Novel organo phosphorus-selenium heteroatom compounds from selenation of diamines

Article abstract of DOI:10.1016/j.tet.2013.04.135

Reaction of Woollins' reagent (WR) with trans-1,2-cyclohexanediamine or 1,3-cyclohexanediamine, followed by treatment with o-xylylenedibromide in THF at room temperature surprisingly led to 3-phenyl-1,5-dihydrobenzo[e][1,3,2] diselenaphosphepine 3-selenide (3). However, using o-phenylenediamine, the same product together with 1,4-dihydrobenzo[d][1,2]diselenine (9) was obtained. Furthermore, treating WR with N,N′-dibenzylethane-1,2-diamine gave rise to 1,3-dibenzyl-2-phenyl-1,3,2-diazaphospholidine 2-selenide (10) and a zwitterionic product N-benzyl-N-(2-(benzylammonio)ethyl)-P- phenylphosphonamidodiselenoate (11). Unexpectedly, WR reacted with 2,2′-disulfanediyldianiline under identical conditions affording the known product: 2-phenyl-2,3-dihydrobenzo[d][1,3,2]thiazaphosphole 2-selenide (13). Three representative X-ray structures are reported.

Full text of DOI:10.1016/j.tet.2013.04.135

Tetrahedron 69 (2013) 5299e5305
Contents lists available at SciVerse ScienceDirect
Tetrahedron
journal homepage: www.elsevier.com/locate/tet
Novel organo phosphoruseselenium heteroatom compounds from
selenation of diamines
*
Guoxiong Hua, Rebecca A.M. Randall, Alexandra M.Z. Slawin, J. Derek Woollins
EaStCHEM School of Chemistry, University of St Andrews, Fife, KY16 9ST, UK
a r t i c l e i n f o
a b s t r a c t
Article history:
Reaction of Woollins’ reagent (WR) with trans-1,2-cyclohexanediamine or 1,3-cyclohexanediamine, fol-
lowed by treatment with o-xylylenedibromide in THF at room temperature surprisingly led to 3-phenyl-
1,5-dihydrobenzo[e][1,3,2]diselenaphosphepine 3-selenide (3). However, using o-phenylenediamine, the
same product together with 1,4-dihydrobenzo[d][1,2]diselenine (9) was obtained. Furthermore, treating
WR with N,N0-dibenzylethane-1,2-diamine gave rise to 1,3-dibenzyl-2-phenyl-1,3,2-diazaphospholidine
Received 1 February 2013
Received in revised form 16 April 2013
Accepted 30 April 2013
Available online 7 May 2013
2-selenide (10) and
a
zwitterionic product N-benzyl-N-(2-(benzylammonio)ethyl)-P-phenyl-
Keywords:
Diamines
Selenides
Woollins’ reagent
o-Xylylenedibromide
PeSe heteroatom compounds
Single crystal X-ray structures
phosphonamidodiselenoate (11). Unexpectedly, WR reacted with 2,20-disulfanediyldianiline under
identical conditions affording the known product: 2-phenyl-2,3-dihydrobenzo[d][1,3,2]thiazaphosphole
2-selenide (13). Three representative X-ray structures are reported.
Crown Copyright Ó 2013 Published by Elsevier Ltd. All rights reserved.
1. Introduction
2. Results and discussion
Selenium compounds have applications in areas, such as organic
synthesis,1 biochemistry,2 xerography,3 the synthesis of conducting
materials,4 semiconductors5 and ligand synthesis.6 A wide range of
reagents can introduce selenium into organic substrates by both nu-
cleophilic and electrophilic pathways, and the resulting selenium-
containing products can be further converted into useful targets that
may or may not retain the Se atom.7 2,4-Bis(phenyl)-1,3-
Reaction of WR with 2 equiv of trans-1,2-cyclohexanediamine in
THF at room temperature proceeded readily leading to the forma-
tion of (1S,2S)-cyclohexane-1,2-diaminium N,N0-(1S,2S)-cyclohex-
ane-1,2-diylbis(P-phenylphosphonamido-diselenoate)
1 in 62%
yield (Scheme 1). As expected, its 31P NMR spectrum consists of
a singlet (dP¼124.6 ppm) accompanied by 77Se satellites (J(P,Se)¼
799 Hz), considerably higher in magnitude than that in sodium
diselenadiphosphethane-2,4-diselenide [{PhP(Se)(m-Se)}2] (Woollins’
reagent, WR) has become known as an efficient selenation reagent in
organic synthetic chemistry since it is not particularly malodorous or
air sensitive.8 Reactions of WR with organic substrates range from
simple oxygeneselenium exchange to the formation of complex
phosphoruseselenium heterocycles as well as surprising phosphor-
useselenium-free products.9e21 Recently, we reported the synthesis of
a
series of ammonium phenylphosphonamidodiselenoates and
phenyl-phosphonamidodiselenoic diamides from the selenation of
primary/secondary amines.22 As part of our study into the reactivity of
WR towards different organic nucleophiles, we herein report the
synthesis of a series of novel diammonium phenyl-phosphona-
midodiselenoates and their derivatives including three representa-
tive X-ray structures.
