Phosphinoyl Radical-Initiated 1,2-Bifunctional Thiocyanodiphenylphosphinoylation of Alkenes

Article abstract of DOI:10.1021/acs.joc.7b02929

1,2-Bifuctional thiocyanodiphenylphosphinoylation of alkenes is established through the phosphinoyl radical addition followed by Cu-catalyzed thiocyanation. This one-pot reaction is applicable to a range of aromatic, aliphatic, and cyclic alkenes to afford thiocyanodiphenylphosphinoylated compounds in satisfactory yields.

Full text of DOI:10.1021/acs.joc.7b02929

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Note
Phosphinoyl Radical-Initiated 1,2-Bifunctional
Thiocyanodiphenylphosphinoylation of Alkenes
Ze-Kun Tao, Cheng-Kun Li, Pei-Zhi Zhang, Adedamola Shoberu, Jian-Ping Zou, and Wei Zhang
J. Org. Chem., Just Accepted Manuscript • DOI: 10.1021/acs.joc.7b02929 • Publication Date (Web): 27 Jan 2018
Downloaded from http://pubs.acs.org on January 27, 2018
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Phosphinoyl RadicalꢀInitiated 1,2ꢀBifunctional
Thiocyanodiphenylphosphinoylation of Alkenes
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ZeꢀKun Tao,† ChengꢀKun Li,† PeiꢀZhi Zhang,† Adedamola Shoberu,†
JianꢀPing Zou,*,† Wei Zhang*,‡
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† Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry and Chemical
Engineering, Soochow University, Jiangsu 215123, China
‡ Department of Chemistry, University of Massachusetts Boston, MA 02125, USA
ABSTRACT: 1,2ꢀBifuctional thiocyanodiphenylphosphinoylation of alkenes is established through
phosphinoyl radical addition followed by Cuꢀcatalyzed thiocyanation. This oneꢀpot reaction is
applicable to
a
range of aromatic, aliphatic, and cyclic alkenes to afford
thiocyanodiphenylphosphinoylated compounds in satisfactory yields.
Radicalꢀinitiated bifunctionalization of alkenes is an attractive method for introducing a set of
groups during a oneꢀpot reaction process.1 On the basis of successful vicinal oxyphosphinoylation,2
hydroxyphosphinoylation, acetoxyphosphinoylation,3 and halophosphinoylation4 reactions reported
in the literature, we recently developed phosphinoyl radicalꢀinitiated aminophosphinoylation and
cyanophosphinoylation reactions (Scheme 1, a and b)5. Introduced in this paper is the extension of
the new method for bifunctional thiocyanodiphenylsphinoylation (Scheme 1, c). Both phosphinoyl
and thiocyano are functional groups commonly found in biologically active compounds. Bifunctional
thiocyanosphinoylated compounds could be useful in the development of new agricultural and
pharmaceutical chemicals,6,7 as well as phosphine ligands for metalꢀcatalyzed reactions.
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Thiocyanates are ubiquitous moieties in bioactive compounds such as antimicrobial7b,8 or
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antiproliferative activitiy.7c as well as key building blocks for construction of various heterocyclic
skeletons.9 Furthermore, organic thiocyanates could be easily isomerized to isothiocyanates under
heating. The later have been widely applied for synthesis of agrochemicals and polymers.10 In
addition, thiocyano is a versatile group which can be used for the synthesis of other organosulfur
compounds such as thiols, thioethers, disulfides, thiocarbamates, and heterocycles.6
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Scheme 1. Phosphorus Radicalꢀinitiated Bifunctionalizations
_____________________________________________________
The development of reaction conditions was carried out using styrene 1a, HP(O)Ph2 2a, and
trimethylsilylisothiocyanate (TMSNCS, 3) as substrates. The initial reaction using CuSCN as a
catalyst, Mn(OAc)3 as an oxidant and Nꢀmethylꢀ2ꢀpyrrolidone (NMP) as a solvent at room
temperature gave desired product 4a in 41% yield (Table 1, entry 1). The ꢀSCN group of 4a was
confirmed by a week IR peak at 2158 cmꢀ1 and a 13CꢀNMR peak at 110.7 ppm, which are in
accordance with that reported in literature.11 If it is a ꢀNCS group, it should have a strong IR peak at
2020ꢀ2100 cmꢀ1 and a broad 13CꢀNMR peak at 134ꢀ143 ppm.10 Conducting reactions between 0 to 55
o
oC indicated that 10 C was a good temperature which gave 54% yield (Table 1, entry 3). The effort
of exploring other oxidants including DTBP, TBHP, Ag2CO3, and AgNO3; alternative SCN sources
such as KSCN, NH4SCN and TsSCN; and different solvents such as DMSO, MeOH, toluene, and
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MeCN, all failed to give better results (see supporting information (SI), Tables S1ꢀS3). The
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screening of Cuꢀcatalysts including CuI, CuBr, CuCl, and Cu(OAc)2 indicated that CuBr2 is better
than CuSCN to give product in 63% yield at 10 mol % loading (Table 1, entries 5ꢀ8, see also SI,
Table S4), whereas a control reaction without using a copper catalyst gave no product (Table 1, entry
9). Exploring different ligands including 2,2'ꢀdipyridine (2,2’ꢀdipy), N,Nꢀdimethylethylenediamine
(DMEDA), N,N,N,Nꢀtetramethylethylenediamine (TMEDA), and 1,10ꢀphenanthroline (phen) (Table
1, entries 10−13), and fine tuning the ratio of reaction components revealed that a reaction of 1:3:3:3
of 1a/2a/3/Mn(OAc)3 with 10 mol % each of CuBr2 and 2,2’ꢀbipy in NMP at 10 °C for 3 h under
argon is an optimized condition to afford product 4a in 69% yield (Table 1, entry 14, see SI, Table
S5).
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Table 1. Optimization of the reaction conditionsa
Cuꢀcat
(mol %)
temp
(°C)
yieldb
(%)
ligand
(mol %)
entry
1

CuSCN (20)
CuSCN (20)
CuSCN (20)
CuSCN (20)
CuBr2 (20)
CuBr2 (5)
25
55
10
0
41
33
54
20
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50
63
30
ndc
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62
50
66

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
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10
6
7
CuBr2 (10)
CuBr2 (1
8
equiv)
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
2,2'ꢀdipy
(10)
DMEDA
(10)
TMEDA
(10)
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13
CuBr2 (10)
CuBr2 (10)
CuBr2 (10)
CuBr2 (10)
10
10
phen (10)
14d
CuBr2 (10)
10
69
2,2'ꢀdipy
(10)
aConditions: 1a (0.5 mmol), 2a (2.5 mmol), 3 (4 mmol),
Mn(OAc)3.2H2O (2.5 mmol) in NMP (3 mL) at 10 °C for 3 h
under Ar. bIsolated yield. cnd means not detected. d1a (0.5
mmol), 2a (1.5 mmol), 3 (1.5 mmol) and Mn(OAc)3.2H2O (1.5
mmol) were used.
