Reactions of lithiated P-diphenyl(alkyl)(N-methoxycarbonyl)phosphazenes with Michael acceptors and aldehydes. Synthesis of 1H-1,2-azaphosphinin-6-ones, β-hydroxy(N-methoxycarbonyl)phosphazenes and 5,6-dihydro-1,3,4-oxazaphosphinin-2-ones

Article abstract of DOI:10.1016/S0040-4020(01)00165-X

Lithium (N-methoxycarbonyl)phosphazenes add C-regioselectively to DMAD, dimethyl malonate, fumarate, and butylidenmalonate in a [1,4] manner. Only one diastereoisomer is observed with the olefinic electrophiles. With DMAD the initial adduct evolves through cyclocondensation with the CO₂Me group of the phosphazene and 1H-1,2-azaphosphinin-6-ones are obtained. Exceptionally, methyl phenylpropiolate reacted exclusively through the carbonyl yielding a mixture of C- and N-acylated compounds. The addition to aldehydes at -80°C affords β-hydroxyphosphazenes diastereoselectively. For lithium α,α-dimethyl(N-methoxycarbonyl)phosphazenes, the intermediate alkoxides cyclocondense at room temperature to 5,6-dihydro-1,3,4-oxazaphosphinin-2-ones.

Full text of DOI:10.1016/S0040-4020(01)00165-X

TETRAHEDRON
Pergamon
Tetrahedron 57 ,2001) 3075±3086
Reactions of lithiated P-diphenylꢀalkyl)ꢀN-methoxycarbonyl)-
phosphazenes with Michael acceptors and aldehydes. Synthesis
of 1H-1,2-azaphosphinin-6-ones, b-hydroxyꢀN-methoxycarbonyl)-
phosphazenes and 5,6-dihydro-1,3,4-oxazaphosphinin-2-ones
²
Â
Â
Â
Â
Â
Julia M. Alvarez-Gutierrez, Emma Peralta-Perez, Isidro Perez-Alvarez and
p
Â
Fernando Lopez-Ortiz
Â
Area de Quõmica Organica, Universidad de Almerõa, Carretera de Sacramento s/n, 04120 Almerõa, Spain
Â
Â
Â
Â
Received 28 November 2000; revised 24 January 2001; accepted 8 February 2001
AbstractÐLithium ,N-methoxycarbonyl)phosphazenes add C-regioselectively to DMAD, dimethyl malonate, fumarate, and butyl-
idenmalonate in a [1,4] manner. Only one diastereoisomer is observed with the ole®nic electrophiles. With DMAD the initial adduct evolves
through cyclocondensation with the CO2Me group of the phosphazene and 1H-1,2-azaphosphinin-6-ones are obtained. Exceptionally, methyl
phenylpropiolate reacted exclusively through the carbonyl yielding a mixture of C- and N-acylated compounds. The addition to aldehydes at
2808C affords b-hydroxyphosphazenes diastereoselectively. For lithium a,a-dimethyl,N-methoxycarbonyl)phosphazenes, the intermediate
alkoxides cyclocondense at room temperature to 5,6-dihydro-1,3,4-oxazaphosphinin-2-ones. q 2001 Elsevier Science Ltd. All rights
reserved.
1. Introduction
Phosphorus-stabilised carbanions are very important
synthetic tools for the formation of carbon±carbon1 and
carbon±heteroatom2 bonds. Numerous examples are
known where these anions have been applied to the synthe-
sis of phosphorus substituted nitrogen heterocycles.3 In the
particular case of phosphazenes, the activation of the a
position to the phosphorus towards the metalation may be
combined with the appropriate functionalisation in the nitro-
gen of the PN linkage in order to achieve cyclocondensation
reactions yielding phosphorus±nitrogen heterocycles where
the phosphazene contributed as a CPNX [XvCO, CvCCO,
P,O)OR)] building block to the formation of six-membered
rings. This strategy has been successfully applied to the
synthesis of 1,3,4-diazaphosphinin-2-ones 1,4 1H-benzo[e]-
1,2-azaphosphinin-4-ones 2,5 1,3-oxaza-2,4-diphosphinine 2-
In principle, phosphazene-stabilised carbanions could react
with electrophiles either through carbon or nitrogen. In fact,
oxides 3,6 and 1,3-diaza-2,4-diphosphinine 2-oxides 4.7
some examples of phosphazene±aminoylide tautomer equi-
libria have been reported showing that the position of the
equilibrium is determined by the substituents on the carbon
and nitrogen atoms of the CPN moiety ,Scheme 1).8
According to quantum mechanic calculations on the model
Keywords: azaphosphinines; oxazaphosphinines; hydroxyphosphazenes;
phosphorus heterocycles; Michael addition.
compound [Li,CH2PH2NH)]´,Me2O)2 the HOMO exhibits a
much higher coef®cient for the carbon than for the
nitrogen,9 which supports the C-regioselectivity exclusively
observed in the reactions of lithium ,N-substituted)phospha-
zenes with electrophiles reported to date.10 Even though, the
p
Corresponding author. Tel.: 134-950-015478; fax: 134-950-015481;
e-mail: ¯ortiz@ual.es
²
Present address: The Scripps Research Institute, BCC-104, 10550 North
Torrey Pines Road, La Jolla, CA 92037, USA
0040±4020/01/$ - see front matter q 2001 Elsevier Science Ltd. All rights reserved.
PII: S0040-4020,01)00165-X

Â
Â
J. M. Alvarez-Gutierrez et al. / Tetrahedron 57 .2001) 3075±3086
3076
Scheme 1.
reactivity of these anions ,and obviously the neutral
species10d) strongly depends on the substituent in the nitro-
gen of the phosphazene. Thus, the addition of dimethyl
acetylenedicarboxylate ,DMAD) to metalated P-dipheny-
l,alkyl),N-phenyl)phosphazenes 9 afforded cyclopente-
nones11 11 in a process initiated by the addition of the
carbanion to one methoxycarbonyl group of the DMAD.12
Instead, we have recently reported13 that the use of the
azide, ,B) alkylation of a simpler phosphazene by treating
10a,b with BuLi followed by addition of the appropriate
n
alkyl halide,10b,d and ,C) one pot process consisting of the
synthesis of the required phosphine by alkylation of lithium
diphenylphosphide15 ,obtained through reductive lithiation
of triphenylphosphine in THF) and subsequent in situ
Staudinger reaction with N3CO2Me.
corresponding ,N-methoxycarbonyl)phosphazenes
10
As mentioned above, the reaction of lithium phosphazenes
10, metalated by treating the neutral compounds with nBuLi
in THF at 2308C during 30 min, with DMAD at 2788C led
to 1H-1,2l5-azaphosphinin-6-ones 12.13 In the ®rst essays
stoichiometric quantities of phosphazene, base and electro-
phile were used and systematically a 50% of the starting
phosphazene was recovered. We reasoned that through the
reaction the lithiated phosphazenes were acting both as
under the same reaction conditions leads to the formation
of 1H-1,2-azaphosphinin-6-ones 12 due to the C-regioselec-
tive addition of the metalated phosphazene to the triple bond
of the DMAD ,Scheme 2).
Here we will give the full details of the synthesis and
structural characterisation of heterocycles 12 and will
present the results of extending the study of the reactivity
of lithium P-diphenyl,alkyl),N-methoxycarbonyl)phospha-
zenes to other Michael acceptors as well as to aldehydes.
With this last electrophiles it has been possible to obtain 5,6-
dihydro-1,3,4-oxazaphosphinin-2-ones 21.
n
nucleophile and as base. Therefore, an excess of BuLi
would be necessary to improve the reaction yield. We
found that by using a phosphazene/nBuLi/DMAD 1:2:2
ratio the heterocycles 12 were obtained practically in
quantitative yields.
The structure of 12 was assigned based on their spectral
data.16,17 The formation of 12 can be explained by a Michael
addition of the lithium phosphazene to the DMAD and
subsequent cyclocondensation promoted by the intramole-
cular attack of the new carbanion to the methoxycarbonyl
bonded to the nitrogen. The 3H-1,2-azaphosphinine
obtained tautomerised to the ®nal 2H-isomer ,Scheme 4).
The NH of compounds 12 justi®es the need for using two
2. Results and discussion
The phosphazenes 10 used in this study are given in Table 1
and were easily prepared in high yield by one of the follow-
ing routes ,Scheme 3): ,A) Staudinger reaction14 of a
commercial phosphine ,R1 H, Me) and methoxycarbonyl
Table 1. d31P ,ppm) and melting points ,8C) of phosphazenes 10
Product
R1
R2
d
31P
Mp
10aa
10ba
10cb
10db
10ec
10fc
10gc
10hb
10ib
10jb
10kb
10lb
H
H
H
H
H
H
H
CH3
CH3
CH3
CH3
H
CH3
CH3CH2
CH2vCHCH2
CH3CH2CH2
,CH3)2CH
PhCH2
CH3
CH3,CH2)3
PhCH2
23.54
28.95
25.79
25.64
26.20
24.10
25.91
34.05
33.64
32.77
32.94
33.35
65±66
86±87
92±93
81±82
70±71
94±95
126±127
112±113
122±133
115±116
77±78
oil
CH2vCHCH2
PhCH2
CH3,CH2)3
a
Method A.
Method B.
Method C.
b
c
Scheme 2. ,i) nBuLi, 2208C, THF, 30 min; ,ii) DMAD, 270±258C, 12 h.

Â
J. M. Alvarez-Gutierrez et al. / Tetrahedron 57 .2001) 3075±3086
Â
3077
renewed interest in the last years.18 Nevertheless, there are
only a few reports on the synthesis of 1,2-l5-azaphosphinine
derivatives.19 The method we present here represents an
ef®cient synthesis of this type of compound using readily
available starting materials.
In order to extend the scope of the reaction and to have an
insight into the mechanism we studied the behaviour of
lithium phosphazenes 10 with other Michael acceptors
related to DMAD. The reaction with ethyl phenylpropiolate
afforded a 55:45 mixture of two compounds 15 ,dP 35.65)
and 16 ,dP 26.55) in 70% yield ,Scheme 5), which could not
be separated. The NMR spectra of the mixture allowed to
identify these compounds as the C- and N-acylation
products, respectively. Thus, the 1H spectrum of 15 showed
Scheme 3. ,i) Li ,2.2 equiv.), THF, 258C, 2 h; ,ii) ,a) NH4Cl, ,b) R1R2CHX;
,iii) N3CO2Me; ,iv) ,a) nBuLi, 2308C, THF, 30 min; ,b) R2X, 270±258C,
3 h.
n
equivalents of BuLi, otherwise up to 50% of the lithium
3
a doublet for the methyl protons ,d 1.70, JPHˆ14.5 Hz),
phosphazene could be quenched assuming the quantitative
formation of heterocycles 12. Taking into account the
reaction mechanism proposed for the synthesis of cyclo-
pentenones 11 one could argue about the feasibility of
compounds 13 and 14 as alternative structures for 12. The
reaction leading to 13±14 would involve the following
steps: ,i) addition of the carbanion to one carbonyl group
of the DMAD, ,ii) metalation of the resulting a-acyl-
phosphazene, and ,iii) intramolecular attack of the nitrogen
to the triple bond. Depending on the regioselectivity, this
attack could produce either 13 or 14 ,Scheme 4). They can
be easily ruled out by considering that both structures lack
any exchangeable proton and, on the contrary, exhibit a
conjugated ketone carbonyl carbon that should appear
close to 200 ppm in the 13C spectrum ,and should show a
correlation with the methyl protons in the 2D HMBC
spectrum), which is not observed.
whereas the ylide fragment of 16 is characterised by a
3
double doublet at d 1.54 ,3JHHˆ7.0, JPHˆ10.1 Hz) and a
double quartet at d 4.49 ,3JHHˆ7.0, 2JPHˆ27.3 Hz). Accord-
ingly, the conjugated carbonyl carbon of 15 and 16
appeared, respectively, at d 182.12 and 159.45 as expected
for a ketone and an amide. To the best of our knowledge,
this is the ®rst time that a competition between C- vs N-
regioselective attack of lithium P-diphenyl,alkyl)phospha-
zenes has been experimentally observed. Also, worthy of
note is the [1,2] addition of lithiated 10a to ethyl phenyl-
propiolate in contrast with the [1,4] addition leading to
heterocycles 12.
Dimethyl maleate and dimethyl butylidenmalonate reacted
with lithium phosphazenes 10b,c in the same way as
DMAD. The reaction yielded the [1,4] adducts 17a,b and
18. The stereoselectivity of the addition was excellent. Only
one diastereoisomer was detected in the 31P NMR spectra of
the crude products ,Scheme 5). Their structures were easily
Surprisingly, in spite of the reaction conditions, the simplest
phosphazene 10a failed to give any heterocycle. By
contrast, lithiated 10a do react with other electrophiles
,see below). l5-Azaphosphinines are compounds of
1
assigned from the conventional analysis of the H, 13C and
DEPT spectra.20 The relative stereochemistry of the
stereogeniccentres was assigned based on the magnitude
of the vicinal coupling constants of the methine protons of
these centres. The small 3JH b values measured, 2.5 Hz for
a
H
Scheme 5. ,i) nBuLi, 2208C, THF, 30 min; ,ii) PhC;CCO2Et, 2700±
258C, 12 h; ,iii) MeO2CCHvCHCO2Me, 2700±258C, 12 h; ,iv)
nPrCHvC,CO2Me)CO2Me, 2700±258C, 12 h.
Scheme 4.