* Corresponding author. Tel.: þ44 1334 463384; e-mail addresses: jdw3@
Scheme 1. Synthesis of (1S,2S)-cyclohexane-1,2-diaminium N,N0-(1S,2S)-cyclohexane-
1,2-diylbis(P-phenylphosphonamidodiselenoate) (1) and its derivative (3).
st-and.ac.uke, jdw3@st-and.ac.uk (J.D. Woollins).
0040-4020/$ e see front matter Crown Copyright Ó 2013 Published by Elsevier Ltd. All rights reserved.
http://dx.doi.org/10.1016/j.tet.2013.04.135

5300
G. Hua et al. / Tetrahedron 69 (2013) 5299e5305
phosphonodiselenoate salts (667e675 Hz),23 indicating a PeSe
bond order of approximately 1.5. This was further substantiated by
the 77Se NMR spectrum, which exhibits a doublet dSe¼ꢀ178.2 ppm
with matching 31Pe77Se coupling.
in THF at room temperature for 43 h led to the formation of 2-
phenyl-2,3-dihydro-1H-benzo[d][1,3,2]diazaphosphole 2-selenide
8, which was one uniquely isolable product in 16% yield after
work-up purification.
Reaction of 1 with an equimolar amount of o-xylylenedibromide
in THF at room temperature for 24 h surprisingly gave 3-phenyl-1,5-
dihydrobenzo[e][1,3,2]diselenaphosphepine 3-selenide 3 (Scheme
1) rather than 12-membered NePeSe heterocycle 2. We surmised
that the intermediate 2 was first formed, then, decomposed to the
seven-membered ring compound 3. To test this presumption, WR
reacted with 2 equiv of 1,3-cyclohexanediamine (cis and trans iso-
mers mixture) to afford cyclohexane-1,3-diaminium N,N0-cyclo-
hexane-1,3-diylbis(P-phenylphosphonamido-diselenoate) 4 [three
isomers: dP¼74.9 (s, J(P,Se)¼786 Hz), 42.2 (s, J(P,Se)¼788 Hz) and
41.0 (s, J(P,Se)¼788 Hz) ppm], the latter was followed by in situ
treatment with an equimolar amount of o-xylylenedibromide
(Scheme 2). Once again, 3-phenyl-1,5 dihydrobenzo[e][1,3,2]dis-
elenaphosphepine 3-selenide 3 was separated as a unique product
rather than the 13-membered NePeSe intermediate 5. The seven-
membered heterocycle 3 might be more stable and its formation
preferable over the 13-membered heterocycle 5 in the reaction.
The synthesis and X-ray structure of compound 8 has been re-
ported previously.24 Heterocycles 3 and 9 are quite stable as solids
and in solution in air and moist atmospheres, and are soluble in
normal organic solvents. Both compounds were fully characterized
by 1H, 13C, 31P and 77Se NMR, IR spectroscopy, mass spectrometry.
Both compounds showed the anticipated molecular ion peaks [M]þ
or [MþH]þ and satisfactory accurate mass measurement in their EI
or CI mass spectra. The 31P NMR spectrum of compound 3 shows
a sharp singlet at 14.1 ppm, flanked by two sets of selenium sat-
ellites (770 and 360 Hz), being a very similar pattern to the anal-
ogous structure we previously reported,12 indicating the presence
of a typical PeSe single bond and a P]Se double bond in this
compound. This is further supported by the 77Se NMR spectrum of
3, which consists of two doublets at 302.2 and ꢀ393.2 ppm. In
compound 9, the 77Se NMR displayed one single peak at 306.2 ppm.
In contrast to the above results, WR reacts with N,N0-dibenyl-
ethane-1,2-diamine to give a different pattern of final products.
Refluxing a toluene solution of WR with an equivalent of N,N0-
dibenzylethane-1,2-diamine for 6 h gave the five-membered PeSe
ring compound 10 in 23% yield and a zwitterionic product N-ben-
zyl-N-(2-(benzylammonio)ethyl)-P-phenylphosphonamido-dis-
elenoate 11 in 63% yield. However, carrying out the same reaction in
THF at room temperature for 40 h gave only 10 in 80.5% isolated
yield (Scheme 4).
Scheme 4. Synthesis of PeSe heteroatom compounds 10 and 11.
Scheme 2. Synthesis of heterocycle (3).
