Manganese(III)-mediated selective diphenylphosphinoyl radical reaction of 1,4-diaryl-1-butynes for the synthesis of 2-phosphinoylated 3,4- dihydronaphathalenes

Article abstract of DOI:10.1021/jo402556a

A diphenylphosphinoyl radical-initiated sequential reaction of 1,4-diaryl-1-butynes and analogues is developed for the synthesis of 2-phosphinoylated 3,4-dihydronaphathalenes and related compounds.

Full text of DOI:10.1021/jo402556a

Note
pubs.acs.org/joc
Manganese(III)-Mediated Selective Diphenylphosphinoyl Radical
Reaction of 1,4-Diaryl-1-butynes for the Synthesis of
2‑Phosphinoylated 3,4-Dihydronaphathalenes
Da-Peng Li,† Xiang-Qiang Pan,† Li-Tao An,∥ Jian-Ping Zou,*,†,‡ and Wei Zhang*,§
†Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry and Chemical Engineering, Soochow University, 199
Renai Street, Suzhou, Jiangsu 215123, China
‡Key Laboratory of Synthetic Chemistry of Natural Substances, Shanghai Institute of Organic Chemistry, Chinese Academy of
Sciences, Ling Ling Road 345, Shanghai 200032, China
§Department of Chemistry, University of Massachusetts Boston, 100 Morrissey Boulevard, Boston, Massachusetts 02125, United
States
∥Jiangsu Key Laboratory for Chemistry of Low-dimensional Material, Department of Chemistry, Huaiyin Teachers College, Huaian,
Jiangsu Province 223300, China
S
* Supporting Information
ABSTRACT: A diphenylphosphinoyl radical-initiated sequential reaction of 1,4-
diaryl-1-butynes and analogues is developed for the synthesis of 2-
phosphinoylated 3,4-dihydronaphathalenes and related compounds.
radical addition and cyclization sequence, but it suffers from the
ormation of a carbon−phosphorus bond by the reaction of
Fphosphorus radicals is a subject with both mechanistic and generation of a significant amount of uncyclized byproduct 3.
synthetic interests.1 The reaction of phosphinoyl radicals
Introduced in this paper is the reaction of diphenylphosphinoyl
[R2P(O)•] is much less abundant than that of phosphinyl
radical with 1,4-diaryl-1-butynes 4 to form 2-phosphinoylated
[R2P•] and phosphonyl [(RO)2P(O)•] radicals.1a The
3,4-dihydronaphathalenes 5 without the formation of acyclic
byproduct (Scheme 1, b).
generation of phosphinoyl radical [R2P(O)•] from diphenyl-
The reaction of diphenylphosphinoyl radical with the model
compound, 1,4-diphenyl-1-butyne 4a, was carried out under the
optimized condition developed for the reactions of 1,4-
diphenylbutenes 1.5 A mixture of 1 equiv of 4a, 2 equiv of
Ph2PH(O), and 3 equiv of Mn(OAc)3 in acetic acid was heated
at 50 °C for 20 min to afford phosphinoylated dihydronapha-
thalene 5a in 76% isolated yield, and no acyclic phosphinoy-
lated byproduct was observed (Scheme 2, a). The reaction of 1-
phenyl-3-(4-chlorophenyl)propyne 6a gave desired phosphi-
noylated indene 7 in 8% yield, whereas phosphinoylated acyclic
compounds 8a (60%) and 8b (10%) were the major products
(Scheme 2, b). Similarly, the reaction of 1-(4-chlorophenyl)-5-
phenylpentyne 9 gave benzo[7]anuulene 10 in 20% yield
together with acyclic compounds 11a (20%) and 11b (18%)
(Scheme 2, c). The reactions of 3-phenylpropyne and 4-
phenylbutyne were also attempted, which gave a mixture
containing polymeric phosphinoylated compounds. Results
from the reactions of different alkynes indicate that the
cyclization of the phosphinoylated vinyl radical is more
favorable for the formation of six-membered dihydronaphatha-
lene 5a than for five-membered indene 7 or seven-membered
or dialkylphosphine oxide has been reported by the Tailades
group2 using Et3B, and the Parsons and the Jany groups using
azo compounds.3 We have recently introduced the (RO)2PH-
(O)/Mn(OAc)3 system to generate phosphonyl radicals for the
phosphonation of arenes and conjugate alkenes/alkynes.4 We
also developed the Ph2PH(O)/Mn(OAc)3 system for the
generation of diphenylphosphinoyl radical to react with 1,4-
diaryl-1-butenes 1 for the preparation of phosphinoylated
tetrahydronaphathalenes 2 (Scheme 1, a).5 This is a novel P-
Scheme 1. Novel Diphenylphosphinoyl Radical-Initiated
Reactions
Received: November 18, 2013
Published: January 24, 2014
© 2014 American Chemical Society
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Scheme 2. Reactions of Diphenylphosphinoyl Radical with
Table 1. Reactions of 1,4-Diarylalkynes 4
Different Diphenylalkynes
benzo[7]anuulene 10 ring systems. Without the phenyl group
at the 1-position, the vinyl radicals are highly reactive for
oxidation and polymerization instead of cyclization.6
A mechanism for the reaction of 4a with 1,4-diphenyl-1-
butyne is proposed in Scheme 3. Phosphinoyl radical selectively
Scheme 3. Proposed Reaction Mechanism
adds to the 2-position of 4a to form vinyl radical 12, which is
stabilized by the 1-phenyl group. Radical 12 is cyclized to form
13 and then carbocation 14 after oxididation with Mn(OAc)3.