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A series of styrene derivatives were used for bifunctional thiocyanodiphenylphosphinoylation
under the optimized conditions. As shown in Scheme 2, starting materials with substitution groups
at different positions of aromatic ring reacted smoothly to give the corresponding difunctionalization
products 4b−n in moderate to good yields. In general, the yields of electronꢀrich substrates are higher
than that of electronꢀwithdrawing substrates. For instance, substrates bearing Meꢀ or MeOꢀ
substituents, regardless of substitution position, afforded products in 69ꢀ79% yields (Scheme 2,
4b−g). Whereas substrates containing electronꢀwithdrawing groups such as Cl, Br, F, CN and NO2
groups gave products in 44−60% yields (Scheme 2, 4h−n). The reaction of 2ꢀvinylnaphthalene was
also attempted to give 4o in 67% yield. But the reaction of 2ꢀvinylpyridine produced a complicated
mixture, the desired product 4p was not isolated. In addition to diphenylphosphine oxide 2a,
dimethylꢀ and diethyl phosphites were also used to form difunctionalization compounds 4q and 4r,
but alkenylphosphonates 4qʹ and 4rʹ were observed as byꢀproducts. The byꢀproducts were generated
from the deprotonation process after the phosphinoyl radical addition. Reactions of vinyl substituted
aryl alkenes were also attempted. αꢀMethylstyrene and βꢀphenylstyrene gave product 4t and 4u in
35% and 48% yields, respectively. But no products were detected from the reactions of βꢀ
methylstyrene and αꢀphenylstyrene. Only 2,2ꢀdiphenylvinyl diphenylphosphine oxide was isolated
(see mechanism discussion later). Reactions of cyclic aromatic alkenes 1,2ꢀdihydronaphthalene and
indene gave 4v and 4w in 65% and 69% yields, respectively.
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Scheme 2. Reactions of Styrene Derivativesa,b
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aConditions: 1 (0.5 mmol), 2a (1.5 mmol), 3 (1.5 mmol), CuBr2 (0.05
mmol), 2,2’ꢀbipy (0.05 mmol), Mn(OAc)3.2H2O (1.5 mmol) in NMP (3
mL) at 10 °C, 3 h under Ar. bIsolated yield.
The thiocyanophosphinoylation reaction is also applicable to nonꢀaromatic alkenes such as
cyclohexene and cyclooctene to give 5a and 5b in 36% and 40% yields, respectively (Scheme 3).
Reactions of aliphatic alkenes containing nonꢀconjugated phenyl, conjugated ester, conjugated or
nonꢀconjugated phthalimide all processed smoothly to afford corresponding products 5c−j in
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satisfactory yields. Interestingly, the reaction for thiocyanated (ꢀSCN) 5j produced an isothiocyanated
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(ꢀNCS) isomer 5j’ as a byproduct through isomerizayion under heating.10
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Scheme 3. Reactions of alkenesa
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aConditions: 1 (0.5 mmol), 2a (1.5 mmol), 3 (1.5 mmol), CuBr2 (0.05 mmol),
2,2’ꢀbipy (0.05 mmol), Mn(OAc)3.2H2O (1.5 mmol) in NMP (3 mL) at 10 °C, 3
h under Ar. Isolated yield.
_________________________________________________
Several control reactions were carried out to understand the mechanism of
thiocyanodiphenylphosphinoylation reaction and thiocyanation (Scheme 4). In the presence of 2,6ꢀ
diꢀtertꢀbutylꢀ4ꢀmethylphenol (BHT), the reaction of styrene under the standard conditions resulted in
a trace amount of expected product 4a together with radical trapping compound 6 (Scheme 4, a). A
similar reaction with TEMPO completely stopped the formation of 4a (Scheme 4, b). These results
suggest that phosphinoyl radical is involved in the reaction of thiocyanodiphenylphosphinoylation.
The reaction of 1,1ꢀdiphenylethylene without a radical tapping agent only gave (2,2ꢀdiphenylvinyl)
diphenylphosphine oxide 7 (Scheme 4, c). The reaction of styrene under the standard conditions with
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the addition of 4.0 equiv of tetrabutylammonium bromide (TBAB) provided product 4a in 68% yield,
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but without brominated product 8 (Scheme 4, d and e). This result cannot prove an ionic process,
which is different from the result of previously reported cyanophosphinoylation reaction.5b
Furthermore, no evidence indicates that SCN radical was involved in the reaction process since no
SCN radical was trapped by 1,1ꢀdiphenylethylene and BHT (see SI, Scheme S1).
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Scheme 4. Control Reactions
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A reaction mechanism for thiocyanodiphenylphosphinoylation is proposed based on the analysis
of the results from the control reactions (Scheme 5). The initial phosphinoyl radical A, generated
from the oxidation of HPOPh2 2a with MnIII, adds to alkene 1 to form radical B.12,13 It then reacts
with a CuII complex E which is formed through the interaction of TMSNCS 3 with CuII to form
complex C.14 Complex C undergoes elimination of F to form thiocyanodiphenylphosphinoylation
products 4 or 5.
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Scheme 5. Mechanism for thiocyanodiphenylphosphinoylation
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MnII
MnIII
O
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HPOPh2
PPh2
A
2
Ln
X
NCS
R1
R1
CuIII
1
POPh2
C
3
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LnCuIIX2
LnCuIIX
D
LnCuIX
POPh2
SCN
SCN
R1
E
POPh2
B
R1
F
MnIII
4 or 5
MnII
In summary, phosphinoyl radicalꢀinitiated bifunctionalization has been developed for
thiocyanodiphenylphosphinoylation through Mn(OAc)3 oxidation of diphenylphosphine oxide
followed phosphinoyl addition to alkene and then Cuꢀcatalyzed thiocyanation. This oneꢀpot reaction
is applicable to
a
range of aromatic, aliphatic, and cyclic alkenes to afford
thiocyanodiphenylphosphinoylation compounds in satisfactory yields.
EXPERIMENTAL SECTION
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General Methods. H NMR (400 MHz) and C NMR (101 MHz) spectra were obtained using
CDCl3 or DMSOꢀd6 as solvent and tetramethylsilane (TMS) as internal standard or 85% H3PO4 as
external standard for 31P NMR (162 MHz). Chemical shifts δ were reported in ppm using TMS as an
internal stand. All coupling constants (J values) were reported in Hertz (Hz). High resolution mass
spectra were recorded on a TOF machine (ESI). Column chromatography was performed with 300ꢀ
400 mesh silica gel using flash column techniques. All alkenes were purified by flash column
chromatography (Al2O3) before use.
Typical procedure for the preparation of diphenyl(2ꢀphenylꢀ2ꢀthiocyanatoethyl)phosphine
oxide (4a). To a Schlenk tube charged with a magnetic stirring bar, CuBr2 (0.05 mmol), 2,2'ꢀ
dipyridyl (0.05 mmol) and Mn(OAc)3·2H2O (1.5 mmol) were added and flushed with argon gas three
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times. A solution of styrene (1a, 0.50 mmol), HP(O)Ph2 (2a, 0.75 mmol) and TMSNCS (3, 0.75
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3
o
mmol) in NMP (2 mL) was injected. The mixture was allowed to stir at 10 C for 0.5 h, then a
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solution of HP(O)Ph2 (2a, 0.75 mmol) and TMSNCS (3, 0.75 mmol) in NMP (1 mL) was injected
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o
again. The mixture was stirred at 10 C for 2.5 h (monitored with TLC). After the substrate was
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consumed, water (60 mL) was added to the reaction mixture, then extracted with ethyl acetate (20
mL×3). The combined organic layer was washed with saturated sodium bicarbonate solution (20
mL×3) and dried with anhydrous Na2SO4, filtered, and concentrated in vacuo. The residue was
purified by flash chromatography on silica gel (1:10 AcOEt:CH2Cl2) to afford product 4a.