We propose a possible pathway for the formation of compounds
10 and 11 in Scheme 5. WR in toluene solution at elevated tem-
perature or in THF solution at room temperature is in equilibrium
with a diselenaphosphorane PhP(Se)2 (A), which is believed to be
a true reactive species.25 The initial step for the formation of
compounds 10 and 11 involves one of the NH groups of the diamine
molecule reacting with a P]Se bond from diselenaphosphorane
PhP(Se)2 to give zwitterionic N-benzyl-N-(2-(benzylammonio)
ethyl)-P-phenylphosphonamidodiselenoate, the latter can readily
cyclize to give five-membered PeSe ring 10 by eliminating a mol-
ecule of H2Se. When the reaction was performed in toluene solu-
tion at elevated temperature, both compounds 10 and 11 co-exist
with compound 10 being dominant. In the case of THF used as
a medium at room temperature, the reaction seemed to be per-
formed completely from the conversion of zwitterionic N-benzyl-
However, in the case of using phenylenediamine in place of
cyclohexanediamine gave little bit different story. The reaction of
WR with an equimolar amount of o-phenylenediamine generating
an intermediate 6 [dP¼40.5 (s, J(P,Se)¼770 Hz) ppm], followed by
treatment with 1 equiv of o-xylylenedibromide under identical
conditions produced two species: 1,4-dihydrobenzo[d][1,2]dis-
elenine 9 and 3 after purification by silica gel column (Scheme 3).
We speculate the presence of unstable 7 as an intermediate, which
eventually degrades to compounds 3 and 9 in this reaction. Fur-
thermore, the reaction of WR with 2 equiv of benzene-1,2-diamine
Scheme 5. A possible mechanism for the formation of compounds 10 and 11.
Scheme 3. Synthesis of heterocycles 3, 8 and 9.

G. Hua et al. / Tetrahedron 69 (2013) 5299e5305
5301
N-(2-(benzylammonio)ethyl)-P-phenylphosphonamidodiselenoate
(11) to five-membered ring 10. It should be noted that in the case of
THF as a donor solvent the low total outcome might contribute
from the slow reaction of THF with WR.
79.5 ppm supporting the presence of the zwitterionic
conformation.
Finally, one more analogous reaction was carried out. WR
reacted with an equimolar amount of 2,20-disulfanediyldianiline
under identical conditions leading to the formation of the unique
product: 2-phenyl-2,3-dihydrobenzo[d][1,3,2]thiazaphosphole 2-
selenide 13 in almost quantitative yield (Scheme 8). Once again
we speculate the presence of intermediate 12, which decomposed
readily to the final stable 2-phenyl-2,3-dihydrobenzo[d][1,3,2]
thiazaphosphole 2-selenide 13 via cleavage of the sulfuresulfur
single bond, followed by loss of a molecule of selenium and finally
cyclization to form a stable five-membered heterocycle. The same
product was obtained from the reaction of WR with 2-
aminobenzenethiol and its characterization has been reported
previouly.12 Thus, the compound will not be discussed here in
detail.
We also carried out the reaction of WR with N,N0-dibenzyl-
ethane-1,2-diamine in THF at room temperature, followed by re-
action with an equimolar amount of o-xylylenedibromide as shown
in Scheme 6. Interestingly, once again, seven-membered ring 3 was
obtained together with the five-membered ring 10. It is presumed
that the similar mechanism as the above is applied as shown in
Scheme 7. It appears that the zwitterionic N-benzyl-N-(2-(benzy-
lammonio)ethyl)-P-phenylphosphonamidodiselenoate 11 behaves
as an intermediate in the reaction, which can either cyclize to give
compound 10 by loss of a molecule of H2Se or further reacts with o-
xylylenedibromide to give another intermediate B, the latter was
not stable and eventually decomposed to deliver one molecule of
seven-membered ring 3 and another molecule of five-membered
heterocycle 10 by loss of one molecule of N,N0-dibenzylethylene-
diamine dihydrobromide. To prove our presumption, we have car-
ried out the reaction of compound 11 with an equivalent of o-
xylylenedibromide at refluxing toluene for 3 h. Not surprisingly,
both compounds 3 and 10 were isolated by silica gel chromatog-
raphy column in respective 36.0% and 59.2% yields.
Scheme 8. Synthesis of PeSe heterocycle 13.
Perspective views of the X-ray structures of 3, 10 and 11 with
selected parameters are shown in Figs. 1e3. Crystal data and details
of the structure determination are given in Table 1. In 3, the newly
formed seven-membered ring is folded and has a chair-like con-
formation; the phenyl ring at the phosphorus atom prefers an axial
Scheme 6. Synthesis of PeSe heterocyclic compounds 3 and 10.
ꢀ
position; the P]Se bond lengths [2.1030(19) A] and the PeSe single
ꢀ
bond distances [2.2386(20) and 2.2559(19) A] are in reasonable
agreement with each other and are consistent with related P/Se
heterocyclic compounds containing the P(Se)(m
-Se) units.12,13,23e29
The internal Se(2)eP(1)eSe(3) angle (109.15(8)ꢁ) in 3 is almost
ideally tetrahedral.
Scheme 7. Possible formation paths for the preparation of PeSe heterocyclic com-
pounds 3 and 10.
The release of H2Se in the above reactions was observed in the
bubbler (the formation of dark Se due to the decomposition of the
H2Se), which connects the N2 line and the top of the condenser and
could be trapped by sodium hydroxide as sodium selenate after the
bubbler.
Compounds 10 and 11 are air and moisture stable and soluble in
polar organic solvents. The identification of 10 and 11 is based on
their 1H, 13C, 31P and 77Se NMR, IR spectroscopy, accurate mass
spectrometry. Both compounds showed the anticipated molecular
ion peaks [MþH]þ, and satisfactory accurate mass measurements.