Deprotonation of 14 gave product 5a. No acyclic phosphinoy-
lation byproducts observed from this reaction indicates that the
terminal phenyl group is important to stabilize the vinyl radical
12 and facilitate the cyclization.6 The structure of 5a has been
confirmed by single crystal X-ray analysis.
The electronic effect of the substitution group on two phenyl
rings of 1,4-diaryl-1-butynes 4 was explored. The results shown
in Table 1 indicate that neither electron-donating nor electron-
withdrawing groups have a significant impact on the product
yield (entries 1−10). It was also found that steric effect at the
ortho-position of 1-phenyl of 4 has limited effect on the product
yield (entries 5−7). The reaction of 1-naphthyl-4-phenylbutyne
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Note
4k was also attempted and gave expected product 5k in good
yield (entry 11).
Good results obtained from the phosphinoyl radical reaction
of 1,4-diphenyl-1-butynes encouraged us to broaden the study
on substrate scope. 4-Phenylbutynes with ester and aldehyde
substituents at the 1-position gave desired products 16a and
16b in good yields (Table 2, entries 1 and 2). The replacement
enol acetate would give the ketone, which could undergo a
+
retro-Mannich reaction losing PhMeNCH2 to give 18. The
reaction of 15e bearing a fused pyridyl unit gave desired six-
membered cyclization product 16e in 20% yield together with
compound 19, which is derived from the addition of
phosphinoyl radical to the sp-carbon close to the phenyl ring.
In summary, we have expanded our recently discovered
phosphinoyl radical addition and cyclization sequence for the
reaction of 1,4-diarylbutynes in the synthesis of 2-phosphinoy-
lated 3,4-dihydronaphathalenes. This reaction has been further
extended for analogue substrates for the synthesis of indene,
benzo[7]anuulene, and other heterocyclic skeletons.
Table 2. Reactions of Alkynes 15
EXPERIMENTAL SECTION
■
1
General Methods. H (300 or 400 MHz) and 13C NMR (75 or
100 MHz) spectra were determined in CDCl3, and chemical shifts are
reported in ppm from internal TMS (δ). High resolution mass spectra
were recorded on a TOF machine (EI). Flash column chromatography
was performed with 300−400 mesh silica gel. All of the reagents were
used directly as obtained commercially unless otherwise noted.
Manganese triacetate,7 but-1-yne-1,4-diyldibenzene,8 1-chloro-4- (3-
phenylprop-2-yn-1-yl)-benzene (6a),9 ethyl-5-phenylpent-2-ynoate
(15a),10 5-phenylpent-2-ynal (15b),11 (3-phenoxyprop-1-yn-1-yl)-
benzene (15c),12 N-methyl-N-(3-phenylprop-2-yn-1-yl)aniline
(15d),13 and 2-(4-methoxyphenyl)-3-(phenylethynyl) pyridine
(15e)14 were prepared according to the reported procedures.
Synthesis of Diarylalkynes 4a and 9. General Procedure for
the Synthesis of but-1-yne-1,4-diyldibenzene (4a) (Scheme 4). To a
solution of PPh3 (1.73 g, 6.6 mmol) in CH2Cl2 (20 mL) was added
resublimed iodine (1.67 g, 6.6 mmol). After 5 min of stirring at room
temperature, a solution of phenylmethanol (0.69 g, 6.4 mmol) in
CH2Cl2 (8 mL) was added to the reaction mixture and stirred for
additional 12 h. The reaction mixture was diluted with diethyl ether
(15 mL) and then washed with aqueous 5% NaHCO3 (10 mL × 3)
and brine (10 mL × 2). The combined organic layer was dried over
anhydrous Na2SO4 and evaporated to give a crude product that was
purified by flash column chromatography (silica gel, petroleum ether)
to afford the benzyl iodide (1.25 g, 90%) as a yellow solid. To a
solution of 1-trimethylsilyl-1-propyne (0.41 g, 3.6 mmol) in dry THF
(30 mL) was added n-BuLi (2.5 M in hexane, 1.32 mL, 3.3 mmol) at
−78 °C. After 2 h of stirring at this temperature, benzyl iodide (0.65 g,
3.0 mmol) in dry THF (10 mL) was added to the reaction mixture and
stirred at −78 °C for 1 h. The reaction mixture was warmed to room
