 Hz), 128.7, 129.0, 131.5 (d, JC–P = 11.0 Hz), ing 5a as a yellow liquid. Yield: 0.126 g, 86%; 1H NMR
132.3 (d, JC–P = 2.0 Hz), 133.0 (d, JC–P = 106.0 Hz), 136.8 (d, (400 MHz, CDCl3): δ 1.30 (t, J = 6.8 Hz, 6H), 4.12–4.24 (m, 4H),
JC–P = 5.0 Hz).
7.28–7.36 (m, 3H), 7.63–7.65 (m, 2H); 13C NMR (100 MHz,
CDCl3): δ 15.9 (d, JC–P = 7.0 Hz), 63.8 (d, JC–P = 5.0 Hz), 123.7
(d, JC–P = 9.0 Hz), 128.8 (d, JC–P = 3.0 Hz), 129.4 (d, JC–P = 1.0
S-Benzyl di-p-tolylphosphinothioate (3t)
The title compound was prepared following the general pro- Hz), 135.5 (d, JC–P = 5.0 Hz).
cedure for 3 (Table 2), using dibenzyldisulfide 1i (0.5 mmol,
O,O-Diethyl Se-(4-methoxyphenyl) phosphoroselenoate (5b)
0.123 g) and di(p-tolyl) phosphine oxide 2b (0.5 mmol,
0.115 g), providing 3t as a colourless liquid. Yield: 0.084 g, The title compound was prepared following the general pro-
48%; 1H NMR (400 MHz, CDCl3): δ 2.31 (s, 6H), 3.91 (d, J = 8.8 cedure for 5 (Table 3), using bis(4-methoxyphenyl)diselenide
Hz, 2H), 7.11–7.14 (m, 5H), 7.16–7.19 (m, 4H), 7.65 (d, J = 8.0 4b (0.5 mmol, 0.186 g) and diethylphosphite 2′a (0.5 mmol,
Hz, 2H), 7.68 (d, J = 8.4 Hz, 2H); 13C NMR (100 MHz, CDCl3): 0.069 g), providing 5b as a yellow liquid. Yield: 0.125 g, 78%;
δ 21.6, 33.2, 127.3, 128.6, 129.0, 129.4 (d, JC–P = 14.0 Hz) 129.9 1H NMR (400 MHz, CDCl3): δ 1.31 (t, J = 7.2 Hz, 6H), 3.80 (s,
(d, JC–P = 107.0 Hz), 131.6 (d, JC–P = 11.0 Hz), 137.0 (d, JC–P
=
3H), 4.14–4.20 (m, 4H), 6.84 (d, J = 8.8 Hz, 2H), 7.540 (d, J = 9.2
6.0 Hz), 142.9 (d, JC–P = 2.0 Hz); 31P (162 MHz, CDCl3): δ 43.9; Hz, 1H). 7.545 (d, J = 9.2 Hz, 1H); 13C NMR (100 MHz, CDCl3):
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δ 16.0 (d, JC–P = 7.0 Hz), 55.3, 63.8 (d, JC–P = 6.0 Hz), 113.7 (d, O,O-Dibutyl Se-(p-tolyl) phosphoroselenoate (5g)9f
JC–P = 8.0 Hz), 115.2 (d, JC–P = 1.0 Hz), 137.3 (d, JC–P = 4.0 Hz),
The title compound was prepared following the general pro-
cedure for 5 (Table 3), using bis(4-methylphenyl)diselenide 4c
(0.5 mmol, 0.170 g) and dibutylphosphite 2′b (0.5 mmol,
160.4; 31P (162 MHz, CDCl3): δ 19.0; HRMS (ESI) exact mass
calcd for C11H17O4PSe + H (M + H), 325.0108; found: 325.0110.
0.097 g), providing 5g as a yellow liquid. Yield: 0.155 g, 85%;
O,O-Diethyl Se-(p-tolyl) phosphoroselenoate (5c)9f
1H NMR (400 MHz, CDCl3): δ 0.89 (t, J = 7.6 Hz, 6H), 1.32–1.39
The title compound was prepared following the general pro-
cedure for 5 (Table 3), using bis(4-methylphenyl)diselenide 4c
(0.5 mmol, 0.170 g) and diethylphosphite 2′a (0.5 mmol,
0.069 g), providing 5c as a yellow liquid. Yield: 0.129 g, 84%;
1H NMR (400 MHz, CDCl3): δ 1.28–1.32 (m, 6H), 2.33 (s, 3H),
4.13–4.21 (m, 4H), 7.12 (d, J = 8.0 Hz, 2H), 7.49–7.52 (m, 2H);
13C NMR (100 MHz, CDCl3): δ 15.9 (d, JC–P = 8.0 Hz), 21.2, 63.7
(d, JC–P = 5.0 Hz), 119.9 (d, JC–P = 9.0 Hz), 130.3 (d, JC–P = 1.0
Hz), 135.6 (d, JC–P = 4.0 Hz), 139.0 (d, JC–P = 2.0 Hz); 31P
(162 MHz, CDCl3): δ 18.9.