Â
Â
J. M. Alvarez-Gutierrez et al. / Tetrahedron 57 .2001) 3075±3086
3078
relative stereochemistry of each isomer was achieved as
previously discussed for 17±18, by associating a small/
large HaHb vicinal coupling with an erythro/threo con-
for the major isomer
3
®guration, respectively. The JH
a b
H
19 were in all cases cero corresponding to the erythro
diastereoisomer, in agreement with the values measured in
b-hydroxy,N-phenyl)phosphazenes.20b,23 On the other hand,
a
b
Scheme 6.
the threo stereoisomer 20 exhibited an average 3JH
H
coupling of 16.5 Hz. The 31P chemical shifts of 19±20
also followed a general trend, with 19 being shielded by
ca. 2 ppm related to 20. Hence, dP can be used as an alter-
native tool for structural assignment on account of the 31P
chemical shifts of both diastereoisomers were known.
17a and 1.7 Hz for 18, are in the expected range21 for an
erythro con®guration. No heterocyclic compounds could be
detected, which suggests that the anion arising from the
initial Michael addition to both electrophiles is now less
reactive than in the case of DMAD due to the delocalisation
through the adjacent carbonyl group,s). The formation of
17±18 supports the mechanism proposed for the analogous
reaction with DMAD and evidences again the different
chemical behaviour of lithium ,N-methoxycarbonyl)-
phosphazenes vs. their N-phenyl derivatives. These last
compounds led to cyclopentenones by reaction with
dimethyl maleate or fumarate.
We reasoned that an increase in the temperature and reac-
tion time could favour the cyclisation of the adduct derived
from the reaction between the metalated phosphazenes 10
and aldehydes. To simplify the stereochemical course of the
reaction we focused on phosphazene 10h having two methyl
groups on the carbon a to the phosphorus. Thus, 10h was
metalated in THF as mentioned above and then benzalde-
hyde was added at 2258C. The reaction was allowed to
reach room temperature and stirred during 10 h. Aqueous
work-up afforded a reaction crude containing a small
amount of the starting phosphazene 10h ,dP 34.05, 13%)
and the b-hydroxy derivative 19f ,dP 39.54, 10%), plus two
new compounds 21a ,dP 26.20, 52%) and 22a ,dP 45.49,
27%) ,Scheme 8).24
So far, all synthesis of phosphorus heterocycles from
,N-methoxycarbonyl)phosphazenes involve
a
cyclo-
condensation step promoted by either a nucleophilic carbon
or nitrogen.10b,13 In principle, cyclisations based on a trans-
esteri®cation reaction, i.e. promoted by an oxygen atom,
could be formally carried out in the two steps process repre-
sented retrosynthetically in Scheme 6, consisting in the
formation of a carbon±carbon bond by addition of a
lithiated ,N-methoxycarbonyl)phosphazene to an aldehyde
or ketone followed by cyclocondensation of the inter-
mediate b-hydroxyphosphazene 19±20 to yield 5,6-
dihydro-1,3,4l5-oxazaphosphinin-2-ones 21.
Increasing the reaction time to 22 h produced a decrease of
the yield of 21a ,45%) in favour of the acyclic compounds
for an overall conversion of 10h of 91%. This result
suggested the existence of an equilibrium between the
heterocycle and the alkoxide precursor. Therefore, the
yield of heterocycle obtained could be increased through
its selective precipitation from the medium using relatively
short reaction times ,Table 3). In diethyl ether 21a proved to
be more soluble than the open chain compounds 19f and
22a. Consequently, the reaction mixture was dominated by
the acyclic derivatives ,4% of 21a entry 3 and 7% of 21b
entry 6 in Table 3). The best results were obtained by
performing the reaction in a mixture THF/diethyl ether
1:1 during 14 h ,entry 4, Table 3). In these conditions 21a
was isolated in 89% yield and only a 11% of 22a remained
in solution. The reaction with p-chlorobenzaldehyde
afforded the highest yield of 21b when pure THF was
used as solvent ,43%, entry 5, Table 3) implying that the
cyclization step is sensitive to the solvent as well as to the
substituent R3 of the electrophile. Signi®cantly, the reaction
works also well with aliphaticaldehydes in THF or mixtures
THF/Et2O 1:1 ,Table 4).
The reaction of lithiated phosphazenes 10 ,prepared by
addition of BuLi to a solution of 10 in THF at 2308C
during 30 min) with aldehydes at 2808C during 2 h afforded
the expected b-hydroxy,N-methoxycarbonyl)phosphazenes
19±20 in high yield with good to excellent diastereo-
selectivity22 ,Scheme 7, Table 2). The assignment of the
n
Scheme 7. ,i) nBuLi, 2358C, THF, 30 min; ,ii) R3CHO, 2808C, 2 h.
Table 2. b-Hydroxyphosphazenes 19±20 obtained
Product
R1
R2
R3
Rdto.,%) 19/20 ,%)
19a/20a
19ba
19c/20c
19d/20d
19ea
19f
19g
19h
19i
H
H
H
H
CH3
C6H5
C6H5
C6H11
p-ClC6H4
p-ClC6H4
C6H5
p-ClC6H4
CH3CH2
C6H4CH2CH2
80
95
90
87
.97
90
95
75
70
83:17
.97
86:14
86:14
.97
CH2C6H5
CH3
CH3
CH2C6H5
CH3
CH3
H
CH3
CH3
CH3
CH3
CH3
CH3
Scheme 8. ,i) nBuLi 2358C, THF ,or THF/Et2O 1:1), 1 h; ,ii) R3CHO,
280±258C, 14 h.
a
The isomer threo is not detectable by NMR.

Â
J. M. Alvarez-Gutierrez et al. / Tetrahedron 57 .2001) 3075±3086
Â
3079
Table 3. Optimization of the synthesis of heterocycles 21 and distribution of compounds obtained
Entry
Solvent
R3
Metalation time ,min)
Reaction time ,h)
21 ,%)
22 ,%)
19 ,%)
Yield ,%)
1
2
3
4
5
6
7
THF
THF
Et2O
Ph
Ph
Ph
Ph
p-ClC6H4
p-ClC6H4
p-ClC6H4
20
20
60
60
30
60
30
14
22
14
14
14
13
26
60
45
4
89
43
7
9
22
90
11
43
93
66
31
33
6
87
91
91
87
97
89
91
THF/Et2Oa
THF
Et2O
14
THF/Et2Ob
34
a
THF/Et2O 1:1, the aldehyde was added at 2808C.
THF/Et2O 1:1.7.
b
Table 4. 1,3,4-Oxazaphosphin-2-ones 21 obtained
carried out at room temperature with phosphazenes having
two methyl groups in the carbon a to the phosphorus then
5,6-dihydro-1,3,4-oxazaphosphinin-2-ones were obtained
through cyclocondensation of the intermediate alcoholate
formed in the addition step to the carbonyl group of the
aldehyde.
Product
R3
Yielda ,%)
d
31P ,ppm)
21a
21b
21c
21d
C6H5
77b
43c
65c
64b
26.20
25.90
25.37
25.94
p-ClC6H4
CH3CH2
PhCH2CH2
a
Isolated yield.
Solvent THF/Et2O 1:1.
Solvent THF.
b
c
4. Experimental
4.1. General
All attempts to obtain oxazaphosphinin-2-ones from
b-hydroxyphosphazenes 19 bearing only one alkyl sub-
stituent in the a position to the phosphorus failed. They
included: ,i) standard conditions above mentioned, ,ii) heat-
ing of neutral 19 at 1408C during 5 h under vacuum, ,iii)
re¯uxing in THF the alkoxide of 19 formed in situ during
10 h. It is worth of mention that in the last case the ratio of
diastereoisomers 19/20 was the same obtained when the
reaction was carried out at room temperature, i.e., no
isomerisation took place.
All reactions were carried out under an atmosphere of nitro-
gen using dried glassware. Solvents were distilled before
use. THF and TMEDA were dried with sodium and potas-
sium respectively, and distilled under nitrogen. All starting
materials were purchased from ALDRICH. Liquids, except
nBuLi, were distilled prior to use. Methyldiphenyl- and
ethyldiphenylphosphine were commercially available. All
other phosphines were prepared by reacting the appropriate
alkyl halide with lithium diphenylphosphide15,25 and trans-
formed in situ in the corresponding phosphazene. TLC was
performed on Merck plates with aluminum backing and
silica gel 60 F254. For column chromatography silica gel
60 ,40±63 mm) from Scharlau was used.
3. Conclusions
Lithium ,N-alkoxycarbonyl)phosphazenes add preferen-
tially in a [1,4] manner to Michael acceptors with an almost
exclusive C-regioselectivity, a behaviour which contrasts
with the exclusive [1,2] addition observed for the analogous
reactions of ,N-phenyl)phosphazenes. Thus, 1H-1,2-
azaphosphinin-6-ones were obtained in high yields with
DMAD. The reactions with dimethyl maleate, fumarate
and butylidenmalonate afforded the corresponding C-alkyl-
ated acyclic compounds with excellent diastereoselectivity.
Most probably, the stabilisation of the anion resulting from
the addition step to these electrophiles prevented their par-
ticipation in a further cyclocondensation reaction. The
results with methyl phenylpropiolate were exceptional: it
is the single case were a lithium ,N-methoxycarbonyl)-
phosphazene added to the carbonyl carbon ,[1,2] mode),
not to the triple bond and for the ®rst time a metalated
phosphazene reacted through both extremes of the stabilised
carbanion giving a mixture of C- and N-acylated com-
pounds. This reaction can be considered the bordeline
example linking the behaviour of lithium ,N-alkoxy-
carbonyl)- and ,N-phenyl)-phosphazenes.
Melting points were recorded on a BuÈchi±Tottoli apparatus
and were uncorrected. Infrared spectra were obtained in
KBr pellets using a UNICAM Mattson 3020 FT spectro-
meter. Mass spectra were determined by electron impact
on a Hewlett Packard 5987A or 1100. Microanalysis was
performed on a Perkin±Elmer 2400. NMR spectra were
measured on a Bruker Avance 300 DPX or a Bruker 400
AMX spectrometer. Chemical shifts are referred to internal
tetramethylsilane for 1H and 13C, and to external 85%
H3PO4 for 31P. 2D NMR Correlation spectra ,COSY,
NOESY, HMQC and HMBC) were acquired using standard
Bruker software and processing routines.
4.2. Synthesis of phosphazenes 10
Method A. To a solution of phosphine ,35 mmol) in diethyl
ether ,50 mL) was added dropwise a solution of methoxy-
carbonyl azide ,35 mmol) in diethyl ether ,30 mL). Once
the nitrogen evolution ceased the reaction mixture was
concentrated under vacuum to a third of its volume. Phos-
phazenes precipitated as white solids. They were ®ltrated,
dried, and used without further puri®cation. Phosphazenes
10a,b were obtained through this method.
The addition to aldehydes at 2808C afforded b-hydroxy,N-
alkoxycarbonyl)phosphazenes in high yield and good to
excellent diastereoselectivities. When the reaction was

