Synthesis and properties of β-(N-acylamino)vinylphosphonium salts. A novel intramolecular [1,3] O-to-N migration of the vinyl group

Article abstract of DOI:10.1016/S0040-4039(01)01892-5

A reaction of β-carbonyl phosphorus ylides with imidoyl halides gives hitherto unknown β-(N-acylamino)vinylphosphonium salts. The key step of the reaction probably involves an intramolecular [1,3] O-to-N migration of the vinyl group, converting the primar

Full text of DOI:10.1016/S0040-4039(01)01892-5

TETRAHEDRON
LETTERS
Pergamon
Tetrahedron Letters 42 (2001) 8725–8727
Synthesis and properties of b-(N-acylamino)vinylphosphonium
salts. A novel intramolecular [1,3] O-to-N migration
of the vinyl group
Roman Mazurkiewicz,a,* Beata Fryczkowska,b Roman Luboradzki,c Andrzej Włochowiczb and
Wojciech Mo´la
aInstitute of Organic Chemistry and Technology, The Silesian University of Technology, Krzywoustego 4,
PL 44-100 Gliwice, Poland
bDepartment of Textile Engineering and Environmental Sciences, Technical University of Ło´dz´, Bielsko-Biała Campus,
Plac Fabryczny 5, PL 43-300 Bielsko-Biała, Poland
cInstitute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44, PL 01-224 Warsaw, Poland
Received 24 July 2001; revised 26 September 2001; accepted 5 October 2001
Abstract—A reaction of b-carbonyl phosphorus ylides with imidoyl halides gives hitherto unknown b-(N-
acylamino)vinylphosphonium salts. The key step of the reaction probably involves an intramolecular [1,3] O-to-N migration of the
vinyl group, converting the primary O-imidoylation product into a b-(N-acylamino)vinylphosphonium salt. © 2001 Elsevier
Science Ltd. All rights reserved.
In 1964 Schweizer1 realised that the addition of nucleo-
philes with a carbonyl function to vinylphosphonium
salts results in phosphorus ylides 2, which can undergo
the intramolecular Wittig reaction to carbo- or hetero-
cyclic systems (Scheme 1).
vinylphosphonium salts 7 as stable, crystalline com-
pounds, usually in good yields.3 The structures of the
b-(N-acylamino)vinylphosphonium salts were con-
firmed by their spectroscopic properties (IR, 1H and 13
C
NMR)4–6 and satisfactory elemental analyses,7 as well
as, in the case of the compound 7d, by a single crystal
X-ray structure determination,8 which revealed its Z-
configuration (Table 1).
For many years this idea has attracted significant atten-
tion of synthetic chemists; many carbo- and hetero-
cyclic systems have been synthesised in this way.2
It is obvious that the final reaction product 7 cannot be
formed in a simple, direct way from ylide 4 and imidoyl
halide 5. In order to explain our results we assume this
reaction to involve the O-imidoylated intermediate 6
and the [1,3] O-to-N sigmatropic migration of its vinyl
group. A similar type of [1,3] sigmatropic migration is
well-known in the literature;9 e.g. O-imidoylated car-
Recently, we have developed a method for the synthesis
of hitherto unknown b-(N-acylamino)vinylphos-
phonium salts 7 by imidoylation of b-carbonyl phos-
phorus ylides 4 with imidoyl halides 5 (Scheme 2).
Treatment of the ylide with an imidoyl halide in aceto-
nitrile at room temperature for 24 h results in
Scheme 1.
Keywords: b-(N-acylamino)vinylphosphonium salts; b-carbonyl ylides; imidoylation; imidoyl halides; rearrangement.
* Corresponding author. Tel.: +48/32/2371724; fax: +48/32/2371549; e-mail: romanm@zeus.polsl.gliwice.pl
0040-4039/01/$ - see front matter © 2001 Elsevier Science Ltd. All rights reserved.
PII: S0040-4039(01)01892-5

