Novel five- to ten-membered organoselenium heterocycles from the seienation of aromatic diols

Article abstract of DOI:10.1002/ejoc.201000075

Reaction of Woollins' reagent - WR, 2,4-bis(phenyl)-1,3- diselenadiphosphetane 2,4-diselenide [[PhP(Se)(μ-Se)}₂] - with aromatic diols in refluxing toluene afforded a series of novel five- to ten-membered phosphorus-selenium heterocycles 1-10 with an O-P(Se)-O or O-P(Se)-Se-P(Se)-O or O-P(Se)-OP(Se)-O linkage in 12-74% isolated yields. It was found that the diphosphorus species O-P(Se)-Se-P(Se)-O rings could be readily reduced into the monophosphorus species O-P(Se)O rings in almost quantitative yields via further reaction with another equivalent of corresponding aromatic diol. All new compounds have been characterized by IR ¹H NMR ¹³C NMR ³¹P NMR ⁷⁷Se NMR, mass spectrometry and elemental analysis or accurate mass measurement. Seven representative X-ray structures are reported.

Full text of DOI:10.1002/ejoc.201000075

FULL PAPER
DOI: 10.1002/ejoc.201000075
Novel Five- to Ten-Membered Organoselenium Heterocycles from the
Selenation of Aromatic Diols
Guoxiong Hua,[a] Amy L. Fuller,[a] Alexandra M. Z. Slawin,[a] and J. Derek Woollins*[a]
Keywords: Main group elements / Heterocycles / Phosphorus / Selenium / Organoselenium compounds
Reaction of Woollins’ reagent Ϫ WR, 2,4-bis(phenyl)-1,3-di-
readily reduced into the monophosphorus species O–P(Se)–
selenadiphosphetane 2,4-diselenide [{PhP(Se)(µ-Se)}2] Ϫ with O rings in almost quantitative yields via further reaction with
aromatic diols in refluxing toluene afforded a series of novel
five- to ten-membered phosphorus-selenium heterocycles 1–
10 with an O–P(Se)–O or O–P(Se)–Se–P(Se)–O or O–P(Se)–O–
P(Se)–O linkage in 12–74% isolated yields. It was found that
the diphosphorus species O–P(Se)–Se–P(Se)–O rings could be
another equivalent of corresponding aromatic diol. All new
compounds have been characterized by IR, 1H NMR, 13C
NMR, 31P NMR, 77Se NMR, mass spectrometry and elemen-
tal analysis or accurate mass measurement. Seven represen-
tative X-ray structures are reported.
phorus-selenium heterocycles from the selenation of aro-
matic diols by WR and seven X-ray crystal structures of the
new heterocycles.
Introduction
Organoselenium heterocyclic compounds have attracted
considerable interest in the past several decades due to their
unique properties[1] and applications as potential pharma-
ceuticals,[2] new materials[3] as well as reagents and cata-
lysts.[4] However, the synthesis of selenium-containing or-
ganic heterocycles is not always easy due to the inconve-
nience of typical selenium reagents such as H2Se, NaHSe,
(Me3Si)2Se, potassium selenocyanate and tetraethylammo-
nium tetraselenotungstate [Et4N]2WSe4, each exhibiting its
Results and Discussion
Heterocycles 1–4 from the Selenation of Catechol or 2,3-
Dihydroxynaphthalene
Refluxing a toluene suspension of WR with one equiva-
own problems including toxicity, solubility, difficulty in lent of catechol or 2,3-dihydroxynaphthalene for 7 h gave
handling and poor reactivity. 2,4-Bis(phenyl)-1,3-diselena- rise to seven-membered diphosphorus species PhP(Se)-
diphosphetane 2,4-diselenide (WR) has less unpleasant Se(Se)PPh(OC6H4O-1,2) (1) and PhP(Se)Se(Se)PPh
chemical properties and can be prepared readily and han- (OC10H6O-2,3) (2) in 39% and 29% yield, along with five-
dled easily.[5] In recent years, WR has been becoming a very membered monophosphorus species PhP(Se)(OC6H4O-1,2)
useful selenium source or selenation reagent in synthetic (3) and PhP(Se)(OC10H6O-2,3) (4) in 42 and 53% yield
chemistry.[6,7]
(Scheme 1).
As part of our studies aimed into the reactivity of WR
Compound 3 and 4 can be obtained as the only sepa-
towards different organic substrates, herein, we report the rated product in 85 and 88% yield by reaction of WR with
preparation of a series of novel five- to ten-membered phos- two equivalents of an aromatic diol in refluxing toluene for
Scheme 1. Reaction of WR with one equivalent of aromatic diol.
10 h (Scheme 2). Compound 3 has been prepared pre-
viously in ca. 30% isolated yield by the reaction of WR
with two equivalents of catechol in toluene at 130 °C for
[a] School of Chemistry, University of St Andrews,
Fife, KY16 9ST, UK
E-mail: jdw3@st-and.ac.uk
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FULL PAPER
1 h.[8] The reaction is apparently time-dependent, prolonged G to give stable product H (compound 3 or 4) and interme-
reaction time here has improved the product yield consider- diate I. Finally, I cyclises again by nucleophilic addition fol-
ably.
lowed by rid of a hydrogen selenide to give a second mole-
cule of product H. All of the intermediates are not stable
enough to survive the reflux in toluene and work up condi-
tion. But the products of D (compound 1 or 2) and H (com-
pound 3 or 4) are quite stable. The attack of the hydroxy
group of the aromatic diol at the phosphorus centers lacks
selectivity to WR or the diphosphorus species 1 or 2. As a
result, both diphosphorus (1 and 2) and monophosphorus
species (3 and 4) form even though the reactants are in 1:1
molar ratio.
Scheme 2. Reaction of WR with two equivalents of aromatic diol.
