Ring-closing olefin metathesis for the synthesis of phosphorus containing heterocycles

Article abstract of DOI:10.1016/S0040-4020(00)00080-6

A series of cyclic phosphorus containing heterocycles 9a-k was prepared in a one-step procedure by ring closing metathesis of dienes 7a-k. (C) 2000 Elsevier Science Ltd.

Full text of DOI:10.1016/S0040-4020(00)00080-6

TETRAHEDRON
Pergamon
Tetrahedron 56 (2000) 2053±2060
Ring-Closing Ole®n Metathesis for the Synthesis of Phosphorus
Containing Heterocycles
*
L. Hetherington, B. Greedy and V. Gouverneur
University of Oxford, The Dyson Perrins Laboratory, South Parks Road, OX1 3QY Oxford, UK
Received 24 September 1999; revised 6 January 2000; accepted 20 January 2000
AbstractÐA series of cyclic phosphorus containing heterocycles 9a±k was prepared in a one-step procedure by ring closing metathesis of
dienes 7a±k. q 2000 Elsevier Science Ltd. All rights reserved.
Introduction
compound 3 are analogs of 1,4-dihydropyridine-3,5-dicarb-
oxylate calcium antagonists and are therefore anti-hyper-
tensive agents.4 1,2-Azaphosphorine such as compound 4
were developed in the search for biodegradable insecticides.5
More recently, cyclic organophosphorus compounds have
been employed for the generation of novel biocatalysts.6
The cyclic phosphonate 5 has been successfully used to
generate antibodies that catalyse the enantioselective
aminolysis of lactones.7
Heterocyclic systems that include a phosphorus linked to an
oxygen or nitrogen atom are common to a diverse array of
important biological molecules, e.g. 1±5 (Scheme 1).
These include cyclophosphamide 1a, an anti-tumor alkyl-
ating agent which together with its structural isomer ifosfa-
mide 1b act as prodrugs relying on metabolism for their
action.1 In another group of compounds, cyclic phospho-
nates as exempli®ed by compound 2 are hexapyranose
analogs modi®ed at the anomeric carbon.2 As a result,
these analogs can regulate key steps in carbohydrate linked
biological processes, e.g. cellular recognition.3 1,4-
Dihydropyridine-5-cyclic phosphonate derivatives such as
We were recently attracted by the versatility and synthetic
applicability of the ring-closing metathesis reaction (RCM)8
using the well-de®ned transition metal catalysts 6a,b9 and
6c10 in the construction of functionalised carbocycles and
heterocycles (Scheme 2).
Scheme 1.
Keywords: ring closing metathesis; phosphorus heterocycles.
* Corresponding author. Fax: 144-1865-275-644; e-mail: veronique.gouverneur@chem.ox.ac.uk
0040±4020/00/$ - see front matter q 2000 Elsevier Science Ltd. All rights reserved.
PII: S0040-4020(00)00080-6

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L. Hetherington et al. / Tetrahedron 56 (2000) 2053±2060
comprehensive study that explores the scope and limitation
of the RCM reaction to generate such phosphorus contain-
ing compounds. As part of a study to prepare new transition
state analogs for antibody catalysis, we extended this
methodology to the preparation of new phosphorus/oxygen
heterocycles with a focus on 3,6-dihydro-1,2-oxaphosphi-
nine 2-oxide and to the synthesis of phosphorus/nitrogen
heterocycles.
Scheme 2.
Results and Discussion
To date, the literature contains only a few examples of RCM
reactions on phosphorus containing compounds. These
include a phosphine,11 phosphinate,12 phosphinate13 or
phosphine oxide14 functionality. However, there exist no
To establish the feasibility of this strategy, a series of
representative dienes were synthesised using three different
procedures (Scheme 3).
Scheme 3.

L. Hetherington et al. / Tetrahedron 56 (2000) 2053±2060
2055
Table 1. RCM of dienes 7a±k in the presence of the Ru-catalyst 6a in CH2Cl2 (re¯ux, 0.02 M)
aIsolated yields.
bMixture of diastereomers.
c100% recovered starting material.
The symmetrical diene 7a was prepared by the addition of
two equivalents of allylic alcohol to phenylphosphonic
dichloride in the presence of two equivalents of triethyl-
amine and a catalytic amount of DMAP in 98% yield.
Similarly, diene 7b was prepared in 41% yield using an
excess of allylamine. Dienes 7c, 7d, 7e and 7f were prepared
in two steps from phenyldichlorophosphine according to a
procedure described in the literature.15 Addition of two
equivalents of the corresponding allylic alcohol in the
presence of pyridine followed by a [2,3] sigmatropic
Arbusov rearrangement at 1308C of the intermediate
phosphonites afforded the expected dienes with non opti-
mised overall yields ranging from 31% to 46%. The major
problem of this route is the concomitant formation of the
phosphonates 8c±f resulting from the oxidation of the inter-
mediate diallyl phenyl phosphonites. However, the desired

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L. Hetherington et al. / Tetrahedron 56 (2000) 2053±2060
dienes 7c±f could be obtained analytically pure by column
chromatography. Dienes 7g, 7h and 7i were prepared from
allylphenylphosphinic methyl ester16 by treatment with PCl5
followed by addition of the corresponding allylic alcohol or
amine in the presence of a catalytic amount of DMAP in
dichloromethane. Finally, dienes 7j and 7k were prepared
from diallylphosphinic acid 17 and the corresponding amines
via the activated phosphinic acid chloride.
and 80% yield, respectively (entries 10 and 11). The reac-
tion of the tertiary phosphinamide 7k was more favourable,
supporting once more the hypothesis that, in some cases, the
catalyst might be inhibited by the complex-forming proper-
ties of the phosphinamide NH group.
Conclusion
The RCM of dienes 7a±k were carried out in dichloro-
methane under re¯ux in the presence of 2±16% (added
portionwise, 2 mol%) of the Ru-catalyst 6a and at a concen-
tration of 0.02 M to give the corresponding cyclised
products with moderate to excellent yields (Table 1).