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Diphenyl(2ꢀphenylꢀ2ꢀthiocyanatoethyl)phosphine oxide (4a). White solid, Mp: 157.8ꢀ159.5 C,
1
68% yield (123.42 mg). H NMR (400 MHz, CDCl3): δ 7.82 – 7.74 (m, 2H), 7.58 – 7.46 (m, 5H),
7.41 – 7.36 (m, 1H), 7.31 – 7.24 (m, 4H), 7.20 – 7.12 (m, 3H), 5.04 – 4.92 (m, 1H), 3.30 – 3.10 (m,
2H); 13C NMR (101 MHz, CDCl3): δ 136.9 (d, J = 4.8 Hz), 131.8 (d, J = 2.7 Hz), 131.3 (d, J = 2.7
Hz), 130.2 (d, J = 5.3 Hz), 130.1 (d, J = 5.4 Hz), 128.7, 128.5, 128.43, 128.40, 128.1, 128.0, 127.0,
110.7, 46.6, 36.0 (d, J = 66.3 Hz); 31P NMR (162 MHz, CDCl3): δ 26.78. IR (cm−1):
(ESIꢀTOF) m/z: (M+Na)+ calcd for C21H18NOPSNa 386.0744, found 386.0754.
ν
2158. HRMS
o
Diphenyl(2ꢀthiocyanatoꢀ2ꢀ(oꢀtolyl)ethyl)phosphine oxide (4b). White solid, mp: 117.2ꢀ119.2 C,
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69% yield (130.1 mg). H NMR (400 MHz, CDCl3): δ 7.84 – 7.75 (m, 2H), 7.60 – 7.46 (m, 5H),
7.41 – 7.36 (m, 1H), 7.21 – 7.31 (m, 3H), 7.11 – 7.03 (m, 2H), 7.01ꢀ6.95 (m, 1H), 5.35 – 5.23 (m,
1H), 3.41 – 3.19 (m, 2H), 2.38 (s, 3H); 13C NMR (101 MHz, CDCl3): δ 135.7, 134.3 (d, J = 4.2 Hz),
131.8 (d, J = 2.7 Hz), 131.2 (d, J = 2.7 Hz), 130.4, 130.1, 130.0 (d, J = 1.4 Hz), 129.9, 128.5, 128.4,
31
128.0, 127.9, 126.2, 126.1, 110.7, 42.5, 36.0 (d, J = 66.1 Hz), 18.9; P NMR (162 MHz, CDCl3): δ
26.91. IR (cm−1):
found 400.0892.
ν
2151. HRMS (ESIꢀTOF) m/z: (M+Na)+ calcd for C22H20NOPSNa 400.0901,
o
Diphenyl(2ꢀthiocyanatoꢀ2ꢀ(pꢀtolyl)ethyl)phosphine oxide (4c). White solid, Mp: 151.9ꢀ154.2 C,
75% yield (141.4 mg). 1H NMR (400 MHz, CDCl3): δ 7.77–7.74 (m, 2H), 7.56 – 7.45 (m, 5H), 7.42
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– 7.37 (m, 1H), 7.25–7.31 (m, 2H), 7.17 – 7.09 (m, 2H), 7.03–6.87 (m, 2H), 5.03 – 4.84 (m, 1H),
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3
4
3.32 – 3.07 (m, 2H), 2.24 (s, 3H); 13C NMR (101 MHz, CDCl3): δ 138.7, 133.8 (d, J = 4.6 Hz), 131.8
(d, J = 2.8 Hz), 131.0 (d, J = 2.8 Hz), 130.2 (d, J = 2.0 Hz), 130.1 (d, J = 2.2 Hz), 129.0, 128.5,
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128.4, 128.0, 127.9, 127.0, 110.8, 46.6, 36.2 (d, J = 66.4 Hz), 20.6; P NMR (162 MHz, CDCl3): δ
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26.85. IR (cm−1):
found 400.0896.
ν
2155. HRMS (ESIꢀTOF) m/z: (M+Na)+ calcd for C22H20NOPSNa 400.0901,
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Diphenyl(2ꢀthiocyanatoꢀ2ꢀ(mꢀtolyl)ethyl)phosphine oxide (4d). White solid, Mp: 122.3ꢀ124 C,
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79% yield (148.9 mg). H NMR (400 MHz, CDCl3): δ 7.92 – 7.67 (m, 3H), 7.55 – 7.46 (m, 5H),
7.40 – 7.35 (m, 1H), 7.30 – 7.27 (m, 1H), 7.09 – 7.04 (m, 2H),7.01 – 6.95 (m, 2H), 5.05 – 4.89 (m,
13
1H), 3.27 – 3.12 (m, 2H), 2.19 (s, 3H). C NMR (101 MHz, CDCl3): δ 138.1, 136.6, 131.8, 131.2,
130.2, 130.1, 129.5, 128.5, 128.39, 128.35, 127.9, 127.8, 127.7, 124.2, 110.8, 46.7, 36.2 (d, J = 66.3
Hz), 20.8; 31P NMR (162 MHz, CDCl3): δ 26.88. IR (cm−1):
ν 2152. HRMS (ESIꢀTOF) m/z:
(M+Na)+ calcd for C22H20NOPSNa 400.0901, found 400.0890.
(2ꢀ(4ꢀMethoxyphenyl)ꢀ2ꢀthiocyanatoethyl)diphenylphosphine oxide (4e). White solid, Mp: 121.9ꢀ
122.8 oC, 72% yield (141.5 mg). 1H NMR (400 MHz, CDCl3): δ 7.83 – 7.73 (m, 2H), 7.59 – 7.32 (m,
8H), 7.24 – 7.08 (m, 2H), 6.84 – 6.64 (m, 2H), 5.50 – 5.10 (m, 1H), 3.73 (s, 3H), 3.07 – 2.94 (m, 1H),
2.87 – 2.60 (m, 1H); 13C NMR (101 MHz, CDCl3): δ 159.7, 133.9, 132.2, 131.8, 131.2 (d, J = 7.6
Hz), 130.8 (d, J = 9.2 Hz), 130.5 (d, J = 9.1 Hz), 129.0, 128.9, 128.7, 128.6, 127.3, 114.3, 55.3 (d, J
= 13.2 Hz), 39.3 (d, J = 67.9 Hz), 29.7; P NMR (162 MHz, CDCl3): δ 26.89. IR (cm−1):
ν 2138.
31
HRMS (ESIꢀTOF) m/z: (M+Na)+ calcd for C22H20NO2PSNa 416.0850, found 416.0864.
(2ꢀ(3ꢀMethoxyphenyl)ꢀ2ꢀthiocyanatoethyl)diphenylphosphine oxide (4f). White solid, Mp: 138.4ꢀ
141.3 oC, 78% yield (153.3 mg). 1H NMR (400 MHz, CDCl3): δ 7.82 – 7.73 (m, 2H), 7.57 – 7.47 (m,
5H), 7.40 – 7.36 (m, 1H), 7.35 – 7.26 (m, 2H),7.14 – 7.04 (m, 1H), 6.89 – 6.83 (m, 1H), 6.78 – 6.67
(m, 2H), 5.13 – 4.82 (m, 1H), 3.71 (s, 3H), 3.29 – 3.02 (m, 2H); 13C NMR (101 MHz, CDCl3): δ
159.2, 138.3 (d, J = 3.8 Hz), 131.9, 131.2, 130.2, 130.1 (d, J = 1.6 Hz), 129.54, 128.52, 128.4, 128.0,
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127.9, 119.3, 114.4, 112.5, 110.7, 54.7, 46.5, 29.2; P NMR (162 MHz, CDCl3): δ 26.90. IR (cm−1):
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ν
2141. HRMS (ESIꢀTOF) m/z: (M+Na)+ calcd for C22H20NO2PSNa 416.0850, found 416.0851.
(2ꢀ(2ꢀMethoxyphenyl)ꢀ2ꢀthiocyanatoethyl)diphenylphosphine oxide (4g). White solid, Mp: 136.6ꢀ
137.1 oC, 69% yield (135.6 mg). 1H NMR (400 MHz, CDCl3): δ 7.81 – 7.75 (m, 2H), 7.56 – 7.48 (m,
5H), 7.41 – 7.37 (m, 1H), 7.33 – 7.27 (m, 2H), 7.25 – 7.22 (m, 1H), 7.19 – 7.12 (m, 1H), 6.83 – 6.77
(m, 1H), 6.67 – 6.60 (m, 1H), 5.33 – 5.23 (m, 1H), 3.75 (s, 3H), 3.40 – 3.31 (m, 1H), 3.28 – 3.17 (m,
1H); 13C NMR (101 MHz, CDCl3): δ 156.0, 131.7 (d, J = 2.6 Hz), 131.1 (d, J = 2.7 Hz), 130.2, 130.1
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(d, J = 1.7 Hz), 130.0, 129.9, 128.4, 128.3, 128.2, 127.9, 127.8, 120.1, 111.5, 110.3, 54.8, 42.4, 34.6
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(d, J = 66.9 Hz); P NMR (162 MHz, CDCl3): δ 26.98. IR (cm−1):
ν 2050. HRMS (ESIꢀTOF) m/z:
(M+Na)+ calcd for C22H20NO2PSNa 416.0850, found 416.0837.