temperature, quenched with brine (30 mL), and then extracted with
diethyl ether (30 mL × 2). The combined organic layer was
concentrated under vacuum to give crude product [4-(4-methox-
yphenyl)-1-butynyl]trimethylsilane. To the resulting silane were added
20 mL of methanol and KOH (0.20 g, 3.6 mmol). After being stirred
overnight, the solution was neutralized with 1 N HCl (5.0 mL) and
then extracted with diethyl ether (15 mL × 3). The organic layer was
dried over MgSO4, concentrated under vacuum, and purified by flash
column chromatography (silica gel, petroleum 40:1 ether/EtOAc) to
afford but-3-yn-1-ylbenzene (0.31g, 80%) as a colorless oil. To a
mixture of but-3-yn-1-ylbenzene (0.26 g, 2.0 mmol), Et3N (30 mL),
PdCl2(PPh3)2 (0.028 g, 0.040 mmol), and iodobenzene (0.49 g, 2.4
mmol) (stirring for 3 min beforehand) was added CuI (3.8 mg, 0.020
mmol). The Ar-flushed flask was sealed, and the mixture was stirred at
room temperature for 12 h. The reaction mixture was filtered and
washed with saturated aqueous NaCl solution (10 mL × 2), and the
of a carbon in 1,4-diarylbutynes 4 with a heteroatom such as O
or N was attempted. The reaction of 15c gave desired product
16c in 30% yield together with acyclic byproduct 17 in 32%
yield (entry 3). The structure of 16c was confirmed by single
crystal X-ray analysis. The reaction of 1-(p-tolyl)-3-N-
methylanilinopropyne 15d gave 18 as a major product (entry
4). It is plausible for the diphenylphosphinoyl radical to add to
the alkyne to give the vinyl radical, which could be oxidized to
the vinyl acetate as in the formation of 8b. Hydrolysis of the
Scheme 4
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Note
filtrate was extracted with diethyl ether (15 mL × 3). The combined
organic layer was dried over MgSO4 and concentrated under vacuum.
The resulting crude product was purified by flash column
chromatography (silica gel, 40:1 petroleum ether/EtOAc) to give 4a
(0.35 g, 85%) as a clear yellow liquid. The Pd-catalyzed coupling
reaction of pent-4-yn-1-ylbenzene and 1-chloro-4-iodobenzene was
used for the synthesis of 9.
Preparation of 2-Phosphinoylated 3,4-Dihydronaphatha-
lenes 5a−k, Their Derivatives, and Byproducts. General
Procedure. To a solution of acetic acid (10 mL), but-1-yne-1,4-
diyldibenzene (1.0 mmol), and diphenylphosphine oxide (2 mmol)
was added Mn(OAc)3 (3 mmol) in 10 portions at 50 °C. After 20 min
the reaction was complete, and the acetic acid was removed under
vacuum. To the residue was added water (20 mL), and the solution
was extracted with ethyl acetate (10 mL × 3). The combined organic
fractions were dried over Na2SO4 and concentrated under vacuum to
yield the crude product, which was purified by flash chromatography
(silica gel, 9:1 petroleum ether/EtOAc) to afford phosphinoylated
dihydronaphathalene 5a.
MHz, CDCl3) δ 149.9 (d, J = 7.5 Hz), 139.3 (d, J = 6.6 Hz), 137.2,
135.6 (d, J = 13.3 Hz), 134.2, 133.9, 133.2, 131.8, 131.7, 130.7, 130.2,
129.8, 129.4, 129.1, 128.7 (d, J = 12.0 Hz), 128.2, 127.9, 127.1, 28.4
(d, J = 5.6 Hz), 26.8 (d, J = 10.2 Hz). HRMS (EI-TOF) m/z: (M+)
calcd for C28H22ClOP 440.1097, found 440.1099.
Methyl 2-(2-(Diphenylphosphoryl)-3,4-dihydronaphthalen-1-yl)-
benzoate (5f). White solid; mp 159−160 °C, 65% yield (302.3 mg);
1H NMR (400 MHz, CDCl3) δ 7.67−7.77 (m, 3H), 7.49−7.58 (m,
2H), 7.42 (d, J = 6.6 Hz, 1H), 7.34−7.41 (m, 2H), 7.27−7.33 (m,
2H), 7.18−7.25 (m, 4H), 7.13−7.16 (m, 2H), 6.93−7.02 (m, 1H),
6.40 (d, J = 7.5 Hz, 1H), 3.63 (s, 3H), 2.79−3.06 (m, 2H), 2.44−2.63
(m, 2H); 13C NMR (100 MHz, CDCl3) δ 166.5, 151.6 (d, J = 7.0 Hz),
139.5, 136.9, 136.1, 132.5, 131.9, 131.8, 131.7 (d, J = 5.0 Hz), 131.5
(d, J = 3.0 Hz), 131.2, 130.7, 128.9, 128.6 (d, J = 12.0 Hz), 128.3,
128.1 (d, J = 7.0 Hz), 127.4, 126.7, 126.5, 51.9, 28.1 (d, J = 6.3 Hz),
26.6 (d, J = 10.8 Hz). HRMS (ESI-TOF) m/z: (M + H)+ calcd for
C30H26O3P 465.1619, found 465.1633.