The 31P NMR spectrum of compound 10 shows one singlet at
84.2 ppm, accompanied by selenium satellites (J(P,Se)¼795 Hz),
indicating the presence of a P]Se double bond. This was further
confirmed by the 77Se NMR spectrum of 9 displaying a doublet at
ꢀ251.1 ppm with a marching coupling constant. The 31P NMR
spectrum of compound 11 also exhibits one singlet at 63.6 ppm
(J(P,Se)¼624 Hz), indicating a PeSe bond order of approximately
1.5. The value supports the presence of the zwitterionic structures
in this compound. The 77Se NMR spectrum of 11 reveals a doublet at
ꢁ
ꢀ
Fig. 1. X-ray structure of compound 3. Selected bond lengths (A) and angles ( ) (esds in
parentheses): Se(1)eP(1) 2.1030(19), Se(2)eP(1) 2.2386(20), Se(3)eP(1) 2.2559(19),
Se(2)eC(3) 1.987(7), Se(3)eC(10) 1.986(7), P(1)eC(11) 1.814(7), C(4)eC(9) 1.401(9);
Se(1)eP(1)eSe(2), 114.21(8), Se(1)eP(1)eSe(3) 112.79(8), Se(2)eP(1)eSe(3) 109.15(8),
P(1)eSe(2)eC(3) 96.0(2), P(1)eSe(3)eC(10) 94.2(2), Se(1)eP(1)eC(11) 116.3(2), Se(2)e
P(1)eC(11) 100.6(2), Se(3)eP(1)eC(11) 102.5(2), Se(2)eC(3)eC(4) 112.6(5).
The structure of 10, in contrast to the reported similar struc-
tures, which are essentially planar,12 has
a
five-membered
PeNeCeCeN ring, which is significantly distorted from planar.
24e27
ꢀ
The P]Se distance (2.0895(16) A) is normal,
while the PeN

5302
G. Hua et al. / Tetrahedron 69 (2013) 5299e5305
Table 1
Details of the X-ray data collections and refinements for compounds 3, 10 and 11
Compound
3
10
11
Formula
M
C14H13PSe3
449.11
Monoclinic
P21/c
8.484(3)
8.297(3)
20.790(6)
90
C22H23N2PSe
425.37
Monoclinic
C2/c
15.288(4)
11.936(3)
21.964(5)
90
C22H25N2PSe2
506.35
Monoclinic
P21/n
10.900(5)
28.459(13)
14.383(6)
90
Crystal system
Space group
ꢀ
a/A
ꢀ
b/A
ꢀ
c/A
a
b
90.104(8)
90
1463.4(8)
4
97.694(6)
90
3971.9(17)
8
92.161(15)
90
4458(3)
8
g
U/A3
Z
g/cmꢀ3
2.038
1.423
1.509
Reflections collected
Independent reflections
Rint
R1
10,949
2643
0.0467
0.0450
0.2054
15,788
4012
0.0806
0.0797
0.3215
29,799
8089
0.1682
0.1373
0.4171
Fig. 2. X-ray structure of compound 10 (hydrogen atoms omitted for clarity). Selected
ꢁ
ꢀ
bond lengths (A) and angles ( ) (esds in parentheses): Se(1)eP(1) 2.0895(16), P(1)e
N(1) 1.682(5), P(1)eN(2) 1.658(5), P(1)eC(17) 1.820(6), N(1)eC(1) 1.470(7), N(1)eC(8)
1.462(7), N(2)eC(9) 1.463(7), N(2)eC(10) 1.475(7); Se(1)eP(1)eN(1) 116.11(18), Se(1)e
P(1)eN(2) 117.90(18), Se(1)eP(1)eC(17) 112.62(18), N(1)eP(1)eN(2) 93.9(2), N(1)e
P(1)eC(17) 107.4(2), N(2)eP(1)eC(17) 107.1(3), P(1)eN(1)eC(1) 119.2(4), P(1)eN(1)e
C(8) 111.7(3), C(1)eN(1)eC(8) 118.0(5), P(1)eN(2)eC(9) 113.1(4), P(1)eN(2)eC(10)
121.3(4), C(9)eN(2)eC(10) 115.9(4).
wR2 [I>2s(I)]
the phosphorus atom, while the exocyclic Se]PeX (X¼Calkyl or N)
[112.62(18)e117.90(18)ꢁ] angles are amongst the widest angles for
the PeNeCeCeN five-membered rings known.31
The structure of compound 11 contains two independent mol-
ecules within the unit cell. The PeN bond distances [1.696(11),
ꢀ
1.670(11) A] are normal, and comparable with those observed in
32
ꢀ
aminophosphazenes N4P4(NMe2)8 [1.69(1) A] or N4P4(NC4H8)8
33
ꢀ
ꢀ
[1.677(7) A]. The PeSe bond distances [2.151(4) [2.151(3) A], and
ꢀ
2.152(3) [2.156(3) A] are considerably longer than those found in
amine salts of bisdiselenophosphonic acid [2.1280(11)e
2.1350(12) A],34 however, they are still intermediate between single
ꢀ
35
ꢀ
ꢀ
bond [ca. 2.38 A] and double bond [ca. 2.08 A], indicating de-
localization of the negative charge over the PSe2 fragment.