Â
Â
J. M. Alvarez-Gutierrez et al. / Tetrahedron 57 .2001) 3075±3086
3080
2
Method B. To a Schlenk with the appropriated phosphazene
,20 mmol) dissolved in 40 mL of dry THF was added a
solution of BuLi ,13.8 mL of a 1.6 M solution in hexane,
3JPCˆ11.9 Hz), 131.52 ,d, JPCˆ9.2 Hz), 131.97, 162.68.
31P NMR ,121.49 MHz, CDCl3), d ,ppm): 25.79. Anal.
Calcd for C17H20NO2P: C, 67.76; H, 6.69; N, 4.65. Found.
C, 67.74; H, 6.72; N, 4.60. MS ,EI) m/z: 301 ,M1, 5%), 259
,100%), 202 ,70%).
n
22 mmol) at 2308C. After 30 min of metallation the
temperature was lowered at 2708C and was added the
desired alkyl halide ,20 mmol). The reaction mixture was
stirred for 6 h and allowed to reach room temperature. Addi-
tion of water ,25 mL) followed by extraction with CH2Cl2
,3£15 mL) and solvent evaporation under vacuum afforded
one colorless oil. Digestion of this oil in diethyl ether
yielded phosphazenes 10e±g as white solids. They were
®ltrated, dried, and used without further puri®cation.
4.2.4. P,P-Diphenyl-P-ꢀ3-butenyl)ꢀN-methoxycarbonyl)-
phosphazene ꢀ10d). White solid. Yield 69%. Mp ,8C):
81±82. IR ,KBr), n ,cm21): 1625, 1589, 1293. H NMR
,300.13 MHz, CDCl3), d ,ppm): 2.23 ,m, 2H), 2.71 ,m,
1
3JPHˆ16.0 Hz, 1H), 3.62 ,s, 3H), 4.97 ,dq, JHHˆ16.8 Hz,
3
2JHHˆ4JHHˆ1.3 Hz, 1H), 4.99 ,dq, 3JHHˆ10.3 Hz,
2JHHˆ4JHHˆ1.3 Hz, 1H), 5.78 ,ddd, JHHˆ16.8 Hz,
3
3
Method C. To a Schlenk with triphenylphosphine ,5.3 g,
20 mmol) dissolved in THF ,40 mL) was added an excess
of freshly cut small pieces of lithium metal ,0.27 g,
40 mmol). The mixture was stirred at room temperature
for 2 h. The unreacted lithium metal was ®ltered off and
ammonium chloride ,1.06 g, 20 mmol) was added slowly
over a period of 30 min. Then, the appropriated alkyl halide
,20 mmol) was added and the color of the solution changed
from red to yellow. The mixture was stirred for 2 h and after
this time a solution of methoxycarbonyl azide ,20 mmol) in
THF ,10 mL) was added. Aqueous work-up as described in
method B afforded phosphazenes 10c,d and h±l.
3JHHˆ10.3 Hz, JHHˆ6.5 Hz) 1H), 7.45±7.60 ,m, 6Har),
7.72±7.75 ,m, 4Har). 13C NMR ,75.46 MHz, CDCl3), d
1
,ppm): 24.68 ,d, JPCˆ71.7 Hz), 25.30, 52.43 ,d,
4JPCˆ3.5 Hz), 115.37, 127.61 ,d, JPCˆ103.6 Hz), 128.57
1
3
2
,d, JPCˆ13.6 Hz), 131.59 ,d, JPCˆ11.9 Hz), 132.13,
136.45 ,d, JPCˆ16.2 Hz), 162.67. 31P NMR ,121.49 MHz,
3
CDCl3), d ,ppm): 25.64. Anal. Calcd for C18H20NO2P: C,
69.00; H, 6.43; N, 4.47. Found. C, 69.05; H, 6.40; N, 4.49.
MS ,EI) m/z: 313 ,M1, 20%), 312 ,40%), 282 ,100%).
4.2.5. P,P-Diphenyl-P-ꢀbutyl)ꢀN-methoxycarbonyl)phos-
phazene ꢀ10e). White solid. Yield 70%. Mp ,8C): 70±71. IR
,KBr), n ,cm21): 1638, 1589, 1298. 1H NMR ,300.13 MHz,
CDCl3), d ,ppm): 0.85 ,t, 3JHHˆ6.1 Hz, 3H), 1.45 ,m, 4H),
2.67 ,m, 2H), 3.60 ,s, 3H), 7.40±7.59 ,m, 6Har), 7.70 ,m,
4Har). 13C NMR ,75.46 MHz, CDCl3), d ,ppm): 13.35,
4.2.1. P,P-Diphenyl-P-ꢀmethyl)ꢀN-methoxycarbonyl)phos-
phazene ꢀ10a). White solid. Yield 98%. Mp ,8C): 65±66. IR
,KBr), n ,cm21): 1630, 1290. 1H NMR ,300.13 MHz,
2
2
1
CDCl3), d ,ppm): 2.17 ,d, JPHˆ13.4 Hz, 3H), 3.55 ,s,
23.32, 23.65 ,d, JPCˆ15.4 Hz), 25.11 ,d, JPCˆ63.40 Hz),
3H), 7.35±7.42 ,m, 6Har), 7.65±7.70 ,m, 4Har). 13C NMR
52.42, 128.47 ,d, 1JPCˆ119.5 Hz), 128.52 ,d,
1
2
,75.46 MHz, CDCl3), d ,ppm): 12.69 ,d, JPCˆ66.1 Hz),
3JPCˆ11.9 Hz), 131.61 ,d, JPCˆ9.1 Hz), 132.03, 162.89.
4
3
52.49 ,d, JPCˆ3.6 Hz), 128.63 ,d, JPCˆ12.0 Hz), 128.94
31P NMR ,121.49 MHz, CDCl3), d ,ppm): 26.20. Anal.
Calcd for C18H22NO2P: C, 68.56; H, 7.03; N, 4.44. Found.
C, 68.52; H, 7.08; N, 4.46. MS ,EI) m/z: 315 ,M1, 5%), 284
,100%), 272 ,60%).
1
2
,d, JPCˆ102.7 Hz), 131.31 ,d, JPCˆ9.6 Hz), 132.24 ,d,
4JPCˆ2.4 Hz), 163.0 ,d, 2JPCˆ1.2 Hz). 31P NMR
,121.49 MHz, CDCl3), d ,ppm): 23.54. Anal. Calcd for
C15H16NO2P: C, 65.93; H, 5.86; N, 5.13. Found. C, 65.90;
H, 5.87; N, 5.15. MS ,API-ES) m/z: 296 ,M1123, 18%),
274 ,M111, 100%), 217 ,95%).
4.2.6. P,P-Diphenyl-P-ꢀ2-methylpropyl)ꢀN-methoxycar-
bonyl)phosphazene ꢀ10f). White solid. Yield 69%. Mp
,8C): 94±95. IR ,KBr), n ,cm21): 1652, 1530, 1298. H
1
3
NMR ,300.13 MHz, CDCl3), d ,ppm): 1.87 ,d, JHH
4.2.2. P,P-Diphenyl-P-ꢀethyl)ꢀN-methoxycarbonyl)phos-
phazene ꢀ10b). White solid. Yield 98%. Mp ,8C): 86±87.
IR ,KBr), n ,cm21): 1629, 1295. H NMR. ,300.13 MHz,
ˆ
2
6.5 Hz, 6H), 1.97 ,m, 1H), 2.71 ,dd, JPHˆ12.0,
3JHHˆ6.9 Hz, 2H), 3.60 ,s, 3H), 7.35±7.50 ,m, 6Har), 7.75
,m, 4Har). 13C NMR ,75.46 MHz, CDCl3), d ,ppm): 23.36
,d, 2JPCˆ33.1 Hz), 24.16 ,d, 3JPCˆ8.8 Hz), 33.12 ,d, 1JPCˆ
63.5 Hz), 52.42 ,d, 4JPCˆ3.5 Hz), 128.64 ,d, 1JPCˆ99.8 Hz),
3
3
CDCl3), d ,ppm): 1.08 ,dt, JHHˆ7.6 Hz, JPHˆ18.0 Hz,
3
3
3H), 2.63 ,dc, JHHˆ7.6 Hz, JPHˆ12.2 Hz, 2H), 3.58 ,s,
3H), 7.40±7.52 ,m, 6Har), 7.70±7.77 ,m, 4Har). 13C NMR
,75.46 MHz, CDCl3), d ,ppm): 5.62 ,d, 2JPCˆ4.8 Hz), 18.75
3
2
128.46 ,d, JPCˆ11.9 Hz), 131.51,d, JPCˆ9.3 Hz), 131.89,
162.79. 31P NMR ,121.49 MHz, CDCl3), d ,ppm): 24.10.
Anal. Calcd for C18H22NO2P: C, 68.56; H, 7.03; N, 4.44.
Found. C, 68.54; H, 7.06; N, 4.47. MS ,EI) m/z: 315 ,M1,
20%), 284 ,100%), 215 ,75%).
1
4
,d, JPCˆ64.3 Hz), 52.53 ,d, JPCˆ3.6 Hz), 127.65 ,d,
1JPCˆ99.7 Hz), 128.68 ,d, JPCˆ12.0 Hz), 131.46 ,d,
3
2JPCˆ9.6 Hz), 132.21 ,d, JPCˆ2.4 Hz), 162.87 ,d,
4
2JPCˆ2.4 Hz). 31P NMR ,121.49 MHz, CDCl3), d ,ppm):
28.95. Anal. Calcd for C16H18NO2P: C, 66.90; H, 6.27; N,
4.88. Found. C, 66.92; H, 6.28; N, 4.85. MS ,API-ES) m/z:
310 ,M1123, 16%), 288 ,M111, 100%), 231 ,52%).
4.2.7. P,P-Diphenyl-P-ꢀ2-phenylethyl)ꢀN-methoxycar-
bonyl)phosphazene ꢀ10g). White solid. Yield 85%. Mp
,8C): 126±127. IR ,KBr), n ,cm21): 1625, 1291. H NMR
1
4.2.3. P,P-Diphenyl-P-ꢀpropyl)ꢀN-methoxycarbonyl)phos-
phazene ꢀ10c). White solid. Yield 72%. Mp ,8C): 92±93. IR
,KBr), n ,cm21): 1626, 1591, 1279. 1H NMR ,300.13 MHz,
CDCl3), d ,ppm): 1.10 ,t, 3JHHˆ7.1 Hz, 3H), 1.50 ,m, 2H),
2.62 ,m, 2H), 3.65 ,s, 3H), 7.41±7.54 ,m, 6Har), 7.80 ,m,
4Har). 13C NMR ,75.46 MHz, CDCl3), d ,ppm): 15.07,
,300.13 MHz, CDCl3), d ,ppm): 2.78±2.86 ,m, 2H), 2.91±
3.01 ,m, 2H), 3.67 ,s, 3H), 7.13±7.28 ,m, 5Har), 7.46±
7.57,m, 6Har), 7.77±7.84 ,m, 4Har). 13C NMR
2
,75.46 MHz, CDCl3), d ,ppm): 27.42 ,d, JPCˆ12.6 Hz),
1
4
27.84 ,d, JPCˆ46.3 Hz), 52.69 ,d, JPCˆ3.6 Hz), 126.40,
1
127.77 ,d, JPCˆ99.7 Hz), 128.06, 128.43, 128.81 ,d,
2
1
2
15.20 ,d, JPCˆ20.7 Hz), 22.28 ,d, JPCˆ62.8 Hz), 52.31
3JPCˆ12.0 Hz), 131.80 ,d, JPCˆ9.0 Hz), 132.37 ,d,
4
1
3
,d, JPCˆ3.6 Hz), 127.51 ,d, JPCˆ103.6 Hz), 128.40 ,d,
4JPCˆ3.0 Hz), 140.52 ,d, JPCˆ15.6 Hz), 162.68 ,d,