(1-(2-Methoxyphenyl)-3,4-dihydronaphthalen-2-yl)-
diphenylphosphine Oxide (5g). White solid, mp 109−110 °C, 70%
yield (306.0 mg); 1H NMR (400 MHz, CDCl3) δ 7.61−7.70 (m, 2H),
7.45−7.55 (m, 3H), 7.35−7.41 (m, 1H), 7.27−7.34 (m, 3H), 7.13−
7.20 (m, 3H), 6.93−7.04 (m, 3H), 6.62−6.72 (m, 1H), 6.56 (d, J = 7.8
Hz, 1H), 6.30 (d, J = 8.0 Hz, 1H), 3.48 (s, 3H), 2.90 (t, J = 8.0 Hz,
2H), 2.56−2.65 (m, 2H); 13C NMR (100 MHz, CDCl3) δ 156.4,
147.7 (d, J = 5.0 Hz), 136.9, 135.4 (d, J = 13.0 Hz), 131.8 (d, J = 8.0
Hz), 131.5 (d, J = 8.0 Hz), 131.3, 131.0, 129.8, 128.9, 128.2 (d, J =
10.0 Hz), 127.9 (d, J = 11.0 Hz), 127.5, 127.0, 126.7, 126.3, 120.1,
109.9, 54.7, 28.2, 26.1 (d, J = 8.9 Hz). HRMS (ESI-TOF) m/z: (M +
H)+ calcd for C29H26O2P 437.1675, found 437.1670.
(5-Fluoro-1-phenyl-3, 4-dihydronaphthalen-2-yl)-
diphenylphosphine Oxide (5h). White solid, mp 107−108 °C, 60%
yield (255.1 mg); 1H NMR (400 MHz, CDCl3) δ 7.45−7.55 (m, 4H),
7.27−7.34 (m, 2H), 7.14−7.25 (m, 5H), 6.83−6.96 (m, 6H), 6.30−
6.35 (m, 1H), 2.78−2.89 (m, 2H), 2.45−2.58 (m, 2H); 13C NMR
(100 MHz, CDCl3) δ 160.2, 157.8, 150.2 (d, J = 3.0 Hz), 150.1 (d, J =
2.0 Hz), 137.7 (d, J = 5.0 Hz), 137.6 (d, J = 5.0 Hz), 136.7 (d, J = 7.0
Hz), 133.7, 132.7, 131.3 (d, J = 10.0 Hz), 131.0, 130.0, 128.1 (d, J =
12.0 Hz), 127.4, 126.8 (d, J = 8.0 Hz), 123.4, 115.8 (d, J = 22.0 Hz),
25.3 (d, J = 10.0 Hz), 19.4 (d, J = 3.0 Hz). HRMS (ESI-TOF) m/z:
(M + H)+ calcd for C28H23FOP 425.1470, found 425.1465.
(7-Chloro-1-(p-tolyl)-3,4-dihydronaphthalen-2-yl)-
diphenylphosphine Oxide (5i). White solid, mp 121−122 °C, 66%
yield (300.4 mg); 1H NMR (300 MHz, CDCl3) δ 7.49−7.61 (m, 4H),
7.33−7.42 (m, 2H), 7.23−7.32 (m, 4H), 7.13−7.18 (m, 1H), 7.07−
7.12 (m, 1H), 6.79 (d, J = 7.8 Hz, 2H), 6.74 (d, J = 7.8 Hz, 2H), 6.66
(s, 1H), 2.84 (t, J = 6.0 Hz, 2H), 2.55−2.66 (m, 2H), 2.19 (s, 3H); 13C
NMR (75 MHz, CDCl3) δ 150.0 (d, J = 6.2 Hz), 137.8, 137.5, 135.4,
134.3, 133.5, 132.9, 132.4, 131.6 (d, J = 8.0 Hz), 131.1, 130.1, 128.9,
128.7, 128.5, 128.3, 127.8, 27.7, 26.4 (d, J = 8.8 Hz), 21.4. HRMS
(ESI-TOF) m/z: (M + H)+ calcd for C29H25ClOP 455.1331, found
455.1335.
(7-Methoxy-1-(p-tolyl)-3,4-dihydronaphthalen-2-yl)-
diphenylphosphine Oxide (5j). White solid, mp 123−124 °C; 64%
yield (288.8 mg); 1H NMR (300 MHz, CDCl3) δ 7.52−7.62 (m, 4H),
7.33−7.42 (m, 2H), 7.22−7.32 (m, 4H), 7.06−7.14 (m, 1H), 6.81 (d, J
= 6.0 Hz, 2H), 6.76−6.78 (m, 1H), 6.72 (d, J = 6.0 Hz, 2H), 6.27 (s,
1H), 3.59 (s, 3H), 2.83 (t, J = 6.0 Hz, 2H), 2.54−2.66 (m, 2H), 2.18
(s, 3H); 13C NMR (75 MHz, CDCl3) δ 158.4, 151.2 (d, J = 8.2 Hz),
137.1, 134.5, 134.1 (d, J = 6.8 Hz), 133.1, 131.7, 131.6, 131.0, 130.2,
129.6 (d, J = 6.8 Hz), 129.4, 128.5 (d, J = 6.8 Hz), 128.2, 114.6, 113.8,
55.4, 27.4 (d, J = 5.3 Hz), 26.8 (d, J = 10.5 Hz), 21.4. HRMS (ESI-
TOF) m/z: (M + H)+ calcd for C30H28O2P 451.1827, found 451.1834.