In conclusion, the reaction of WR with diamines (trans-1,2-
cyclohexanediamine, 1,3-cyclohexanediamine, o-phenylenediamine,
N,N0-dibenzylethane-1,2-diamine and 2,20-disulfanediyldianiline)
wasinvestigated. The results showed thatWRreacting withtrans-1,2-
cyclohexanediamine, 1,3-cyclohexanediamine and o-phenylenedi-
amine, followed by further treatment with o-xylylenedibromide with
formation of the same product: 3-phenyl-1,5-dihydrobenzo[e][1,3,2]
diselenaphosphepine 3-selenide. In the case of o-phenylenediamine,
another product 1,4-dihydrobenzo[d][1,2,3,6]diselenadiazine was
also obtained along with 3-phenyl-1,5-dihydrobenzo[e][1,3,2]dis-
elenaphosphepine 3-selenide. The reaction of WR with N,N0-dibe-
nylethane-1,2-diamine gave a different pattern of final products: 1,3-
dibenzyl-2-phenyl-1,3,2-diazaphospholidine 2-selenide and zwit-
terionic N-benzyl-N-(2-(benzylammonio)ethyl)-P-phenylphosphona
midodiselenoate; the reaction mixture was further treated with o-
xylylenedibromide leading once again to the appearance of 3-phenyl-
1,5-dihydrobenzo[e][1,3,2]diselenaphosphepine 3-selenide. Further-
more, cleavageof theSeSsinglebond in2,20-disulfanediyldianilineby
WR resulted in the formation of a known 2-phenyl-2,3-dihydrobenzo
[d][1,3,2]thiazaphosphole 2-selenide.
Fig. 3. X-ray structure of the anion in 11 (up picture: one representative molecule;
below picture: two independent molecules perꢁunit cell) (hydrogen atoms omitted for
ꢀ
clarity). Selected bond lengths (A) and angles ( ) (esds in parentheses) (dimension for
second independent molecule in square parentheses): Se(1)eP(1) 2.151(4) [2.151(3)],
Se(2)eP(1) 2.152(3) [2.156(3)], P(1)eN(1) 1.696(11) [1.670(11)], P(1)eC(17) 1.811(13)
[1.845(13)]; Se(1)eP(1)eSe(2) 115.74(15) [116.47(15)], Se(1)eP(1)eC(17) 107.9(5)
[108.6(4)], Se(2)eP(1)eC(17) 110.5(4) [110.3(4)], P(1)eN(1)eC(1) 113.7(8) [113.9(8)],
Se(1)eP(1)eN(1) 108.5(4) [109.4(4)], Se(2)eP(1)eN(1) 111.7(4) [109.6(4)], N(1)eP(1)e
C(17) 101.6(6) [101.5(6)].
3. Experimental section
3.1. General
Unless otherwise stated, all reactions were carried out under an
oxygen free nitrogen atmosphere using pre-dried solvents and
standard Schlenk techniques, subsequent chromatographic and
work-up procedures were performed in air. 1H (270 MHz), 13C
(67.9 MHz), 31Pe{1H} (109 MHz) and 77See{1H} (51.4 MHz refer-
enced to external Me2Se) NMR spectra were recorded at 25 ꢁC
(unless stated otherwise) on a JEOL GSX 270. IR spectra were
recorded as KBr pellets in the range of 4000e250 cmꢀ1 on
ꢀ
bond lengths (1.682(5) and 1.658(5) A) are significant shorter than
ꢀ
the typical PeN single bond length (1.77 A) but much longer than
30
ꢀ
the normal P]N double bond (1.57 A) indicating some multiple
bond character present in this structure. The internal NePeN angle
N(1)eP(1)eN(2) 93.9(2) of the five-membered PeNeCeCeN ring is
slightly bigger than the smallest angle [91.34(14)ꢁ and 92.3(2)ꢁ] at

G. Hua et al. / Tetrahedron 69 (2013) 5299e5305
5303
a PerkineElmer 2000 FTIR/Raman spectrometer. Mass spectrome-
try was performed by the EPSRC National Mass Spectrometry Ser-
vice Centre, Swansea and the University of St Andrews Mass
Spectrometry Service. X-ray crystal data for 3, 10 and 11 were col-
lected using the St Andrews Robotic diffractometer (Saturn724
xylylenedibromide. A brown suspension of m-cyclohexanediamine
(cis and trans isomer mixture, 0.23 g, 2.0 mmol) and WR (0.54 g,
1.0 mmol) in tetrahydrofuran (50 mL) was stirred at room tem-
perature for 4 h, during which time a pale white suspension was
formed. Then, o-xylylenedibromide (0.264 g, 1.0 mmol) was added.