(m, 4H), 1.58–1.66 (m, 4H), 2.33 (s, 3H), 4.06–4.12 (m, 4H),
7.11 (d, J = 8.0 Hz, 2H), 7.49–7.52 (m, 2H); 13C NMR (100 MHz,
CDCl3): δ 13.5, 18.6, 21.1, 32.0 (d, JC–P = 7.0 Hz), 67.4 (d, JC–P
=
6.0 Hz), 119.9 (d, JC–P = 8.0 Hz), 130.2 (d, JC–P = 1.0 Hz), 135.5
(d, JC–P = 5.0 Hz), 138.9 (d, JC–P = 3.0 Hz); 31P (162 MHz,
CDCl3): δ 19.0.
O,O-Dibutyl Se-(o-tolyl) phosphoroselenoate (5h)
The title compound was prepared following the general pro-
cedure for 5 (Table 3), using bis(2-methylphenyl)diselenide 4d
(0.5 mmol, 0.170 g) and dibutylphosphite 2′b (0.5 mmol,
0.097 g), providing 5h as a yellow liquid. Yield: 0.150 g, 83%;
1H NMR (400 MHz, CDCl3): δ 0.88 (t, J = 7.2 Hz, 6H), 1.31–1.38
(m, 4H), 1.57–1.64 (m, 4H), 2.51 (s, 3H), 4.02–4.12 (m, 4H),
7.10 (d, J = 7.6 Hz, 1H), 7.24 (d, J = 4.0 Hz, 2H), 7.70 (d, J = 7.6
Hz, 1H); 13C NMR (100 MHz, CDCl3): δ 13.4, 18.5, 23.3, 31.9 (d,
JC–P = 7.0 Hz), 67.4 (d, JC–P = 7.0 Hz), 124.7 (d, JC–P = 9.0 Hz),
126.6, 129.1, 130.4, 137.0 (d, JC–P = 3.0 Hz), 141.7 (d, JC–P = 4.0
Hz); 31P (162 MHz, CDCl3): δ 18.3; HRMS (ESI) exact mass
calcd for C15H25O3PSe + H (M + H), 365.0785; found: 365.0786.
O,O-Diethyl Se-(o-tolyl) phosphoroselenoate (5d)
The title compound was prepared following the general pro-
cedure for 5 (Table 3), using 2-methyl diphenyldiselenide 4d
(0.5 mmol, 0.170 g) and diethylphosphite 2′a (0.5 mmol,
0.069 g), providing 5d as a yellow liquid. Yield 0.134 g, 87%;
1H NMR (400 MHz, CDCl3): δ 1.27–1.31 (m, 6H), 2.52 (s, 3H),
4.11–4.19 (m, 4H), 7.09–7.14 (m, 1H), 7.25–7.27 (m, 2H), 7.71
(d, J = 8.0 Hz, 1H); 13C NMR (100 MHz, CDCl3): δ 15.9 (d, JC–P
=
7.0 Hz), 23.4, 63.8 (d, JC–P = 6.0 Hz), 124.7 (d, JC–P = 8.0 Hz),
126.8, 129.3 (d, JC–P = 2.0 Hz), 130.5 (d, JC–P = 2.0 Hz), 137.2
(d, JC–P = 3.0 Hz), 141.9 (d, JC–P = 4.0 Hz); 31P (162 MHz, CDCl3)
δ 18.2; HRMS (ESI) exact mass calcd for C11H17O3PSe + H
(M + H), 309.0159; found: 309.0137.
5,5-Dimethyl-2-(phenylselanyl)-1,3,2-dioxaphosphinane
2-oxide (5i)9g
The title compound was prepared following the general pro-
cedure for 5 (Table 3), using diphenyldiselenide 4a (0.5 mmol,
0.156 g) and 5,5 dimethyl 1,3,2-dioxaphosphirane-2-oxide 2′c
(0.5 mmol, 0.079 g), providing 5i as a yellow liquid. Yield:
Se-(4-Bromophenyl) O,O-diethyl phosphoroselenoate (5e)
The title compound was prepared following the general pro-
cedure for 5 (Table 3), using bis(4-bromophenyl)diselenide 4e
(0.5 mmol, 0.235 g) and diethylphosphite 2′a (0.5 mmol,
0.069 g), providing 5e as a yellow liquid. Yield: 0.166 g, 89%;
1H NMR (400 MHz, CDCl3): δ 1.32 (t, J = 7.2 Hz, 6H), 4.16–4.22
(m, 4H), 7.44 (d, J = 7.6 Hz, 2H), 7.51 (d, J = 8.4 Hz, 2H); 13C
1
0.140 g, 92%; H NMR (400 MHz, CDCl3): δ 0.85 (s, 3H), 1.27
(s, 3H), 3.82 (d, J = 11.2 Hz, 1H), 3.88 (d, J = 11.2 Hz, 1H), 4.15
(dd, J = 3.6 & 10.4 Hz, 2H), 7.29–7.36 (m, 3H), 7.70–7.72 (m,
2H); 13C NMR (100 MHz, CDCl3): δ 20.3, 22.0, 32.4 (d, JC–P
=
7.0 Hz), 78.1 (d, JC–P = 7.0 Hz), 121.7 (d, JC–P = 7.0 Hz), 129.0 (d,
JC–P = 3.0 Hz), 129.6, 135.8 (d, JC–P = 5.0 Hz); 31P (162 MHz,
CDCl3): δ 10.2.