Mechanistically, we propose that the reaction proceeds
through a step-wise nucleophilic substitution in which the
selenium bridge in WR is broken once or twice and the P–
Se bonds are replaced by P–O bonds step by step. The driv-
ing force of the reaction lies in that P–O bond is much
stronger than P–Se bond, and five membered-ring is more
stable than seven-membered ring. Scheme 3 illustrates the
process through electron push and proton transfer. First,
one of the hydroxy group of the diol attacks one of the
phosphorus centres of WR to afford the unstable zwitterion
A. Immediate intramolecular proton transfer from the O
atom to the Se atom in A gives B. Cyclisation of B gives
rise of C via a second nucleophilic addition of the other
hydroxy group of the diol to the second P=Se double bond
within the molecule C. Loss of one molecule of hydrogen
selenide from intermediate C results in the first product D
(compound 1 or 2). D reacts with another molecule of aro-
matic diol to generate two molecules of product H through
To confirm at least one aspect of the mechanism, the
isolated diphosphorus species 1 and 2 were treated with an-
other equivalent of corresponding aromatic diol
(Scheme 4). The monophosphorus species 3 or 4 formed in
almost quantitative yields (98% and 99%) in this way.
Scheme 4. Ring contraction of diphosphorus species into mono-
phosphorus species.
The release of H2Se in the above reactions was observed
intermediates E. Intermediate E collapses into two smaller in the bubbler (the formation of dark Se due to the decom-
fragments F and G. F passes on the proton to intermediate position of the H2Se) which connects the N2 line and the
Scheme 3. Possible mechanism of the formation of heterocycles 1–4.
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Novel Five- to Ten-Membered Organoselenium Heterocycles
top of the condenser and could be trapped by sodium hy-
droxide as sodium selenate after the bubbler.
The characterisation of 3 has been reported previously.[8]
The proposed structures of 1, 2 and 4 are based on their
microanalysis, 1H, 13C, 31P and 77Se NMR, IR spectro-
scopic data and mass spectrometric data. The microanaly-
ses of 1, 2 and 4 were satisfactory, and all compounds
showed the anticipated [M]+ or [MH]+ peak in their mass
spectra. The 31P NMR spectra of 1 and 2 show sharp sing-
lets at δ = 77.7 and 79.7 ppm, respectively, There are two
sets of selenium satellites associated with the equivalent
phosphorus centres with J(P,Se) at 465 and 852 Hz for 1,
and 465 and 864 Hz for 2. The lower magnitude couplings
are attributed to the P–Se single bonded selenium atoms,
and the higher magnitude values to the P=Se double
bonded atoms. Detailed inspection of NMR spectra reveals
the presence of a 2J(P,P) coupling of 9.4 Hz for 1 and
9.5 Hz for 2. Meanwhile, the 31P NMR spectrum of 4 com-
prises a singlet at δ = 115.9 ppm, flanked by 77Se satellite
J(P,Seexo) 965 Hz, these values are similar to that in com-
pound 3,[8] confirming the presence of only a phosphorus–
selenium double bond, with a doublet at –188.3 ppm ac-
companied by a coupling constant of 965 Hz in the 77Se
NMR spectrum.
Scheme 5. Reaction of WR with one equivalent of 1,1Ј-methyl-
enebis(2-naphthol).
by decomposition of diphosphorus species 5, driven by the
stability of the six-membered ring, although the extrusion
of a naphthalyne seems quite surprising (Scheme 7).
Heterocycles 5–7, 9 and 10 from the Selenation of 1,1Ј-
Methylenebis(2-naphthol) or 2,2Ј-Methylenebis(4-
chlorophenol)
Reaction of WR with one molar equivalent of 1,1Ј-meth-
ylenebis(2-naphthol) in the refluxing toluene gave the ex-
Scheme 7. Possible formation of monophosphorus species 5 from
pected ten-membered diphosphorus species 5 (51% isolated diphosphorus species 7.
yield) and eight-membered monophosphorus species 6
(31% isolated yield), but surprisingly, another six-mem-
The similar reaction of WR with two equivalents of 2,2Ј-
bered monophosphorus species 7 was isolated in 12% yield methylenebis(4-chlorophenol) provided the expected eight-
(Scheme 5).
membered monophosphorus species 9 in 74% yield and the
Treating WR with two equivalents of 1,1Ј-methyl- ten-membered diphosphorus species 10 with an O–P(Se)–
enebis(2-naphthol) in refluxing toluene generated only two O–P(Se)–O linkage in 24% yield. Obviously, the result is
isolable products, eight-membered monophosphorus spe- consistent with the mechanism in Scheme 3. We suppose
cies 6 and six-membered monophosphorus species 7 in that WR first reacts with one molecule of 2,2Ј-methyl-
62%, and 15% yield (Scheme 6).
enebis(4-chlorophenol) leading to intermediate 8, which is
Apparently, compound 6 is the ring contraction product not thermodynamically stable but reacts with another mole-
of compound 5, following a similar mechanism to that de- cule of 2,2Ј-methylenebis(4-chlorophenol) to afford com-
scribed in Scheme 3. Due to the relative labiliity of the pound 9. The ten-membered diphosphorus species 10 could
methylene between the two naphthalene groups and the be the hydrolysis product of 8 during column chromatog-
large ring size of ten-membered diphosphorus species 5, the raphy, which was performed with no special exclusion of air
six-membered monophosphorus species 7 might be formed and the silica was not dried (Scheme 8).
Scheme 6. Reaction of WR with two equivalents of 1,1Ј-methylenebis(2-naphthol).
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Scheme 8. Reaction of WR with two equivalents of 2,2Ј-methylenebis(4-chlorophenol).