Under these conditions, RCM of the diene 7c proceeded
smoothly to give the phenyl-substituted six-membered
oxaphosphinine oxide 9c in excellent yield (entry 1). The
cyclic products 9d and 9e possessing a methyl group respec-
tively on position 6 and 3 could also be prepared con-
veniently and in very high yields (entries 2 and 3).
However, the formation of the structural isomer 9g
possessing the methyl group on the ole®n, was less favour-
able. Indeed, only 31% of product 9g was isolated after
three days in the presence of 10% alkylidene 6a (entry 4).
The tetrasubstituted cyclic ole®n 9f could not be obtained
using this procedure. Indeed, the alkylidene 6a showed no
reaction with the disubstituted diene 7f over ®ve days
supporting the hypothesis that steric effects are unfavour-
able for promoting ring closure (entry 5).18 The cyclisation
of the diene 7a including a phosphonate group was surpris-
ingly sluggish and gave only 34% of the seven-membered
adduct 9a after ®ve days in the presence of 16% of catalyst.
1H NMR and mass analysis of the crude mixture showed
only unreacted starting material and no trace of dimer (entry
6).
In summary, the work presented here has established a
general strategy based on the RCM reaction for the
synthesis of various phosphorus containing ®ve-, six- and
seven-membered heterocycles. During the course of this
study, it was reported by Hanson et al. that 6-membered
allylphosphonamides, ®ve-membered vinylphosphonamides
and various ®ve-, six- and seven-membered phosphonates
could be prepared by RCM of the corresponding dienes.20
His results are consistent with our observations as he also
found that the reactions with substrates including free NH
groups might be sluggish and required prolonged reaction
time and higher amount of the catalyst. Both papers are
complementary and show that the RCM is a valuable
synthetic route for a wide range of differently substituted
phosphorus containing heterocycles. Application of this
methodology to new transition state analogs is in progress
in this laboratory.
Experimental
General methods
Allylphenylphosphinic methyl ester,16 diallylphenylphos-
phinic acid17 and ammonium phosphinate21 were prepared
as described in the literature. The ruthenium alkylidene 6a
was purchased from Strem. 1H NMR and 13C NMR spectra
were recorded on Bruker DPX-400 and Bruker AM-500
spectrometers. 31P NMR spectra were recorded on a Bruker
AM-500 spectrometer at 202 MHz and were referenced
externally to phosphoric acid (dPˆ0 ppm). Infrared spectra
were recorded using a Perkin±Elmer Paragon 1000 FT-IR
spectrometer. Mass spectra (m/z) were recorded on a Micro-
mass Platform-I APCI spectrometer. HRMS were
performed on a Micromass Autospec 5000 OATof. Thin
layer chromatography was performed using Merck alu-
minium foil backed sheets pre-coated with Kieselgel 60
F254. Plates were visualised using UV light or KMnO4.
Column chromatography was performed using Sorbsile
C60 H (40±60) silica gel.
Having established that the formation of differently substi-
tuted oxaphosphinine oxides (entries 1 to 4) was feasible,
attention was turned towards the compatibility of RCM for
the preparation of the corresponding nitrogen containing
heterocycles. It was presumed that RCM of dienes including
free allylic phosphinamide or phosphonamide NH groups
might be problematic as it was previously observed by
other groups that cyclisation of subtrates containing free
allylic amide NH group could be dif®cult.19 Interestingly,
the reaction of the diene 7h required only 3% of catalyst 6a
for 85% yield of product 9h after 18 h (entry 7). Exposure of
the phenyl-substituted diene 7i to the same alkylidene 6a
showed lower reactivity in converting this substrate to 9i.
Indeed, after 48 h in the presence of 8% of alkylidene 6a,
63% of the expected cyclic product 9i was isolated (entry 8).
When the phosphonamide 7b was subjected to RCM con-
dition, only 36% of the desired product 9b could be isolated
after three days in the presence of 6% of the Ru-catalyst 6a
(entry 9). For this reaction, the NMR and mass spectrum of
the crude mixture show only unreacted starting material
with no trace of a dimer or other side products. The lower
reactivity of substrate 7b supports the observation that the
formation of a seven-membered ring combined with the
presence of free allylic NH groups is not favourable to the
RCM reaction. Finally, we examined the reactivity of phos-
phinamides 7j and 7k. These dienes with alkylidene 6a
afforded the expected 5-membered ring products in 43%
Phenylphosphonic acid diallyl ester 7a.22 To a solution of
phenylphosphonic dichloride (0.3 ml, 2.12 mmol), a cata-
lytic amount of DMAP and Et3N (0.65 ml, 4.7 mmol) in
CH2Cl2 (10 ml) at 08C was added allylic alcohol (0.32 ml,
4.71 mmol). The mixture was allowed to warm to room
temperature and was stirred overnight. The solvent was
removed under reduced pressure and the residue was treated
with pentane (10 ml). After ®ltration of the salts, the residue
was puri®ed by column chromatography; yield: 0.5 g
(98%); Rfˆ0.2 (hexane:EtOAc, 3:2); dH (CDCl3, 400
MHz) 7.86±7.80 (m, 2H), 7.59±7.54 (m, 1H), 7.50±7.45
(m, 2H), 5.98±5.89 (m, 2H), 5.34 (d, 2H, Jˆ17.1 Hz),
5.22 (d, 2H, Jˆ10.4 Hz), 4.64±4.49 (m, 4H); dC (CDCl3,

L. Hetherington et al. / Tetrahedron 56 (2000) 2053±2060
2057
101 MHz) 132.8 (d, Jˆ6.8 Hz), 132.6 (d, Jˆ2.8 Hz), 131.8
(d, Jˆ10.1 Hz), 128.5 (d, Jˆ15.0 Hz), 127.8 (d,
Jˆ189.5 Hz), 118.0, 66.5 (d, Jˆ5.3 Hz); dP (CDCl3,
202 MHz) 20.9; nmax (neat, cm21) 1650, 1249, 1012; m/z
(CI1, NH3) 239.0 (M1H1).