NMR (100 MHz, CDCl3): δ 16.0 (d, JC–P = 7.0 Hz), 64.1 (d, JC–P
=
6.0 Hz), 122.7 (d, JC–P = 8.0 Hz), 132.7, 136.3 (d, JC–P = 5.0 Hz),
137.0 (d, JC–P = 5.0 Hz); 31P (162 MHz, CDCl3): δ 17.6; HRMS
(ESI) exact mass calcd for C10H14BrO3PSe + H (M + H),
372.9107; found: 372.9079.
2-((4-Methoxyphenyl)selanyl)-5,5-dimethyl-1,3,2-
dioxaphosphinane 2-oxide (5j)
O,O-Dibutyl Se-phenyl phosphoroselenoate (5f)9g
The title compound was prepared following the general pro-
The title compound was prepared following the general pro- cedure for 5 (Table 3), using bis(4-methoxyphenyl)diselenide
cedure for 5 (Table 3), using diphenyldiselenide 4a (0.5 mmol, 4b (0.5 mmol, 0.170 g) and 5,5 dimethyl 1,3,2-dioxaphosphir-
0.156 g) and dibutylphosphite 2′b (0.5 mmol, 0.097 g), provid- ane-2-oxide 2′c (0.5 mmol, 0.079 g), providing 5j as a yellow
1
ing 5f as a yellow liquid. Yield 0.164 g, 94%; 1H NMR liquid. Yield: 0.150 g, 90%; H NMR (400 MHz, CDCl3): δ 0.86,
(400 MHz, CDCl3): δ 0.86–0.90 (m, 6H), 1.31–1.36 (m, 4H), (s, 3H), 1.26 (s, 3H), 3.78 (s, 3H), 3.83 (d, J = 11.2 Hz, 1H), 3.89
1.59–1.63 (m, 4H), 4.04–4.14 (m, 4H), 7.27–7.34 (m, 3H), (d, J = 11.2 Hz, 1H), 4.14 (dd, J = 4.4 &10.8 Hz, 2H), 6.85 (d, J =
7.62–7.65 (m, 2H); 13C NMR (100 MHz, CDCl3): δ 13.3, 18.4, 8.8 Hz, 2H), 7.602 (d, J = 8.8 Hz, 1H), 7.607 (d, J = 8.8 Hz, 1H);
31.8 (d, JC–P = 7.0 Hz), 67.3 (d, JC–P = 7.0 Hz), 123.5 (d, JC–P
=
13C NMR (100 MHz, CDCl3): δ 20.4, 22.1, 32.5 (d, JC–P = 6.0 Hz),
8.0 Hz), 128.5 (d, JC–P = 3.0 Hz), 129.2, 135.2 (d, JC–P = 4.0 Hz); 53.3, 78.0 (d, JC–P = 7.0 Hz), 111.4 (d, JC–P = 8.0 Hz), 115.4 (d,
31P (162 MHz, CDCl3): δ 18.5.
JC–P = 1.0 Hz), 137.6 (d, JC–P = 4.0 Hz), 160.5 (d, JC–P = 2.0 Hz);
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31P (162 MHz, CDCl3): δ 10.9; HRMS (ESI) exact mass calcd for mass calcd for C15H23NOS + H (M + H), 266.1579; found:
C12H17O4PSe + H (M + H), 337.0108; found: 337.0089.
266.1561.
5,5-Dimethyl-2-(o-tolylselanyl)-1,3,2-dioxaphosphinane 2-oxide (5k)
The title compound was prepared following the general pro-
cedure for 5 (Table 3), using 2-methyl diphenyldiselenide 4d
(0.5 mmol, 0.170 g) and 5,5 dimethyl 1,3,2-dioxaphosphirane-
2-oxide 2′c (0.5 mmol, 0.079 g), providing 5k as a yellow liquid.