Compounds 5–7, 9 and 10 are soluble in common chlori- plane in 1 and 2, respectively]. The structure of 4 has a
nated solvents and air stable for several months as solids. different motif compared to the above structures. The five-
Their formulations were ascertained by IR, MS (including membered O–P–O–C–C is co-planar with the naphthalene
accurate mass measurement), solution multinuclear NMR ring, whilst the phenyl ring and exocyclic selenium atoms
spectroscopy and in most cases additionally by single-crys- lie on opposite sides of the heterocyclic ring. The internal
tal X-ray structure determination. The 31P NMR spectra of P–Se bond lengths [single bond, 2.2507(10), 2.2635(9) Å for
5 and 7 exhibit sharp singlets at δ = 75.5 and 85.3 ppm, 1, and 2.2496(11), 2.2496(11) Å for 2] and the exocyclic
respectively, which are flanked by two sets of satellites for P=Se double bond lengths [2.0820(9) and 2.0735(10) Å for
the endocyclic and exocyclic selenium atoms [J(P,Seendo
)
1, 2.0771(11) and 2.0771(11) Å for 2] are similar to those
and J(P,Seexo): 468 and 855 Hz for 5, 434 and 857 Hz for in other compounds which contain the P(Se)(µ-Se)
7], thus indicating the presence of single P–Se bonds and unit.[8–10] The geometry around the phosphorus atoms in
double P=Se bonds in each compound. Meanwhile, the 31P 1 and 2 [Se(1)–P(1)–Se(2) 108.42(3)° and Se(2)–P(3)–Se(3):
NMR spectra of 6, 9 and 10 display sharp singlets at δ = 105.65(3)° for 1, Se(1)–P(1)–Se(2) 106.52(5)° and Se(1A)–
88.7, 90.3 and 76.8 ppm, respectively, which are ac- P(1A)–Se(2) 106.52(5)° for 2] are distorted from ideal tetra-
companied by single set of satellites for the exocyclic sele- hedral geometry due to steric effects of the phenyl groups.[8]
nium atoms [J(P,Seexo): 923 Hz for 6, 920 Hz for 9, and The transannular P···P bond lengths are 3.54 and 3.52 Å
954 Hz for 10], indicating only double P=Se bonds present for 1 and 2, respectively, being marginally longer than those
in each compound. The 77Se NMR spectra for 5 and 7 con-
tain signals arising from exocyclic selenium atoms [δ = 57.8
and 9.6 ppm; J(P,Seexo) = 856 and 856 Hz, respectively] and
endocyclic selenium atoms [δ = 414.5 and 367.5 ppm;
J(P,Seendo) = 468 and 434 Hz, respectively]. The 77Se NMR
spectra for 6, 9 and 10 show doublets due to the exocyclic
selenium atoms [δ = –222.0, –251.5 and –164.3 ppm;
J(P,Seexo) = 923, 924 and 954 Hz, respectively].
X-Ray Structures of 1, 2, 4, 5, 7, 9 and 10
Compounds 1, 2 and 4 were crystallized from dichloro-
methane solutions with slow diffusion of hexane to give
transparent, colorless, cubic crystals. The compounds are
stable to air and moisture for several months. The X-ray
structures of 1, 2 and 4 (Figures 1, 2, and 3) confirm the
presence of the five-, and seven-membered rings. The struc- Figure 1. Single crystal X-ray structure of 1 (hydrogen atoms omit-
ted for clarity). Selected bond lengths [Å] and angles [°] (esd values
tures of 1 and 2 are best described as boat conformation
in parentheses): P(1)–Se(1) 2.0820(9), P(1)–Se(2) 2.2507(10), P(2)–
with two phosphorus atoms at the stern and prow positions,
Se(2) 2.2635(9), P(2)–Se(3) 2.0735(10), P(1)–O(1) 1.621(2), P(2)–
in 1 and 2 the P2O2 mean plane is inclined by 61.9(2) and
O(2) 1.606(2), P(1)–C(7) 1.798(2), P(2)–C(13) 1.793(2), O(1)–C(1)
79.2(1)°, respectively with respect to the P2C2 plane. The
two phenyl rings attached to phosphorus atoms are almost
parallel and, in contrast to previous structures, in both 1
and 2 the exocyclic P=Se groups are almost coplanar with
the P–Se–P backbone [the Se=P···P=Se plane is inclined by
1.406(2), O(2)–C(6) 1.411(3); P(1)–Se(2)–P(2) 103.33(3), Se(1)–
P(1)–Se(2) 108.42(3), Se(1)–P(1)–O(1) 116.82(9), Se(1)–P(1)–C(7)
116.95(11),
Se(2)–P(1)–O(1)
104.64(10),
Se(2)–P(1)–C(7)
108.94(13), O(1)–P(1)–C(7) 100.14(11), Se(2)–P(2)–Se(3) 105.65(3),
Se(2)–P(2)–O(2) 105.15(9), Se(2)–P(2)–C(13) 109.38(10), Se(3)–
P(2)–O(2) 118.45(8), Se(3)–P(2)–C(13) 117.45(13), O(2)–P(2)–C(13)
only 22.96(3) and 21.99(1)° with respect to the P–Se–P 100.03(13), P(1)–O(1)–C(1) 119.85(19), P(2)–O(2)–C(6) 123.05(19).