3,4-Dihydro-[1,2′-binaphthalen]-2-yl)diphenylphosphine Oxide
(5k). White solid, mp 169−170 °C; 70% yield (320.0 mg); 1H
NMR (400 MHz, CDCl3) δ 7.64−7.73 (m, 1H), 7.46−7.62 (m, 6H),
7.34−7.45 (m, 3H), 7.20−7.25 (m, 3H), 7.05−7.19 (m, 5H), 6.96−
7.04 (m, 2H), 6.63−6.73 (m, 1H), 2.92−3.07 (m, 2H), 2.67−2.80 (m,
2H); 13C NMR (75 MHz, CDCl3) δ 150.5 (d, J = 8.1 Hz), 137.0,
135.6 (d, J = 13.5 Hz), 134.5 (d, J = 6.8 Hz), 132.4 (d, J = 6.1 Hz),
131.2 (d, J = 9.0 Hz), 130.7, 130.0, 129.8, 129.1, 128.4, 128.1, 128.0,
Diphenyl(1-phenyl-3,4-dihydronaphthalen-2-yl)phosphine Oxide
1
(5a). White solid, mp 146−147 °C, 76% yield (308.7 mg); H NMR
(300 MHz, CDCl3) δ 7.54−7.67 (m, 4H), 7.34−7.43 (m, 2H), 7.26−
7.34 (m, 4H), 7.16−7.24 (m, 2H), 7.01−7.11 (m, 3H), 6.92−7.00 (m,
3H), 6.64 (d, J = 7.7 Hz, 1H), 2.92 (t, J = 6.0 Hz, 2H), 2.58−2.69 (m,
2H); 13C NMR (100 MHz, CDCl3) δ 151.3 (d, J = 8.2 Hz), 137.4 (d, J
= 6.8 Hz), 137.2, 136.2 (d, J = 13.7 Hz), 134.6, 133.5, 131.7 (d, J = 9.7
Hz), 131.4, 130.5, 129.4, 129.2, 128.5 (d, J = 12.0 Hz), 128.1, 127.9,
127.7 (d, J = 8.0 Hz), 126.9, 28.4 (d, J = 6.2 Hz), 26.6 (d, J = 10.5 Hz).
HRMS (EI-TOF) m/z: (M+) calcd for C28H23OP 406.1487, found
406.1485 (M+, 70.00).
(1-(4-Chlorophenyl)-3,4-dihydronaphthalen-2-yl)-
diphenylphosphine Oxide (5b). White solid, mp 111−112 °C, 69%
yield (303.7 mg); 1H NMR (400 MHz, CDCl3) δ 7.54−7.62 (m, 4H),
7.40−7.46 (m, 2 H), 7.29−7.36 (m, 4 H), 7.16−7.24 (m, 2 H), 7.06 (t,
J = 8.0 Hz, 1 H), 6.94 (d, J = 8.0 Hz, 2 H), 6.89 (d, J = 8.0 Hz, 2 H),
6.62 (d, J = 8.0 Hz, 1 H), 2.90 (t, J = 8.0 Hz, 2 H), 2.58−2.65 (m,
2H); 13C NMR (100 MHz, CDCl3) δ 149.7 (d, J = 7.6 Hz), 136.7,
135.5 (d, J = 7.0 Hz), 135.2 (d, J = 13.7 Hz), 133.8, 133.4, 132.7,
131.4, 131.3 (d, J = 10.0 Hz), 131.1, 129.2, 128.7, 128.2 (d, J = 12.0
Hz), 127.6, 127.4 (d, J = 6.0 Hz), 126.5, 27.8 (d, J = 6.2 Hz), 26.2 (d, J
= 10.3 Hz). HRMS (EI-TOF) m/z: (M+) calcd for C28H22ClOP
440.1097, found 440.1102.
Diphenyl(1-(p-tolyl)-3,4-dihydronaphthalen-2-yl)phosphine
1
Oxide (5c). White solid, mp 105−106 °C, 70% yield (294.1 mg); H
NMR (300 MHz, CDCl3) δ 7.52−7.63 (m, 4H), 7.34−7.42 (m, 2H),
7.24−7.36 (m, 4H), 7.16−7.22 (m, 1H), 7.01−7.09 (m, 1H), 6.82 (d, J
= 7.5 Hz, 2H), 6.74 (d, J = 7.5 Hz, 2H), 6.69 (d, J = 7.5 Hz, 1H), 2.90
(t, J = 6.0 Hz, 2H), 2.57−2.68 (m, 2H), 2.19 (s, 3H); 13C NMR (100
MHz, CDCl3) δ 151.5 (d, J = 8.2 Hz), 137.5 (d, J = 4.8 Hz), 136.4 (d,
J = 13.7 Hz), 134.8, 134.65 (d, J = 7.0 Hz), 133.7, 132.0 (d, J = 9.6
Hz), 131.4, 130.6, 129.6, 129.3, 128.8 (d, J = 6.0 Hz), 128.6, 128.4,
127.9, 127.1, 28.7 (d, J = 5.9 Hz), 26.7 (d, J = 10.5 Hz), 21.7. HRMS
(EI-TOF) m/z: (M+) calcd for C29H25OP 420.1643, found 420.1643.
