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T. Lebbe et al. / Tetrahedron 56 (2000) 157–164
resonances and proves the structure given above for the
Exhaustive oxidation of 2a. Preparation of 5
macrocyclic secondary tertiary phosphine 8. In the mass
spectrum of
8
intense peaks for MϩϪH371,
To a solution of 3.00 g (4.94 mmol) of 2a (isomer I) in
100 mL of H2O excess bromine (12.0 g; 75.1 mmol) was
added dropwise and the reaction mixture was stirred for
4 h at ambient temperature. After evaporation of all
volatiles, 0.1N KOH was added until the reaction mixture
showed a pH value of 8–9. The nickel(II) hydroxide formed
was filtered off and the filtrate evaporated to dryness in
vacuo. The solid residue was extracted twice with 40 mL
of ethanol. After addition of 1 mL of conc. HCl the solvent
was removed in vacuo. The solid obtained was extracted
with a mixture of 10 mL of isopropanol and 60 mL of
CH2Cl2. Removal of the solvents from the extract under
reduced pressure gave a colorless powder which was dried
in vacuo (20ЊC, 10Ϫ3 mbar). Yield: 2.34 g (90%).
According to the elemental analysis, the product contained,
in addition to water, appreciable amounts of chlorine and
bromine, obviously bound to 5 as HCl and HBr which could
not be removed even on prolonged heating in vacuo at 80ЊC.
The contents of HCl and HBr were determined by titration
with 0.1N KOH. The composition of the product calculated
on the basis of the elemental analysis and the results of the
titration may be given as C18H32O5P4·1.2HCl·0.15HBr·H2O
(Mr526.3): C, 41.08; H, 6.77; Br, 2.28; Cl 8.08. Found: C,
41.26; H, 6.61; Br, 2.05; Cl, 8.19.
MϩϪCH3357 and MϩϪC2H4344 m/e are observed.
Vapor phase osmometry gave an apparent molecular weight
of 376 in CH2Cl2 (theoretical 372).
Only a very few examples for PH functional macrocyclic
phosphines and their Mo(CO)3 complexes have been
reported in the literature so far.23 Kyba and Liu23a obtained
the 11 membered ditertiary secondary phosphine F in a
multistage high dilution macrocyclization of (o-
PhPLi)2C6H4 with bis(3-chloropropyl)(1-naphthylmethyl)-
phosphine sulfide in a low total yield of ca. 15%. The
1-naphthylmethyl PH protecting group was removed by
treatment with excess potassium naphthalenide. Trisecond-
ary 1,5,9-triphosphacyclododecane has been obtained by
Edwards et al.23c using template mediated cyclization
reactions similar to those reported by Norman et al.23b
Experimental
Apparatus and materials
All manipulations were carried out by using standard
vacuum line and inert atmosphere techniques. The
complexes 1, 2a–2c were prepared as reported earlier by
us.1,2 The 31P, 19F and 13C NMR spectra were obtained by
using JEOL FX 90Q and Bruker AC 250 and AC 400
Preparation of 4
0.46 g (0.87 mmol) of the product obtained above were
dissolved in 30 mL of water and the solution was neutra-
lized with 0.1N KOH. The solvent was removed in vacuo
and the residue extracted with a mixture of 20 mL of CH2Cl2
and 2 mL of isopropanol. After filtration the extract was
evaporated in vacuo to dryness yielding a colorless powder
which was dried in vacuo. Yield: 0.41 g (93%). According
to the elemental analyses, the product contained small quan-
tities of potassium chloride and bromide. Anal. Calcd. for
C18H31KO5P4·H2O (Mr508.4): C, 42.52; H, 6.54. Found:
C, 42.18; H, 6.76.
1
spectrometers equipped with standard H, 19F, 31P and 13C
probe accessories. 31P (relative to external 85% H3PO4), 19F
1
(relative to internal CCl3F) and 13C, H (relative to internal
Me4Si) chemical shifts downfield from the standard are
given positive values. Mass spectra were determined on a
Varian MAT 311a instrument at 70 eV.
Partial oxidation of 2c
A slow stream of air was bubbled through a capillary into a
solution of 1.00 g (2.08 mmol) of 2c (isomer I) in 50 mL of
water at reflux temperature for 7 d. The reaction mixture
was concentrated in vacuo (20ЊC, 10Ϫ3 mbar) to 10 mL
and washed twice with 50 mL of CH2Cl2. The aqueous
phase was separated, the solvent stripped off under reduced
pressure and the remaining residue was extracted twice with
50 mL of CH2Cl2. The extracts were concentrated under
reduced pressure to 15 mL. The precipitate formed on addi-
tion of methyl(tert-butyl)ether was collected by filtration
and dried in vacuo (20ЊC, 10Ϫ3 mbar). Yield: 0.34 g
(33%) 3. Anal. Calcd. for C18H31ClNiO2P4 (Mr497.5): C,
43.46; H, 6.28; Cl, 7.13. Found: C, 43.04; H, 6.38; Cl, 7.10.
Preparation of 6
To a solution of 3.6 g (5.93 mmol) of 2a (isomer I) in a
mixture of H2O (10 mL) and conc. HCl (10 mL) excess
hydrogen peroxide (10 mL, 30%) was added dropwise.
The temperature of the reaction mixture increased and
bromine was evolved. Upon addition of further conc. HCl
(10 mL) and H2O2 (1 mL) the green colored solution was
heated for 3 h at 70ЊC. All volatiles were then stripped off
under reduced pressure and the solid obtained was dissolved
in 50 mL of water. Potassium hydroxide (0.1N aqueous
solution) was added until the solution showed a pH value
of about 8. The Ni(OH)2 precipitated was filtered off and the
solvent was removed under reduced pressure (20ЊC,
10Ϫ3 mbar). The solid was extracted twice with 30 mL of
EtOH. After acidifying the extracts with HCl the solvent
was removed in vacuo. The residue obtained was dissolved
in a mixture of 30 mL of MeOH and 10 mL of trimethyl
orthoformate HC(OMe)3 and the solution was heated at
reflux for 18 h. All volatiles were stripped off in vacuo
and the residue was extracted twice with 20 mL of
CH2Cl2. Upon addition of 100 mL of petrolether 40/60 to
On slow evaporation of a CH2Cl2 solution of 3, yellow
crystals of composition 3·H2O were obtained which were
used for the X-ray structural analysis. 13C{1H} NMR (D2O):
d133.8 (d, J10.1 Hz), 133.7 (d, J2.0 Hz), 130.4 (d,
J10.2 Hz), 127.6 (d, J48.7 Hz), 24.3 (d, J88.1 Hz,
broad), 24.2 (dt, J34.0, 5.1 Hz), 22.9 (dt, J4.7,
16.2 Hz), 21.0 (dt, JϷ5, 15 Hz), 17.1 (s, broad), 7.6 (t,
J14.1 Hz).
Lebbe, Thomas