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Novel Five- to Ten-Membered Organoselenium Heterocycles
observed in the four-membered P2Se2 ring system (3.1 Å) ing atoms (selenium or oxygen atoms) between two PhP=Se
and considerably shorter than those measured in a six- groups in the new rings. Interestingly the P=Se groups in 5
membered P2Se4 ring system (4.3 Å).[11] However, the exo- are rotated onto opposite sides of the P–Se–P group
cyclic P–Seexo bond length [2.0547(10) Å] in 4 is shorter whereas the P=Se groups in 10 are approximately on the
than that in the above structures. It is clear that 4 must be same side of the P–O–P unit. The structure of 7 is best
somewhat strained. The geometry around phosphorus atom described as a boat conformation consisting of a highly
[O(1)–P(1)–Se(1) 114.51(10)°, O(2)–P(1)–Se(1) 116.24(12)°] puckered six-membered C3OPSe ring with the naphthalene
is highly distorted due to the five-membered ring strain.
ring and phenyl ring being in opposite positions and being
inclined by 74.1°. In the crystal 5 adopts a less symmetric
conformation with a highly puckered C5O2P2Se ring, lead-
ing to two naphthalene rings being in nearly vertical posi-
tion (89.7°) and an angle of 53.0° for two phenyl rings. The
C5O2P ring in 9 is also highly puckered but has approximate
molecular C2 symmetry, resulting in two phenyl rings being
bent towards the same face of the molecule with an inter-
Figure 2. Single crystal X-ray structure of 2 (hydrogen atoms omit-
ted for clarity). Selected bond lengths [Å] and angles [°] (esd values
in parentheses): Se(1)–P(1) 2.0771(11), Se(2)–P(1) 1 2.2496(11),
Se(2)–P(1) 2.2496(11), Se(1A)–P(1A) 2.0771(11) P(1)–O(1)
1.621(2), P(1)–C(6) 1.790(4), O(1)–C(1) 1.398(5); P(1A)–Se(2)–P(1)
102.74(6), O(1)–P(1)–C(6) 100.91(17), O(1)–P(1)–Se(1) 117.97(11),
C(6)–P(1)–Se(1) 116.30(14), O(1)–P(1)–Se(2) 105.05(10), C(6)–
P(1)–Se(2) 109.42(14), Se(1)–P(1)–Se(2) 106.52(5), C(1)–O(1)–P(1)
120.1(2).
Figure 4. Single crystal X-ray structure of 5 (hydrogen atoms omit-
ted for clarity). Selected bond lengths [Å] and angles [°] (esd values
in parentheses): Se(1)–P(1) 2.0836(12), Se(2)–P(2) 2.0705(12),
Se(3)–P(1) 2.2439(11), Se(3)–P(2) 2.2660(12), P(1)–O(1) 1.605(3),
P(2)–O(2) 1.628(3), P(1)–C(22) 1.795(4), P(2)–C(28) 1.817(4), O(1)–
C(1) 1.417(4), O(2)–C(13) 1.421(5); P(1)–Se(3)–P(2) 103.62(4),
Se(1)–P(1)–Se(3) 105.99(5), Se(1)–P(1)–O(1) 120.39(11), Se(1)–
P(1)–C(22) 113.34(15), Se(3)–P(1)–O(1) 106.95(11), Se(3)–P(1)–
C(22) 109.27(13), O(1)–P(1)–C(22) 100.48(19), Se(2)–P(2)–Se(3)
120.22(5),
Se(2)–P(2)–O(2)
114.35(12),
Se(2)–P(2)–C(28)
115.06(15), Se(3)–P(2)–O(2) 98.85(11), Se(3)–P(2)–C(28) 98.51(15),
O(2)–P(2)–C(28) 107.52(17), P(1)–O(1)–C(1) 128.0(2).
Figure 3. Single crystal X-ray structure of 4 (hydrogen atoms omit-
ted for clarity). Selected bond lengths [Å] and angles [°] (esd values
in parentheses): Se(1)–P(1) 2.0547(10), P(1)–O(1) 1.630(3), P(1)–
O(2) 1.630(3), P(1)–C(11) 1.789(4), O(1)–C(1) 1.402(4); O(1)–P(1)–
O(2) 95.99(12), O(1)–P(1)–C(11) 105.72(15), O(2)–P(1)–C(11)
104.53(15),
O(1)–P(1)–Se(1)
114.51(10),
O(2)–P(1)–Se(1)
116.24(12), C(1)–O(1)–P(1) 110.5(2).
The structures of 5 (which co-crystallised with one mole-
cule of dichloromethane), 7, 9, and 10 (which crystallised
with two crystallographically independent molecules and a
half of molecule of dichloromethane in the asymmetric
unit) are illustrated in Figures 4, 5, 6, and 7. Compounds 7
and 9 contain the same monophosphorus unit PhP=Se de-
rived from the cleavage of WR ring. Meanwhile, the struc-
tures of 5 and 10 reveal very similar conformations of their
Figure 5. Single crystal X-ray structure of 7 (hydrogen atoms omit-
ted for clarity). Selected bond lengths [Å] and angles [°] (esd values
in parentheses): Se(1)–P(1) 2.2346(11), Se(2)–P(1) 2.0781(14), P(1)–
C(12) 1.795(4), Se(1)–C(11) 1.989(5), P(1)–O(1) 1.624(3), O(1)–C(1)
1.403(5); P(1)–Se(1)–C(11) 93.10(14), Se(1)–P(1)–O(1) 102.21(12),
Se(2)–P(1)–O(1) 117.55(14), O(1)–P(1)–C(12) 99.5(2), O(1)–C(1)–
C(2) 117.9(4), Se(1)–P(1)–Se(2) 113.46(5), Se(1)–P(1)–C(12)
ten-membered rings even though they have different bridg- 108.75(16), Se(2)–P(1)–C(12) 113.90(17), P(1)–O(1)–C(1) 118.9(2).