The mixture was stirred at room temperature for 24 h. Upon re-
moving unreacted solid and solvent, the residue was purified by
silica gel column chromatography (1:9 ethyl acetate/dichloro-
methane) to give 0.360 g of the title compound as a greenish yellow
solid in 81% isolated yield. The same product was obtained as
above.
CCD) at 125 K with graphite monochromated Mo K
a
u
radiation
steps ac-
36,37
ꢀ
(l¼0.71073 A).
Intensity data were collected using
cumulating area detector images spanning at least a hemisphere of
reciprocal space. All data were corrected for Lorentz polarization
effects. Absorption effects were corrected on the basis of multiple
equivalent reflections or by semi-empirical methods. Structures
were solved by direct methods and refined by full-matrix least-
squares against F2 by using the program SHELXTL.38 Hydrogen
atoms were assigned riding isotropic displacement parameters and
constrained to idealized geometries. CCDC 916232 3, 916234 10,
916233 11, contain the supplementary crystallographic data for this
paper. These data can be obtained free of charge via
www.ccdc.cam.ac.uk/conts/retrieving.html or from the Cambridge
Crystallographic Data centre, 12 Union Road, Cambridge CB2 1EZ,
UK; fax (þ44) 1223 336 033; e-mail: deposit@ccdc.cam.ac.uk.
3.2.4. Synthesis of 2-phenyl-2,3-dihydro-1H-benzo[d][1,3,2]-dia-
zaphosphole 2-selenide (8). A mixture of o-phenylenediamine
(0.216 g, 2.0 mmol) and WR (0.54 g, 1.0 mmol) in dry tetrahydro-
furan (60 mL) was stirred at room temperature for 43 h. Upon re-
moving unreacted solid and solvent, the residue was purified by
silica gel column chromatography (eluent 1:9 ethyl acetate/
dichloromethane) to give 0.095 g (16.2%) of 2-phenyl-2,3-dihydro-
1H-benzo[d][1,3,2]diazaphosphole 2-selenide (8) as a pale yellow
solid, mp 144e145 ꢁC. Selected IR (KBr, cmꢀ1): 2141(s), 1489(s),
1435(m), 1381(s), 1272(s), 1248(m), 1103(s), 883(s), 743(s), 654(m),
3.2. Synthesis
562(s). 1H NMR (CD2Cl2,
d), 7.91e7.85 (m, 4H, ArH), 7.44e7.34 (m,
3.2.1. Synthesis of trans-1,2-cyclohexanediamine N,N0-(1S,2S)-cyclo-
hexane-1,2-diylbis(P-phenylphosphonamidodiselenoate) (1). A mix-
ture of trans-1,2-cyclohexanediamine (0.228 g, 2.0 mmol) and WR
(0.54 g, 1.0 mmol) in tetrahydrofuran (50 mL) was stirred at room
temperature for 4 h. The red suspension disappeared and a bright
yellow suspension formed. Upon filtration to remove unreacted solid
the filtrate was dried in vacuo to give a golden solid (0.705 g, 93%
yield), mp 160e162 ꢁC. Selected IR (KBr, cmꢀ1): 2930(w), 2858(w),
1434(s), 1260(m), 1184(s), 1091(s), 1062(s), 888(m), 747(m), 692(s),
5H, ArH), 6.71 (d, J(P,H)¼19 Hz, 2H, NH) ppm. 13C NMR (CD2Cl2,
d),
138.2 (d, J(P,C)¼110.5 Hz, AreC), 133.1 (d, J(P,C)¼4.4 Hz, AreC),
132.5 (d, J(P,C)¼3.4 Hz, AreC), 131.3 (d, J(P,C)¼13.9 Hz, AreC), 128.2
(d, J(P,C)¼14.9 Hz, AreC), 120.7 (AreC), 110.9 (AreC), 110.8
(AreC) ppm. 31P NMR (CD2Cl2,
d
), 70.7 (s, J(P,Se)¼831 Hz) ppm. 77Se
NMR (CD2Cl2,
d
), ꢀ105.3 (d, J(P,Se)¼830 Hz) ppm. MS (CIþ m/z), 295
[MþH]þ. Accurate mass measurement [CIþ, m/z]: 288.9959
[MþH]þ, calculated mass for C12H11N2P74SeH: 288.9957.
545(vs, PeSe).1H NMR (THF-d8,
d), 8.31e7.97 (m, 4H, ArH), 7.38e7.25
3.2.5. Synthesis of 3-phenyl-1,5-dihydrobenzo[e][1,3,2]-diselenaphos
phepine 3-selenide (3) and 1,4-dihydrobenzo[d][1,2]diselenine (9)
from WR, o-phenylenediamine and o-xylylenedibromide. A suspen-
sion of o-phenylenediamine (0.216 g, 2.0 mmol) and WR (0.54 g,
1.0 mmol) and o-xylylenedibromide (0.264 g, 1.0 mmol) in dry
tetrahydrofuran (60 mL) was stirred at room temperature for 24 h,
during which time a pale white suspension was formed. Upon re-
moving unreacted solid and solvent, the residue was purified
by silica gel column chromatography to give 3-phenyl-1,5-
dihydrobenzo[e][1,3,2]diselenaphosphepine 3-selenide (3) as
a pale yellow solid (eluent 1:1 hexane/dichloromethane) and 1,4-
dihydrobenzo[d][1,2]diselenine (9) as a reddish yellow solid (elu-
ent dichloromethane).