NH3) 251.1 (M1H1); HRMS calcd for C14H21O2P (M1H1)
251.1201, found 251.1204.
2-(Methyl)allylphenylphosphinic acid but-2-enyl ester
(mixture of Z and E isomers) 7e. Same procedure as for
7c with 1.88 ml (22 mmol) of but-2-en-ol, 1.8 ml (22 mmol)
of pyridine, 32 ml Et2O, 1.36 ml (10 mmol) of dichloro-
phenylphosphine; yield: 1.13 g (45%); Rfˆ0.5 (hexane:
EtOAc, 1:1); dH (CDCl3, 400 MHz) (pminor isomer)
7.72±7.66 (m,2H), 7.5±7.46 (m,1H), 7.42±7.38 (m,2H),
5.77±5.64 (m,2H), 5.53 (m,1H), 5.11±4.87 (m,2H), 4.47±
4.41 (m,1H), 4.24±4.19 (m,1H), 2.78±2.69 (m,1H), 1.63
(dd, Jˆ6.4, 1.0 Hz, 3H), 1.22 (ddd, Jˆ7.6, 17.2, 1.2 Hz,
3H) (p1.15 (ddd, Jˆ17.6, 1.2 Hz); dC (CDCl3, 101 MHz)
(pminor isomer) 134.2 (d, Jˆ6.7 Hz) (p134 (d, Jˆ8.7 Hz)),
132.4 (d, Jˆ8.5 Hz) (p132.3 (d, Jˆ8.5 Hz)), 132.1 (d,
Jˆ2.3 Hz), 130.6 (p130.5), 130.4 (d, Jˆ139.5 Hz), 128.1
(d, Jˆ11.7 Hz) (p128.3 (d, Jˆ11.4 Hz)), 126.17 (d,
Jˆ7.1 Hz) (p126.14 (d, Jˆ6.9 Hz)), 117.4 (d, Jˆ11.9 Hz)
(p117.6 (d, Jˆ11.6 Hz)), 65.2 (d, Jˆ6.5 Hz), 39.2 (d,
Jˆ97.7 Hz) (p39.5 (d, Jˆ96.5 Hz)), 17.6, 12.1 (d,
Jˆ3.7 Hz) (p12.6 (d, Jˆ3.7 Hz)); dP (CDCl3, 202 MHz)
(pminor isomer) 45.6 (p45.5); nmax (neat, cm21) 1228; m/z
(CI1, NH3) 251.2 (M1H1); HRMS calcd for C14H21O2P
(M1H1) 251.1201, found 251.1205.
N, N0-Diallyl-p-phenylphosphonic diamide 7b. Same
procedure as for 7a with 0.3 ml (2.12 mmol) of phenyl phos-
phonic dichloride a catalytic amount of DMAP and 3 ml
Et3N (21.2 mmol), 1.6 ml allylamine (21.2 mmol). yield:
0.2 g (41%); Rfˆ0.2 (1% MeOH in EtOAc); dH (CDCl3,
500 MHz) 7.87±7.83 (m, 2H), 7.54±7.51 (m, 1H), 7.48±
7.44 (m, 2H), 5.91±5.84 (m, 2H), 5.27 (dd, 2H, Jˆ16.8,
1.3 Hz), 5.13 (dd, 2H, Jˆ10.5, 1.5 Hz), 3.64±3.58 (m,
4H), 2.56 (br s, 2H); dC (CDCl3, 101 MHz) 136.5 (d,
Jˆ6.5 Hz), 131.7 (d, Jˆ2.5 Hz), 131.5 (d, Jˆ9.2 Hz),
124.9 (d, Jˆ184.0 Hz), 115.4, 43.2; dP (CDCl3, 202 MHz)
22.0; nmax (neat, cm21) 3216, 1644, 1189; m/z (CI1, NH3)
237.2 (M1H1); HRMS calcd for C12H18 N2OP (M1H1)
237.1157, found 237.1156.
Allylphenylphosphinic acid allyl ester 7c.15 To a solution
of allylic alcohol (1.1 ml, 16.1 mmol) and pyridine (1.3 ml,
16.1 mmol) in Et2O (30 ml) at 08C was added a solution of
dichlorophenylphosphine (1 ml, 7.4 mmol) in Et2O (1 ml).
The mixture was allowed to warm to room temperature and
then re¯uxed for 1 h. Salts were ®ltered off and the solvent
was removed under reduced pressure. The residue was
heated neat to 1308C overnight. The crude mixture was
puri®ed by column chromatography; yield: 0.5 g (31%);
Rfˆ0.3 (EtOAc); dH (CDCl3, 500 MHz) 7.78±7.76 (m,
2H), 7.57±7.54 (m, 1H), 7.50±7.46 (m, 2H), 5.95±5.88
(m, 1H), 5.81±5.71 (m, 1H), 5.33 (dd, 1H, Jˆ17.1,
2.0 Hz), 5.21 (dd, 1H, Jˆ10.4, 1.5 Hz), 5.15 (dd, 1H,
Jˆ10.1, 4.0 Hz), 5.08 (dd, 1H, Jˆ17.1, 5.1 Hz), 4.56 (m,
1H, Jˆ13.5, 5.5 Hz), 4.32 (dd, 1H, Jˆ13.0, 5.5 Hz), 2.86±
2.77 (m, 2H); dC (CDCl3, 126 MHz) 133.0 (d, Jˆ7.0 Hz),
132.0, 131.8 (d, Jˆ9.4 Hz), 130.0 (d, Jˆ124.9 Hz), 128.5
(d, Jˆ12.5 Hz), 127.0 (d, Jˆ9.3 Hz), 120.5 (d, Jˆ13.4 Hz),
117.7, 65.0 (d, Jˆ5.5 Hz), 36.0 (d, Jˆ97.0 Hz); dP (CDCl3,
202 MHz) 42.4; nmax (neat, cm21) 1638, 1233, 1018; m/z
(CI1, NH3) 223.1 (M1H1).
