150
A.M. Winter et al. / Journal of Organometallic Chemistry 682 (2003) 149ꢀ154
/
2. Experimental
(500.12 MHz, CD2Cl2): d 6.78 (m, 4H, PPhPh? H6), 7.01
(m, 4H, PPhPh? H5), 7.13 (t, 3JHH
7.7 Hz, 2H, PPhPh?
H7), 7.36 (m, 4H, PPhPh? H6), 7.46 (t, JHH
ꢂ
/
3
2.1. General remarks, materials, and instrumentation
ꢂ7.7 Hz,
/
2H, PPhPh? H7), 7.50 (m, 2H, H3), 7.58 (m, 2H, H4),
7.72 (m, 2H, H2), 7.93 (m, 4H, PPhPh? H5), 8.04 (m, 2H,
Reactions were performed under Ar using standard
Schlenk techniques according to previously described
procedures [14,15] unless otherwise specified.
H1), 8.30 (s, br, 1H, NH). 31P{1H}-NMR (121.4 MHz,
1
CD2Cl2): d 37.1 (d, JRhP
ꢂ115.8 Hz). MS (DCI): m/z
/
Benzene, hexane and etheral solvents were distilled
from benzophenone ketyl, CH2Cl2 from LiAlH4,
MeOH, EtOH and toluene from sodium. Deuterated
solvents were degassed and distilled from LiAlD4.
[(COE)2RhCl]2 was prepared according to the procedure
of Van der Ent and Onderdelinden [16]. 2,2?-Dibromo-
diphenylamine was prepared according to the procedure
described by Jones and Mann [17]. Note! We found that
674 (RhCl{HN[(o-PPh2)C6H4]2}ꢁ), Calc. 674.91; m/z
639 (Rh{HN[(o-PPh2)C6H4]2}ꢁ), Calc. 639.48. UVꢀ
vis
/
(CH2Cl2): o236
1530.
ꢂ
/
2.70ꢄ
/
104, o270
ꢂ
/
2.51ꢄ
/
104, o394
ꢂ
/
2.4. Synthesis of Rh(H)(Cl)(THF){N[(o-
PPh2)C6H4]2} (1b)
a temperature of 255ꢀ
Chapman rearrangement to occur.
/
265 8C was necessary for the
A suspension of 86 mg (0.02 mmol) [(COE)2RhCl]2
and 138 mg (0.26 mmol) 2,2?-bis(diphenylphosphino)di-
phenylamine (1) in 25 ml THF was stirred at r.t. for 3.5
h and refluxed for 4 h. After vacuum removal of the
solvent and dissolution in 3 ml toluene the product
precipitates as a yellow solid. Yield: 44 mg (24.7%).
Anal. Calc. for C40H37ClNOP2Rh: C, 64.28; H, 4.99; N,
2.2. Synthesis of 2,2?-
bis(diphenylphosphino)diphenylamine HN[(o-
PPh2)C6H4]2 (1)
Under a nitrogen atmosphere 58 ml (97.44 mmol) of
n-butyl lithium (1.68 M in hexane) was added dropwise
to 9.9 g (30.09 mmol) of 2,2?-dibromodiphenylamine in
50 ml Et2O at 0 8C. The reaction mixture was allowed to
stir for 1.5 h. 17.5 ml (97.48 mmol) diphenylchlorophos-
phine in 50 ml Et2O were added dropwise at 0 8C and
the solution was stirred at room temperature (r.t.)
overnight. The reaction mixture was then hydrolyzed
with 30 ml of concentrated hydrochloric acid, the
solution washed with water, and the product precipi-
tated with EtOH. The colorless 2,2?-bis(diphenylphos-
phino)diphenylamine (1) can be purified by recrystalli-
zation from CH2Cl2 and EtOH. Yield: 7.8 g (48.3%).