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G. Hua, A. L. Fuller, A. M. Z. Slawin, J. D. Woollins
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Figure 6. Single crystal X-ray structure of 9 (hydrogen atoms omitted for clarity). The right hand picture illustrates the “Klingon bird of
prey” like shape of the molecule. Selected bond lengths [Å] and angles [°] (esd values in parentheses): Se(1)–P(1) 2.0670(17), P(1)–O(1)
1.611(4), P(1)–O(2) 1.606(4), O(1)–C(1) 1.408(6), O(2)–C(9) 1.414(5), P(1)–C(14) 1.784(5); Se(1)–P(1)–O(1) 115.37(17), Se(1)–P(1)–C(14)
119.5(2), O(1)–P(1)–C(14) 99.8(2), P(1)–O(1)–C(1) 124.4(3), Se(1)–P(1)–O(2) 114.87(16), O(1)–P(1)–O(2) 104.9(2), O(2)–P(1)–C(14)
100.0(2), P(1)–O(2)–C(9) 122.4(3).
ring angle of 58.7° and an overall appearance which is remi- {2.0453(3) [2.046(3)] and 2.064(2) [2.062(2)] Å} are similar
niscent of a Klingon “Bird of Prey” warship. The structure to that [2.0547(10) Å] in 4, but slightly shorter than those
of 10 is similar to 5 with a less symmetric conformation in other compounds which contain the P(Se)(µ-Se)
along with a highly puckered C5O2P2O ring, three phenyl unit.[7,8,12,13] and those in compounds 1 and 2. The geome-
rings being towards the same side above the new ring. The try around P {Se(1)–P(1)–O(1): 102.21(12)° for 7, Se(3)–
exocyclic P=Se double bond lengths [2.0781(14) Å for 7, P(1)–O(1): 106.95(11)° and Se(3)–P(2)–O(2): 98.85(11)° for
2.0836(12) and 2.0705(12) Å for 5 and 2.0670(17) Å for 9] 5, O(1)–P(1)–O(2): 104.9(2)° for 9 and O(3)–P(1)–O(1):
are similar to those in other compounds which contain the 96.5(3)° [95.8(3)°] and O(3)–P(2)–O(2): 104.8(3)° [105.9(2)°
P(Se)(µ-Se) unit.[8–10] However, the P=Se lengths in 10 for 10]} is highly distorted.
In summary, a series of novel five- to ten-membered
phosphorus-selenium heterocycles with an O–P(Se)–O or
O–P(Se)–Se–P(Se)–O or O–P(Se)–O–P(Se)–O linkage have
been successfully prepared from the selenation of aromatic
diols by WR. The large diphosphorus species O–P(Se)–Se–
P(Se)–O rings could be readily reduced into the small mono-
phosphorus species O–P(Se)–O rings via further treatment
with one equivalent of aromatic diol. The method offers a
new approach to the library of phosphorus-selenium
heterocyclic compounds. The structures of the novel hetero-
1
cycles have been elucidated by using H, 31P, 77Se NMR
spectroscopy and microanalysis or accurate mass measure-
ments in conjunction with single-crystal X-ray crystallogra-
phy.
Figure 7. Single crystal X-ray structure of 10 (hydrogen atoms
Experimental Section
omitted for clarity). Selected bond lengths [Å] and angles [°] (esd
values in parentheses) (dimensions for second independent mole-
General: Unless otherwise stated, all reactions were carried out un-
cule in square parentheses): Se(1)–P(1) 2.0453(3) [2.046(3)], Se(2)–
der on oxygen free nitrogen atmosphere using pre-dried solvents
and standard Schlenk techniques, while subsequent chromato-
graphic and work up procedures were performed in air. 1H
(270 MHz), 13C (67.9 MHz), 31P{1H} (109 MHz) and 77Se-{1H}
(51.4 MHz referenced to external Me2Se) NMR spectra were re-
corded in CDCl3 at 25 °C (unless stated otherwise) on a JEOL
GSX 270. IR spectra were recorded as KBr pellets in the range of
4000–250 cm–1 on a Perkin–Elmer 2000 FTIR/Raman spectrome-
ter. Microanalysis was performed by the University of St-Andrews
microanalysis service. Mass spectrometry was performed by the
EPSRC National Mass Spectrometry Service Centre, Swansea and
the University of St Andrews Mass Spectrometry Service.
P(2) 2.064(2) [2.062(2)], P(1)–O(1) 1.593(6) [1.597(5)], P(1)–O(3)
1.627(6) [1.622(7)], P(1)–C(14) 1.759(9) [1.789(9)], P(2)–O(2)
1.581(5) [1.597(5)], P(2)–O(3) 1.602(7) [1.622(7)], P(2)–C(20)
1.804(9) [1.801(11)], O(1)–C(1) 1.411(8) [1.419(10)], O(2)–C(9)
1.428(11) [1.419(10)]; P(1)–O(3)–P(2) 136.8(4) [136.4(4)], Se(1)–
P(1)–O(3) 118.7(2) [118.4(2)], Se(1)–P(1)–O(1) 116.1(2) [117.0(2)],
Se(1)–P(1)–C(14) 117.3(4) [117.9(3)], O(3)–P(1)–O(1) 96.5(3)
[95.8(3)], O(3)–P(1)–C(14) 99.4(3) [100.4(4)], O(1)–P(1)–C(14)
105.6(4) [103.7(3)], Se(2)–P(2)–O(3) 117.3(3) [118.3(2)], Se(2)–P(2)–
O(2) 109.2(2) [107.9(2)], Se(2)–P(2)–C(20) 115.1(3) [116.2(3)], O(3)–
P(2)–O(2) 104.8(3) [105.9(2)], O(3)–P(2)–C(20) 99.49(4) [99.4(4)],
O(2)–P(2)–C(20) 109.4(4) [108.3(3)], P(1)–O(1)–C(1) 123.0(6)
[122.7(6)], P(2)–O(2)–C(9) 132.5(5) [131.9(5)].