2-(Methyl)allylphenyl-phosphinic acid 2-(methyl)allyl
ester 7f. Same procedure as for 7c with 1.36 ml
(16.16 mmol)
of
2-methyl-2-propen-1-ol,
1.31 ml
(16.2 mmol) of pyridine, 30 ml Et2O, 1 ml (7.4 mmol) of
dichlorophenylphosphine; yield: 0.6 g (31%); Rfˆ0.5
(hexane:EtOAc, 2:3); dH (CDCl3, 400 MHz) 7.77±7.72
(m, 2H), 7.53±7.49 (m, 1H), 7.46±7.41 (m, 2H), 4.98 (s,
1H), 4.87 (s, 1H), 4.83±4.81 (m, 1H), 4.64 (d, 1H,
Jˆ5.2 Hz), 4.64 (dd, 2H, Jˆ12.4, 5.2 Hz), 4.27 (dd, 2H,
JABˆ12.4, 6.0 Hz), 2.82±2.68 (m, 2H), 1.77 (t, 3H,
Jˆ1.4 Hz), 1.71 (s, 3H); dC (CDCl3, 101 MHz) 141.0 (d,
Jˆ7.3 Hz), 136.3 (d, Jˆ9.6 Hz), 132.8 (d, Jˆ1.7 Hz), 132.4
(d, Jˆ9.6 Hz), 130.7 (d, Jˆ124.4 Hz), 129.0 (d,
Jˆ12.6 Hz), 116.5 (d, Jˆ11.0 Hz), 113.3, 68.1 (d,
Jˆ6.3 Hz), 40.1 (d, Jˆ95.6 Hz), 24.6, 19.7; dP (CDCl3,
202 MHz) 42.1; nmax (neat, cm21) 1648, 1230, 1007; m/z
(CI1, NH3) 251.2 (M1H1); HRMS calcd for C14H20O2P
(M1H1) 251.1201, found 251.1203.
But-2-enylphenylphosphinic acid 1-(methyl)allyl ester
7d. Same procedure as for 7c with 1.41 ml (16.3 mmol) of
1-buten-3-ol, 1.31 ml (16.3 mmol) pyridine, 30 ml Et2O,
1 ml (7.4 mmol) dichlorophenylphosphine; two diastereomers
A and B (1:1 ratio); yield: 0.8 g (46%); Rfˆ0.3 (EtOAc:
Hexane, 2:1); dH (CDCl3, 400 MHz) (mixture of
diastereomers) 7.79±7.71 (m, 2H), 7.53±7.40 (m, 3H),
5.99±5.91 (m, 1H, A or B), 5.79±5.71 (m, 1H, A or B),
5.48±4.98 (m, 4H), 4.98±4.91 (m, 1H, A or B), 4.82±4.77
(m, 1H, A or B), 2.68 (dd, 2H, Jˆ6.4, 17.1 Hz), 1.63±1.59
(m, 3H), 1.44 (d, 3H, Jˆ6.8 Hz, A or B), 1.25 (d, 3H, Jˆ6.0,
A or B); dC (CDCl3, 101 MHz) (mixture of diastereomers)
139.0 (d, Jˆ3.9 Hz, A or B), 138.6 (d, Jˆ5.5, A or B), 132.0
(d, Jˆ18.9 Hz), 131.6 (d, Jˆ9.6 Hz), 131.5 (d, Jˆ
125.3 Hz), 131.1 (d, Jˆ13.3 Hz), 128.2 (d, Jˆ12.5 Hz),
119.3, 115.4, 73.0 (d, Jˆ6.5 Hz, A or B), 72.5 (d, Jˆ
6.3 Hz, A or B), 35.0 (d, Jˆ97.9 Hz), 22.8 (A or B), 22.2
(A or B), 18.0; dP (CDCl3, 202 MHz) 42.1 (A or B), 41.5 (A
or B) nmax (neat, cm21) 1646, 1592, 1227, 1007; m/z (CI1,
Allylphenylphosphinic acid 2-(methyl)allyl ester 7g. To a
solution of 0.5 g of allylphenylphosphinic acid in CH2Cl2
(5 ml) was added PCl5 (0.53 g). The mixture was stirred at
room temperature for 24 h. The solvent was removed under
reduced pressure and the residue was placed at the vacuum
pump for 15 min. To a solution of the crude phosphinic acid
chloride (0.3 g) at 08C in CH2Cl2 (10 ml) was then added
dropwise a catalytic amount of DMAP, Et3N (0.42 ml,
3 mmol) and 2-methyl allylic alcohol (0.25 ml, 3 mmol).
The mixture was stirred for 72 h. The solvent was removed
under reduced pressure and the crude product puri®ed by
column chromatography; yield: 80 mg (39%); Rfˆ0.4
(EtOAc); dH (CDCl3, 400 MHz) 7.81±7.76 (m, 2H),
7.597.55 (m,1H), 7.51±7.46 (m, 2H), 5.83±5.71 (m,1H),
5.17±5.06 (m,2H), 5.02 (d, 1H, Jˆ1.2 Hz), 4.92 (d, 1H,
Jˆ1.2 Hz), 4.47 (dd, 1H, Jˆ12.6, 6.3 Hz), 4.19 (dd, 1H,
Jˆ12.6, 6.6 Hz), 2.82 (dd, Jˆ7.6, 16.8 Hz), 1.75 (s, 3H);
dC (CDCl3, 101 MHz) 140.4 (d, Jˆ7.2 Hz), 132.4 (d,

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L. Hetherington et al. / Tetrahedron 56 (2000) 2053±2060
Jˆ2.6 Hz), 131.8 (d, Jˆ9.7 Hz), 129.9 (d, Jˆ125.2 Hz),
128.5 (d, Jˆ12.6 Hz), 127.0 (d, Jˆ13.2 Hz), 112.7, 67.6
(d, Jˆ6.3 Hz), 35.9 (d, Jˆ97.1 Hz), 19.1; dP (CDCl3,
202 MHz) 42.14; nmax (neat, cm21) 1648, 1230, 1007;
HRMS calcd for C13H18O2P (M1H1) 237.1044, found
237.1045.