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R. Mazurkiewicz et al. / Tetrahedron Letters 42 (2001) 8725–8727
Scheme 2.
Table 1. Synthesis of b-(N-acylamino)vinylphosphonium salts 7
Ylide 4
Imidoyl halide 5
b-(N-Acylamino)vinylphosphonium salt 7
R1
R2
R3
R4
X
No.
Yield (%)
Mp (°C)
H
H
H
H
H
H
H
Me
H
H
H
Me
Me
Me
Me
H
Me
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Me
PhCH2
Me
Me
Ph
PhCH2
Me
I
7a
7b
7c
7d
7e
7f
91
71
64
66
85
72
87
99
133–134
238–239
273–275
140–141
182–183
192–193
175–177
Resin
Cl
Cl
Cl
I
Cl
Cl
Cl
7g
7h
boxamides undergo a similar rearrangement.10 An
analogous rearrangement also probably takes place in
the case of well-known acylations of b-carbonyl ylides;
however, being a degenerate rearrangement, it cannot
be directly observed.
J
J
H–H=14.7 Hz, CH), 6.92 (dd, 1H, JP–H=17.0 Hz,
H–H=14.9 Hz, CH), 2.05 (s, 3H, Me); 7b: 7.8–7.2 (m,
22H, Ph and CH), 3.78 (s, 3H, Me); 7c: 7.82–7.26 (m,
25H, Ph), 7.05 (dd, 1H, JP–H=14.1 Hz, JH–H=15.0 Hz,
CH), 6.84 (dd, 1H, JP–H=17.4 Hz, JH–H=15.3 Hz, CH),
5.87 (s, 2H, CH2); 7d: 7.90–7.18 (m, 18H, Ph), 6.98 (d,
1H, JP–H=16.5 Hz, CH), 6.77 (d, 2H, J=7.2 Hz, o-Ph),
2.98 (s, 3H, Me), 2.75 (s, 3H, Me); 7e: (in DMSO-d6):
7.87–7.67 (m, 15H, Ph3P), 7.45–7.38 (m, 1H, Ph), 7.32–
7.25 (m, 2H, Ph), 6.93 (d, 1H, JP–H=16.2 Hz, CH),
6.90–6.85 (m, 2H, Ph), 2.84 (s, 3H, Me), 2.56 (s, 3H, Me);
7f: 7.9–6.5 (m, 26H, Ph and CH), 2.45 (s, 3H, Me); 7g:
7.85–7.22 (m, 25H, Ph), 6.25 (d, 1H, CH, JP–H=14.4 Hz),
5.52 (s, 2H, CH2), 1.66 (s, 3H, CH3); 7h: 7.88–7.18 (m,
20H, Ph), 6.91 (d, 1H, JP–H=20.4 Hz, CH), 3.75 (s, 3H,
NMe), 2.42 (d, 3H, JP–H=15.6 Hz, CMe).
The phosphonium salts 7 can be considered to be
prospective precursors for the synthesis of amino
derivatives of carbo- and heterocyclic systems (see
Scheme 1), synthesis of N-acylynamines (by b-elimina-
tion of Ph3P and HX if R2=H) or N-vinylamides (by
hydro-de-phosphonation of phosphonium salts 7).
References
6. 13C NMR spectra of 7a–h (75 MHz, CDCl3, l (ppm)/JC–P
(Hz)): 7a: 176.6 (CꢀO); 86.1/99.5 (Ca), 151.1/17.6 (Cb);
119.2/91.1, 133.7/10.7, 130.2/13.1, 134.5/3.0 (Ph3P, C-1,
C-2, C-3, C-4); 135.6, 122.5, 128.7, 125.2 (Ph, C-1, C-2,
C-3, C-4); 25.5 (Me); 7b: 170.9 (CꢀO); 83.5/100.5 (Ca),
150.8/17.8 (Cb); 119.4/91.4, 133.8/10.6, 130.2/12.9, 134.7/
3.0 (Ph3P, C-1, C-2, C-3, C-4); 132.8, 128.6, 127.8, 131.3
(Ph, C-1, C-2, C-3, C-4); 34.5 (Me); 7c: 171.6 (CꢀO);
85.1/100.5, (Ca) 149.7/17.8, (Cb) 119.1/91.8, 133.8/11.0,
130.2/12.9, 134.7/3.0 (Ph3P, C-1, C-2, C-3, C-4); 136.2,
133.0, 131.5, 128.9, 128.8, 128.6, 128.1, 127.5 (PhCO+
PhCH2); 47.9 (CH2); 7d: 170.4 (CꢀO); 99.4/97.6, (Ca)
161.6/8.6, (Cb) 120.6/92.5, 133.8/10.3, 130.0/12.8, 134.3/
3.1 (Ph3P, C-1, C-2, C-3, C-4); 133.2, 128.4, 127.0, 131.0
(Ph, C-1, C-2, C-3, C-4); 37.8 (NMe); 26.1/15.4 (CMe);
7e: (in DMSO-d6): 169.2 (CꢀO); 98.2/94.9, (Ca) 160.9/8.0,
(Cb) 120.6/92.5, 133.5/10.7, 129.7/12.8, 134.1/3.0 (Ph3P,
C-1, C-2, C-3, C-4); 133.3, 128.0, 127.1, 130.7 (Ph, C-1,
C-2, C-3, C-4); 36.7 (NMe); 24.8/15.5 (CMe); 7f: 170.3
(CꢀO); 98.2/94.4, (Ca) 161.0/5.2, (Cb) 120.1.1/91.8, 134.1/
10.3, 130.0/13.0, 134.0/3.0 (Ph3P, C-1, C-2, C-3, C-4);
133.0, 127.8, 127.3, 130.8 (Ph, C-1, C-2, C-3, C-4); 27.4/
15.5 (CMe); 7g: 172.1 (CꢀO); 98.8/95.9, (Ca) 164.4/10.6,
(Cb) 119.0/90.6, 133.2/10.9, 130.6/13.3, 135.1/3.1 (Ph3P,
1. (a) Schweizer, E. E. J. Am. Chem. Soc. 1964, 86, 2744; (b)
Schweizer, E. E.; Light, K. K. J. Am. Chem. Soc. 1964,
86, 2963; (c) Schweizer, E. E.; Berninger, C. J. J. Chem.
Soc., Chem. Commun. 1965, 92–93; (d) Schweizer, E. E.;
O’Neill, G. J. J. Org. Chem. 1965, 30, 2082–2083.
2. (a) Zbiral, E. In Organophosphorus Reagents in Organic
Synthesis; Cadogan, J. I. G., Ed.; London, 1979; pp.
250–266; (b) Johnson, A. W.; Kaska, W. C.; Ostoja
Starzewski, K. A.; Dixon, D. A.; Ylides and Imines of
Phosphorus; John Wiley & Sons: New York, 1993; pp.
112–114; (c) Burley, I.; Newson, A. T. Tetrahedron Lett.
1994, 35, 7099–7102.
3. General procedure: To a solution of imidoyl halide 5 (2.4
mmol) in MeCN (3.6 cm3) ylide 4 (2 mmol) was added,
and the mixture was left at room temperature for 24 h.
The phosphonium salt was precipitated from the reaction
mixture with Et2O (5–8 cm3). The product can be purified
further, if necessary, by column chromatography on silica
gel eluting with a mixture of CH2Cl2 and MeOH (97:3,
v/v).
4. The most characteristic amide carbonyl frequency falls in
the range 1690–1660 cm−1
.
5. 1H NMR spectral data of 7a–h (300 MHz, CDCl3, l): 7a:
7.75–7.21 (m, 20H, Ph), 7.10 (dd, 1H, JP–H=13.8 Hz,