1.87. Found: C, 64.07; H, 5.10; N, 1.81%. 1H-NMR
1
21.77 (dt, JRhH
11.4 Hz, 1H, Rh-H), 1.64 (m, br, 4H,
(500.12 MHz, CD2Cl2): d ꢃ
/
ꢂ29.5 Hz,
/
2JPH
ꢂ
/
CH2CH2O), 3.52 (m, br, 4H, CH2CH2O), 6.61 (m, 2H,
H3), 7.06 (m, 2H, H2), 7.46 (m, 14H, H4, H6, H7), 7.64
(m, 4H, H5), 7.69 (m, 2H, H1), 7.94 (m, 4H, H5).
31P{1H}-NMR (121.4 MHz, CD2Cl2): d 35.1 (d,
1JRhP
ꢂ
108.8 Hz). 13C{1H}-NMR (125.76 MHz,
/
CD2Cl2): d 25.8 (s, CH2CH2O), 68.4 (s, CH2CH2O),
118.0 (m), 118.1 (s), 128.9 (m), 129.1 (m), 130.5 (s), 131.1
(s), 131.4 (s), 133.6 (m), 134.7 (m), 135.4 (s). MS (DCI):
m/z 674 [Mꢃ
/
{Hꢁ
THF}ꢁ], Calc. 674.89; m/z 639
/
(Rh{N[(o-PPh2)C6H4]2}ꢁ), Calc. 639.48.
m.p. 200ꢀ
/
201 8C. Anal. Calc. for C36H29NP2: C, 80.44;
H, 5.44; N, 2.61. Found: C, 80.29; H, 5.53; N, 2.62%.
2.5. Synthesis of Rh(CO){N[(o-PPh2)C6H4]2} (1c)
2
1H-NMR (500.12 MHz, C6D6): d 6.67 (dd, JHH
Hz, 7.5 Hz, 2H, H3), 7.00 (m, 16H, H1, H2, H4, H6), 7.31
ꢂ7.5
/
2.5.1. Method A
(m, 11H, NH, H5, H7). 31P{1H}-NMR (202.47 MHz,
40 mg (0.05 mmol) of Rh2Cl4{HN[(o-PPh2)C6H4]2}
(1a) were added to sodium amalgam prepared from 25
ml (1.69 mmol) mercury and 5 mg (0.23 mmol) sodium.
20 ml of THF were added and the flask was flushed with
carbon monoxide. The reaction mixture was stirred
vigorously for 18 h at r.t. The solid was allowed to
settle and the solution was filtered in air. The air stable
yellow product is obtained by removal of the solvent in
C6D6): d ꢃ
19.2 (s). IR (KBr pellet): 3340 cmꢃ1 (nNꢀH).
/
MS (DCI): m/z 538 (Mꢁ), Calc. 537.58. m/z 532 [Mꢃ
/
PPh2ꢁ], Calc. 351.39.
2.3. Synthesis of Rh2Cl4{HN[(o-PPh2)C6H4]2} (1a)
A solution of 198 mg (0.83 mmol) RhCl3 hydrate
(42.9% Rh) and 481 mg (0.89 mmol) 2,2?-bis(diphenyl-
phosphino)diphenylamine (1) in 50 ml MeOH was
refluxed under a nitrogen atmosphere for 18 h. A yellow
precipitate forms which can be isolated by filtration,
washing with hexane, and recrystallization from
vacuo, and recrystallized from CH2Cl2ꢀhexane. Yield:
/
18 mg (60%).
2.5.2. Method B
25 mg (0.03 mmol) Rh(COE){N[(o-PPh2)C6H4]2} (1d)
were dissolved in 30 ml benzene and left under one
atmosphere of carbon monoxide for several hours at r.t.
Rh(CO){N[(o-PPh2)C6H4]2}) (1c) precipitated as a yel-
low powder. Yield: 100% (based on 31P{1H}-NMR).
CH2Cl2ꢀhexane. The crystals formed quickly turn to a
/
powder when removed from the mother liquor. Yield:
316 mg (84.7%). Anal. Calc. for C36H29Cl4NP2Rh2: C,
1
48.82; H, 3.30. Found: C, 48.83; H 3.23%. H-NMR