2612
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© 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Org. Chem. 2010, 2607–2615

Novel Five- to Ten-Membered Organoselenium Heterocycles
X-ray crystal data for compounds 2 and 4 were collected at 93 K
by using a Rigaku MM007 High brilliance RA generator/confocal
optics and Mercury CCD system. Data for 1, 5, 7, 9 and 10 were
collected using the St Andrews Robotic diffractometer (Saturn 724
Reaction of WR with Equimolar Aromatic Diol (A): A suspension
of WR (0.54 g, 1.0 mmol) with aromatic diol (1.0 mmol) in 20 mL
of toluene was refluxed for 7 h, during which time the dark red
suspension became a yellow solution with some grey precipitate of
CCD) at 125 K with graphite monochromated Mo-Kα radiation elemental selenium. Upon cooling to room temperature the solvent
(λ = 0.71073 Å).[14,15] Intensity data were collected using ω steps was removed in vacuo, the crude residue extracted into dichloro-
accumulating area detector images spanning at least a hemisphere
of reciprocal space. All data were corrected for Lorentz polariza-
tion effects. Absorption effects were corrected on the basis of mul-
tiple equivalent reflections or by semi-empirical methods. Struc-
tures were solved by direct methods and refined by full-matrix le-
ast-squares against F2 by using the program SHELXL.[16] Hydro-
gen atoms were assigned riding isotropic displacement parameters
and constrained to idealized geometries.
methane (5 mL) and purified by column chromatography (1:9 ethyl
acetate/toluene as eluent) to give compounds 1–4.
Reaction of WR with Two Molar Equivalents of Aromatic Diol (B):
A solution of WR (0.54 g, 1.0 mmol) with aromatic diol (2.0 mmol)
in 20 mL of toluene was refluxed for 10 h, during which time the
dark red suspension became a yellow solution with some grey pre-
cipitate of elemental selenium. Upon cooling to room temperature
the solvent was removed in vacuo, the crude residue extracted into
dichloromethane (5 mL) and purified by column chromatography
(1:9 ethyl acetate/toluene as eluent) to give compounds 3 and 4.
CCDC-761969 (for 1), -761970 (for 10), -761971 (for 2), -761972
(for 4), -761973 (for 5), -761974 (for 7), -761975 (for 9) contain the
supplementary crystallographic data for this paper. These data can
be obtained free of charge from The Cambridge Crystallographic
Data Centre via www.ccdc.cam.ac.uk/data_request/cif (see also
Tables 1 and 2).
Reaction of 1 or 2 with Equimolar of the Corresponding Aromatic
Diol (C): A mixture of 1 or 2 (1.0 mmol) with aromatic diol
(1.0 mmol) in 20 mL of toluene was refluxed for 7 h. Upon cooling
to room temperature the solvent was removed in vacuo, the crude
residue extracted into dichloromethane (5 mL) and purified by col-
umn chromatography (1:9 ethyl acetate/toluene as eluent) to give
compounds 3 and 4.
Table 1. Details of the X-ray data collections and refinements for
1, 2 and 4.
Compound 1: Greenish yellow crystals (220 mg) in 39% yield. Se-
Compound
1
2
4
lected IR (KBr): ν = 1485 (s), 1434 (m), 1233 (s), 1099 (m), 915
˜
Formula
M
Crystal system
Space group
a /Å
b /Å
c /Å
α
C18H14O2P2Se3 C22H16O2P2Se3 C16H11O2PSe
561.13
triclinic
P1
8.3203(4)
9.6324(4)
13.5237(6)
103.2960(14)
91.4965(15)
115.0917(13)
945.81(7)
2
(m), 885 (s), 762 (m), 737 (m), 715 (m), 682 (m), 546 (s, P=Se) cm–1.
1H NMR (CDCl3): δ = 7.72–7.56 (m, 4 H, ArH), 7.44–7.31 (m, 6
H, ArH), 7.22–7.15 (m, 4 H, ArH) ppm. 13C NMR (CDCl3): δ =
133.7, 132.7, 130.2, 130.1, 130.0, 128.5, 128.3, 127.8, 124.3 ppm.
31P NMR (CD2Cl2): δ = 77.7 [s, J(P,Seendo) = 465, J(P,Seexo) =
852 Hz] ppm. 77Se NMR (CDCl3): δ = 434.7 [d, J(P,Seendo) =
465 Hz], 77.3 [d, J(P,Seexo) = 852 Hz] ppm. Mass spectrum (EI+,
m/z): 562 [M]+. C18H14O2PSe (372.24): calcd. C 38.5, H 2.5; found
C 38.9, H 2.8.
611.17
345.18
orthorhombic monoclinic
¯
Cmc2(1)
14.040(3)
9.6720(17)
16.270(3)
90
90
90
2209.4(7)
4
5.156
P21/c
14.462(3)
7.7917(15)
13.186(3)
90
114.195(4)
90
1355.4(5)
4
2.885
β
γ
U /A3
Z
Compound 2: A white solid (178 mg) in 29% yield. Selected IR
µ /mm–1
6.0130
(KBr): ν = 1503 (w), 1461 (m), 1434 (m), 1241 (m), 1103 (m), 1079
˜
(m), 904 (s), 720 (m), 683 (m), 533 (s, P=Se) cm–1. 1H NMR
(CD2Cl2): δ = 8.01 (m, 2 H, ArH), 7.96 [m, J(H,H) = 7.2 Hz, 2 H,
ArH], 7.74–7.60 (m, 6 H, ArH), 7.38 [m, J(H,H) = 7.2 Hz, 2 H,
ArH], 7.22 (m, 4 H, ArH) ppm. 13C NMR (CD2Cl2, 25 °C): δ =
154.5, 144.3, 132.9, 130.0, 129.9, 128.5, 127.9, 127.2, 121.9 ppm.
31P NMR (CD2Cl2): δ = 79.7 [s, J(P,Seendo) = 465, J(P,Seexo) =
Reflections collected 10009
Independent reflec-
tions
7054
8383
4343
2012
2485
Rint
0.0210
0.0256;
0.0694
0.0376
0.0317;
0.0614
0.0434
0.0446;
0.1072
R1; wR2 [IϾ2σ(I)]
Table 2. Details of the X-ray data collections and refinements for 5, 7, 9 and 10.