Methyl 4-(2-(Diphenylphosphoryl)-3,4-dihydronaphthalen-1-yl)-
benzoate (5d). White solid, mp 152−153 °C, 65% yield (301.7 mg);
1H NMR (300 MHz, CDCl3) δ 7.67 (d, J = 8.1 Hz, 2H), 7.53−7.64
(m, 4H), 7.35−7.44 (m, 2H), 7.24−7.34 (m, 4H), 7.15−7.24 (m, 2H),
6.97−7.10 (m, 3H), 6.54 (d, J = 7.8 Hz, 1H), 3.88 (s, 3H), 2.89 (t, J =
6.0 Hz, 2H), 2.54−2.66 (m, 2H); 13C NMR (100 MHz, CDCl3) δ
167.1, 150.3 (d, J = 7.0 Hz), 142.6 (d, J = 6.1 Hz), 137.1, 135.5 (d, J =
13.2 Hz), 134.1, 133.1, 131.8 (d, J = 10.0 Hz), 131.6, 130.6, 129.6,
129.3, 129.1, 128.7, 128.6, 127.8, 127.0, 52.4, 28.3 (d, J = 5.1 Hz), 26.7
(d, J = 10.2 Hz). HRMS (EI-TOF) m/z: (M+) calcd for C30H25O3P
464.1541, found 464.1541.
(1-(2-Chlorophenyl)-3,4-dihydronaphthalen-2-yl)-
diphenylphosphine Oxide (5e). White solid, mp 120−121 °C; 70%
yield (308.1 mg); 1H NMR (300 MHz, CDCl3) δ 7.55−7.68 (m, 4H),
7.37−7.48 (m, 3H), 7.28−7.36 (m, 3H), 7.14−7.27 (m, 2H), 7.03−
7.10 (m, 2H), 6.95−7.02 (m, 2H), 6.81−6.86 (m, 1H), 6.60 (d, J = 7.7
Hz, 1H), 2.90 (t, J = 6.0 Hz, 2H), 2.56−2.68 (m, 2H); 13C NMR (100
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Note
127.8, 127.6, 127.4 (d, J = 2.3 Hz), 127.2, 126.5, 126.1, 125.8, 28.1 (d,
J = 6.0 Hz), 26.2 (d, J = 10.2 Hz). HRMS (ESI-TOF) m/z: (M + H)+
calcd for C32H26OP 457.1721, found 457.1716.
(E)-(3-(4-Chlorophenyl)-1-phenylprop-1-en-2-yl)-
diphenylphosphine Oxide (8a). Yellow oil, 60% yield (257.5 mg); 1H
NMR (400 MHz, CDCl3) δ 7.64−7.71 (m, 2H), 7.38−7.52 (m, 8H),
7.28−7.35 (m, 5H), 7.04−7.10 (m, 1H), 6.98 (d, J = 7.2 Hz, 1H),
6.85−6.90 (m, 2H), 6.80−6.84 (m, 1H), 3.79 (d, J = 108.8 Hz, 2H);
13C NMR (75 MHz, CDCl3) δ 136.1(d, J = 10.6 Hz), 133.0, 132.3,
131.8 (d, J = 15.3 Hz), 131.0, 130.3, 129.8 (d, J = 7.2 Hz), 129.0 (d, J
= 11.0 Hz), 128.8, 128.6 (d, J = 7.5 Hz), 128.3, 128.1 (d, J = 7.1 Hz),
127.6, 123.7 (d, J = 8.8 Hz), 31.6 (d, J = 8.6 Hz). HRMS (ESI-TOF)
m/z: (M + H)+ calcd for C27H23ClOP 429.1175, found 429.1140.
(9-(4-Chlorophenyl)-6,7-dihydro-5H-benzo[7]annulen-8-yl)-
diphenylphosphine Oxide (10). Colorless oil; 20% yield (95.4 mg);
1H NMR (400 MHz, CDCl3) δ 7.70−7.76 (m, 2H), 7.61−7.67 (m,
1H), 3.63 (s, 3H); 13C NMR (75 MHz, CDCl3) δ 159.8, 148.5, 137.3
(d, J = 6.4 Hz), 136.0, 135.1, 134.9, 134.6, 131.7, 131.6, 130.9, 130.9,
128.6, 128.4, 128.3, 128.1, 128.0, 127.8, 126.4, 120.3, 118.9, 109.1,
55.1. HRMS (ESI-TOF) m/z: (M + Na)+ calcd for C32H24NNaO2P
508.1442, found 508.1438.