(2ꢀ(4ꢀChlorophenyl)ꢀ2ꢀthiocyanatoethyl)diphenylphosphine oxide (4h). White solid, Mp: 194.8ꢀ
196.6 oC, 58% yield (115.1 mg). 1H NMR (400 MHz, CDCl3): δ 7.81 – 7.72 (m, 2H), 7.60 – 7.39 (m,
6H), 7.34 – 7.27 (m, 2H), 7.22 – 7.14 (m, 2H), 7.14 – 7.01 (m, 2H), 5.02 – 4.90 (m, 1H), 3.28 – 3.04
(m, 2H); 13C NMR (101 MHz, CDCl3): δ 135.2 (d, J = 4.2 Hz), 134.7, 132.0 (d, J = 2.8 Hz), 131.3 (d,
J = 3.1 Hz), 131.2 (d, J = 4.0 Hz), 130.1, 130.0, 128.58, 128.55, 128.47, 128.1, 128.0, 110.3, 46.0,
36.2 (d, J = 65.8 Hz ); 31P NMR (162 MHz, CDCl3): δ 26.62. IR (cm−1):
m/z: (M+Na)+ calcd for C21H17ClNOPSNa 420.0355, found 420.0338.
ν 2156. HRMS (ESIꢀTOF)
(2ꢀ(2ꢀChlorophenyl)ꢀ2ꢀthiocyanatoethyl)diphenylphosphine oxide (4i). Yellow solid, Mp: 122.7ꢀ
125 oC, 56% yield (111.2 mg). 1H NMR (400 MHz, CDCl3): δ 7.85 – 7.72 (m, 2H), 7.67 – 7.49 (m,
5H), 7.46 – 7.41 (m, 1H), 7.40 – 7.31 (m, 3H), 7.31 – 7.26 (m, 1H), 7.21 – 7.09 (m, 2H), 5.49 – 5.29
(m, 1H), 3.42 – 3.12 (m, 2H); 13C NMR (101 MHz, CDCl3): δ 134.8 (d, J = 5.2 Hz), 133.4, 132.4 (d,
J = 2.3 Hz), 132.0 (d, J = 2.3 Hz), 130.8, 130.6 (d, J = 2.8 Hz), 130.5, 130.2, 130.1, 129.0, 128.9,
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128.7, 128.6, 127.3, 110.8, 43.4, 35.4 (d, J = 66.0 Hz); P NMR (162 MHz, CDCl3): δ 26.59. IR
(cm−1):
ν
2146. HRMS (ESIꢀTOF) m/z: (M+Na)+ calcd for C21H17ClNOPSNa 420.0355, found
420.0364.
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(2ꢀ(3ꢀChlorophenyl)ꢀ2ꢀthiocyanatoethyl)diphenylphosphine oxide (4j). White solid, Mp: 158.6ꢀ
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2
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159.8 oC, 60% yield (119.1 mg). 1H NMR (400 MHz, CDCl3): δ 7.81 – 7.72 (m, 2H), 7.63 – 7.45 (m,
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5H), 7.43 – 7.37 (m, 1H), 7.36 – 7.28 (m, 2H), 7.21 – 7.00 (m, 4H), 5.02 – 4.91 (m, 1H), 3.25 – 3.06
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(m, 2H); 13C NMR (101 MHz, CDCl3): δ 138.7 (d, J = 4.4 Hz), 134.2, 132.0 (d, J = 2.8 Hz), 131.5 (d,
J = 2.9 Hz), 130.1, 130.0, 129.7, 128.9, 128.6, 128.5, 128.1, 128.0, 127.2, 125.4, 110.1, 45.9, 35.9 (d,
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J = 65.8 Hz); 31P NMR (162 MHz, CDCl3): δ 26.48. IR (cm−1):
ν 2157. HRMS (ESIꢀTOF) m/z:
(M+Na)+ calcd for C21H17ClNOPSNa 420.0355, found 420.0357.
(2ꢀ(4ꢀBromophenyl)ꢀ2ꢀthiocyanatoethyl)diphenylphosphine oxide (4k). White solid, Mp: 196ꢀ
198.4 oC, 50% yield (110.0 mg). 1H NMR (400 MHz, CDCl3): δ 7.82 – 7.69 (m, 2H), 7.61 – 7.39 (m,
6H), 7.34 – 7.22 (m, 4H), 7.17 – 7.04 (m, 2H), 5.04 – 4.87 (m, 1H), 3.30 – 3.03 (m, 2H); 13C NMR
(101 MHz, CDCl3): δ 135.7 (d, J = 3.8 Hz), 132.0 (d, J = 1.9 Hz), 131.5, 131.2 (d, J = 2.2 Hz),
130.14, 130.05, 128.7, 128.6, 128.5, 128.2, 128.0, 122.9, 110.3, 46.0, 36.2 (d, J = 66.0 Hz); 31P
NMR (162 MHz, CDCl3): δ 26.49. IR (cm−1):
ν
2156. HRMS (ESIꢀTOF) m/z: (M+Na)+ calcd for
C21H17BrNOPSNa 463.9850, found 463.9856.
(2ꢀ(4ꢀFluorophenyl)ꢀ2ꢀthiocyanatoethyl)diphenylphosphine oxide (4l). White solid, Mp: 176.6ꢀ
o
178.8 C, 55% yield (104.8 mg). 1H NMR (400 MHz, CDCl3): δ 7.86 – 7.69 (m, 2H), 7.65 – 7.38
(m, 6H), 7.35 – 7.27 (m, 2H), 7.26 – 7.18 (m, 2H), 6.95 – 6.64 (m, 2H), 5.09 – 4.91 (m, 1H), 3.38 –
2.78 (m, 2H); 13C NMR (101 MHz, CDCl3): δ 163.6, 161.1, 132.5 (d, J = 3.9 Hz), 131.9 (d, J = 2.7
Hz), 131.3 (d, J = 2.7 Hz), 130.1, 130.0, 129.0 (d, J = 8.6 Hz), 128.5 (d, J = 12.0 Hz), 128.0 (d, J =
12.1 Hz), 115.5, 115.3, 110.5, 46.0, 36.3 (d, J = 66.1 Hz); 31P NMR (162 MHz, CDCl3): δ 26.64. IR
(cm−1):
ν
2156. HRMS (ESIꢀTOF) m/z: (M+Na)+ calcd for C21H17FNOPSNa 404.0650, found
404.0652.