R. Mazurkiewicz et al. / Tetrahedron Letters 42 (2001) 8725–8727
8727
C-1, C-2, C-3, C-4); 136.8, 135.7, 131.9, 129.00, 128.98,
128.6, 128.5, 127.8 (PhCO+PhCH2); 52.3 (CH2); 24.3/5.3
(Me); 7h: 171.8 (CꢀO); 95.0/91.9 (Ca), 149.5/25.8 (Cb);
117.5/89.3, 133.7/10.2, 130.5/12.6, 135.1/2.6 (Ph3P, C-1,
C-2, C-3, C-4); 132.0, 128.7, 127.9, 131.1 (Ph, C-1, C-2,
C-3, C-4); 36.0 (NMe), 16.6/8.3 (CMe).
76.47/76.21, 5.47/5.22, 2.62/2.32, 5.80/5.61; 7g:
C35H31ClNOP: 76.70/76.48, 5.70/5.91, 2.56/2.62, 5.65/
5.48; 7h: C29H27ClNOP: 73.80/73.51, 5.77/6.01, 2.97/3.04,
6.56/6.36.
8. Crystallographic data (excluding structure factors) for the
structure 7d have been deposited with the Cambridge
Crystallographic Data Centre as supplementary publica-
tion number CCDC 166899.
9. Curtin, D. Y.; Miller, L. L. J. Am. Chem. Soc. 1967, 89,
637–645.
10. (a) Hitzler, M. G.; Lutz, M.; Shrestha-Dawadi, P. B.;
Jochims, J. C. Liebigs Ann. 1996, 247–257; (b)
Mazurkiewicz, R. Acta Chim. Hung. 1990, 127, 439–450.
7. Elemental analyses for 7a–h (formula: C, H, N, P–calcd/
found): 7a: C28H25INOP: 61.21/61.12, 4.59/4.66, 2.55/
2.41, 5.64/5.77; 7b: C28H25ClNOP: 73.44/73.51, 5.50/5.74,
3.06/3.00, 6.76/6.63; 7c: C34H29ClNOP: 76.47/76.70, 5.47/
5.30, 2.62/2.78, 5.80/6.00; 7d: C29H27ClNOP: 73.80/73.54,
5.77/5.92, 2.97/2.91, 6.56/6.42; 7e: C29H27INOP: 61.71/
62.09, 4.83/4.59, 2.49/2.74, 5.50/5.42; 7f: C34H29ClNOP: