Yield: 81%. 1H NMR: d 1.87 (s, 12H, Me), 2.36 (s, 6H, Me), 3.82
(s, 3H, OMe), 3.96 (d, 4H, NCH2, 3JPH = 9.2), 6.26 (d, 2H, NCH,
1
128.6 (d, 2JPC = 13.8), 130.8, 137.8 (d, 3JPC = 7.6). 31P{ H} NMR:
d 86.0 (s). 19F{ H} NMR: d −82.5 (s). LRMS for C20H24N2P+ m/z
1
3JPH = 23.1), 6.57 (d, 4H, Ar, 3JHH = 8.8), 6.85 (d, 4H, Ar, 3JHH
=
=
(ESI) 323.2 (M+, 100%), 324.2 (30), 382.7 (48), 241.1 (28). Calcd
for C21H24F3N2O3PS: C 53.4; H 5.1; N 5.9; found C 53.0; H 4.9; N
5.8%.
1
8.8), 6.95 (s, 4H, Ar).13C{ H} NMR: d 19.8, 21.4, 48.1 (d, 2JPC
15.2), 55.8, 115.3, 116.7 (d, 2JPC = 19.1), 124.8, 129.6, 130.9, 131.3,
1
1
136.8, 139.9, 158.4. 31P{ H} NMR: d 17.9 (s). 19F{ H} NMR: d
−78.8 (s). LRMS for C36H42N4O2P+ m/z (ESI) 593.2 (M+, 100%),
594.3 (30). Calcd for C37H42F3N4O3PS: C 59.8; H 5.7; N 7.5; found
C 59.3; H 5.5; N 7.1%.
1,4-Bis(4-methoxyphenyl)-7,8-dimethyl-1,4-diaza-5-phopshoni-
aspiro[4.4]non-7-ene trifluoromethanesulfonate salt (6b). Yield:
1
4
76%. H NMR: d 1.59 (d, 6H, CH3, JHH = 1.2), 2.98 (dd, 4H,
PCH2, 4JHH = 1.2, 2JPH = 12.0), 3.80 (s, 6H, OCH3), 4.04 (d, 4H,
3
1
NCH2, JPH = 7.6), 6.93 (m, 4H, Ar), 7.33 (m, 4H, Ar). 13C{ H}
1,4,6,9-Tetramesityl-1,4,6,9-tetraaza-5-phosphoniaspiro[4.4]-
non-2-ene trifluoromethanesulfonate salt (7d). Yield: 85%. 1H
NMR (258 K): d 1.44 (s, 6H, Me), 1.69 (s, 6H, Me), 2.19 (s, 6H,
Me), 2.22 (s, 6H, Me), 2.37 (s, 6H, Me), 2.52 (s, 6H, Me), 3.52 (dd,
NMR: d 16.2 (d, 2JPC = 15.3), 32.6 (d, 1JPC = 67.5), 51.0 (d, 3JPC
=
2
9.2), 55.8, 115.9, 124.1, 126.9, 127.9 (d, JPC = 12.3), 129.5 (d,
3JPC = 6.1), 159.2. 31P{ H} NMR: d 84.0 (s). 19F{ H} NMR: d
−82.4 (s). LRMS for C22H28N2P+ m/z (ESI) 383.1 (M+, 100%),
384.1 (32), 465.2 (7).
1
1
2H, NCH2, 3JPH = 21.6, 3JHH = 6.2), 4.18 (d, 2H, NCH2, 3JHH
=
6.2), 5.96 (d, 2H, NCH, 3JPH = 22.8), 6.56 (s, 2H, Ar), 6.58 (s, 2H,
1
1,4-Bis(2,6-diisopropylphenyl)-7,8-dimethyl-1,4-diaza-5-phops-
honiaspiro[4.4]non-7-ene trifluoromethanesulfonate salt (6c). In
this case, product 6c could not be separated from starting
phosphenium 1c. Yield: 30% (by 1H NMR spectroscopy). 1H
Ar), 6.78 (s, 2H, Ar), 6.85 (s, 2H, Ar). 13C{ H} NMR (258 K): d
18.5, 19.2, 19.5, 20.8, 22.3, 51.6 (d, 2JPC = 16.0), 118.7 (d, 2JPC
=
18.4), 129.1, 130.0, 130.8, 133.6, 133.9, 135.5, 136.1, 137.1, 137.3,
1
1
138.3, 138.8. 31P{ H} NMR: d 21.4 (s). 19F{ H} NMR: d −81.9
(s). HRMS: C40H50N4P+ calcd (found) 617.3768 (617.3768). Calcd
for C41H50F3N4O3PS: C 64.2; H 6.6; N 7.3; found C 64.7; H 6.8; N
7.3%.
3
NMR: d 1.29 (d, 3H, CHCH3, JHH = 6.8), 1.31 (d, 3H, CH3,
3JHH = 6.8), 1.50 (d, 6H, CH3, 4JHH = 1.2), 2.77 (dd, 4H, PCH2,
4JHH = 1.2, 2JPH = 10.8), 3.15 (spt, 4H, CHCH3, 3JHH = 6.8), 3.93
(d, 4H, NCH2, JPH = 7.2), 7.24 (m, 6H, Ar). 31P{ H} NMR: d
3
1
1
80.6 (s). 19F{ H} NMR: d −74.7 (s).
Crystallography†
1,4-Dimesityl-7,8-dimethyl-1,4-diaza-5-phopshoniaspiro[4.4]-
non-7-ene trifluoromethanesulfonate salt (6d). Yield: 53%. 1H
NMR: d 1.51 (d, 6H, CH3, 4JHH = 0.8), 2.29 (s, 6H, p-ArCH3), 2.38
(s, 12H, o-ArCH3), 2.79 (dd, 4H, PCH2, 4JHH = 0.8, 2JPH = 10.8),
Crystals of 3b were grown from concentrated CHCl3 solution as
colourless plates. Data were collected at low temperature (−80 ◦C)
˚
at a wavelength of 0.71073 A on a Bruker PLATFORM/SMART
1000 CCD area detector diffractometer. Unit cell parameters were
calculated and refined from the full data sets using full-matrix
least-squares on F2. Programs for diffractometer operation, data
collection, data reduction and absorption correction were those
supplied by Bruker. The SHELXL-97 suite of programs38 was
used to solve the structure by direct methods.
1
3.96 (d, 4H, NCH2, 3JPH = 6.8), 6.94 (s, 4H, Ar). 13C{ H} NMR:
d 16.0 (d, 3JPC = 13.8), 18.2, 18.9, 20.9, 30.9 (d, 1JPC = 68.3), 49.8
(d, 2JPC = 10.8), 127.0 (d, 2JPC = 11.6), 129.7, 130.0, 130.4, 136.7,
1
1
137.2, 137.7, 139.4. 31P{ H} NMR: d 79.9 (s). 19F{ H} NMR:
d −78.3 (s). LRMS for C26H36N2P+ m/z (ESI) 407.1 (M+, 100%),
408.2 (60). Calcd for C27H36F3N2O3PS: C 58.3; H 6.5; N 5.0; found
C 58.2; H 6.4; N 5.4%.
Crystals of 1a and 4·3 CHCl3 were grown as pale yellow plates
and colourless blocks, respectively, from concentrated CHCl3
solution, while those of 5 were grown from concentrated CH2Cl2
solution as colourless plates. The crystals were cut and mounted
on glass fibres. Data were collected at low temperature (−123 ◦C)
General procedure for the synthesis of tetraazaphospholenium
trifluoromethane sulfonate salts 7a–d. To a solution of the
appropriate phosphenium triflate salt (1a–d, 0.34 mmol) in dry
CH2Cl2 (5 mL) was added dropwise a solution of N,Nꢀ-dimesityl-
1,4-diaza-1,3-butadiene (0.41 mmol) in dry CH2Cl2 (5 mL). The
resultant solution was stirred for 10 min at r.t. The reaction
˚
at a wavelength of 0.71073 A on a Nonius Kappa-CCD area
detector diffractometer running COLLECT software (Nonius
B.V., 1997–2002). Unit cell parameters were calculated and refined
from the full data sets using full-matrix least-squares on F2.
Crystal cell refinement and data reduction were carried out using
HKL2000 DENZO-SMN (Otwinowski & Minor, 1997), and ab-
sorption corrections were applied using HKL2000 DENZO-SMN
(SCALEPACK). In all cases, the reflection data and systematic
absences were consistent with the monoclinic space group #14.
The SHELXTL/PC V6.14 for Windows NT (Sheldrick, G.M.,
2001) suite of programs was used to solve the structures by direct
methods. Subsequent difference Fourier syntheses allowed the
remaining atoms to be located.
was monitored by 13P{ H} NMR spectroscopy in non-deuterated
1
solvent. Solvent was removed in vacuo and the residue washed with
Et2O (2 × 2 mL).
1,4-Dimesityl-6,9-diphenyl-1,4,6,9-tetraaza-5-phosphoniaspiro-
[4.4]non-2-ene trifluoromethanesulfonate salt (7a). Yield: 98%.
1H NMR: d 1.82 (s, 12H, Me), 2.34 (s, 6H, Me), 4.03 (d, 4H,
3
3
NCH2 JPH = 9.2), 6.29 (d, 2H, NCH, JPH = 23.6), 6.65 (d,
4H, Ar, JPH = 8.0), 6.93 (s, 4H, Ar) 7.30 (m, 6H, Ar).13C{ H}
4
1
2
2
NMR: d 19.7, 21.0, 48.0 (d, JPC = 15.1), 116.7 (d, JPC = 18.9),
3
3
123.6 (d, JPC = 4.5), 127.2, 130.2, 130.8 (d, JPC = 2.3), 131.3,
136.7 (d, 3JPC = 2.8), 136.9 (d, 2JPC = 6.2), 139.9 (d, 3JPC = 1.5).
Data collection and refinement parameters for 1a, 3b, 4·3CHCl3,
31P{ H} NMR: d 18.5 (s). 19F{ H} NMR: d −78.7 (s). LRMS for
C34H38N4P+ m/z (ESI) 533.1 (M+, 100%), 534.2 (38), 323.1 (15).
Calcd for C35H38F3N4O3PS: C 61.5; H 5.6; N 8.2; found C 61.4; H
5.3; N 7.9%.
and 5 are collected in Table 3.
1
1
Conclusions
1,4-Dimesityl-6,9-di(4-methoxyphenyl)-1,4,6,9-tetraaza-5-pho-
sphoniaspiro[4.4]non-2-ene trifluoromethanesulfonate salt (7b).
The use of LiAlH4 instead of NaBH4 in diimine reductions
and NMM instead of Et3N in dehydrohalogenation reactions
This journal is
The Royal Society of Chemistry 2008
Dalton Trans., 2008, 3461–3469 | 3467
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