(3-Phenoxy-1-phenylprop-1-en-2-yl)diphenylphosphine Oxide
(17). White solid, mp 233−234 °C, 32% yield (131.6 mg); 1H
NMR (300 MHz, CDCl3) δ 7.53−7.64 (m, 4H), 7.37−7.40 (m, 5H),
7.24−7.36 (m, 8H), 6.87−6.96 (m, 1H), 6.75−6.85 (m, 3H), 4.47 (d, J
= 15.4 Hz, 2H); 13C NMR (75 MHz, CDCl3) δ 158.3 (d, J = 9.5 Hz),
140.8 (d, J = 14.3 Hz), 140.2 (d, J = 7.5 Hz), 133.3, 132.1, 131.9, 131.6
(d, J = 10.5 Hz), 131.3, 129.2, 128.5, 128.2, 128.1 (d, J = 2.8 Hz),
127.7, 127.5, 62.9 (d, J = 8.7 Hz). HRMS (ESI-TOF) m/z: (M + H)+
calcd for C27H24O2P 411.1514, found 411.1505.
2-(Diphenylphosphoryl)-1-(p-tolyl)ethanone (18). White solid, mp
1
152−153 °C,50% yield (167.6 mg); H NMR (400 MHz, CDCl3) δ
7.88 (d, J = 8.0 Hz, 2H), 7.76−7.85 (m, 4H), 7.50−7.55 (m, 2H),
7.42−7.49 (m, 4H), 7.21 (d, J = 8.0 Hz, 2H), 4.12 (d, J = 12.0 Hz,
2H), 2.38 (s, 3H); 13C NMR (100 MHz, CDCl3) δ 192.3, 144.6,
134.4, 132.4, 132.1, 131.4, 131.1 (d, J = 10.0 Hz), 129.3 (d, J = 18.0
Hz), 128.5 (d, J = 12.0 Hz), 43.1 (d, J = 58.0 Hz), 21.6. HRMS (ESI-
TOF) m/z: (M + H)+ calcd for C21H20O2P 335.1201, found 335.1195.
((7-Methoxy-5H-indeno[1,2-b]pyridin-5-ylidene)(phenyl)methyl)-
diphenylphosphine Oxide (19). Yellow oil, 50% yield (254.1 mg); 1H
NMR (400 MHz, CDCl3) δ 8.73−8.78 (m, 1H), 7.64−7.68 (m, 1H),
7.54−7.63 (m, 3H), 7.48−7.53 (m, 1H), 7.44 (d, J = 8.2 Hz, 2H),
7.36−7.42 (m, 2H), 7.26−7.35 (m, 3H), 7.23 (d, J = 6.8 Hz, 2H),
7.06−7.15 (m, 3H), 6.83−6.89 (m, 1H), 6.72 (d, J = 8.8 Hz, 2H), 3.75
(s, 3H); 13C NMR (75 MHz, CDCl3) δ 160.0, 157.1, 149.8, 147.9 (d, J
= 22.5 Hz), 143.4, 143.1, 138.8, 136.6, 135.3, 133.1, 132.5, 132.1 (d, J
= 6.2 Hz), 131.1 (d, J = 10.8 Hz), 130.7 (d, J = 7.5 Hz), 129.1 (d, J =
4.5 Hz), 128.53, 128.49, 128.3 (d, J = 1.4 Hz), 123.9 (d, J = 10.5 Hz),
122.0, 113.8, 55.2. HRMS (ESI-TOF) m/z: (M + Na)+ calcd for
C32H24NNaO2P 508.1442, found 508.1433.
1H), 7.52−7.57 (m, 1H), 7.39−7.50 (m, 5H), 7.29−7.35 (m, 1H),
7.06−7.23 (m, 6H), 6.99 (d, J = 8.0 Hz, 1H), 6.88 (d, J = 6.8 Hz, 1H),
2.30−2.50 (m, 3H), 2.22−2.28 (m, 1H), 1.51−1.55 (m, 2H); 13C
NMR (75 MHz, CDCl3) δ 149.4 (d, J = 22.5 Hz), 143.9 (d, J = 27.8
Hz), 141.3, 134.5, 133.0, 132.3 (d, J = 9.0 Hz), 131.0 (d, J = 6.6 Hz),
130.3, 129.8, 129.1 (d, J = 7.5 Hz), 128.8 (d, J = 11.3 Hz), 128.5 (d, J
= 6.2 Hz), 128.2 (d, J = 8.2 Hz), 125.9, 125.7, 123.1 (d, J = 10.9 Hz),
35.4, 23.0, 25.9 (d, J = 9.8 Hz). HRMS (ESI-TOF) m/z: (M + Na)+
calcd for C29H24ClNaOP 477.1151, found 477.1131.