(2ꢀ(4ꢀCyanophenyl)ꢀ2ꢀthiocyanatoethyl)diphenylphosphine oxide (4m). White solid, Mp: 155.6ꢀ
157.6 oC, 48% yield (93.12 mg). 1H NMR (400 MHz, CDCl3): δ 7.81 – 7.66 (m, 3H), 7.58 – 7.51 (m,
2H), 7.51 – 7.47 (m, 2H), 7.41 – 7.34 (m, 6H), 7.29 – 7.26 (m, 1H), 5.59 – 5.50 (m, 1H), 3.50 – 3.22
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(m, 2H); 13C NMR (101 MHz, CDCl3): δ 145.0 (d, J = 3.1 Hz), 131.9 (d, J = 2.8 Hz), 131.6, 131.2 (d,
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J = 2.7 Hz), 130.1, 130.04 (d, J = 1.8 Hz), 129.96, 128.5, 128.4, 128.0, 127.9, 126.6, 117.7, 111.8,
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44.1, 40.8 (d, J = 63.4 Hz); 31P NMR (162 MHz, CDCl3): δ 26.32. IR (cm−1):
TOF) m/z: (M+H)+ calcd for C22H18N2OPS 389.0877, found 389.0866.
ν 2230. HRMS (ESIꢀ
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(2ꢀ(4ꢀNitrophenyl)ꢀ2ꢀthiocyanatoethyl) diphenylphosphine oxide (4n). White solid, Mp: 168.1ꢀ
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o
1
171.1 C, 44% yield (89 mg). H NMR (400 MHz, CDCl3): δ 7.90 (d, J = 8.3 Hz, 2H), 7.80 – 7.63
(m, 2H), 7.60 – 7.30 (m, 8H), 7.23 (t, J = 6.8 Hz, 2H), 5.70ꢀ5.50 (m, 1H), 3.60 – 3.18 (m, 2H). 13C
NMR (101 MHz, CDCl3): δ 147.4 (d, J = 16.0 Hz), 132.4, 131.7, 130.7, 130.62, 130.57, 130.49,
129.0 (d, J = 9.1 Hz), 128.7, 128.4 (d, J = 10.1 Hz), 123.6, 44.1, 29.7. 31P NMR (162 MHz, CDCl3):
δ 26.34. IR (cm−1):
ν
2156. HRMS (ESIꢀTOF) m/z: (M+Na)+ Calcd for C21H17N2NaO3PS 431.0595,
found 431.0595.
(2ꢀ(Naphthalenꢀ2ꢀyl)ꢀ2ꢀthiocyanatoethyl)diphenylphosphine oxide (4o). White solid, Mp: 161.1ꢀ
162.5 oC, 67% yield (138.4 mg). 1H NMR (400 MHz, CDCl3): δ 7.81 – 7.75 (m, 2H), 7.73 – 7.62 (m,
4H), 7.57 – 7.33 (m, 8H), 7.18 – 7.10 (m, 1H), 7.09 – 6.92 (m, 2H), 5.25 – 5.12 (m, 1H), 3.37 – 3.19
(m, 2H); 13C NMR (101 MHz, CDCl3): δ 133.9 (d, J = 4.1 Hz), 132.8, 132.2, 131.9 (d, J = 1.8 Hz),
130.9 (d, J = 2.1 Hz), 130.2, 130.1 (d, J = 4.4 Hz), 130.0, 128.6, 128.5, 128.4, 127.74, 127.70, 127.6,
127.1, 127.0, 126.4, 126.1, 110.6, 47.0, 36.2 (d, J = 66.7 Hz). 31P NMR (162 MHz, CDCl3): δ 26.84.
IR (cm−1):
436.0895.
ν
2043. HRMS (ESIꢀTOF) m/z: (M+Na)+ Calcd for C25H20NOPSNa 436.0901, found
Mixture of dimethyl (2ꢀthiocyanatoꢀ2ꢀ(pꢀtolyl)ethyl)phosphonate (4q) and dimethyl (4ꢀ
methylstyryl) phosphonate (4q’). Colorless liquid. 15% (4q) and 23% (4q’) yield (47.3 mg),
respectively, 4q : 4q’ =1 : 1.33, analyzed by 1H NMR spectrum; 1H NMR (400 MHz, CDCl3): δ 7.50
(dd, J = 22.6, 17.5 Hz, 1.34H), 7.40 (d, J = 8.1 Hz, 2.66H), 7.28 (d, J = 8.2 Hz, 2H), 7.23 – 7.17 (m,
4.66H), 6.16 (t, J = 17.8 Hz, 2H), 4.75 (dd, J = 16.0, 8.2 Hz, 1H), 3.77 (d, J = 11.1 Hz, 8H), 3.64 (d,
J = 11.1 Hz, 3H), 3.47 (d, J = 11.0 Hz, 3H), 2.70 (dd, J = 19.0, 7.4 Hz, 2H), 2.37 (s, 4H), 2.35 (s,
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3H); 13C NMR (101 MHz, CDCl3): δ 149.2 (d, J = 6.8 Hz), 140.4, 139.1, 133.8 (d, J = 6.0 Hz), 131.6,
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129.4, 129.1, 127.3, 126.9, 111.5, 109.6, 52.2, 52.1 (d, J = 4.3 Hz), 52.01, 51.96, 51.91, 47.0, 32.3,
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31.0, 21.0, 20.8; 31P NMR (162 MHz, CDCl3): δ 26.68, 22.89. IR (cm−1):
ν 2054. HRMS (ESIꢀTOF)
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of 4q m/z: (M+Na)+ Calcd for C12H16NO3PSNa 308.0486, found 308.0472; HRMS (ESIꢀTOF) of
4q’ m/z: (M+Na)+ Calcd for C11H15O3PNa 249.0657, found 249.0650.
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Mixture of diethyl (2ꢀthiocyanatoꢀ2ꢀ(pꢀtolyl)ethyl)phosphonate (4r) and diethyl (4ꢀmethylstyryl)
phosphonate (4r’). Colorless liquid. 21% (4r) and 19% (4r’) yield (245.5 mg), respectively, 4r : 4r’
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=1 : 0.89, analyzed by H NMR spectrum; H NMR (400 MHz, CDCl3): δ 7.47 (dd, J = 22.6, 17.5
Hz, 0.89H), 7.30 – 7.23 (m, 2.79H), 7.21 – 7.16 (m, 3.77H), 6.19 (t, J = 17.7 Hz, 0.89H), 4.76 (dt, J
= 15.5, 7.7 Hz, 1H), 4.17 – 4.07 (m, 3.56H), 4.04 – 3.96 (m, 2H), 3.93 – 3.73 (m, 2H), 2.72 – 2.63
(m, 2H), 2.36 (s, 2.67H), 2.34 (s, 3H), 1.34 (t, J = 7.1 Hz, 5.34H), 1.22 (t, J = 7.1 Hz, 3H), 1.13 (t, J
= 7.1 Hz, 3H). 13C NMR (101 MHz, CDCl3): δ 167.7, 167.6, 133.7, 133.4, 131.6, 131.4, 130.4 (d, J
= 9.3 Hz), 130.3 (d, J = 9.3 Hz), 129.98 (d, J = 9.4 Hz), 129.95 (d, J = 9.6 Hz), 128.4 (d, J = 3.7 Hz),
128.3 (d, J = 3.8 Hz), 123.0, 122.8, 109.8, 44.6, 42.0 (d, J = 1.8 Hz), 39.9 (d, J = 64.0 Hz), 37.7 (d, J
= 3.7 Hz), 36.4, 35.8, 34.7 (d, J = 4.9 Hz), 34.7; 31P NMR (162 MHz, CDCl3): δ 23.88, 20.02. IR
(cm−1):
ν
2150. HRMS (ESIꢀTOF) of 4r m/z: (M+Na)+ Calcd for C14H20NO3PSNa 336.0799, found
336.0808; HRMS (ESIꢀTOF) of 4r’ m/z: (M+Na)+ Calcd for C13H19O3PNa 277.0970, found
277.0957.