Compound
5
7
9
10
Formula
M
C34H26Cl2O2P2Se3
836.31
C17H13OPSe2
422.18
C19H13Cl2O2PSe
454.15
C25.25H18.5Cl2.5O3P2Se
678.42
Crystal system
Space group
monoclinic
P21/n
monoclinic
P21/n
monoclinic
P21/c
triclinic
P1
¯
a /Å
b /Å
c /Å
α
9.6007(16)
11.5387(18)
29.679(5)
90
94.742(4)
90
3276.6(9)
4
1.695
9.1244(15)
8.6606(13)
20.178(3)
90
102.065(4)
90
1559.3(4)
4
1.798
11.868(3)
7.585(2)
21.097(6)
90
104.045(6)
90
1842.3(9)
4
1.637
12.990(5)
13.829(5)
16.436(5)
94.306(3)
107.147(6)
108.060(9)
2636(17)
4
β
γ
U /A3
Z
µ /mm–1
1.709
Reflections collected
Independent reflections
Rint
19447
5756
0.0500
0.0402; 0.1404
9508
2704
0.0390
0.0382; 0.1370
10247
3214
0.0530
0.0637; 0.1640
27400
9120
0.0770
0.1021; 0.2457
R1; wR2 [IϾ2σ(I)]
Eur. J. Org. Chem. 2010, 2607–2615
© 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjoc.org
2613

G. Hua, A. L. Fuller, A. M. Z. Slawin, J. D. Woollins
FULL PAPER
864 Hz] ppm. 77Se NMR (CD2Cl3): δ = 352.8 [d, J(P,Seendo) =
465 Hz], 67.08 [d, J(P,Seexo) = 864 Hz] ppm. Mass spectrum (EI+,
m/z): 612 [M]+. C22H16O2P2Se3 (611.19): calcd. C 43.2, H 2.6;
found C 43.5, H 2.7.
125.5, 123.7, 122.7, 121.3, 25.3 ppm. 31P NMR (CD2Cl2): δ = 85.3
[s, J(P,Seendo) = 434, J(P,Seexo) = 857 Hz] ppm. 77Se NMR
(CD2Cl2): δ = 367.5 [d, J(P,Seendo) = 434 Hz]; 9.6 [d, J(P,Seexo) =
856 Hz] ppm. Mass spectrum (CI+, m/z): 425 [M + H]+. Accurate
mass measurement (EIMS): 423.9031, calculated mass for
C17H13OPSe2: 423.9034.
Compound 4: A colorless solid (182 mg in 53% yield from method
A; 304 mg in 88% yield from method B and 342 mg in 99% from
method C). Selected IR (KBr): ν = 1454 (m), 1233 (m), 1154 (m),
˜
Synthesis of 9 and 10: Mixture of 2,2Ј-methylenebis(4-chloro-
phenol) (0.54 g, 2.0 mmol) and WR (0.54 g, 1.0 mmol) in 20 mL of
toluene was refluxed for 7 h. The red suspension disappeared and
a pale green solution was formed. Upon cooling to room tempera-
ture and removing solvent the residue was purified by silica gel to
give compounds 9 (eluent by 50:50 hexane/dichloromethane) and
10 (eluent by dichloromethane).
1111 (m), 882 (s), 858 (s), 784 (m), 750 (m), 720 (m), 640 (m), 532
1
(s, P=Se) cm–1. H NMR (CD2Cl2): δ = 7.93–7.78 (m, 4 H, ArH),
7.62 [d, J(H,H) = 7.2 Hz, 2 H], 7.51–7.44 (m, 6 H, ArH) ppm. 13C
NMR (CDCl3): δ = 145.1 [d, J(P,C) = 117 Hz], 134.3 [d, J(P,C) =
3.1 Hz], 131.1 [d, J(P,C) = 13.5 Hz], 130.5, 128.8 [d, J(P,C) =
15.6 Hz], 127.6, 125.9, 109.9, 108.9 ppm. 31P NMR (CDCl3): δ =
115.9 [s, J(P,Seexo) = 965 Hz] ppm. 77Se NMR (CDCl3): δ = –188.3
[d, J(P,Seexo) = 965 Hz] ppm. Mass spectrum (EI+, m/z): 346 [M]+,
266 [M – Se]+. C16H11O2PSe (345.20): calcd. C 55.7, H 3.2; found
C 55.4, H 3.4.
Compound 9: Pale yellow solid (346 mg in 74% yield). Selected IR
(KBr): ν = 3076 (w), 2930 (w), 1479 (s), 1438 (m), 1400 (m), 1225
˜
(s), 1167 (s), 1111 (s), 932 (s), 873 (m), 854 (s), 816 (s), 731 (s), 646
(s), 537 (m) cm–1. 1H NMR (CD2Cl2): δ = 8.22 (m, 2 H, ArH),
7.64 (m, 3 H, ArH), 7.39 (m, 2 H, ArH), 7.21 (m, 2 H, ArH), 6.99
(m, 2 H, ArH), 4.46 (s, 2 H, CH2) ppm. 13C NMR (CD2Cl2): δ =
147.1 [d, J(P,C) = 10.4 Hz], 135.0 [d, J(P,C) = 3.1 Hz], 133.5 [d,
J(P,C) = 3.1 Hz], 131.4, 130.6 [d, J(P,C) = 12.5 Hz], 130.2, 128.8,
128.6, 128.4, 125.7, 125.6, 33.1 ppm. 31P NMR (CD2Cl2): δ = 90.3
[s, J(P,Seexo) = 920 Hz] ppm. 77Se NMR (CD2Cl2): δ = –251.5 [d,
J(P,Seexo) = 924 Hz] ppm. Mass spectrum (CI+, m/z): 455 [M +
H]+. Accurate mass measurement (EIMS): 453.9190, calculated
mass for C19H13Cl2O2PSe: 453.9195.
Synthesis of 5–7: Mixture of 1,1Ј-methylenebis(2-naphthol) (1.0 or
2.0 mmol) and WR (0.54 g, 1.0 mmol) in 20 mL of toluene was
refluxed for 7 h. The red suspension disappeared and a pale green
solution was formed. Upon cooling to room temperature and re-
moving solvent in vacuo, the residue was purified by silica gel
chromatography column (eluent by 50:50 hexane/dichloromethane)
to give compounds 5, 6 and 7. Only compounds 6 and 7 were ob-
tained in the case of the ratio of WR/diol = 1:2.
Compound 5: Orange solid (381 mg in 51% yield). Selected IR
(KBr): ν = 3051 (w), 2923 (w), 1628 (m), 1599 (m), 1513 (m), 1462
˜
Compound 10: Pale yellow solid (160 mg in 24% yield). Selected IR
(m), 1266 (m), 1216 (vs), 995 (m), 959 (m), 845 (m), 809 (s), 742
(KBr): ν = 3052 (w), 2948 (w), 2921 (w), 1481 (s), 1438 (m), 1401
˜
1
(s) cm–1. H NMR (CD2Cl2): δ = 8.24–7.04 (m, 29 H, ArH), 4.74
(m), 1216 (m), 1167 (s), 1112 (s), 943 (s), 899 (s), 815 (s), 725 (s),
(s, 4 H, CH2) ppm. 13C NMR (CD2Cl2): δ = 153.8, 148.6 [d, J(P,C)
= 10.5 Hz], 134.8, 133.8, 132.8, 132.0, 131.6, 131.4, 129.8, 129.4,
128.9, 128.7, 128.5, 127.8, 127.6, 126.7, 126.5, 126.4, 125.6, 124.7,
124.4, 123.6, 123.2, 123.0, 121.2, 120.2, 118.5, 118.1, 117.9, 117.7,
109.4, 21.5 ppm. 31P NMR (CD2Cl2): δ = 75.5 [s, J(P,Seendo) = 468,
J(P,Seexo) = 855 Hz] ppm. 77Se NMR (CDCl3): δ = 414.5 [d,
J(P,Seendo) = 468 Hz], 57.8 [d, J(P,Seexo) = 856 Hz] ppm. Mass spec-
trum (EI+, m/z): 754 [M]+. Accurate mass measurement (EIMS):
753.8745, calculated mass for C33H24O2PSe3: 753.8747.
1
688 (m), 643 (m), 543 (m) cm–1. H NMR (CD2Cl2): δ = 7.96–7.16
(m, 16 H, ArH), 4.36 (s, 2 H, CH2) ppm. 13C NMR (CD2Cl2): δ =
148.5, 133.5, 131.1, 131.0, 130.7, 130.6, 130.5, 128.9, 128.8, 128.7,
127.9, 122.7, 30.6 ppm. 31P NMR (CD2Cl2): δ = 76.8 [s, J(P,Seexo
)
= 954 Hz] ppm. 77Se NMR (CD2Cl2): δ = –164.3 [d, J(P,Seexo) =
954 Hz] ppm. Mass spectrum (CI+, m/z): 659 [M + H]+. Accurate
mass measurement (EIMS): 657.8436, calculated mass for
C25H18Cl2O3P2Se2: 657.8439.
Compound 6: White solid (200 mg in 31% yield from the ratio of
WR/diol = 1:1 and 399 mg in 62% yield the ratio of WR/diol =
Acknowledgments
1:2). Selected IR (KBr): ν = 3057 (w), 2923 (w), 1621 (m), 1593 (s),
˜
We are grateful to the University of St Andrews and the Engineer-
ing and Physical Science Research Council (EPSRC) for financial
support.
1514 (m), 1460 (m), 1434 (m), 1405 (m), 1244 (vs), 1212 (m), 959
1
(m), 804 (s), 730 (m), 733 (m) cm–1. H NMR (CD2Cl2): δ = 8.36
[d, J(H,H) = 8.5 Hz, 2 H, ArH], 8.05 (m, 2 H, ArH), 7.87 (m, 2
H, ArH), 7.77 (m, 2 H, ArH), 7.63 (m, 3 H, ArH), 7.49 (m, 2 H,
ArH), 7.31 (m, 2 H, ArH), 7.06 (m, 2 H, ArH), 4.59 (s, 3 H, CH2)
ppm. 13C NMR (CD2Cl2): δ = 148.9 [d, J(P,C) = 12.5 Hz], 150.0
[d, J(P,C) = 12.5 Hz], 132.9, 132.3, 132.0, 130.6, 130.4, 129.0, 128.9,
128.4, 127.3, 126.9, 125.5, 124.4, 123.7, 122.4, 121.3, 121.2, 117.8,
111.2, 22.4 ppm. 31P NMR (CD2Cl2): δ = 88.7 [s, J(P,Seexo) =
923 Hz] ppm. 77Se NMR (CD2Cl2): δ = –222.0 [d, J(P,Seexo) =
923 Hz] ppm. Mass spectrum (CI+, m/z): 647 [M + H]+. Accurate
mass measurement (EIMS): 645.8614, calculated mass for
C27H19O2PSe: 645.8618.
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Compound 7: Reddish white solid (52 mg in 12% yield from the
ratio of WR/diol = 1:1 and 64 mg in 15% yield from the ratio of
WR/diol = 1:2). Selected IR (KBr): ν = 3050 (w), 2920 (w), 1592
˜
(m), 1510 (m), 1460 (m), 1435 (m), 1215 (vs), 1055 (s), 997 (m), 953
1
(m), 890 (s), 816 (s), 690 (m), 554 (m) cm–1. H NMR (CD2Cl2): δ
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ppm. 13C NMR (CD2Cl2): δ = 148.9 [d, J(P,C) = 12.5 Hz], 133.0,
132.9, 132.1, 130.9, 130.7, 130.6, 130.5, 129.6, 129.0, 128.8, 127.4,
2614
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© 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Org. Chem. 2010, 2607–2615

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Received: January 20, 2010
Published Online: March 17, 2010
Eur. J. Org. Chem. 2010, 2607–2615
© 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjoc.org
2615