Jˆ12.2 Hz), 43.8, 34.4 (d, Jˆ83.8 Hz); dP (CDCl3,
202 MHz) 38.1; nmax (neat, cm21) 3182, 1637, 1226; m/z
(CI1, NH3) 258.1 (M1H1).
Diallyl phosphinic acid (S)-2-(methoxycarbonyl)pyrro-
lidyl amide 7k. Same procedure as for 7j with 0.5 g
(3.42 mmol) of diallyl phosphinic acid, a catalytic amount
of DMF, 20 ml of CH2Cl2, 0.9 ml (10.32 mmol) of oxalyl
chloride then a catalytic amount of DMAP, 1.43 ml
(10.26 mmol) of Et3N, 20 ml of CH2Cl2, 1.7 g
(10.26 mmol) of the hydrochloride salt of l-proline methyl
ester; yield: 0.4 g (41%); Rfˆ0.4 (10% MeOH in EtOAc);
dH (CDCl3, 400 MHz) 5.95±5.80 (m, 2H), 5.25±5.17 (m,
4H), 4.39±4.34 (m, 1H), 3.71 (s, 3H), 3.33±3.29 (m, 2H),
2.74±2.61 (m, 4H), 2.16±2.09 (m, 2H), 2.06±1.85 (m, 2H);
dC (CDCl3, 101 MHz) 174.6, 128.4 (d, Jˆ8.6 Hz), 128.0 (d,
Jˆ9.1 Hz), 120.0 (d, Jˆ10.9 Hz), 59.0, 52.1, 46.8, 34.7 (d,
Jˆ82.4 Hz), 33.3 (d, Jˆ82.7 Hz), 31.1 (d, Jˆ5.5 Hz), 25.2
(d, Jˆ6.1 Hz); dP (CDCl3, 202 MHz) 40.7; nmax (neat,
cm21) 1743, 1637, 1210, 920; m/z (CI1, NH3) 258.1
(M1H1); HRMS calcd for C12H21 NO3P (M1H1)
258.1259, found 258.1256.
Allylphenylphosphinic acid allyl amide 7h. Same pro-
cedure as for 7g with 0.5 g of allylphenylphosphinic acid,
5 ml of CH2Cl2, 0.53 g of PCl5 then 1.07 ml (7.6 mmol) of
Et3N, 0.57 ml (7.65 mmol) of allylamine; yield: 232 mg
(38%); Rfˆ0.6 (10% MeOH in EtOAc); dH (CDCl3,
500 MHz) 7.87±7.80 (m,2H), 7.56±7.42 (m,3H), 5.93±
5.77 (m,2H), 5.24±5.06 (m,4H), 3.57 (m,1H), 3.44 (m,
1H) 2.87 (br s,1H), 2.85±2.70 (m,2H); dC (CDCl3,
126 MHz) 136.2 (d, Jˆ8.4 Hz), 132.3 (d, Jˆ8.6 Hz),
132.0 (d, Jˆ3.4 Hz), 130.9 (d, Jˆ125.1 Hz),128.5 (d,
Jˆ13.1 Hz), 128.3 (d, Jˆ9.6 Hz), 120.1 (d, Jˆ12.4 Hz),
115.8, 42.7, 36.6 (d, Jˆ87.7 Hz); dP (CDCl3, 202 MHz)
31.1; nmax (neat, cm21) 3187, 1638, 1176; m/z (CI1, NH3)
222.1 (M1H1); HRMS calcd for C12H17ONP (M1H1)
222.1048, found 222.1041.
Allylphenylphosphinic acid 1-(phenyl)allyl amide 7i.
0.5 g of allylphenylphosphinic acid, 5 ml CH2Cl2, 0.53 g
of PCl5 then 1.07 ml (7.6 mmol) of Et3N, 1.02 g
(7.66 mmol) 1-(phenyl)allylamine; yield (mixture of two
diastereomers A and B, ratio 1:1): 270 mg (33%); Rfˆ0.6
(10% MeOH in EtOAc); dH (CDCl3, 400MHz) (mixture of
two diastereomers A and B, ratio 1:1) 7.86±7.67 (m, 2H),
7.57±7.16 (m, 8H), 6.12±6.05 (m, 1H), 6.00±5.70 (m, 1H),
5.27±5.07 (m, 4H), 4.79±4.74 (m, 1H), 3.33±3.24 (m, 1H),
2.79 (dd, 2H, Jˆ7.6, 17.2, dia A or B), 2.73 (dd, 2H, Jˆ7.6,
17.4, A or B); dC (CDCl3, 101 MHz) (mixture of two
diastereomers) 142.0, 141.9, 140.1, 140.1, 139.6, 132.3,
132.2, 131.9, 131.8, 130.6, 128.6, 128.5, 128.4, 128.3,
128.2, 127.4, 127.4, 127.0, 120.2 (d, Jˆ12.3 Hz), 115.6,
or B), 36.7 (d,
General procedure for ring-closing metathesis reactions
To a solution of the diene 7a±k in dry CH2Cl2 (0.02 M) was
added portionwise (2 mol%) the Grubbs' catalyst. The reac-
tion was re¯uxed until maximum conversion as shown by
1
TLC or H NMR. The reaction was then concentrated and
puri®ed by column chromatography.
2-Phenyl-4,7-dihydro-[1,3,2]dioxaphosphepine 2-oxide
9a. 100 mg (0.4 mmol) of 7a, 20 ml of CH2Cl2, catalyst
(42 mg, 12%), 5 d; yield: 31 mg (34%); Rfˆ0.2 (hexane:
EtOAc, 1:1); dH (CDCl3, 400 MHz) 7.90±7.85 (m, 2H),
7.62±7.57 (m, 1H), 7.52±7.47 (m, 2H), 5.81 (t, 2H,
Jˆ1.8 Hz), 4.88 (dd, 2H, JABˆ15.8 Hz), 4.59 (dd, 2H,
JABˆ15.5 Hz); dC (CDCl3, 101 MHz) 132.8 (d, Jˆ2.9 Hz),
131.6 (d, Jˆ9.7 Hz), 128.6 (d, Jˆ15.2 Hz) 127.5, 63.6 (d,
56.7, 36.9 (d, Jˆ87.6 Hz,
A
Jˆ88.0 Hz, A or B); dP (CDCl3, 202 MHz) 29.9; nmax
(CHCl3, cm21) 3019, 1222; m/z (CI1, NH3) 298.2
(M1H1); HRMS calcd for C18H21NOP (M1H1)
298.1361, found 298.1371.