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Diphenyl(2ꢀphenylꢀ2ꢀthiocyanatopropyl)phosphine oxide (4t). White solid, Mp: 154.6–155.5 C,
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35% yield (66.0 mg). H NMR (400 MHz, CDCl3): δ 7.82–7.70 (m, 2H), 7.60 – 7.54 (m, 2H), 7.53 –
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7.45 (m, 3H), 7.44 – 7.32 (m, 5H), 7.26 – 7.14 (m, 3H), 3.03 – 2.89 (m, 2H), 2.17 (s, 3H). C NMR
(101 MHz, CDCl3): δ 143.13, 143.07, 131.8 (d, J = 2.6 Hz), 131.5 (d, J = 2.5 Hz), 130.7 (d, J = 9.4
Hz), 130.4 (d, J = 9.2 Hz), 128.9, 128.8, 128.64, 128.58, 128.5, 128.0, 124.7, 64.6 (d, J = 3.3 Hz),
43.9 (d, J = 67.5 Hz), 30.3 (d, J = 1.8 Hz). 31P NMR (162 MHz, CDCl3): δ 24.96. IR (cm−1):
HRMS (ESIꢀTOF) m/z: (M+Na)+ Calcd for C22H20NOPSNa 400.0901, found 400.0887.
ν
2229.
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1,2ꢀDiphenylꢀ2ꢀthiocyanatoethyl diphenylphosphine oxide (4u). White solid, Mp: 135.6–136.5
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oC, 48% yield (105.4 mg). 1H NMR (400 MHz, CDCl3): δ 7.56 – 7.44 (m, 6H), 7.39 – 7.35 (m, 2H),
7.29 – 7.15 (m, 9H), 7.08 – 6.99 (m, 3H), 5.45 (dd, J = 11.0, 8.0 Hz, 1H), 4.26 (dd, J = 11.2, 6.2 Hz,
1H). 13C NMR (101 MHz, CDCl3): δ 136.5 (d, J = 1.6 Hz), 133.8 (d, J = 4.7 Hz), 132.3, 131.8, 130.6
(d, J = 2.7 Hz), 130.5 (d, J = 2.9 Hz), 130.1, 130.0, 129.9, 129.5, 128.6, 128.3, 128.2, 128.0, 127.7 (d,
J = 11.8 Hz), 127.4 (d, J = 11.9 Hz), 111.0, 55.4 (d, J = 3.0 Hz), 51.7 (d, J = 62.4 Hz). 31P NMR
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(162 MHz, CDCl3): δ 28.86. IR (cm−1):
ν
2148. HRMS (ESIꢀTOF) m/z: (M+Na)+ Calcd for
C27H22NNaOPS 462.1057, found 462.1065.
Diphenyl(1ꢀthiocyanatoꢀ1,2,3,4ꢀtetrahydronaphthalenꢀ2ꢀyl)phosphine oxide (4v). White solid,
Mp: 183.2–184.6 oC, 65% yield (127.1 mg), dr = 8:1. 1H NMR (400 MHz, CDCl3): δ 7.97 – 7.85 (m,
4H), 7.85 – 7.80 (m, 0.48H), 7.61 – 7.47 (m, 6.72H), 7.37 – 7.29 (m, 0.24H), 7.24 – 7.06 (m, 4.24H),
5.39 (t, J = 9.1 Hz, 0.12H), 5.08 (d, J = 9.0 Hz, 1H), 3.61 – 2.97 (m, 2H), 2.99 – 2.92 (m, 0.12H),
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2.89 – 2.70 (m, 1.24H), 2.62 – 2.29 (m, 1H), 2.14 – 2.04 (m, 1H), 2.03 – 1.98 (m, 0.24H). C NMR
(101 MHz, CDCl3): δ 137.6, 135.5, 131.9, 131.7, 131.5, 131.1, 130.7, 130.6, 130.5, 130.4, 130.3,
130.2, 129.7, 129.3, 129.0, 128.6, 128.5 (d, J = 2.5 Hz), 128.4, 127.8, 127.1, 126.6, 126.2, 111.6,
54.1, 48.3 (d, J = 2.4 Hz), 38.5 (d, J = 65.1 Hz), 27.7 (d, J = 9.8 Hz), 26.0 (d, J = 3.5 Hz), 22.2, 21.0,
18.8. 31P NMR (162 MHz, CDCl3): δ 31.54, 30.92. IR (cm−1):
ν 2054. HRMS (ESIꢀTOF) m/z:
(M+Na)+ Calcd for C23H20NNaOPS 412.0901, found 412.0894.
Diphenyl(1ꢀthiocyanatoꢀ2,3ꢀdihydroꢀ1Hꢀindenꢀ2ꢀyl)phosphine oxide (4w). Colorless liquid, 69%
yield (245.5 mg), dr > 20:1. 1H NMR (400 MHz, CDCl3): δ 7.94 – 7.81 (m, 4H), 7.58 – 7.47 (m, 6H),
7.34 – 7.30 (m, 1H), 7.27 – 7.21 (m, 2H), 7.17 – 7.10 (m, 1H), 5.06 (dd, J = 14.0, 5.4 Hz, 1H), 3.71
– 3.57 (m, 1H), 3.46 – 3.27 (m, 2H). 13C NMR (101 MHz, CDCl3): δ 140.8 (d, J = 5.0 Hz), 138.2 (d,
J = 4.8 Hz), 132.0 (d, J = 2.7 Hz), 131.8 (d, J = 2.6 Hz), 130.8, 130.7, 130.5, 130.4, 129.1, 128.6,
128.4, 127.4, 124.4, 124.3, 110.3, 52.1, 44.9 (d, J = 69.3 Hz), 31.9. 31P NMR (162 MHz, CDCl3): δ
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31.55. IR (cm−1):
found 398.0731.
ν
2046. HRMS (ESIꢀTOF) m/z: (M+Na)+ calcd for C22H18NOPSNa 398.0744,
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Diphenyl (2ꢀthiocyanatocyclohexyl) phosphine oxide (5a). Colorless liquid, 36% yield (61.3 mg),
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dr > 20:1. H NMR (400 MHz, CDCl3): δ 7.94 – 7.82 (m, 3H), 7.80 – 7.71 (m, 2H), 7.57ꢀ7.50 (m,
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3H), 7.49ꢀ7.40 (m, 2H), 4.80ꢀ4.72 (m, 1H), 2.91ꢀ2.82 (m, 1H), 2.55ꢀ2.44 (m, 1H), 2.05 – 1.87 (m,
3H), 1.84 – 1.74 (m, 1H), 1.73 – 1.63 (m, 1H), 1.65 – 1.56 (m, 1H), 1.55 – 1.41 (m, 1H). 13C NMR
(101 MHz, CDCl3): δ 131.4, 131.2 (d, J = 2.0 Hz), 130.31, 130.26, 130.23, 130.18, 128.5, 128.4 (d, J
= 8.6 Hz), 128.2, 52.2 (d, J = 3.3 Hz), 42.1 (d, J = 64.6 Hz), 33.5, 22.3 (d, J = 3.0 Hz), 21.9, 21.2. 31P
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NMR (162 MHz, CDCl3): δ 32.64. IR (cm−1):
ν
2150. HRMS (ESIꢀTOF) m/z: (M+Na)+ calcd for
C19H20NNaOPS 364.0901, found 364.0910.