Â
J. M. Alvarez-Gutierrez et al. / Tetrahedron 57 .2001) 3075±3086
Â
3081
2
3
2JPCˆ2.0 Hz). 31P NMR ,121.49 MHz, CDCl3), d ,ppm):
25.91. Anal. Calcd for C22H22NO2P: C, 72.71; H, 6.10; N,
3.85. Found. C, 72.75; H, 6.13; N, 3.89. MS ,API-ES) m/z:
364 ,M111, 100%), 307 ,8%).
5.07 ,dd, JHHˆ1.6, JHHˆ10.5 Hz, 1H), 5.73 ,ddd,
3
3
3JHHˆ10.5, JHH 17.0, JHHˆ5.7 Hz, 1H), 7.48±7.75 ,m,
6Har), 7.78±7.82 ,m, 4Har). 13C NMR ,75.46 MHz,
1
CDCl3), d ,ppm): 12.51, 29.04 ,d, JPCˆ66.1 Hz), 34.03,
4
1
52.55 ,d, JPCˆ4.2 Hz), 117.59, 125.52 ,d, JPCˆ93.7 Hz),
4.2.8. P,P-Diphenyl-P-ꢀ1-methylethyl)ꢀN-methoxycar-
bonyl)phosphazene ꢀ10h). White solid. Yield 95%. Mp
125.62 ,d, 1JPCˆ94.3 Hz), 128.55 ,d, 3JPCˆ12.0 Hz), 132.30
4
2
,d, JPCˆ2.4 Hz), 132.84 ,d, JPCˆ9.0 Hz), 135.04 ,d,
,8C): 112±113. IR ,KBr), n ,cm21): 1622, 1299. H NMR
3JPCˆ15.6 Hz), 162.67 ,d, JPCˆ2.4 Hz). 31P NMR
1
2
3
,300.13 MHz, CDCl3), d ,ppm): 1.17 ,dd, JPHˆ16.9,
,121.49 MHz, CDCl3), d ,ppm): 32.94. Anal. Calcd for
C19H22NO2P: C, 69.72; H, 6.73; N, 4.28. Found. C, 69.75;
H, 6.72; N, 4.26. MS ,API-ES) m/z: 328 ,M111, 100%),
271 ,27%).
3JHHˆ7.1 Hz, 6H), 2.67 ,dsep, JPHˆ12.3, JHHˆ7.1 Hz,
1H), 3.59 ,s, 3H), 7.48±7.61 ,m, 6Har), 7.78±8.50 ,m,
4Har). 13C NMR ,75.46 MHz, CDCl3), d ,ppm): 16.01 ,d,
2
3
1
4
2JPCˆ1.7 Hz), 24.31 ,d, JPCˆ66.9 Hz), 55.53 ,d, JPCˆ
1
3
4.2.12. P,P-Diphenyl-P-ꢀ1-benzylpenthyl)ꢀN-methoxy-
carbonyl)phosphazene ꢀ10l). Oil. Yield 95%. IR ,neat), n
3.9 Hz), 125.48 ,d, JPCˆ93.4 Hz), 128.48 ,d, JPCˆ
4
2
11.6 Hz), 132.23 ,d, JPCˆ2.2 Hz), 132.92 ,d, JPCˆ
,cm21): 1692, 1293. H NMR ,300.13 MHz, CDCl3), d
1
8.8 Hz), 162.76 ,d, JPCˆ1.7 Hz). 31P NMR ,121.49 MHz,
2
3
,ppm): 0.56 ,t, JHHˆ7.1 Hz, 3H), 0.93±1.80 ,m, 6H),
CDCl3), d ,ppm): 34.05. Anal. Calcd for C17H20NO2P: C,
67.77; H, 6.64; N, 4.66. Found. C, 67.75; H, 6.63; N, 4.69.
MS ,API-ES) m/z: 302 ,M111, 100%), 245 ,35%).
2.80 ,m, 1H), 2.99 ,m, 1H), 3.28 ,m, 1H), 3.55 ,s, 3H,),
7.1±7.41 ,m, 11Har), 7.77±7.80 ,m, 4Har). 13C NMR
,75.46 MHz, CDCl3), d ,ppm): 13.51, 22.33, 28.49, 29.74
,d, 3JPCˆ9.0 Hz), 33.66, 39.20 ,d, 1JPCˆ69.7 Hz), 52.62 ,d,
4.2.9. P,P-Diphenyl-P-ꢀ1-methylpenthyl)ꢀN-methoxycar-
bonyl)phosphazene ꢀ10i). White solid. Yield 92%. Mp
4JPCˆ3.7 Hz), 126.12 ,d, JPCˆ96.1 Hz), 126.25 ,d, JPCˆ
1
1
93.1 Hz), 127.02±132.26 ,11Car), 132.57 ,d, JPCˆ9.0 Hz),
2
1
,8C): 122±123. IR ,KBr), n ,cm21): 1629, 1292. H NMR
132.65 ,d, 2JPCˆ8.4 Hz), 139.77 ,d, 3JPCˆ12.6 Hz), 162.62
,d, 2JPCˆ1.8 Hz). 31P NMR ,121.49 MHz, CDCl3), d ,ppm):
33.35. Anal. Calcd for C26H30NO2P: C, 74.46; H, 7.16; N,
3.34. Found. C, 74.44; H, 7.17; N, 3.35. MS ,API-ES) m/z:
420 ,M111, 100%), 362 ,23%).
,300.13 MHz, CDCl3), d ,ppm): 0.83 ,t, 3JHHˆ6.6 Hz, 3H),
3
3
1.2 ,m, 4H), 1.14 ,dd, JPHˆ18.0, JHHˆ7.0 Hz, 3H), 1.43
,m, 1H), 1.82 ,m, 1H), 3.04 ,m 1H), 3.57 ,s, 3H), 7.44±7.56
,m, 6Har), 7.73±7.81 ,m, 4Har). 13C NMR ,75.46 MHz,
3
CDCl3), d ,ppm): 12.68 ,d, JPCˆ1.8 Hz), 13.86, 22.28,
1
2
28.98 ,d, JPCˆ64.9 Hz), 29.03 ,d, JPCˆ1.5 Hz), 29.59 ,d,
4
1
3JPCˆ13.2 Hz), 52.46 ,d, JPCˆ3.6 Hz), 125.68 ,d, JPCˆ
4.3. General procedure for the reaction of lithium
phosphazenes with Michael acceptors
1
3
93.4 Hz), 125.79 ,d, JPCˆ93.4 Hz), 128.43 ,d, JPCˆ
4
2
12.0 Hz), 132.14 ,d, JPCˆ1.8 Hz), 132.81 ,d, JPCˆ
8.4 Hz), 132.88 ,d, 2JPCˆ9.0 Hz), 162.64 ,d,
2JPCˆ1.8 Hz). 31P NMR ,121.49 MHz, CDCl3), d ,ppm):
33.64. Anal. Calcd for C20H26NO2P: C, 76.92; H, 8.33; N,
4.49. Found. C, 76.90; H, 8.34; N, 4.50. MS ,API-ES) m/z:
344 ,M111, 100%), 287 ,13%).
Synthesis of 12, 15, 16, 17 and 18. To a solution of
3.1 mmol of BuLi in 10 ml of dry THF at 2208C was
n
added dropwise a solution of 3 mmol of the appropriated
phosphazene in 20 ml of THF. After 30 minutes of metala-
tion the reaction was cooled to 2708C. Then 1.5 mmol of
electrophile dissolved in 20 ml of THF were added. The
solution was allowed to reach room temperature overnight,
quenched with water and extracted 3 times with dichloro-
methane. The combined organic layers were dried with
MgSO4 and solvents were evaporated under reduced pres-
sure. Puri®cation was achieved through column chromato-
graphy using ether as eluent. Solid compounds were then
recrystallyzed from hexane/dichloromethane. The electro-
philes used were: DMAD, ethyl phenylpropiolate, dimethyl
maleate, and dimethyl butylidenmalonate.
4.2.10. P,P-Diphenyl-P-ꢀ1-methylbenzyl)ꢀN-methoxycar-
bonyl)phosphazene ꢀ10j). White solid. Yield 75%. Mp
1
,8C): 115±116. IR ,KBr), n ,cm21): 1630, 1292. H NMR
3
,300.13 MHz, CDCl3), d ,ppm): 1.03 ,dd, JPHˆ15.5 Hz,
3JHHˆ7.0 Hz,
3H),
2.21
,ddd,
3JPHˆ15.9 Hz,
3
3JHHˆ13.6 Hz, JHHˆ11.9 Hz, 1H), 3.28±3.42 ,m, 2H),
3.61 ,s, 3H), 7.14±7.30 ,m, 5Har), 7.48±7.58 ,m, 6Har),
7.81±7.88 ,m, 4Har). 13C NMR ,75.46 MHz, CDCl3), d
1
,ppm): 12.53, 31.61 ,d, JPCˆ63.7 Hz), 35.57, 52.64 ,d,
4JPCˆ3.6 Hz), 125.36 ,d, JPCˆ95.5 Hz), 125.75,d,
1
1JPCˆ93.1 Hz), 126.48, 128.46, 128.60 ,d, JPCˆ11.4 Hz),
3
4.3.1. 1H-2,2-Diphenyl-4,5-dimethoxycarbonyl-3-methyl-
1,2-azaphosphinin-6-one ꢀ12a). White solid. Yield 90%.
Mp ,8C): 172±173. IR ,KBr), n ,cm21): 1724, 1624,
128.66 ,d, 3JPCˆ11.4 Hz), 128.99, 132.38 ,d, 4JPCˆ2.4 Hz),
2
2
132.78 ,d, JPCˆ9.0 Hz), 132±96 ,d, JPCˆ9.6 Hz), 138.85
3
2
,d, JPC 15.0 Hz), 162.72 ,d, JPCˆ2.4 Hz). 31P NMR
,121.49 MHz, CDCl3), d ,ppm): 32.77. Anal. Calcd for
C23H24NO2P: C, 73.19; H, 6.41; N, 3.71. Found. C, 73.20;
H, 6.43; N, 3.70. MS ,API-ES) m/z: 378 ,M111, 100%),
321 ,70%).
1
1498. H NMR ,300.13 MHz, CDCl3), d ,ppm): 1.74 ,d,
3JPHˆ13.2 Hz, 3H), 3.74 ,s, 3H), 3.84 ,s, 3H), 7.49±7.67
,m, 10Har), 14.03 ,s, 1H). 13C NMR ,75.46 MHz, CDCl3), d
2
,ppm): 14.17 ,d, JPCˆ9.2 Hz), 51.78, 52.13, 81.44,d,
3JPCˆ18.3 Hz), 86.49 ,d, JPCˆ80.9 Hz), 127.25 ,d, JPCˆ
1
1
2
3
109.7 Hz), 128.95 ,d, JPCˆ13.0 Hz), 132.35 ,d, JPCˆ
4
2
4.2.11. P,P-Diphenyl-P-ꢀ1-methylbut-3-enyl)ꢀN-methoxy-
carbonyl)phosphazene ꢀ10k). White solid. Yield 90%. Mp
10.7 Hz), 132.90 ,d, JPCˆ3.1 Hz), 149.66 ,d, JPCˆ
2
8.4 Hz), 168.62 ,d, JPCˆ20.6 Hz), 170.55, 171.56 ,d,
1
,8C): 77±78. IR ,KBr), n ,cm21): 1616, 1285. H NMR
3JPCˆ6.1 Hz). 31P NMR ,121.49 MHz, CDCl3), d ,ppm):
26.55. Anal. Calcd for C21H20NO5P: C, 63.48; H, 5.07; N,
3.52. Found: C, 63.52; H, 5.04; N, 3.51%. MS ,EI) m/z: 397
,M1, 100%), 350 ,29%), 337 ,33%).
3
,300.13 MHz, CDCl3), d ,ppm): 1.14 ,dd, JPHˆ17.5,
3JHHˆ7.3 Hz, 3H), 1.78 ,m, 1H), 2.68 ,m, 1H), 3.13 ,m,
2
3
1H), 3.61 ,s, 3H), 5.02 ,dd, JHHˆ1.6, JHHˆ17.0 Hz, 1H),