(E)-(1-(4-Chlorophenyl)-5-phenylpent-1-en-2-yl)-
diphenylphosphine Oxide (11a). Colorless oil, 20% yield (95.8 mg);
1H NMR (400 MHz, CDCl3) δ 7.51−7.62 (m, 4H), 7.30−7.34 (m,
2H), 7.18−7.26 (m, 7H), 7.13−7.17 (m, 2H), 7.06−7.12 (m, 1H),
6.95 (d, J = 6.8 Hz, 2H), 6.87 (d, J = 7.6 Hz, 2H), 2.35−2.44 (m, 2H),
2.14−2.26 (m, 2H), 1.65−1.78 (m, 2H); 13C NMR (75 MHz, CDCl3)
δ 144.1 (d, J = 4.5 Hz), 141.6, 135.8, 134.2 (d, J = 3.8 Hz), 133.8,
133.4, 132.0 (d, J = 4.3 Hz), 131.4, 131.3, 130.9, 128.3 (d, J = 4.0 Hz),
128.2, 127.6, 125.8, 36.8, 35.4, 31.7. HRMS (ESI-TOF) m/z: (M +
Na)+ calcd for C29H26ClNaOP 479.1307, found 479.1304.
ASSOCIATED CONTENT
Ethyl-2-(diphenylphosphoryl)-3,4-dihydronaphthalene-1-carbox-
■
1
ylate (16a). Yellow oil, 65% yield (276.3 mg); H NMR (400 MHz,
S
* Supporting Information
1H and 13C NMR spectra for compounds 5a−k, 8a, 10, 11a,
16a−c, 16e, 17, 18, and 19, X-ray ellipsoid plot of compounds
5a, 16c, and crystallographic data (CIF). This material is
available free of charge via the Internet at http://pubs.acs.org.
CDCl3) δ 7.58−7.70 (m, 6H), 7.50−7.55 (m, 2H), 7.38−7.44 (m,
2H), 7.27−7.31 (m, 3H), 7.18−7.23 (m, 1H), 4.08−4.26 (m, 2H),
3.46−3.53 (m, 2H), 2.88−3.08 (m, 2H), 1.10 (t, J = 7.1 Hz, 3H); 13C
NMR (75 MHz, CDCl3) δ 167.2 (d, J = 12.4 Hz), 163.0 (d, J = 12.4
Hz), 138.7 (d, J = 19.5 Hz), 137.9, 130.7, 129.7, 129.3 (d, J = 8.3 Hz),
128.5 (d, J = 8.3 Hz), 127.0 (d, J = 7.3 Hz), 126.0, 126.0 (d, J = 2.3
Hz), 123.9, 121.3 (d, J = 8.3 Hz), 60.7, 34.9, 29.7 (d, J = 7.5 Hz), 13.7.
HRMS (ESI-TOF) m/z: (M + Na)+ calcd for C25H23NaO3P 425.1283,
found 425.1275.
AUTHOR INFORMATION
Corresponding Authors
*E-mail: jpzou@suda.edu.cn.
*E-mail: wei2.zhang@umb.edu.
■
2-(Diphenylphosphoryl)-3,4-dihydronaphthalene-1-carbalde-
1
hyde (16b). Yellow oil, 55% yield (197.5 mg); H NMR (400 MHz,
Notes
CDCl3) δ 10.96 (s, 1H), 7.67−7.81 (m, 6H), 7.57−7.62 (m, 2H),
7.48−7.54 (m, 4H), 7.13−7.21 (m, 2H), 2.68−2.73 (m, 2H), 2.26−
2.31 (m, 2H); 13C NMR (75 MHz, CDCl3) δ 193.9 (d, J = 8.0 Hz),
148.4 (d, J = 5.3 Hz), 136.6, 132.6, 131.7 (d, J = 10.0 Hz), 129.8, 128.9
(d, J = 12.2 Hz), 128.5, 128.4, 128.3, 127.6 (d, J = 3.6 Hz), 126.9,
126.1, 27.5 (d, J = 10.2 Hz), 27.2 (d, J = 6.3 Hz). HRMS (ESI-TOF)
m/z: (M + H)+ calcd for C23H20O2P 359.1201, found 359.1191.
Diphenyl(4-phenyl-2H-chromen-3-yl)phosphine Oxide (16c).
The authors declare no competing financial interest.
ACKNOWLEDGMENTS
■
J.P.Z. thanks the grant support by National Natural Science
Foundation of China (No. 20772088, 21172163) and the
Priority Academic Program Development of Jiangsu Higher
Education Institutions for financial support.
1
White solid, mp 121−122 °C,30% yield (122.7 mg); H NMR (300
MHz, CDCl3) δ 7.55−7.66 (m, 4H), 7.36−7.44 (m, 2H), 7.27−7.35
(m, 4H), 7.03−7.11 (m, 2H), 6.90−7.10 (m, 5H), 6.78−6.85 (m, 1H),
6.62−6.67 (m, 1H), 4.89 (d, J = 6.0 Hz, 2H); 13C NMR (75 MHz,
CDCl3) δ 155.3, 149.3 (d, J = 6.0 Hz), 134.9 (d, J = 4.0 Hz), 133.2,
131.8, 131.5, 131.3, 131.2, 129.8, 128.3, 128.1 (d, J = 7.5 Hz), 127.9,
127.5, 125.0 (d, J = 10.5 Hz), 121.5, 116.0, 65.2 (d, J = 17.2 Hz).
HRMS (ESI-TOF) m/z: (M + H)+ calcd for C27H22O2P 409.1357,
found 409.1363.
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■
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