Diphenyl (2ꢀthiocyanatocyclooctyl) phosphine oxide (5b). Colorless liquid, 40% yield (73.2 mg),
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dr > 20:1. H NMR (400 MHz, CDCl3): δ 7.88ꢀ7.80 (m, 4H), 7.58 – 7.37 (m, 6H), 5.01 – 4.66 (m,
1H), 3.04 – 2.94 (m, 1H), 2.35 – 2.22 (m, 1H), 2.14 – 2.05 (m, 2H), 2.03 – 1.80 (m, 2H), 1.73 – 1.58
(m, 5H), 1.58 – 1.45 (m, 1H), 1.38 – 1.28 (m, 1H). 13C NMR (101 MHz, CDCl3): δ 131.2, 130.9,
130.8, 130.2, 130.1, 128.3, 128.2, 128.0, 127.9, 52.0, 45.6 (d, J = 71.5 Hz), 32.7 (d, J = 6.0 Hz), 27.8
(d, J = 8.9 Hz), 25.4, 25.3, 24.7, 24.1. 31P NMR (162 MHz, CDCl3): δ 36.87. IR (cm−1):
HRMS (ESIꢀTOF) m/z: (M+Na)+ calcd for C21H24NOPSNa 392.1214, found 392.1208.
ν 2150.
(2ꢀMethylꢀ3ꢀphenylꢀ2ꢀthiocyanatopropyl)diphenylphosphine oxide (5c). Red liquid, 33% yield
(34.5 mg). 1H NMR (400 MHz, CDCl3): δ 7.87 – 7.80 (m, 2H), 7.78 – 7.70 (m, 2H), 7.54 – 7.42 (m,
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6H), 7.36 – 7.21 (m, 5H), 3.38 (q, J = 14.1 Hz, 2H), 3.00 – 2.85 (m, 2H), 1.57 (s, 3H); C NMR
(101 MHz, CDCl3): δ 134.7, 131.7 (d, J = 2.7 Hz), 131.6 (d, J = 2.6 Hz), 130.7, 130.34, 130.25,
130.0, 129.9, 128.6 (d, J = 3.6 Hz), 128.5 (d, J = 3.6 Hz), 127.8, 127.1, 111.3, 58.6 (d, J = 2.4 Hz),
46.0 (d, J = 2.2 Hz), 39.8 (d, J = 64.5 Hz), 27.2 (d, J = 3.2 Hz); 31P NMR (162 MHz, CDCl3): δ
26.29. IR (cm−1):
found 414.1042.
ν
2152. HRMS (ESIꢀTOF) m/z: (M+Na)+ calcd for C23H22NOPSNa 414.1057,
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Diphenyl(3ꢀphenylꢀ2ꢀthiocyanatopropyl)phosphine oxide (5d). White solid, Mp: 108.2–110.6 C,
48% yield (91.0 mg). 1H NMR (400 MHz, CDCl3): δ 7.85 – 7.78 (m, 2H), 7.75 – 7.69 (m, 2H), 7.57
– 7.46 (m, 6H), 7.31 – 7.25 (m, 3H), 7.19 – 7.15 (m, 2H), 4.60 – 4.41 (m, 1H), 3.57 (dd, J = 14.6, 3.7
Hz, 1H), 3.17 – 3.01 (m, 3H); 13C NMR (101 MHz, CDCl3): δ 137.4, 131.7 (d, J = 2.5 Hz), 131.6 (d,
J = 2.5 Hz), 130.5, 130.4, 130.1, 130.0, 129.0, 128.9, 128.5 (d, J = 5.1 Hz), 128.4 (d, J = 5.0 Hz),
127.8, 126.5, 48.0, 45.4 (d, J = 4.0 Hz), 39.3 (d, J = 64.7 Hz); 31P NMR (162 MHz, CDCl3): δ 28.32.
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IR (cm−1):
400.0894.
ν
2147. HRMS (ESIꢀTOF) m/z: (M+Na)+ calcd for C22H20NOPSNa 400.0901, found
Diphenyl(4ꢀphenylꢀ2ꢀthiocyanatobutyl)phosphine oxide (5e). Colorless liquid, 50% yield (98.3
mg). 1H NMR (400 MHz, CDCl3): δ 7.75 – 7.70 (m, 4H), 7.55 – 7.46 (m, 6H), 7.25 – 7.15 (m, 3H),
7.11 – 7.09 (m, 2H), 3.56 – 3.35 (m, 1H), 2.94 – 2.77 (m, 3H), 2.70 – 2.63 (m, 1H), 2.54 – 2.42 (m,
1H), 2.13 – 2.03 (m, 1H); 13C NMR (101 MHz, CDCl3): δ 139.4, 132.2 (d, J = 2.7 Hz), 130.8, 130.7,
130.5, 130.4, 129.0, 128.9, 128.6, 128.42 (d, J = 6.7 Hz), 128.38, 126.4, 110.5, 44.2 (d, J = 2.0 Hz),
37.3 (d, J = 24.8 Hz), 36.9 (d, J = 37.0 Hz), 32.7; 31P NMR (162 MHz, CDCl3): δ 27.50. IR (cm−1):
ν
2151. HRMS (ESIꢀTOF) m/z: (M+Na)+ calcd for C23H22NOPSNa 414.1057, found 414.1044.
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Diphenyl (2ꢀthiocyanatooctyl) phosphine oxide (5f). Colorless liquid, 38% yield (70.3 mg). H
NMR (400 MHz, CDCl3): δ 7.83 – 7.65 (m, 4H), 7.58 – 7.41 (m, 6H), 4.49 – 4.29 (m, 1H), 3.15ꢀ3.03
(m, 1H), 3.01 – 2.83 (m, 1H), 2.13 – 1.94 (m, 1H), 1.83 – 1.70 (m, 1H), 1.30 – 1.11 (m, 8H), 0.87 –
0.82 (m, 3H). 13C NMR (101 MHz, CDCl3): δ 131.6 (d, J = 2.7 Hz), 131.5 (d, J = 2.7 Hz), 130.5,
130.4, 130.1, 130.0, 128.4 (d, J = 3.9 Hz), 128.30, 128.26, 48.8, 40.2 (d, J = 64.4 Hz), 39.3 (d, J =
3.6 Hz), 31.0, 27.8, 26.9, 22.0, 13.6. 31P NMR (162 MHz, CDCl3): δ 28.39. IR (cm−1):
HRMS (ESIꢀTOF) m/z: (M+Na)+ calcd for C21H26NNaOPS 394.1370, found 394.1359.
ν 2058.
2ꢀ(Diphenylphosphoryl)ꢀ1ꢀthiocyanatoethyl acetate (5g). Colorless liquid, 65% yield (112.1 mg).
1H NMR (400 MHz, CDCl3): δ 7.85 – 7.70 (m, 4H), 7.60 – 7.47 (m, 6H), 6.48 – 4.28 (m, 1H), 3.45 –
3.29 (m, 1H), 3.09ꢀ2.89 (m, 1H), 1.66 (s, 3H); 13C NMR (101 MHz, CDCl3): δ 167.6, 132.1, 131.8,
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130.5 (d, J = 7.9 Hz), 130.1 (d, J = 8.0 Hz), 128.63, 128.57, 128.4, 128.3, 108.4, 76.7, 72.0, 19.5; P
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NMR (162 MHz, CDCl3): δ 26.27. IR (cm−1):
ν
2054. HRMS (ESIꢀTOF) m/z: (M+Na)+ calcd. for
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C17H16NO3PSNa 368.0486, found 368.0480.
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2ꢀ((2ꢀDiphenylphosphorylꢀ1ꢀthiocyanato)ethyl)isoindolineꢀ1,3ꢀdione (5h). Yellow liquid, 58%
yield (125.3 mg). 1H NMR (400 MHz, CDCl3): δ 7.79 – 7.68 (m, 6H), 7.65 – 7.57 (m, 3H), 7.55 –
7.50 (m, 2H), 7.21 – 7.12 (m, 3H), 6.49 – 6.32 (m, 1H), 4.15 – 3.95 (m, 1H), 3.00 (t, J = 13.3 Hz,
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1H); 13C NMR (101 MHz, CDCl3): δ 165.2, 134.1, 132.2 (d, J = 1.9 Hz), 131.3 (d, J = 1.9 Hz), 130.5,
130.2 (d, J = 1.5 Hz), 130.1 (d, J = 1.3 Hz), 128.7, 128.6, 128.1, 128.0, 123.4, 108.9, 51.0, 32.9 (d, J
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= 64.5 Hz); P NMR (162 MHz, CDCl3): δ 25.30. IR (cm−1):
ν 2150. HRMS (ESIꢀTOF) m/z:
(M+Na)+ calcd for C23H17N2O3PSNa 455.0595, found 455.0584.
2ꢀ((10ꢀDiphenylphosphorylꢀ9ꢀthiocyanato)decyl)isoindolineꢀ1,3ꢀdione (5i). Colorless liquid,
52% yield (141.4 mg). 1H NMR (400 MHz, CDCl3): δ 7.84 – 7.67 (m, 8H), 7.56 – 7.44 (m, 6H), 4.59
– 4.22 (m, 1H), 3.65 (t, J = 7.3 Hz, 2H), 3.20 – 3.02 (m, 1H), 3.00 – 2.90 (m, 1H), 2.09 – 1.97 (m,
1H), 1.80 – 1.71 (m, 1H), 1.68 – 1.58 (m, 2H), 1.48 – 1.40 (m, 1H), 1.35 – 1.15 (m, 9H); 13C NMR
(101 MHz, CDCl3): δ 168.0, 133.4, 132.3, 132.0, 131.7, 131.6 (d, J = 2.8 Hz), 131.5 (d, J = 2.7 Hz),
131.1, 130.4 (d, J = 9.3 Hz), 130.0 (d, J = 9.3 Hz), 128.4 (d, J = 4.0 Hz), 128.3 (d, J = 4.0 Hz), 122.7,
48.8, 40.5, 39.9, 39.2 (d, J = 3.5 Hz), 37.6, 28.7, 28.6, 28.0 (d, J = 10.2 Hz), 26.8, 26.3; 31P NMR
(162 MHz, CDCl3): δ 28.07. IR (cm−1):
ν
2150. HRMS (ESIꢀTOF) m/z: (M+Na)+ calcd for
C31H33N2O3PSNa 567.1847, found 567.1850.
Mixture of 2ꢀ((4ꢀdiphenylphosphorylꢀ3ꢀthiocyanato)butyl)isoindolineꢀ1,3ꢀdione (5j) and 2ꢀ((4ꢀ
diphenylphosphorylꢀ3ꢀisothiocyanato)butyl)isoindolineꢀ1,3ꢀdione (5j’). Colorless liquid. 23% (5j)
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and 37% (5j’) yield (144.9 mg), respectively, 5j : 5j’ =1 : 0.6, analyzed by H NMR spectrum; 1H
NMR (400 MHz, CDCl3): δ 7.82 – 7.77 (m, 3H), 7.74 – 7.65 (m, 9.4H), 7.57 – 7.31 (m, 10H), 4.32 –
4.22 (m, 1H), 3.89 – (m, 3.2H), 3.49 – 3.35 (m, 0.6H), 3.13 – 2.95 (m, 2H), 2.94 – 2.78 (m, 1.2H),
2.69 – 2.59 (m, 1H), 2.55 – 2.44 (m, 0.6H), 2.28 – 2.17 (m, 1H), 2.15 – 2.05 (m, 0.6H); 13C NMR
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(101 MHz, CDCl3): δ 167.7, 167.6, 133.7, 133.4, 131.8 (d, J = 2.7 Hz), 131.7 (d, J = 2.8 Hz), 131.6
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(d, J = 4.3 Hz), 131.5 (d, J = 2.9 Hz), 131.4, 130.5, 130.4, 130.3, 130.2, 130.03, 130.00, 129.94,
129.90, 128.5, 128.43, 128.40, 128.36, 128.31, 128.28, 128.25, 123.0, 122.8, 109.8, 44.6, 42.0 (d, J
= 1.9 Hz), 40.2, 39.6, 37.7 (d, J = 3.8 Hz), 35.8, 34.70 (d, J = 4.9 Hz), 34.65; 31P NMR (162 MHz,
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CDCl3): δ 27.85, 27.39. IR (cm−1):
ν
2224, 2152. HRMS (ESIꢀTOF) m/z: (M+Na)+ calcd for
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C25H21N2O3PSNa 483.0908, found 483.0918.
(3,5ꢀDiꢀtertꢀbutylꢀ4ꢀhydroxybenzyl)diphenylphosphine oxide (BHTꢀPOPh2) (6). White solid, Mp:
o
1
176.6ꢀ177.5 C, 28% yield (58.8 mg). H NMR (400 MHz, CDCl3): δ 7.73 – 7.60 (m, 4H), 7.54 –
7.48 (m, 2H), 7.47 – 7.37 (m, 4H), 6.73 (d, J = 2.1 Hz, 2H), 5.06 (s, 1H), 3.57 (d, J = 13.8 Hz, 2H),
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1.28 (s, 18H). C NMR (101 MHz, CDCl3): δ 152.3 (d, J = 3.4 Hz), 135.3 (d, J = 2.6 Hz), 132.0,
131.3 (d, J = 2.6 Hz), 131.0, 130.9, 128.0, 127.9, 126.5 (d, J = 5.0 Hz), 120.6 (d, J = 8.0 Hz), 37.5 (d,
J = 67.2 Hz), 33.7, 29.6. 31P NMR (162 MHz, CDCl3): δ 30.91. HRMS (ESIꢀTOF) m/z: (M+H)+
calcd for C27H33O2PNa 443.2116, found 443.2124.
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(2,2ꢀDiphenylvinyl)diphenylphosphine oxide (7). White solid, Mp: 205.3ꢀ207.5 C, 65% yield
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(123.5 mg). H NMR (400 MHz, CDCl3): δ 7.75 – 7.60 (m, 4H), 7.38 – 7.26 (m, 11H), 7.26 – 7.19
(m, 2H), 7.15 – 7.05 (m, 3H), 6.79 (d, J = 16 Hz, 1H). 13C NMR (101 MHz, CDCl3): δ 161.7 (d, J =
2.2 Hz), 141.4 (d, J = 16.2 Hz), 137.5 (d, J = 6.7 Hz), 133.7 (d, J = 106.2 Hz), 130.6 (d, J = 2.6 Hz),
130.4 (d, J = 9.5 Hz), 129.8, 129.1, 128.2, 127.9 (d, J = 3.2 Hz), 127.82, 127.75, 127.1, 119.9 (d, J =
103.9 Hz). 31P NMR (162 MHz, CDCl3): δ 19.21. HRMS (ESIꢀTOF) m/z: (M+H)+ calcd for
C26H22OP 381.1408, found 381.1395.
ASSOCIATED CONTENT
Supporting Information
The Supporting Information is available free of charge on the ACS Publications website at DOI:
10.1021/acs.joc.
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1H, 13C and 31P NMR spectra for compounds 4ꢀ7 (PDF)
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AUTHOR INFORMATION
Corresponding Author
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*Eꢀmail: jpzou@suda.edu.cn.
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*Eꢀmail: wei2.zhang@umb.edu.
ORCID
JianꢀPing Zou: 0000ꢀ0002ꢀ8092ꢀ9527
Wei Zhang: 0000ꢀ0002ꢀ6097ꢀ2763
Notes
The authors declare no competing financial interest.
ACKNOWLEDGEMENTS
J.ꢀP.Z. appreciates the generous financial support from National Natural Science Foundation of
China (No. 21172163, 21472133), the Priority Academic Program Development of Jiangsu Higher
Education Institutions (PAPD) & State, and Local Joint Engineering Laboratory for Novel
Functional Polymeric Materials.
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