Â
J. M. Alvarez-Gutierrez et al. / Tetrahedron 57 .2001) 3075±3086
Â
3082
4
4
4.3.2. 1H-2,2-Diphenyl-4,5-dimethoxycarbonyl-3-ethyl-
1,2-azaphosphinin-6-one ꢀ12b). White solid. Yield 91%.
Mp ,8C): 130±131. IR ,KBr), n ,cm21): 1729, 1620,
132.93 ,d, JPCˆ2.4 Hz), 134.85 ,d, JPCˆ1.0 Hz), 150.34
,d, 2JPCˆ9.0 Hz), 168.28 ,d, 2JPCˆ20.4 Hz), 170.66, 171.68
,d, 3JPCˆ5.4 Hz). 31P NMR ,121.49 MHz, CDCl3), d ,ppm):
27.37. Anal. Calcd for C23H22NO5P: C, 65.25; H, 5.24; N,
3.31. Found: C, 65.21; H, 5.27; N, 3.29%. MS ,EI) m/z: 424
,M111, 100%), 392 ,34%).
1
1591. H NMR ,300.13 MHz, CDCl3), d ,ppm): 0.58 ,t,
3
3
3JHHˆ7.1 Hz, 3H), 2.15 ,dq, JHHˆ7.1, JPHˆ23.7 Hz,
2H), 3.72 ,s, 3H), 3.83 ,s, 3H), 7.47±7.68 ,m, 10Har),
13.98 ,s, 1H). 13C NMR ,75.46 MHz, CDCl3), d ,ppm):
2
14.78, 22.25 ,d, JPCˆ8.8 Hz), 51.71, 51.98, 81.98 ,d,
4.3.6. 1H-2,2-Diphenyl-4,5-dimethoxycarbonyl-3-phenyl-
methyl-1,2-azaphosphinin-6-one ꢀ12f). White solid. Yield
75%. Mp ,8C): 180±181. IR ,KBr), n ,cm21): 1730, 1625,
1
1
3JPCˆ20.9 Hz), 93.22 ,d, JPCˆ77.9 Hz), 127.82 ,d, JPCˆ
3
2
109.2 Hz), 128.91 ,d, JPCˆ12.9 Hz), 132.45 ,d, JPCˆ
4
2
1
10.4 Hz), 132.92 ,d, JPCˆ2.4 Hz), 149.22 ,d, JPCˆ
1492. H NMR ,300.13 MHz, CDCl3), d ,ppm): 3.71 ,5H),
2
8.8 Hz), 168.53 ,d, JPCˆ20.9 Hz), 170.64, 171.60 ,d,
3.80 ,s, 3H), 6.50 ,m, 5Har), 7.50±8.06 ,m, 10Har), 14.01 ,s,
1H). 13C NMR ,75.46 MHz, CDCl3), d ,ppm): 34.45 ,d,
3JPCˆ6.4 Hz). 31P NMR ,121.49 MHz, CDCl3), d ,ppm):
25.67. Anal. Calcd for C22H22NO5P: C, 64.23; H, 5.39; N,
3.40. Found: C, 64.26; H, 5.41; N, 3.44%. MS ,EI) m/z: 411
,M1, 100%), 364 ,67%), 335 ,92%).
2JPCˆ16.6 Hz), 51.76, 51.88, 82.48 ,d, JPCˆ19.0 Hz),
2
1
90.05 ,d, JP1Cˆ79.5 Hz), 125.98, 126.18, 127.14, 127.64,
3
128.01 ,d, JPCˆ102.2 Hz), 128.69 ,d, JPCˆ13.1 Hz),
2
132.45.,d, JPCˆ10.9 Hz), 137.85, 150.67, 168.52 ,d,
4.3.3. 1H-2,2-Diphenyl-4,5-dimethoxycarbonyl-3-propyl-
1,2-azaphosphinin-6-one ꢀ12c). White solid. Yield 90%.
Mp ,8C): 160±161. IR ,KBr), n ,cm21): 1745, 1620, 1567.
1H NMR ,300.13 MHz, CDCl3), d ,ppm): 0.62 ,t,
3JHHˆ7.2 Hz, 3H), 0.94 ,m, 2H), 2.07 ,m, 2H), 3.77 ,s,
3H), 3.90 ,s, 3H), 7.30±7.70 ,m, 10Har), 14.02 ,s, 1H). 13C
NMR ,75.46 MHz, CDCl3), d ,ppm): 14.00, 23.60, 31.27 ,d,
2JPCˆ21.4 Hz), 170.66, 171.73. 31P NMR ,121.49 MHz,
CDCl3), d ,ppm): 26.77. Anal. Calcd for C27H24NO5P: C,
68.49; H, 5.11; N, 2.96. Found: C, 68.52; H, 5.09; N, 2.99%.
MS ,EI) m/z: 473 ,M1, 40%), 391 ,100%), 354 ,20%).
4.3.7. 2-[DiphenylꢀN-methoxycarbonyl)phosphoranili-
den]-5-phenylpent-4-in-3-one ꢀ16)/Diphenylꢀethyliden)-
ꢀN-methoxycarbonyl)phophoranyl]-N-methoxycarbonyl-
3-phenylpropargyl amide ꢀ15). Isolated as a 55:45
mixture. Oil. Yield 70%. IR ,neat), n ,cm21): 1725, 1620.
NMR data for 15. 1H NMR ,300.13 MHz, CDCl3), d ,ppm):
3
2JPCˆ8.4 Hz), 51.66, 51.92, 81.53 ,d, JPCˆ 19.12 Hz),
1
1
91.92 ,d, JPCˆ78.4 Hz), 127.72 ,d, JPCˆ 109.2 Hz),
128.83 ,d, JPCˆ13.0 Hz,), 132.36 ,d,3JPCˆ 11.8 Hz),
2
4
2
132.87 ,d, JPCˆ2.7 Hz), 149.33 ,d, JPCˆ8.7 Hz), 168.55
,d, JPCˆ20.6 Hz), 170.59, 171.56 ,d, JPCˆ5.1 Hz). 31P
NMR ,121.49 MHz, CDCl3), d ,ppm): 25.98. Anal. Calcd
for C23H24NO5P: C, 64.94; H, 5.69; N, 3.29. Found: C,
64.90; H, 5.65; N, 3.31%. MS ,EI) m/z: 425 ,M1, 40%),
364 ,29%), 335 ,55%).
1.70 ,d, JPHˆ14.5 Hz, 3H), 3.57 ,s, 3H), 7.21±7.92 ,m,
2
3
3
15Har). 13C NMR ,75.46 MHz, CDCl3), d ,ppm): 9.90 ,d,
2JPCˆ3.2 Hz), 52.05, 86.78, 92.98, 118.96±133.33
,18Car1PCˆ), 161.5, 182.12. 31P NMR ,121.49 MHz,
CDCl3), d ,ppm): 35.65.
4.3.4. 1H-2,2-Diphenyl-4,5-dimethoxycarbonyl-3-iso-
propyl-1,2-azaphosphinin-6-one ꢀ12d). White solid.
4.3.8. Diphenylꢀethyliden)ꢀN-methoxycarbonyl)phophor-
anyl]-N-methoxycarbonyl-3-phenylpropargyl amide ꢀ16).
Isolated as a 55:45 mixture. Oil. Yield 70%. IR ,neat), n
,cm21): 1725, 1620. NMR data for 16. Oil. 1H NMR
Yield 91%. Mp ,8C): 147±148. IR ,KBr), n ,cm21): 1745,
1625, 1556. H NMR ,300.13 MHz, CDCl3), d ,ppm):0.73
1
3
3
,d, JHHˆ7.2 Hz, 6H), 2.62 ,m, 1H), 3.64 ,s, 3H), 3.87 ,s,
,300.13 MHz, CDCl3), d ,ppm): 1.54 ,dd, JHHˆ10.1,
3H), 7.41±7.69 ,m, 10Har), 12.68 ,s, 1H). 13C NMR
3JPHˆ7.0 Hz 3H), 3.54 ,s, 3H), 4.49 ,dq, JHHˆ7.0,
3
2
,75.46 MHz, CDCl3), d ,ppm): 22.07, 30.12 ,d, JPCˆ
2JPHˆ27.3 Hz, 1H), 7.21±7.92 ,m, 15Har). 13C NMR
3
8.6 Hz), 51.45, 51.72, 82.02 ,d, JPCˆ19.70 Hz), 96.20 ,d,
,75.46 MHz, CDCl3), d ,ppm): 10.37 ,C-5), 52.05, 83.35
1
3
1
1JPCˆ74.3 Hz), 127.66 ,d, JPCˆ108.5 Hz), 128.52 ,d,
,d, JPCˆ21.8 Hz), 86.50 ,d, JPCˆ115.5 Hz), 92.90,
118.96±133.33 ,18Car), 159.45, 161.57. 31P NMR
,121.49 MHz, CDCl3), d ,ppm): 26.55.
2
3JPCˆ12.9 Hz), 132.60 ,d, JPC 10.2 Hz), 132.7, 148.21 ,d,
2JPCˆ9.2 Hz), 168.81 ,d, 2JPCˆ21.1 Hz), 170.45, 171.56 ,d,
3JPCˆ4.5 Hz). 31P NMR ,121.49 MHz, CDCl3), d ,ppm):
25.71. Anal. Calcd for C23H24NO5P: C, 64.94; H, 5.69; N,
3.29. Found: C, 64.92; H, 5.71; N, 3.30%. MS ,EI) m/z: 425
,M1, 40%), 410 ,100%), 378 ,34%).
4.3.9. ꢀ2Sp,10Rp)-Dimethyl 2-[1-[diphenylꢀN-methoxycar-
bonyl)phosphoranyl]-ethyl]-butanedioate ꢀ17a). Oil.
1
Yield 85%. IR ,neat), n ,cm21): 1740, 1642, 1298. H
3
NMR ,300.13 MHz, CDCl3), d ,ppm): 1.17 ,dd, JHH
ˆ
3
2
3
4.3.5. 1H-2,2-Diphenyl-4,5-dimethoxycarbonyl-3-pro-
penyl-1,2-azaphosphinin-6-one ꢀ12e). White solid. Yield
75%. Mp ,8C): 167±168. IR ,KBr), n ,cm21): 1740, 1623,
7.3, JPHˆ16.8 Hz, 3H), 2.41 ,dd, JHHˆ17.0, JHH
ˆ
2
3
2.5 Hz, 1H), 2.59 ,dd, JHHˆ17.0, JHHˆ11.2 Hz, 1H),
3
3
3.35 ,tt, JHHˆ2.5 and 11.2, JPHˆ11.2 Hz, 1H), 3.47
1
3
2
1545. H NMR ,300.13 MHz, CDCl3), d ,ppm): 2.92 ,dd,
,ddq, JHHˆ2.5 and 7.3, JPHˆ14.3 Hz, 1H), 3.55 ,s, 3H),
3.56 ,s, 3H), 3.67 ,s, 3H), 7.37±7.61 ,m, 6Har), 7.73±7.85
,m, 4Har). 13C NMR ,75.46 MHz, CDCl3), d ,ppm): 9.56 ,d,
2JPCˆ1.9 Hz), 30.62 ,d, 1JPCˆ68.3 Hz), 30.68, 39.64, 51.58,
3JPHˆ11.3 Hz), 3.76 ,s, 3H), 3.82 ,s, 3H), 4.63 ,dq,
3JHHˆ17.0 Hz, JHHˆ4JHHˆ1.2 Hz, 1H), 4.65 ,dq, JHH
ˆ
ˆ
2
3
9.4 Hz, JHHˆ4JHHˆ1.2 Hz, 1H), 5.30 ,ddd, JHH
2
3
3
3
4
1
17.0 Hz, JHHˆ9.4 Hz, JHHˆ6.5 Hz, 1H), 7.49±7.56 ,m,
52.42, 52.64 ,d, JPCˆ3.3 Hz), 125.84 ,d, JPCˆ95.6 Hz),
126.47±132.52 ,10Car), 162.29, 171.99, 173.28 ,d,
3JPCˆ17.5 Hz). 31P NMR ,121.49 MHz, CDCl3), d ,ppm):
28.72. Anal. Calcd for C22H26NO6P: C, 61.25; H, 6.07; N,
3.25. Found: C, 61.22; H, 6.10; N, 3.28%. MS ,EI), m/z: 430
,M121, 10%), 414 ,30%), 529 ,70%), 202 ,100%).
5Har) 7.60±7.70 ,m, 5Har), 13.91 ,s, 1H). 13C NMR
2
,75.46 MHz, CDCl3), d ,ppm): 32.71 ,d, JPCˆ8.4 Hz),
3
51.72, 51.90, 82.48 ,d, JPCˆ18.6 Hz), 89.06 ,d,
1
1JPCˆ89.06 Hz), 115.87, 127.38 ,d, JPCˆ109.9 Hz),
3
2
128.83 ,d, JPCˆ13.2 Hz), 132.61 ,d, JPCˆ10.8 Hz),