Jˆ6.7 Hz); dP (CDCl3, 202 MHz) 24.5; nmax (neat, cm21
)
1256; m/z (CI1, NH3) 211.0 (M1H1); HRMS calcd for
C10H12O3P (M1H1) 211.0524, found 211.0527.
Diallyl phosphinic acid benzyl amide 7j. To a solution of
diallyl phosphinic acid (0.4 g, 2.74 mmol) and a catalytic
amount of DMF in CH2Cl2 (10 ml) at 08C was added oxalyl
chloride (0.7 ml, 8.02 mmol). After addition, the mixture
was allowed to warm to room temperature and was stirred
for 1 h. The solvent was removed under reduced pressure
and the crude acid chloride was used without puri®cation in
the next step. To a solution of the crude phosphinic acid
chloride, a catalytic amount of DMAP and Et3N (1.9 ml,
13.6 mmol) in CH2Cl2 (15 ml) at 08C was added the benzyl-
amine (1.5 ml, 13.7 mmol). The mixture was allowed to
warm to room temperature and was stirred for 72 h. The
solvent was removed under reduced pressure and the residue
was treated with Et2O (10 ml). After ®ltration of the salts,
the residue was puri®ed by column chromatography; yield:
0.5 g (79%); Rfˆ0.4 (5% MeOH in EtOAc); dH (CDCl3,
400 MHz) 7.35±7.26 (m, 5H), 5.91±5.79 (m, 2H), 5.25±
4.17 (m, 4H), 4.21±4.17 (m, 2H), 2.74 (br s, 1H), 2.66
(dd, 4H, Jˆ15.9, 7.5 Hz); dC (CDCl3, 101 MHz) 139.7,
128.7, 128.3 (d, Jˆ8.9 Hz), 127.5 (d, Jˆ6.9 Hz), 120.3 (d,
2-Phenyl-1,3,4,7-tetrahydro-[1,3,2]diazaphosphepine
2-oxide 9b. 77 mg (0.3 mmol) of 7b, 17 ml of CH2Cl2,
catalyst (18 mg, 6%), 3 d; yield: 24 mg (36%); Rfˆ0.2
(5% MeOH in EtOAc); dH (CDCl3, 500 MHz) 7.95±7.91
(m, 2H), 7.58±7.55 (m, 1H), 7.51±7.47 (m, 2H), 5.70 (t, 2H,
Jˆ2.2 Hz), 3.91 (m, 2H), 3.67 (m, 2H), 3.29 (br, 2H); dC
(CDCl3, 126 MHz) 131.8, 131.2 (d, Jˆ9.2 Hz), 128.9, 128.5
(d, Jˆ13.1 Hz), 39.5; dP (CDCl3, 202 MHz) 26.0; nmax
(CHCl3, cm21) 3019, 1520, 1210; m/z (CI1, NH3) 209.0
(M1H1); HRMS calcd for C10H14 N2OP (M1H1)
209.0844, found 209.0839.
2-Phenyl-3,6-dihydro-[1,2]oxaphosphinine 2-oxide 9c.
100 mg (0.5 mmol) of 7c, 20 ml of CH2Cl2, catalyst
(14 mg, 4%), 16 h; yield: 80 mg (92%); Rfˆ0.3 (3%
MeOH in EtOAc); dH (CDCl3, 500 MHz) 7.85±7.81 (m,
2H), 7.59±7.56 (m, 1H), 7.51±7.47 (m, 2H), 5.96±5.85 (m,
2H), 5.06±4.99 (m, 1H), 4.76±4.69 (m, 1H), 2.75±2.57 (m,
2H); dC (CDCl3, 126 MHz) 132.6, 131.0 (d, Jˆ135.6 Hz),
130.9 (d, Jˆ10.6 Hz), 128.6 (d, Jˆ13.2 Hz), 126.2 (d,

L. Hetherington et al. / Tetrahedron 56 (2000) 2053±2060
2059
Jˆ16.4 Hz), 120.5 (d, Jˆ9.0 Hz), 66.1 (d, Jˆ7.2 Hz), 25.3
(d, Jˆ89.8 Hz); dP (CDCl3, 202 MHz) 32.1; nmax (neat,
cm21) 1227, 1068; m/z (CI1, NH3) 195.0 (M1H1);
HRMS calcd for C10H12O2P (M1H1) 195.0575, found
195.0575.
(d, Jˆ135.7 Hz), 128.6 (d, Jˆ13.0 Hz), 114.9 (d, Jˆ
9.2 Hz), 68.7 (d, Jˆ11.5 Hz), 25.0 (d, Jˆ86.1 Hz), 19.3;
dP (CDCl3, 202 MHz) 32.3; nmax (neat, cm21) 1227, 1068;
m/z (CI1, NH3) 195.0 (M1H1); HRMS calcd for C11H14O2P
(M1H1) 209.0730, found 209.0731.
2-Phenyl-6-methyl-3,6-dihydro-[1,2]oxaphosphinine
2-oxide 9d. 120 mg (0.5 mmol) of 7d, 20 ml of CH2Cl2,
catalyst (28 mg, 8%), 21 h; two diastereomers A and B
(ratio 1:1); yield: 84 mg (84%); Rfˆ0.2 (EtOAc); dH
(CDCl3, 400 MHz) 7.83±7.73 (m, 2H), 7.55±7.49 (m,
1H), 7.46±7.41 (m, 2H), 5.89±5.72 (m, 2H), 5.25±5.14
(m, 1H, A or B), 4.88±4.81 (m, 1H, A or B), 2.67±2.41
(m, 2H), 1.51 (d, 3H, Jˆ6.7 Hz, A or B), 1.44 (d, 3H,
Jˆ6.8, A or B); dC (CDCL3, 101 MHz) 132.5 (d, Jˆ
2.4 Hz, A or B), 132.4 (d, Jˆ2.4 Hz, A or B), 132.0,
131.4 (d, Jˆ13.7 Hz, A or B), 131.2 (d, Jˆ10.3 Hz, A
or B), 130.8, 130.5 (d, Jˆ10.1 Hz), 128.6 (d, Jˆ6.8 Hz, A
or B), 128.5 (d, Jˆ7.1 Hz, A or B), 120.1 (d, Jˆ9.2 Hz, A or
B), 119.5 (d, Jˆ8.3 Hz, A or B), 75.7 (d, Jˆ8.2 Hz, A or B),
71.6 (d, Jˆ7.1 Hz, A or B), 25.2 (d, Jˆ90.5 Hz, A or B),
24.3 (d, Jˆ90.2 Hz, A or B), 22.6 (d, Jˆ3.6 Hz, A or B),
22.1 (d, Jˆ7.2 Hz, A or B); dP (CDCl3, 202 MHz) 32.9
(A or B), 31.1 (A or B); nmax (neat, cm21) 1226; m/z
(CI1, NH3) 209.1 (M1H1), 417.1 (2M1H1); HRMS
calcd for C11H14O2P (M1H1) 209.0731, found
209.0732.
2-Phenyl-3,6-dihydro-1H-[1,2]azaphosphinine 2-oxide 9h.
65 mg (0.3 mmol) of diene 7h, 15 ml of CH2Cl2, catalyst
(7.5 mg, 3%), 18 h; yield: 46.6 mg (85%); Rfˆ0.3 (10%
MeOH in EtOAc); dH (CDCl3, 500 MHz) 7.86±7.80
(m, 2H), 7.55±7.51 (m, 1H), 7.48±7.43 (m, 2H), 5.86±
5.76 (m, 2H), 4.15±3.82 (m, 1H), 3.89±3.82 (m, 1H), 2.99
(br, 1H), 2.72±2.52 (m, 2H); dC (CDCl3, 126 MHz) 133.7
(d, Jˆ123.6 Hz), 131.9 (d, Jˆ3.3 Hz), 131.2 (d, Jˆ9.4 Hz),
128.5 (d, Jˆ12.4 Hz), 126.3 (d, Jˆ16.0 Hz), 119.9
(d, Jˆ9.4 Hz), 43.2 (d, Jˆ3.8 Hz), 26.8 (d, Jˆ88.9 Hz);
dP (CDCl3, 202 MHz) 21.5; nmax (CHCl3, cm21) 3019,
1520, 1220; m/z (CI1, NH3) 194.1 (M1H1); HRMS calcd
for C10H13NOP (M1H1) 194.0735, found 194.0736.
2,6-Diphenyl-3,6-dihydro-1H-[1,2]-azaphosphinine 2-oxide
9i. 100 mg (0.3 mmol) of 7i, 20 ml of CH2Cl2, catalyst
(22 mg, 8%), 24 h; yield: 57 mg (63%); Rfˆ0.4 (EtOAc);
dH (CDCl3, 400 MHz) 7.91±7.86 (m, 2H), 7.56±7.47
(m, 4H), 7.39±7.35 (m, 2H), 7.31±7.27 (m, 2H), 5.06±
5.05 (m, 1H), 3.15 (s, 1H), 2.76±2.72 (m, 2H), 5.87±5.77
(m, 2H); dc (CDCl3, 101 MHz) 142.5, 131.9, 130.9, 130.7,
128.9, 128.5 (d, Jˆ12.5 Hz), 128.0, 127.0, 118.7 (d,
Jˆ8.2 Hz), 59.8 (d, Jˆ3.1 Hz), 26.4 (d, Jˆ88.6 Hz); dP
(CDCl3, 202 MHz) 21.2; nmax (CHCl3, cm21) 3020, 1522,
1210; m/z (CI1, NH3) 270.1 (M1H1), 539.1 (2M1H1);
HRMS calcd for C16H17NOP (M1H1) 270.1048, found
270.1042.
2-Phenyl-3-methyl-3,6-dihydro-[1,2]oxaphosphinine
2-oxide 9e. 100 mg (0.4 mmol) of diene 7e, 20 ml of
CH2Cl2, catalyst (26 mg, 8%); yield: 79 mg (95%); less
polar diastereomer: Rfˆ0.3 (2% MeOH in AcOEt); dH
(CDCl3, 250 MHz) 7.91±7.82 (m, 2H), 7.63±7.46 (m,
3H), 5.86±5.64 (m, 2H), 5.05±4.94 (m, 1H), 4.75 (m,
1H), 2.75 (m, 1H), 1.30 (dd, Jˆ7.45, 16.8 Hz); dC
(CDCL3, 62.9 MHz) 133.0, 131.9 (d, Jˆ9.9 Hz), 130.4 (d,
Jˆ133.7 Hz), 128.97 (d, Jˆ12.8 Hz), 127.96 (d, Jˆ8.1 Hz),
125.3 (d, Jˆ15.2 Hz), 66.1 (d, Jˆ6.9 Hz), 29.4 (d,
Jˆ91.5 Hz), 14.4; dP (CDCl3, 202 MHz) 36.2 nmax (neat,
cm21) 1226; more polar diastereomer: Rfˆ0.23 (2%
MeOH in AcOEt); dH (CDCl3, 250 MHz) 7.86±7.76 (m,
2H), 7.59±7.42 (m, 3H), 5.94±5.77 (m, 2H), 5.08±4.95
(m, 1H), 4.85±4.70 (m, 1H), 2.65 (m, 1H), 1.00 (dd,
Jˆ7.48, 18.9 Hz); dC (CDCL3, 62.9 MHz) 132.8, 132.3
(d, Jˆ9.4 Hz), 129.4 (d, Jˆ133.0 Hz), 129.0 (d,
Jˆ13.5 Hz), 128.7 (d, Jˆ6.2 Hz), 125.5 (d, Jˆ15.0 Hz),
66.6 (d, Jˆ7.3 Hz), 30.7 (d, Jˆ89.4 Hz), 16.7; dP (CDCl3,
202 MHz) 38.3; nmax (neat, cm21) 1226; HRMS calcd for
C11H14O2P (M1H1) 209.0730, found 209.0731.