Conclusions
In conclusion, we have developed a general and green syn-
thetic protocol for the phosphorylation of chalcogenides under
catalyst-free and solvent-free conditions. The developed
method is highly atom-economical and shows good functional
group tolerance. Disulfides, diselenides, and ditellurides pos-
sessing different substituents coupled with a variety of phos-
phorus surrogates under the optimized reaction conditions
provided the corresponding products phosphinothioates,
phosphoroselenoates and phosphorotelluroates, respectively,
in good to excellent yields. Furthermore, to establish the
potential applicability of this procedure in organic synthesis,
large-scale experiments were also performed.
1
Yield: 0.140 g, 88%; H NMR (400 MHz, CDCl3): δ 0.84 (s, 3H),
1.26 (s, 3H), 2.56 (s, 3H), 3.85 (d, J = 11.2 Hz, 1H), 3.91 (d, J =
11.2 Hz, 1H), 4.11 (dd, J = 4.4 &10.8 Hz, 2H), 7.10–7.14 (m,
1H), 7.27 (d, J = 4.4 Hz, 2H), 7.77 (d, J = 7.2 Hz, 1H); 13C NMR
(100 MHz, CDCl3): δ 20.5, 22.1, 23.6, 32.5 (d, JC–P = 7.0 Hz),
78.1 (d, JC–P = 8.0 Hz), 123.1 (d, JC–P = 8.0 Hz), 127.0, 129.6 (d,
JC–P = 3.0 Hz), 130.7 (d, JC–P = 3.0 Hz), 137.6 (d, JC–P = 4.0 Hz),
142.5 (d, JC–P = 4.0 Hz); 31P (162 MHz, CDCl3): δ 10.1; HRMS
(ESI) exact mass calcd for C12H17O3PSe + H (M + H), 321.0159;
found: 321.0135.
O,O-Diethyl Se-propyl phosphoroselenoate (5l)9c
Conflicts of interest
The title compound was prepared following the general pro-
cedure for 5 (Table 3), using dipropyldiselenide 4f (0.5 mmol,
0.122 g) and diethylphosphite 2′a (0.5 mmol, 0.069 g), provid-
ing 5l as a yellow liquid. Yield: 0.101 g, 78%; 1H NMR
(400 MHz, CDCl3): δ 1.01 (t, J = 7.6 Hz, 3H), 1.37 (t, J = 7.2 Hz,
6H), 1.75–1.84 (m, 2H), 2.82–2.89 (m, 2H), 4.13–4.20 (m, 4H);
13C NMR (100 MHz, CDCl3): δ 14.1, 15.8 (d, JC–P = 8.0 Hz), 24.4
(d, JC–P = 4.0 Hz), 28.4 (d, JC–P = 4.0 Hz), 63.1 (d, JC–P = 6.0 Hz);
31P (162 MHz, CDCl3): δ 21.5.
There are no conflicts to declare.
Acknowledgements
The Council of Scientific and Industrial Research (No. 02
(0341)/18/EMR-II) is gratefully acknowledged for financial
support. P. S. thanks the UGC and R. B. thanks the CSIR-India
for their fellowships. S. S. B. is DST INSPIRE Faculty (IFA-2014/
CH-167), DST-India. We thank MRC-MNIT Jaipur for NMR
data collection.
O,O-Diethyl Te-phenyl phosphorotelluroate (7a)9c
The title compound was prepared following the general pro-
cedure for 5 (Table 3), using diphenylditelluride 6 (0.5 mmol,
0.204 g) and diethylphosphite 2′a (0.5 mmol, 0.069 g), provid-
ing 7a as a brown liquid. Yield: 0.137 g, 80%; 1H NMR
(400 MHz, CDCl3): δ 1.31 (t, J = 7.2 Hz, 6H), 4.10–4.18 (m, 4H),
7.23–7.27 (m, 2H), 7.35 (dd, J = 1.2 & 7.6 Hz, 1H).7.83 (t, J = 7.6
Hz, 2H); 13C NMR (100 MHz, CDCl3): δ 15.8 (d, JC–P = 7.0 Hz),
63.5 (d, JC–P = 6.0 Hz), 108.9 (d, JC–P = 8.0 Hz), 128.9, 129.7,
139.9 (d, JC–P = 3.0 Hz); 31P (162 MHz, CDCl3): δ −0.3.
Notes and references
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The title compound was prepared following the general pro-
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0.204 g) and dibutylphosphite 2′b (0.5 mmol, 0.097 g), provid-
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CDCl3): δ 13.6, 18.7, 31.9 (d, JC–P = 7.0 Hz), 67.2 (d, JC–P
6.0 Hz), 108.8 (d, JC–P = 8.0 Hz), 128.9, 129.6, 139.9 (d, JC–P
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