(m, 6H, ArH), 6.21 (m, 6H, NH3), 4.32 (d, J(P,H)¼13.5 Hz, 2H, NH),
4.24e4.15 (m, 2H, CH), 3.64e3.58 (m, 2H, CH), 3.17e2.85 (m, 8H,
CH2), 1.79e1.73 (m, 8H, CH2) ppm. 13C NMR (THF-d8,
d), 141.7 (d,
J(P,C)¼127.1 Hz), 130.7 (d, J(P,C)¼12.5 Hz), 130.3 (d, J(P,C)¼3.1 Hz),
127.3 (d, J(P,C)¼13.5 Hz), 62.4 (d, J(P,C)¼8.3 Hz), 54.4, 31.3 (d, J(P,C)¼
13.5 Hz), 30.5, 24.7, 24.1 ppm. 31P NMR (THF-d8,
d
), 124.6 (s, J(P,Se)¼
799 Hz) ppm. 77Se NMR (THF-d8,
d
), ꢀ178.2 (d, J(P,Se)¼799 Hz) ppm.
MS (ESꢀ m/z), 323 [1/2M]ꢀ. Accurate mass measurement [ESꢀ, m/z]:
322.8965 [1/2M]ꢀ, calculated mass for ½[C18H22N2P2Se4]: 322.8969.
3.2.2. Synthesis of 3-phenyl-1,5-dihydrobenzo[e][1,3,2]-diselenaphos
phepine 3-selenide (3) from 1 and o-xylylenedibromide. A brown
suspension of (1S,2S)-cyclohexane-1,2-diamine (0.25 g, 2.0 mmol)
and WR (0.54 g,1.0 mmol) in tetrahydrofuran (50 mL) was stirred at
room temperature for 4 h, during which time a pale white sus-
pension was formed. Then, o-xylylenedibromide (0.264 g,
1.0 mmol) was added. The mixture was stirred at room temperature
for 24 h. Upon removing unreacted solid and solvent, the residue
was purified by silica gel column chromatography (1:9 ethyl ace-
tate/dichloromethane) to give 0.381 g of the title compound as
a greenish yellow solid in 84% yield. Mp 196e197 ꢁC. Selected IR
(KBr, cmꢀ1): 1434(s), 1179(m), 1090(s), 745(s), 688(m), 535(vs),
3.2.5.1. 3-Phenyl-1,5-dihydrobenzo[e][1,3,2]diselenaphosphepine
3-selenide (3). 0.100 g as a pale yellow solid in 22% isolated yield.
3.2.5.2. 1,4-Dihydrobenzo[d][1,2]diselenine (9). 0.400 g as a red-
dish yellow solid in 76% isolated yield, mp118e120 ꢁC. Selected IR
(KBr, cmꢀ1): 1484(m), 1159(m), 759(s), 579(m). 1H NMR (CD2Cl2,
d
),
),
7.39e7.30 (m, 4H, ArH), 3.94 (s, 4H, CH2) ppm. 13C NMR (CD2Cl2,
d
130.9 (AreC), 128.1 (AreC), 127.6 (AreC), 24.1 (CH2) ppm. 77Se NMR
(CD2Cl2, d
), 306.2 ppm. MS (EIþ m/z), 266 [M]þ. Accurate mass
488(m). 1H NMR (CD2Cl2,
13.5 Hz, 4H, SeCH2) ppm. 13C NMR (CD2Cl2,
J(P,C)¼3.1 Hz), 131.7 (d, J(P,C)¼11.4 Hz), 130.4, 129.2 (d, J(P,C)¼
d
), 8.18e7.24 (m, 9H, ArH), 4.67 (d, J(P,H)¼
measurement [EIþ, m/z]: 255.9003 [M]þ, calculated mass for
d
), 139.0, 133.3 (d,
C8H786Se2: 255.9005.
14.5 Hz), 128.4, 32.4 ppm. 31P NMR (CD2Cl2,
d
), 14.1 (s, J(P,Se)¼
3.2.6. Synthesis of 1,3-dibenzyl-2-phenyl-1,3,2-diaza-phospholidine
2-selenide (10) from N,N0-dibenzylethylenediamine and WR in THF at
room temperature. A THF (50 mL) suspension of N,N0-dibenzyle-
thylenediamine (0.46 g, 2.0 mmol) and WR (0.54 g, 1.0 mmol) was
stirred at room temperature for 40 h to give a greyish yellow sus-
pension. Upon filtering to remove unreacted solid and evaporating
to remove solvent the residue was purified by silica gel column to
provide 0.341 g of the title compound as an yellow solid (1:4 ethyl
369 Hz, J(P,Se)¼770 Hz) ppm. 77Se NMR (CD2Cl2,
d), 302.2 (d,
J(P,Se)¼369 Hz), ꢀ393.2 (d, J(P,Se)¼770 Hz) ppm. Accurate mass
measurement [CIþ, m/z]: 452.8318 [MþH]þ, calculated mass for
C14H13PSe3H: 452.8329.