Â
J. M. Alvarez-Gutierrez et al. / Tetrahedron 57 .2001) 3075±3086
Â
3083
4.3.10. ꢀ2Sp,10Rp)-Dimethyl 2-[1-[diphenylꢀN-methoxy-
carbonyl)phosphoranyl]-propyl]-butanodioate ꢀ17b).
Oil. Yield 83%. IR ,neat), n ,cm21): 1732, 1627, 1296. H
4.4.2. ꢀ1Sp,2Sp)-2-[DiphenylꢀN-methoxycarbonyl)phos-
phoranyl]-1-phenyl-1-propanol ꢀ20a). White solid. Yield
80%. IR ,KBr), n ,cm21): 3499, 1630. 1H NMR
1
3
NMR ,300.13 MHz, CDCl3),
d
,ppm): 1.28 ,t,
,300.13 MHz, CDCl3), d ,ppm): 0.55 ,dd, JHHˆ9.4,
2
3JHHˆ6.0 Hz, 3H), 1.81 ,m, 2H), 2.60 ,m, JHHˆ17.1,
3JPHˆ17.1 Hz, 3H), 3.10 ,m, 1H), 3.52 ,s, 3H), 4.50 ,dd,
3
3
3JHHˆ2.4, JHHˆ11.2 Hz, 2H), 3.50 ,m, 2H), 3.63 ,s, 3H),
3JPHˆ9.4, JHHˆ17.1 Hz), 4.75 ,s, 1H), 7.17±7.43 ,m,
3.64 ,s, 3H), 3.73 ,s, 3H), 7.49±7.62 ,m, 6H), 7.83±7.93 ,m,
4H). 13C NMR ,75.46 MHz, CDCl3), d ,ppm): 12.95 ,d,
15Har). 13C NMR ,75.46 MHz, CDCl3), d ,ppm): 11.60,
1
4
37.50 ,d, JPCˆ68.6 Hz), 52.70 ,d, JPCˆ4.0 Hz), 74.79 ,d,
2JPCˆ3.8 Hz), 125.30±142.19 ,18Car), 162.21. 31P NMR
,121.49 MHz, CDCl3), d ,ppm): 32.64. MS ,EI) m/z: 394
,M111, 100%), 219 ,20%), 201 ,25%).
3JPCˆ14.2 Hz), 18.49, 30.56, 37.21, 37.64 ,d, JPCˆ
1
3
66.5 Hz), 51.72, 52.56, 52.75 ,d, JPCˆ3.3 Hz), 126.11 ,d,
3
1JPCˆ97.0 Hz), 128.82 ,d, JPCˆ11.9 Hz), 132.29 ,d,
2JPCˆ12.0 Hz), 132.53, 162.38, 172.15, 174.12 ,d,
3JPCˆ178.6 Hz). 31P NMR ,121.49 MHz, CDCl3), d
,ppm): 29.11. Anal. Calcd for C23H28NO6P: C, 62.02; H,
6.34; N, 3.14. Found: C, 62.05; H, 6.31; N, 3.18%. MS
,EI) m/z: 417 ,M121, 10%), 416 ,20%), 400 ,75%), 391
,100%).
4.4.3. ꢀ1Rp,2Sp)-1,3-Diphenyl-2-[diphenylꢀN-methoxy-
carbonyl)phosphoranyl]-1-propanol ꢀ19b). Oil. Yield
1
95%. IR ,KBr), n ,cm21): 3260, 1647, 1613, 1308. H
NMR ,300.13 MHz, CDCl3), d ,ppm): 2.91±3.35 ,m, 3H),
3
3.79 ,s, 3H), 5.43 ,d, JHHˆ10.5 Hz, 1H), 6.13±6.81 ,m,
5Har), 7.21±7.98 ,m, 15Har, Har). 13C NMR ,75.46 MHz,
4.3.11. ꢀ2Rp,10Rp)-Dimethyl 2-[1-[1-diphenyl[ꢀN-methoxy-
carbonyl)phosphoranyl]-ethyl]-butyl]-propanedioate
ꢀ18). Oil. Yield 60%. IR ,neat), n ,cm21): 1738, 1640, 1300.
1H NMR ,300.13 MHz, CDCl3), d ,ppm): 0.68 ,t,
1
CDCl3), d ,ppm): 26.87, 47.53 ,d, JPCˆ81.0 Hz), 53.22
4
2
,d, JPCˆ3.4 Hz), 69.20 ,d, JPCˆ9.2 Hz), 125.11±142.20
3
,23Car), 142.20 ,d, JPCˆ3.7 Hz), 163.08. 31P NMR
,121.49 MHz, CDCl3), d ,ppm): 32.64. Anal. Calcd for
C32H24NO3P: C, 74.19; H, 6.01; N, 2.98. Found: C,
74.21; H, 6.05; N, 3.01. MS ,EI) m/z: 470 ,M1, 100%),
201 ,15%).
3
3JHHˆ7.0 Hz, 3H), 1.01,m, 2H), 1.20 ,dd, JHHˆ7.0,
3JPHˆ17.8 Hz, 3H), 1.47 ,m, 1H), 2.66 ,m, 1H), 2.96 ,ddc,
3JHHˆ7.0 and 1.7, 2JPHˆ14.4 Hz, 3H), 3.54 ,s, 3H), 3.55 ,s,
3H), 3.60 ,s, 3H), 3.95 ,d, 3JHHˆ2.6 Hz, 1H), 7.30±7.83 ,m,
10Har). 13C NMR ,75.46 MHz, CDCl3), d ,ppm): 9.43,d,
4.4.4. ꢀ1Rp,2Sp)-1-Ciclohexyl-2-[P-diphenylꢀN-methoxy-
carbonyl)phosphoranyl]-1-propanol ꢀ19c)/ꢀ1Sp,2Sp)-1-
Ciclohexyl-2-[P-diphenylꢀN-methoxycarbonyl)phos-
phoranyl]-1-propanol ꢀ20c). 19c/20c Isolated as a 86:14
mixture. White solid. Yield 90%. IR ,KBr), n ,cm21):
3260, 1650.1322.
3
2JPCˆ2.2 Hz), 13.42, 20.56, 31.86 ,d, JPC 12.4 Hz), 32.11
1
2
,d, JPCˆ66.7 Hz), 36.36 ,d, JPCˆ2.2 Hz), 51.37, 51.87,
1
51.90, 52.34, 126.10 ,d, JPCˆ90.4 Hz), 126.69 ,d,
1JPCˆ93.8 Hz), 128.37±132.40 ,10Car), 162.42, 169.47,
169.52. 31P NMR ,121.49 MHz, CDCl3), d ,ppm): 29.46.
Anal. Calcd for C25H32NO6P: C, 63.42; H, 6.76; N, 2.96.
Found: C, 63.47; H, 6.81; N, 2.30. MS ,EI) m/z: 473 ,M1,
100%,), 443,50%), 417,10%).
NMR data for 19c. 1H NMR ,300.13 MHz, CDCl3), d
3
,ppm): 0.80±2.12 ,m, 11H, Cy), 1.15 ,dd, JPHˆ25.2,
3JHHˆ7.2 Hz, 3H), 2.79 ,m, 1H), 3.63 ,s, 3H), 3.72 ,dd,
3
3JPHˆ9.0, JHHˆ9.2 Hz, 1H), 5.15 ,s, OH), 7.45±7.53 ,m,
4.4. General procedure for the synthesis of b-hydroxy-
phosphazenes 19 and 20
6Har), 7.75±7.82 ,m, 4Har). 13C NMR ,75.46 MHz, CDCl3),
d ,ppm): 6.36 ,d, 2JPCˆ1.6 Hz), 26.22, 26.44, 26.60, 29.67,
1
2
30.28, 33.87 ,d, JPCˆ67.0 Hz), 40.06 ,d, JPCˆ8.8 H),
To a solution of 0.5 mmol of the appropriated phosphazene
in THF ,25 mL) was added a solution of nBuLi ,0.38 mL of
a 1.6 M solution in hexane, 0.6 mmol) at 2308C. After
30 min of metallation, the temperature was lowered at
2808C and was added the corresponding aldehyde
,0.5 mmol). The reaction mixture was stirred for 2 h. Addi-
tion of water ,25 mL) followed by extraction with ethyl
acetate ,3£15 mL) and solvent evaporation under vacuum
afforded a crude product which was puri®ed by precipitation
from diethyl ether.
4
2
53.62 ,d, JPCˆ3.3 Hz), 72.0 ,d, JPCˆ4.1 Hz), 126.79 ,d,
1JPCˆ86.7 Hz), 127.04 ,d, 1JPCˆ98.6 Hz), 128.71 ,d, 3JPCˆ
3
2
11.9 Hz), 128.99 ,d, JPCˆ11.4 Hz), 131.95 ,d, JPCˆ
2
4
8.3 Hz), 131.98 ,d, JPCˆ8.8 Hz), 132.18 ,d, JPCˆ
3.1 Hz), 132.41 ,d, JPCˆ2.6 Hz), 163.16. 31P NMR
4
,121.49 MHz, CDCl3), d ,ppm): 31.72.
NMR data for 20c. 1H NMR ,300.13 MHz, CDCl3), d
3
,ppm): 0.80±2.12 ,m, 11H, Cy), 0.97 ,dd, JPHˆ18.5,
3
3JHHˆ7.5 Hz, 3H), 3.06 ,m, 1H), 3.57 ,dd, JPHˆ8.8,
3
3JHHˆ15.8 Hz, 1H), 3.60 ,s, 3H), 3.57 ,dd, JPHˆ9.0,
4.4.1. ꢀ1Rp,2Sp)-2-[diphenylꢀN-methoxycarbonyl)phos-
phoranyl]-1-phenyl-1-propanol ꢀ19a). White solid. Yield
80%. IR ,KBr), n ,cm21): 3499, 1630. 1H NMR
3JHHˆ9.2 Hz, 1H), 4.8 ,s, OH), 7.45±7.53 ,m, 6Har),
7.75±7.82 ,m, 4Har). 13C NMR ,75.46 MHz, CDCl3), d
,ppm): 12.51, 25.49, 26.78, 26.90, 30.70, 30.98, 34.58 ,d,
3
,300.13 MHz, CDCl3), d ,ppm): 1.00 ,dd, JHHˆ6.7,
2
1JPCˆ70.6 Hz), 39.83 ,d, JPCˆ11.0 Hz), 53.47 ,d,
3JPHˆ13.6 Hz, 3H), 2.71 ,m, 1H), 3.66 ,s, 3H), 5.26 ,d,
3JPHˆ9.7 Hz, 1H), 7.17±7.43 ,m, 15Har). 13C NMR
,ppm): 5.49, 39.50 ,d,
4
4JPCˆ3.3 Hz), 75.92 ,d, JPCˆ4.1 Hz), 128.29±133.22
,10Car), 162.44. 31P NMR ,121.49 MHz, CDCl3), d ,ppm):
,75.46 MHz, CDCl3),
d
33.23. MS ,API-ES) m/z: 398 ,M1).
1JPCˆ63.3 Hz), 52.95 ,d, JPCˆ3.6 Hz), 69.06 ,d,
2JPCˆ2.0 Hz), 125.30±142.19 ,18Car), 162.93. 31P NMR
,121.49 MHz, CDCl3), d ,ppm): 29.78. Anal. Calcd for
C32H24NO3P: C, 70.22; H, 6.15; N, 3.56. Found: C, 70.25;
H, 6.11; N, 3.52. MS ,EI) m/z: 394 ,M111, 100%), 219
,20%), 201 ,25%).
4
4.4.5. ꢀ1Rp,2Sp)-ꢀp-Chlorophenyl)-2-[ꢀP-diphenyl)ꢀN-meth-
oxycarbonyl)phosphoranyl]-1-propanol ꢀ19d)/ꢀ1Sp,2Sp)-
ꢀp-chlorophenyl)-2-[ꢀP-diphenyl)ꢀN-methoxycarbonyl)-
phosphoranyl]-1-propanol ꢀ20d). 19d/20d Isolated as a

Â
Â
J. M. Alvarez-Gutierrez et al. / Tetrahedron 57 .2001) 3075±3086
3084
86:14 mixture. White solid. Yield 87%. IR ,KBr), n ,cm21):
3291, 1650, 1322.
4.4.8. 1-ꢀp-Chlorophenyl)-2-[P-diphenylꢀN-methoxycar-
bonyl)phosphoranyl]-2-methyl-1-propanol ꢀ19g). White
solid. Yield 95%. Mp ,8C): 194 ,decomposed). IR ,KBr),
n ,cm21): 3408, 1666, 1284. 1H NMR ,300.13 MHz,
1
NMR data for 19d. H NMR ,300.13 MHz, CDCl3), d
3
3
3
,ppm): 1.09 ,dd, JPHˆ16.9, JHHˆ7.1 Hz, 3H), 2.72 ,dq,
CDCl3), d ,ppm): 0.93 ,d, JPHˆ18.2 Hz, 3H), 1.35 ,d,
3
3
2JPHˆ14.7, JHHˆ7.5 Hz, 1H), 3.72 ,s, 3H), 5.29 ,d,
3JPHˆ15.3, 3H), 3.72 ,s, 3H), 5.11 ,d, JPHˆ7.7 Hz, 1H),
3JPHˆ9.7 Hz, 1H), 6.42 ,s, OH), 7.34±7.56 ,m, 10Har),
7.35±7.73 ,m, 10Har), 8.05±8.11 ,m, 4Har). 13C NMR
,75.46 MHz, CDCl3), d ,ppm): 16.43, 21.61, 41.85 ,d,
7.71±7.80 ,m, 2Har), 7.83±7.90 ,m, 2Har). 13C NMR
4
,75.46 MHz, CDCl3),
d
,ppm): 5.89, 39.56 ,d,
1JPCˆ69.5 Hz), 53.00 ,d, JPCˆ3.6 Hz), 75.69, 125.32 ,d,
4
1
1JPCˆ39.5 Hz), 53.24 ,d, JPCˆ3.6 Hz), 68.93, 126.24 ,d,
1JPCˆ89.9 Hz), 125.44 ,d, JPCˆ78.9 Hz), 132.41 ,d,
1JPCˆ95.5 Hz), 126.54 ,d, JPCˆ86.0 Hz), 127.11, 128.20,
4JPCˆ2.5 Hz), 132.55 ,d, JPCˆ2.5 Hz), 128.04, 128.48 ,d,
1
4
3
3
128.80 ,d, JPCˆ12.6 Hz), 131.94 ,d, 2JPCˆ9.6 Hz), 132.09
3JPCˆ10.9 Hz), 128.62 ,d, JPCˆ10.9 Hz), 129.85, 133.28
2
4
2
2
,d, JPCˆ9.6 Hz), 132.44 ,d, JPCˆ2.9 Hz), 133.44, 141.06
,d, 3JPCˆ14.4 Hz), 163.12. 31P NMR ,121.49 MHz, CDCl3),
d ,ppm): 30.40.
,d, JPCˆ8.7 Hz), 133.49 ,d, JPCˆ9.1 Hz), 137.38 ,d,
3JPCˆ12.5 Hz), 162.30. 31P NMR ,121.49 MHz, CDCl3), d
,ppm): 39.36. Anal. Calcd for C24H26NO3PCl: C, 61.71; H,
5.57; N, 2.79. Found: C, 61.67; H, 5.59; 2.81. MS ,API-ES)
m/z: 441 ,M1, 4%), 367 ,10%), 201 ,61%), 183 ,100%).
1
NMR data for 20d. H NMR ,300.13 MHz, CDCl3), d
3
3
,ppm): 0.61 ,dd, JPHˆ17.9, JHHˆ7.3 Hz, 3H), 3.10 ,m,
3
3
4.4.9. 1-Ethyl-2-[P-diphenylꢀN-methoxycarbonyl)phos-
phoranyl]-2-methyl-1-propanol ꢀ19h). White solid. Yield
75%. Mp ,8C): 185. IR ,KBr), n ,cm21): 3460, 1647, 1289.
1H NMR ,300.13 MHz, CDCl3), d ,ppm): 1.00 ,d,
1H), 3.57 ,s, 3H), 4.5 ,dd, JPHˆ8.1, JHHˆ17.6 Hz, 1H),
6.60 ,s, OH), 7.34±7.56 ,m, 10Har), 7.71±7.80 ,m, 2Har),
7.83±7.90 ,m, 2Har). 13C NMR ,75.46 MHz, CDCl3), d
1
,ppm): 11.83, 37.72 ,d, JPCˆ37.7 Hz), 52.89 ,d,
3
3JPHˆ18.2 Hz, 3H), 1.04 ,t, JHHˆ8.9 Hz, 3H), 1.33 ,d,
1
4JPCˆ3.6 Hz), 74.41, 125.0 ,d, JPCˆ97.3 Hz), 126.32 ,d,
3JPHˆ16.7 Hz, 3H), 3.61 ,s, 3H), 1.43±1.50 ,m, 2H), 3.82
3
1JPCˆ88.3 Hz), 127.97±129.3 ,5Car), 128.62 ,d, JPCˆ11.4
3
3
3
H C-13), 132.49 ,d, 2JPCˆ8.4 Hz), 132.61 ,d, 2JPCˆ8.4 Hz),
132.72 ,d, 4JPCˆ2.9 Hz), 140.44 ,d, 3JPCˆ12.6 Hz), 162.39.
31P NMR ,121.49 MHz, CDCl3), d ,ppm): 33.11. MS ,API-
ES) m/z: 428 ,M111, 100%), 201 ,40%).
,ddd, JPHˆ12.6, JHHˆ8.1, JHHˆ4.4 Hz, 1H), 6.50 ,s,
OH), 7.50±7.58 ,m, 6Har), 7.82±7.88 ,m, 2Har), 7.95±8.01
,m, 2Har). 13C NMR ,75.46 MHz, CDCl3), d ,ppm): 11.28,
3
1
17.16, 21.45, 23.26 ,d, JPCˆ9.5 Hz), 43.10 ,d, JPCˆ
4
2
67.4 Hz), 53.00 ,d, JPCˆ3.7 Hz), 75.06 ,d, JPCˆ3.3 Hz),
126.33 ,d, 1JPCˆ94.7 Hz), 126.62 ,d, 1JPCˆ77.8 Hz), 128.37
4.4.6.
ꢀ1Rp,2Sp)-1-ꢀp-Chlorophenyl)-2-[P-diphenylꢀN-
methoxycarbonyl)phosphoranyl]-3-phenyl-1-propanol
ꢀ19e). White solid. Yield 95%. Mp ,8C): 124. IR ,KBr), n
3
4
,d, JPCˆ11.2 Hz), 132.05 ,d, JPCˆ2.9 Hz), 132.12 ,d,
4JPCˆ2.9 Hz), 133.33 ,d, JPCˆ8.3 Hz), 132.72 ,d,
2
2JPCˆ8.7 Hz), 162.56. 31P NMR ,121.49 MHz, CDCl3), d
,ppm): 38.89. Anal. Calcd for C20H26NO3P: C, 66.86; H,
7.24; N, 3.9. Found: C, 66.82; H, 7.26; N, 3.92. MS ,API-
ES) m/z: 360 ,M111, 100%), 285 ,48%), 201 ,23%).
1
,cm21): 3279,1633, 1318. H NMR ,300.13 MHz, CDCl3),
d ,ppm): 2.86±3.30 ,m, 3H), 3.81 ,s, 3H), 5.37 ,d,
3JPHˆ10.7 Hz, 1H), 6.42 ,s, OH), 6.23±7.60 ,m, 15Har),
7.71±7.77 ,m, 2Har), 7.90±7.97 ,m, 2Har). 13C NMR
,75.46 MHz, CDCl3),
d
,ppm): 27.35, 47.85 ,d,
4
1JPCˆ61.3 Hz), 53.52 ,d, JPCˆ2.9 Hz), 60.02 ,d,
4.4.10. 2-[P-DiphenylꢀN-methoxycarbonyl)phosphoranyl]-
1,2di-methyl-1-propanol ꢀ19i). White solid. Yield 70% Mp
,8C): 152. IR ,KBr), n ,cm21): 3459, 1646, 1270. 1H NMR
3JPCˆ2.2 Hz), 127.18, 127.90, 139.43 ,d, JPCˆ5.4 Hz),
3
126.42±132.75 ,17Car), 140.96 ,d, JPCˆ14.4 Hz), 163.33.
3
3
31P NMR ,121.49 MHz, CDCl3), d ,ppm): 29.30. Anal.
Calcd for C29H27NO3PCl: C, 69.13; H, 5.36; N, 2.78.
Found: C, 69.16; H, 5.37; N, 2.74. MS ,API-ES) m/z: 503
,M1, 4%), 472 ,10%), 201 ,100%).
,300.13 MHz, CDCl3), d ,ppm): 0.95 ,d, JPHˆ17.5 Hz,
3
3H), 1.35 ,d, JPHˆ16.5 Hz, 3H), 1.62±1.72 ,m, 1H),
1.75±1.86 ,m, 1H), 2.60±2.70 ,m, 1H), 2.98±3.07 ,m,
3
3
1H), 3.63 ,s, 3H), 3.98 ,ddd, JPHˆ10.2, JHHˆ8.1,
4JHHˆ1.8 Hz), 6.64 ,s, OH), 7.18±7.30 ,m, 5Har), 7.50±
7.59 ,m, 6Har), 7.80±7.83 ,m, 2Har), 7.95±8.02 ,m, 2Har).
13C NMR ,75.46 MHz, CDCl3), d ,ppm): 17.20, 21.42,
4.4.7. 2-[P-DiphenylꢀN-methoxycarbonyl)phosphoranyl]-
1-phenyl-2-methyl-1-propanol ꢀ19f). White solid. Yield
90%. Mp ,8C): 136. IR ,KBr), n ,cm21): 3541, 1658,
3
1
32.37 ,d, JPCˆ9.0 Hz), 32.63, 43.17 ,d, JPCˆ66.7 Hz),
4
2
1
53.00 ,d, JP1Cˆ3.6 Hz), 72.45 ,d, JPCˆ3.0 Hz), 125.72,
1332. H NMR ,300.13 MHz, CDCl3), d ,ppm): 0.84 ,d,
1
3
3JPHˆ17.8 Hz, 3H), 1.28 ,d, JPHˆ16.5 Hz, 3H), 3.63 ,s,
126.28 ,d, JPCˆ95.5 Hz), 126.70 ,d, JPCˆ75.5 Hz),
128.26, 128.37 ,d, 3JPCˆ12.0 Hz), 128.41 ,d,
3
3H), 5.05 ,d, JPHˆ8.1 Hz, 1H), 7.10 ,s, OH), 7.27±7.66
4
3JPCˆ11.4 Hz), 128.57, 132.10 ,d, JPCˆ4.0 Hz), 132.13
,m, 11Har), 7.95±8.05 ,m, 4Har). 13C NMR ,75.46 MHz,
4
2
1
,d, JPCˆ3.0 Hz), 133.28 ,d, JPCˆ8.4 Hz), 133.76 ,d,
2JPCˆ9.0 Hz), 142.24, 162.62. 31P NMR ,121.49 MHz,
CDCl3), d ,ppm): 38.94. Anal. Calcd for C26H30NO3P: C,
71.72; H, 6.90; N, 3.22. Found: C, 71.76; H, 6.87; N, 3.21.
MS ,API-ES) m/z: 436 ,M111, 100%), 361 ,23%), 201
,5%).
CDCl3), d ,ppm): 16.60, 21.80, 42.16 ,d, JPCˆ69.2 Hz),
4
1
53.07 ,d, JPCˆ3.6 Hz), 76.93, 125.64 ,d, JPCˆ90.0 Hz),
1
126.26 ,d, JPCˆ76.8 Hz), 127.59, 127.72, 128.63, 128.76
2
2
,d, JPCˆ8.1 Hz), 128.61 ,d, JPCˆ8.1 Hz), 132.39 ,d,
4JPCˆ3.0 Hz), 132.52 ,d, JPCˆ2.5 Hz), 133.40 ,d, JPCˆ
4
3
3
3
8.6 Hz), 133.83 ,d, JPCˆ9.1 Hz), 138.87 ,d, JPCˆ
12.2 Hz), 162.47. 31P NMR ,121.49 MHz, CDCl3), d
,ppm): 39.54. Anal. Calcd for C24H26NO3P: C, 70.76; H,
6.39; N, 3.44. Found: C, 70.71; H, 6.41; N, 3.47. MS
,API-ES) m/z: 407 ,M1, 10%), 334 ,26%), 201 ,100%),
183 ,100%).
4.5. General method for the synthesis of oxaza-
phosphinin-2-ones 21
To a solution of phosphazene 10h ,0.15 g, 0.5 mmol) in

Â
J. M. Alvarez-Gutierrez et al. / Tetrahedron 57 .2001) 3075±3086
Â
3085
diethyl ether ,15 mL) was added a solution of nBuLi
,0.38 mL of a 1.6 M solution in hexane, 0.6 mmol) in
THF ,15 mL) at 2358C. The mixture was stirred for 1 h.
Then, the temperature was lowered at 2808C and was added
the corresponding aldehyde ,0.5 mmol). The reaction was
allowed to reach ambient temperature and stirred for 14 h.
Solvents elimination under vacuum and addition of Et2O
afforded heterocycles 21a and 21d as white solids.
Compounds 21b±c were obtained in the same way except
for the solvent used. In this case phosphazene 10h was
dissolved in THF.
1H NMR ,300.13 MHz, CDCl3), d ,ppm): 1.13 ,d,
3JPHˆ17.7 Hz, 6H), 1.60±1.70 ,m, 1H), 1.82±1.94 ,m,
1H), 2.62±2.72 ,m, 1H), 3.02±3.12 ,m, 1H), 4.14 ,dt,
4
3JPHˆ3JHHˆ10.5, JHHˆ1.3 Hz, 1H), 7.18±7.21 ,m, 5Har),
7.43±7.58 ,m, 6Har), 7.75±7.82 ,m, 2Har), 8.04±8.11 ,m,
2Har). 13C NMR ,75.46 MHz, CDCl3), d ,ppm): 15.96 ,d,
3
2JPCˆ2.3 Hz), 21.13, 29.09 ,d, JPCˆ8.4 Hz), 31.85, 32.74
1
1
,d, JPCˆ48.78.4 Hz), 77.05, 124.87 ,d, JPCˆ105.11 Hz),
1
125.73 ,d, JPCˆ97.9 Hz), 125.97, 128.40, 128.56, 128.82
3
3
,d, JPCˆ12.0 Hz), 129.10 ,d, JPCˆ12.0 Hz), 131.87 ,d,
2JPCˆ8.4 Hz), 132.77 ,d, JPCˆ9.6 Hz), 133.07 ,d,
2
4JPCˆ2.4 Hz), 141.14, 157.25. 31P NMR ,121.49 MHz,
CDCl3), d ,ppm): 25.94. Anal. Calcd for C25H26NO2P: C,
74.44; H, 6.45; N, 3.48. Found: C, 74.46; H, 6.46; N, 3.45.
MS ,API-ES) m/z: 404 ,100%, M111), 361 ,24%), 201
,25%).
4.5.1.
4-Diphenyl-6-phenyl-5,5-dimethyl-1,3,4-oxaza-
phosphinin-2-one ꢀ21a). White solid. Yield 77%. Mp
,8C): 144 ,decomposed). IR ,KBr), n ,cm21): 1663, 1291.
1H NMR ,300.13 MHz, CDCl3), d ,ppm): 1.09 ,d,
3
3JPHˆ16.5 Hz, 3H), 1.15 ,d, JPHˆ15.2 Hz, 3H), 5.28 ,d,
3JPHˆ9.9 Hz, 1H), 7.26±7.33 ,m, 5Har), 7.60±7.70 ,m,
6Har), 8.00±8.08 ,m, 2Har), 8.12±8.19 ,m, 2Har). 13C
NMR ,75.46 MHz, CDCl3), d ,ppm): 15.49, 21.87, 33.81
4.5.5. 1-p-Chlorophenyl-2-methyl-2-diphenylphosphoryl-
1-propanol ꢀ22b). Isolated as a by-product in the synthesis
of 21b by fractional precipitation of the crude reaction in
Et2O. White solid. Yield 83%. Mp ,8C): 176. IR ,KBr), n
1
1
,d, JPCˆ47.2 Hz), 80.21, 125.25 ,d, JPCˆ105.9 Hz),
1
,cm21): 3415, 1164. H NMR ,300.13 MHz, CDCl3), d
1
125.83 ,d, JPCˆ97.1 Hz), 127.74, 128.46, 129.96±133.11
,ppm): 0.96 ,d, 3JPHˆ17.0 Hz, 3H), 1.18 ,d,
,3Car), 133.32 ,d, JPCˆ11.4 Hz), 157.02. 31P NMR
3
3
3JPHˆ15.3 Hz, 3H), 4.96 ,d, JPHˆ8.8 Hz, 1H), 6.05 ,s,
,121.49 MHz, CDCl3), d ,ppm): 26.20. Anal. Calcd for
C23H22NO2P: C, 73.60; H, 5.87; N, 3.73. Found: C, 73.64;
H, 5.86; N, 3.70. MS ,API-ES) m/z: 376 ,100%, M111),
244 ,15%), 202 ,27%).
OH), 7.19±7.32 ,m, 4Har), 7.53±7.67 ,m, 3Har), 8.00±8.12
,m, 4Har). 13C NMR ,75.46 MHz, CDCl3), d ,ppm): 15.0,
1
21.64, 76.32, 40.72 ,d, JPCˆ66.7 Hz), 125.06 ,d,
3
1JPCˆ106.3 Hz), 127.65, 128.63 ,d, JPCˆ11.3 Hz), 128.67
,d, 1JPCˆ10.9 Hz), 129.71, 131.97 ,d, 2JPCˆ8.5 Hz), 132.15
4.5.2. 6-p-Chlorophenyl-4,4-diphenyl-5,5-dimethyl-1,3,4-
oxazaphosphin-2-one ꢀ21b). White solid. Yield 42%. Mp
,8C): 146 ,decomposed). IR ,KBr), n ,cm21): 1663, 1291.
1H NMR ,300.13 MHz, CDCl3), d ,ppm): 1.06 ,d,
4
4
,d, JPCˆ2.8 Hz), 132.19 ,d, JPCˆ2.8 Hz), 132.33 ,d,
2JPCˆ8.5 Hz), 137.04 ,d, JPCˆ12.6 Hz). 31P NMR
3
,121.49 MHz, CDCl3), d ,ppm): 45.44. Anal. Calcd for
C22H22O2PCl: C, 68.67; H, 5.72. Found: C, 68.66; H, 5.73.
MS ,API-ES) m/z: 386 ,M111, 100%), 201 ,25%).
3
3JPHˆ7.5 Hz, 3H), 1.13 ,d, JPHˆ8.6 Hz, 3H), 5.25 ,d,
3JPHˆ9.6 Hz, 1H), 7.18±7.31 ,m, 4Har), 7.53±7.67 ,m,
3Har), 8.0±8.20 ,m, 4Har). 13C NMR ,75.46 MHz, CDCl3),
1
d ,ppm): 15.48, 21.80, 33.78 ,d, JPCˆ46.86 Hz), 79.59,
1
1
125.06 ,d, JPCˆ106.3 Hz), 125.65 ,d, JPCˆ98.0 Hz),
129.14, 131.18, 156.61. 31P NMR ,121.49 MHz, CDCl3),
d ,ppm): 25.90. Anal. Calcd for C23H21NO2PCl: C, 67.40;
H, 5.13; N, 3.42. Found: C, 67.43; H, 5.14; N, 3.39. MS
,API-ES) m/z: 409 ,M1, 27%), 410 ,M111, 33%), 407
,100%), 201 ,22%).
References
1. ,a) Organophosphorus Reagents in Organic Synthesis;
Cadogan, J. I. G., Ed.; Academic: New York, 1980.
,b) Clayden, J.; Warren, S. Angew. Chem., Int. Ed. Engl.
1996, 35, 241. ,c) Amer, A.; Zimmer, H. In Handbook of
Organophosphorus Chemistry; Engel, R., Ed.; Marcel Dekker:
New York, 1992; pp 241. ,d) Kolodiazhnyi, O. I. Phosphorus
Ylides. Chemistry and Application in Organic Synthesis;
Wiley-VCH: New York, 1999.
4.5.3. 6-Ethyl-5,5-dimethyl-4,4-diphenyl-1,3,4-oxazaphos-
phin-2-one ꢀ21c). White solid. Yield 65%. Mp ,8C): 148
1
,decomposed). IR ,KBr), n ,cm21): 1651, 1290. H NMR
,300.13 MHz, CDCl3), d ,ppm): 1.09 ,t, 3JHHˆ7.7 Hz, 3H),
2. ,a) Bennani, Y. L.; Hanessian, S. Chem. Rev. 1997, 97, 3161.
,b) Katriztky, A. R.; Pif¯, M.; Lang, H.; Anders, E. Chem. Rev.
3
3
1.15 ,d, JPHˆ16.2 Hz, 3H), 1.26 ,d, JPHˆ15.4 Hz, 3H),
4.04 ,dt, JPHˆ3JHHˆ9.5, JHHˆ2.6 Hz, 1H)), 7.52±7.58
,m, 6Har), 7.77±7.95 ,m, 2Har), 8.05± 8.11 ,m, 2Har). 13C
NMR ,75.46 MHz, CDCl3), d ,ppm): 10.86, 15.99, 20.46 ,d,
3
4
Á
1999, 99, 665. ,c) Greck, C.; Genet, J. P. Synlett 1997, 741.
3. ,a) Feistauer, H.; Neidlein, R. Helv. Chim. Acta 1995, 78,
1806. ,b) Arcadi, A.; Attanasi, O. A.; De Crescentini, L.;
Rossi, E.; Serra-Zanetti, F. Tetrahedron 1996, 52, 3997.
,c) Palacios, F.; Ochoa de Retana, A. M.; Oyarzabal
Tetrahedron 1999, 55, 5947 ,and references therein).
3JPCˆ8.4 Hz), 49.33 ,d, JPCˆ48.1 Hz), 79.84, 125.35 ,d,
1
1JPCˆ104.5 H), 126.03 ,d, JPCˆ97.3 Hz), 128.86 ,d,
1
3JPCˆ12.0 Hz), 129.07 ,d, JPCˆ12.0 Hz), 131.85 ,d,
3
2JPCˆ9.0 Hz), 132.23 ,d, JPCˆ2.6 Hz), 132.92 ,d,
3
Â
4. Barluenga, J.; Lopez-Ortiz, F.; Palacios, F. Tetrahedron Lett.
2JPCˆ9.6 Hz), 157.39. 31P NMR ,121.49 MHz, CDCl3), d
,ppm): 25.37. Anal. Calcd for C19H22NO2P: C, 69.72; H,
6.73; N, 4.28. Found: C, 69.70; H, 6.71; N, 4.32. MS
,API-ES) m/z: 328 ,100%, M111), 285 ,14%), 201 ,23%).
1987, 28, 2875.
5. Barluenga, J.; Lopez-Ortiz, F.; Palacios, F. Tetrahedron Lett.
1987, 28, 4327.
Â
Â
6. Peralta-Perez, E.; Ahrens, B.; Davidson, M. G.; Raithby, P. R.;
Â
Teat, S. J.; Perez-Alvarez, I.; Lopez-Ortiz, F. Synlett 2001,
Â
Â
4.5.4. 5,5-Dimethyl-4,4-diphenyl-6-ꢀ2phenylethyl)- 1,3,4-
oxazaphosphin-2-one ꢀ21d). White solid. Yield 64%. Mp
,8C): 152 ,decomposed). IR ,KBr), n ,cm21): 1649, 1291.
275.
7. Andujar-Sanchez, M. C.; Perez-Alvarez, I.; Lopez-Ortiz, F.
Tetrahedron Lett., submitted for publication.
Â
Â
Â
Â

Â
Â
J. M. Alvarez-Gutierrez et al. / Tetrahedron 57 .2001) 3075±3086
3086
8. ,a) Mastryukova, T. A.; Kabachnik, M. Y. Russ. Chem. Rev.
1983, 52, 1012. ,b) Grim, S. O.; Kettler, P. B. J. Chem. Soc.,
Chem. Commun. 1991, 979. ,c) Avis, M. V.; Vrieze, K.;
Kooijman, H.; Veldman, N.; Spek, A. L.; Elsevier, C. J.
Inorg. Chem. 1995, 34, 4093. ,d) Avis, M. V.; van der
Boom, M. E.; Elsevier, C. J.; Smeets, W. J. J.; Spek, A. L.
van der Boom. J. Organomet. Chem. 1997, 527, 263.
9. Tejerina, B.; PhD Thesis, Oviedo, 1999.
Figure 1. Selected long range 1H, 13C correlations observed in the
400.13 MHz gHMBC spectrum of 12a revealing key connectivities in the
heterocyclic ring and the methoxycarbonyl substituents.
10. ,a) Schmidbaur, H.; Jonas, G. Chem. Ber. 1967, 100, 1120.
,b) Barluenga, J.; Lopez, F.; Palacios, J. Chem. Res. 1985, 211.
,c) Roy, A. K.; Hani, R.; Neilson, R. H.; Wisian-Neilson, P.
Organometallics 1987, 6, 378. ,d) Johnson, A. W. Ylides and
Imines of Phosphorus; John Wiley: New York, 1993.
17. Quin, L. D. In Phosphorus-31 NMR Spectroscopy in Stereo-
chemical Analysis; Verkade, J. G., Quin, L. D., Eds.; VCH:
New York, 1987; pp 391.
Â
11. Alvarez-Gutierrez, J. M.; Lopez-Ortiz, F. Chem. Commun.
Â
Â
1996, 1583.
Â
12. Alvarez-Gutierrez, J. M.; Lopez-Ortiz, F.; Garcõa-Granda, S.;
18. ,a) Avarvari, N.; Le Floch, P.; Mathey, F. J. Am. Chem. Soc.
1996, 118, 11978. ,b) Oshovsky, G. V.; Pinchuk, A. M.;
Tolmachev, A. A. Mendeleev Commun. 1999, 161.
19. ,a) Foucaud, A.; Bedel, C. Tetrahedron Lett. 1991, 32, 2619.
,b) Bieger, K.; Tejeda, J.; Reau, R.; Dahan, F.; Bertrand, G.
J. Am. Chem. Soc. 1994, 116, 8087. ,c) Foucaud, A.; Bedel, C.
Tetrahedron 1995, 51, 9625. ,d) Avarvari, N.; Le Floch, P.;
Ricard, L.; Mathey, F. Organometallics 1997, 16, 4089.
,e) Yamamoto, H.; Kobayashi, T.; Nitta, M. Heterocycles
1998, 48, 1903.
Â
Â
Â
Â
Rodrõguez-Gonzalez, A. J. Chem. Soc., Perkin Trans. 1 2000,
Â
4469.
Â
13. Alvarez-Gutierrez, J. M.; Lopez-Ortiz, F. Tetrahedron. Lett.
Â
Â
1996, 37, 2841.
14. ,a) Staudinger, H.; Meyer, J. Helv. Chim. Acta 1919, 2, 635.
,b) Gololobov, Y. G.; Kasukhin, L. F. Tetrahedron 1992, 48,
1353.
15. ,a) Issleib, K.; Thomas, G. Chem. Ber. 1960, 93, 803.
,b) Aguiar, A. M.; Beisler, J.; Mills, A. J. Org. Chem. 1962,
27, 1001.
20. The use of dimethyl fumarate as electrophile also afforded 17a
although in lower yield compared to the reaction with the cis
isomer.
16. Structural elucidation of 12a: The molecular ion of the mass
spectrum matched the molecular weight of one molecule of
10b plus one molecule of DMAD with loss of methanol ,m/z
21. ,a) Buss, A. D.; Cruse, W. B.; Kennard, O.; Warren, S.
J. Chem. Soc., Perkin Trans. 1 1984, 1284. ,b) Barluenga,
1
397, M1 100%). Accordingly, the H spectrum showed only
Â
J.; Lopez-Ortiz, F.; Palacios, F. Synthesis 1988, 562.
two methoxy groups at d 3.53 and 3.90. The methyl protons of
the phosphazene appeared as a doublet ,3JPHˆ12.1 Hz) at d
1.71, a value consistent with a methyl group bonded to a sp2
carbon. The amide proton was assigned to the broad singlet at
22. Determined by integration of the inverse-gated proton
decoupled 31P NMR spectra of the crude reactions using a
pulse width of 158 and a relaxation delay of 10 s. Whenever
possible the diastereomericratio thus obtained was corrobo-
2
1
d 14.02 ,doublet of JPHˆ5.6 Hz in DMSO-d6). The most
rated with the integrals measured in the H spectra for well
relevant signals of the 13C spectrum were the nonaromatic
quaternary carbons. Particularly, the singlet at d 81.14 and
the doublets at 86.49 ,1JPCˆ105.6 Hz) and 149.46
,2JPCˆ20.7 Hz). The 31P, 13C couplings observed are charac-
teristics for nuclei separated by one and two bonds, respec-
tively.17 The spectrum showed also three carbonyl signals at d
168.49 ,2JPCˆ8.7 Hz), 170.41, and 171.39 ,3JPCˆ6.0 Hz). The
structure was ®nally established through the analysis of the 2D
HMBC spectrum. The methyl and NH proton correlations
allowed identi®cation of the connectivity of the six-membered
ring as indicated in Fig. 1. The assignment of the methoxy-
carbonyl groups was achieved by identifying in the 2D HMQC
spectrum, the direct connection between the respective proton
and carbon of each methoxy group and then the long range
correlation of the corresponding pair of proton and carbonyl
carbon.
resolved signals of each isomer.
23. The calculated dihedral angle HaCCHb ,MM, ChemWindow
6.0 Bio-Rad Laboratories, Sadtler 1998) for the minimal
energy conformations of compounds 19a±20a gave values
of 878 for 19a and 1808 for 20a, which implies that, respec-
tively, a vanishing small and a very large 3JH
vicinal
a
b
H
couplings should be observed in excellent agreement with
the values experimentally measured for both compounds.
24. Compound 22a has been previously synthesised by reaction of
the corresponding phosphine oxide and benzaldehyde in the
presence of nBuLi. Davidson, A. H.; Earnshaw, C.; Grayson, J.
I.; Warren, S. J. Chem. Soc., Perkin Trans. 1 1977, 1452. The
spectroscopic data of 22a match those previously reported.
25. Gilhenay, D. G.; Mitchell, C. M. In The Chemistry of
Organophosphorus Compounds; Hartley, F. R., Patai, S.,
Eds.; John Wiley: New York, 1992; vol. 1, pp 151.