1-Benzylamino-3-phospholene 1-oxide 9j.23 100 mg (0.43
mmol) of 7j, 20 ml of CH2Cl2, catalyst (21 mg, 6%), 2 d;
two rotamers A and B (ratio 2:1); yield: 38 mg (43%);
Rfˆ0.1 (5% MeOH in EtOAc); dH (CDCl3, 400 MHz)
7.36±7.27 (m, 5H), 5.92 (d, 2H, Jˆ31.7 Hz, A), 5.78 (d,
2H, Jˆ30.4 Hz, B), 4.18 (d, 2H, Jˆ9.2 Hz), 3.92 (s, 2H, B),
2.45 (dAB, 4H, Jˆ12.0 Hz, JABˆ17.2 and 17.9 Hz, A), 2.02
(d, 4H, Jˆ12.7 Hz, B); dC (CDCl3, 126 MHz) 134.1, 128.8
(d, Jˆ8.9 Hz), 128.6 (d, Jˆ21.9 Hz), 127.6, 127.5 (d,
Jˆ14.9 Hz), 44.4 (s, A or B), 43.0 (s, A or B), 30.8 (d,
Jˆ84.3 Hz), 29.7; dP (CDCl3, 202 MHz) 64.2, 63.7; nmax
(CHCl3, cm21) 3019, 1217; m/z (CI1, NH3) 208.1
(M1H1).
1-[(S)-2-(methoxycarbonyl)pyrrolidino]-3-phospholene
1-oxide 9k. 100 mg (0.4 mmol) of diene 7k, 20 ml of
CH2Cl2, catalyst (21 mg, 6%), 4 d; yield: 71 mg (80%);
Rfˆ0.3 (10% MeOH in EtOAc); dH (CDCl3, 400 MHz)
6.00±5.84 (m, 2H), 4.37 (dt, 1H, Jˆ3.2, 8.4 Hz), 3.70 (s,
3H), 3.13 (td, 2H, Jˆ6.8, 3.2 Hz), 2.68±2.60 (m, 1H), 2.44
(d, 3H, Jˆ12.4 Hz), 2.21±2.02 (m, 2H), 1.97±1.89 (m, 2H);
dC (CDCl3, 101 MHz) 174.6, 127.7 (d, Jˆ14.7 Hz), 126.7
(d, Jˆ15.0 Hz), 59.4 (d, Jˆ2.3 Hz), 52.1, 46.4 (d,
Jˆ3.9 Hz), 30.9 (d, Jˆ6.4 Hz), 29.7 (d, Jˆ82.1 Hz), 29.6
(d, Jˆ83.6 Hz), 25.1 (d, Jˆ6.8 Hz); dP (CDCl3, 202 MHz)
65.6; nmax (neat, cm21) 1741, 1613; m/z (CI1, NH3) 230.1
(M1H1); HRMS calcd for C10H16NO3P (M1H1)
230.0946, found 230.0944.
2-Phenyl-4,5-dimethyl-3,6-dihydro-[1,2]oxaphosphinine
2-oxide 9f. 50 mg (0.2 mmol) of diene 7f, 10 ml of CH2Cl2,
catalyst (9 mg, 6%), 5 d; yield: 0% (100% recovered diene
7f).
2-Phenyl-5-methyl-3,6-dihydro-[1,2]oxaphosphinine
2-oxide 9g. 75 mg (0.32 mmol) of diene 7g, 15 ml of
CH2Cl2, catalyst (25 mg, 10%), 3 d; yield: 21 mg (31%);
Rfˆ0.16 (AcOEt); dH (CDCl3, 400 MHz) 7.86±7.80 (m,
2H), 7.59±7.55 (m, 1H), 7.51±7.47 (m, 2H), 5.60 (dxm,
Jˆ23.2 Hz, 2H), 4.90±4.85 (m, 1H), 4.58±4.50 (m, 1H),
2.66±2.56 (m, 2H), 1.72 (s, 3H); dC (CDCl3, 100.6 MHz)
133.0 (d, Jˆ15.3 Hz), 132.5, 130.9 (d, Jˆ11.4 Hz), 130.8

2060
L. Hetherington et al. / Tetrahedron 56 (2000) 2053±2060
9. (a) Nguyen, S. T.; Grubbs, R. H.; Ziller, J. W. J. Am. Chem. Soc.
Acknowledgements
1993, 115, 9858. (b) Nguyen, S. T.; Johnson, L. K.; Grubbs, R. H.;
Ziller, J. W. J. Am. Chem. Soc. 1992, 114, 3974. (c) Schwab, P.;
Grubbs, R. H.; Ziller, J. W. J. Am. Chem. Soc. 1996, 118, 100.
10. (a) Bazan, G. C.; Oskam, J. H.; Cho, H.-N.; Park, L. Y.;
Schrock, R. R. J. Am. Chem. Soc. 1991, 113, 6899. (b) Schrock,
R. R.; Murdzek, J. S.; Bazan, G. C.; Robbins, J.; DiMare, M.;
O'Regan, M. J. Am. Chem. Soc. 1990, 112, 3875.
11. Leconte, M.; Jourdan, I.; Pagano, S.; Lefebvre, F.; Basset,
J.-M. J. Chem. Soc., Chem. Commun. 1995, 857.
12. Hanson, P. R.; Stoinova, D. S. Tetrahedron Lett. 1998, 39,
3939.
We would like to thank Dr R. Procter for recording the
HRMS spectra, E. McGuinness for recording the NMR
spectra and Dr S. Ramcharitar for helpful suggestions on
this manuscript.
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