3.2.3. Synthesis of 3-phenyl-1,5-dihydrobenzo[e][1,3,2]-diselenaphos
phepine 3-selenide (3) from WR, m-cyclohexanediamine and o-

5304
G. Hua et al. / Tetrahedron 69 (2013) 5299e5305
acetate/dichloromethane as eluent). 80% isolated yield. Mp
100e102 ꢁC. Selected IR (KBr, cmꢀ1): 1492(m), 1452(m), 1435(m),
1206(m), 1139(vs), 1098(s), 1064(s), 1027(m), 930(s), 737(vs),
the title compound as a milky solid in 99% isolated yield, mp
160e162 ꢁC. Selected IR (KBr, cmꢀ1): 1578(m), 1470(s), 1454(s),
1437(m), 1368(s), 1259(m), 1096(s), 892(s), 743(vs), 687(m), 554(s),
695(s), 606(m), 511(s). 1H NMR (CD2Cl2,
d
), 8.02e7.94 (m, 2H, ArH),
7.53e7.43 (m, 4H, ArH), 7.30e7.19 (m, 9H, ArH), 4.08e3.88 (m, 4H,
CH2), 3.23e3.02 (m, 4H, CH2) ppm. 13C NMR (CD2Cl2,
), 137.6, 132.4,
488(s). 1H NMR (CD2Cl2,
d), 8.07e7.98 (m, 2H, ArH), 7.57e7.42 (m,
3H, ArH), 7.23e7.07 (m, 2H, ArH), 6.93e6.88 (m, 2H, ArH), 5.67 (d,
d
J(P,H)¼12.9 Hz, 1H, NH) ppm. 13C NMR (CD2Cl2,
), 139.9 (d, J(P,C)¼
d
132.2, 131.9, 128.5, 128.4, 128.3, 128.0, 127.4, 49.9 (d, J(P,C)¼7.3 Hz),
72.7 Hz), 132.7 (d, J(P,C)¼3.1 Hz), 131.2 (d, J(P,C)¼14.5 Hz), 128.4 (d,
J(P,C)¼14.5 Hz),126.7,124.2 (d, J(P,C)¼6.2 Hz),121.8,112.9 (d, J(P,C)¼
46.5 (d, J(P,C)¼7.3 Hz) ppm. 31P NMR (CD2Cl2,
), 84.2 (s, J(P,Se)¼
d
795 Hz) ppm. 77Se NMR (CD2Cl2,
d
), ꢀ251.1 (d, J(P,Se)¼795 Hz) ppm.
11.4 Hz) ppm. 31P NMR (CD2Cl2,
d
), 74.5 (s, J(P,Se)¼840 Hz) ppm.
MS (CIþ m/z), 427 [MþH]þ. Accurate mass measurement [CIþ, m/z]:
427.0837 [MþH]þ, calculated mass for C22H23PSeH: 427.0837.
77Se NMR (CD2Cl2,
d
), ꢀ32.8 (d, J(P,Se)¼840 Hz) ppm. MS (CIþ, m/z),
312 [MþH]þ. Accurate mass measurement [CIþ, m/z]: 311.9506
[MþH]þ, calculated mass for C12H10NPSeH: 311.9509.
3.2.7. Synthesis of 1,3-dibenzyl-2-phenyl-1,3,2-diaza-phospholidine
2-selenide (10) and N-benzyl-N-(2-(benzylammonio)ethyl)-P-phe-
nylphosphonamidodiselenoate (11) from N,N0-dibenzylethane-1,2-
diamine and WR in refluxing toluene. A solution of N,N0-dibenzyl-
ethane-1,2-diamine (0.46 g, 2.0 mmol) and WR (0.54 g,1.0 mmol) in
20 mL of dry toluene was refluxed for 6 h. A slightly green sus-
pension was formed. Upon cooling to room temperature the mix-
ture was filtered to remove unreacted solid and evaporating to
remove solvent the residue was purified by silica gel column to
afford compound 9 as an orange solid and compound 10 as
a greenish white solid (1:4 ethyl acetate/dichloromethane as
eluent).
Acknowledgements
The authors are grateful to the University of St Andrews for fi-
nancial support and the EPSRC National Mass Spectrometry Service
Centre (Swansea) for mass spectral measurements.
Supplementary data
Supplementary data related to this article can be found at http://
dx.doi.org/10.1016/j.tet.2013.04.135.
3.2.7.1. 1,3-Dibenzyl-2-phenyl-1,3,2-diazaphospholidine 2-sele-
nide (10). 0.121 g, 28% isolated yield.
References and notes
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129.5, 129.3, 128.8, 128.5, 128.0, 127.7, 51.7, 50.4, 43.0 (d, J(P,C)¼
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