Inorganic Chemistry
Article
[
In(C H ) ][CHB Cl ] (1). A Schlenk flask was charged with
(s, CHB , 1H), 2.40 (sept, J = 6.8 Hz, CH(CH ) , 4H), 1.34 (d, J =
7
8 3
11 11
11
3 2
Ag[CHB Cl ] (0.78 g, 1.20 mmol), indium metal (0.28 g, 2.40
6.8 Hz, CH(CH ) , 12H), 1.24 (d, J = 6.8 Hz, CH(CH ) , 12H). This
11
11
3
2
3
2
mmol), and toluene (50 mL). The suspension was stirred at 80 °C for
2
4 h. Upon cooling to room temperature, light-brown needle-shaped
crystals formed. The crystals were isolated and dried under vacuum.
[IPr·H] [CB Cl ] (5). A solution of IPr (0.09 g, 0.22 mmol) in
2
11 11
1
Yield: 0.73 g, 64%. H NMR (400.13 MHz, C D Br): δ 7.13 (t, J = 7.3
fluorobenzene (10 mL) was added to a solution of 1 (0.10 g, 0.11
mmol) in fluorobenzene (10 mL) at room temperature. A small
amount of a black precipitate formed and was separated by filtration
through a medium-porosity sintered-glass frit. The solution was
concentrated to ca. 10 mL under vacuum, and subsequent cooling at
6
5
Hz, m-H(tol), 2H), 7.06 (d, J = 7.2 Hz, p-H(tol), 1H), 7.01 (d,
partially obscured by C D Br, o-H(tol), 2H), 2.75 (s, CHB Cl , 1H),
6
5
11 11
1
3
1
2
.16 (s, CH (tol), 3H). C{ H} NMR (100.61 MHz, C D Br): δ
3
6
5
1
38.11 (i-C), 129.51 (o-C), 128.67 (m-C), 125.89 (p-C), 47.98 (br,
11
1
CHB Cl ), 21.61 (o-CH ). B NMR (128.38 MHz, C D Br): δ −2.1
−20 °C for 7 days afforded yellowish crystals of 5. H NMR (400.13
11
11
3
6
5
(
s, 1B), −9.4 (s, 5B), −12.2 (s, 5B). Crystals of 1 slowly lose toluene
MHz, C D Br): δ 7.10 (m), 6.88 (m), 2.51 (m, br, CH(CH ) , 4 H),
6
5
3 2
13
1
1.10 (t, J = 7.7 Hz, CH(CH ) , 24 H). C{ H} NMR (100.61 MHz,
3 2
C D Br): δ 145.26 (C ), 133.58 (C ), 130.82, 130.14, 130.07, 124.16,
6
5
q
q
[
In(C H Br) ][CHB Cl ] (2). A small grease-free Schlenk flask
123.67, 115.46, 115.25, 28.85 (CH(CH ) ), 24.47 (CH ), 23.79
3 2 3
6
5
1.5
11 11
equipped with a Teflon valve was charged with Ag[CHB Cl ] (0.19
g, 0.30 mmol), indium powder (0.07 g, 0.60 mmol), and
bromobenzene (ca. 3 mL). The suspension was stirred at 80 °C for
4 h, and a few crystals were formed after cooling to room
(CH3). 11B NMR (128.38 MHz, C D Br): δ −1.5 (s, 1B), −9.1 (s,
11
11
6
5
5B), −12.3 (s, 5B).
[In(PhCCPMes )][CHB Cl ]·0.5C H F (6·0.5C H F). A small
2
11 11
6
5
6 5
2
grease-free Schlenk flask equipped with a Teflon valve was charged
temperature. The crystals were dissolved with brief heating with a
heat gun. The brownish supernatant liquid was filtered through a
medium-porosity frit and concentrated to ca. 0.5 mL under vacuum,
and subsequent cooling to −20 °C for 2 days afforded small colorless
crystals of 2. Yield: 0.14 g, 59%. The low yield is due to the small-scale
with 1 (0.05 g, 0.05 mmol), PhCCPMes (0.02 g, 0.05 mmol), and
2
fluorobenzene (ca. 2 mL). The resulting orange solution was stored at
1
−20 °C for 2 days to afford small crystals of 6. H NMR (400.13 MHz,
C D Br): δ 7.07 (m, Ph, 4H), 6.88 (t, J = 8.8 Hz, p-Ph, 1H), 6.71 (d,
6
5
4
JPH = 3.3 Hz, m-Mes, 4H), 2.79 (s, CHB Cl , 1H), 2.45 (s, o-
11
11
1
Mes
Mes
13
1
and mechanical losses. H NMR (400.13 MHz, C D Br): δ 7.29, 7.02,
CH3 , 12H), 2.12 (s, p-CH3 , 6H). C{ H} NMR (100.61 MHz,
C D Br): δ 142.16 (d, J = 20.5 Hz), 131.72 (s), 130.63 (d, JPC = 8.7
6
5
6
.94 (C H Br signals, partially obscured by the solvent), 2.75 (s,
6 5
6
5
PC
13
1
CHB Cl , 1H). C{ H} NMR (100.61 MHz, C D Br): δ 131.59 (o-
Hz), 129.05 (d, JPC = 3.1 Hz), 128.59 (s), 126.90 (s), 125.86 (s), 124.2
(d, JPC = 3.0 Hz), 115.33 (d, J = 20.9 Hz), 47.70 (br, CHB Cl ),
11
11
6
5
C),130.13 (m-C), 126.94 (p-C), 122.70 (i-C), 48.12 (br, CHB Cl ).
1
1
11
PC
11 11
1
1
Mes
Mes
11
B NMR (128.38 MHz, C D Br): δ −2.2 (s, 1B), −9.4 (s, 5B), −12.1
s, 5B).
Semiquantitative Assessment of the Absence of Silver in Samples
of 1 and 2. Late transition metals are known to form well-defined
23.14 (br, o-CH3 ), 21.16 (p-CH3 ). B NMR (128.38 MHz,
C D Br): δ −2.0 (s, 1B), −9.3 (s, 5B), −12.1 (s, 5B). P{ H} NMR
(161.97 MHz, C D Br): δ −56.2 (w ∼ 58 Hz).
6
5
31
1
(
6
5
6
5
1/2
Hydroamination Reactions. All work was carried out in J. Young
type NMR tubes, which were charged with 20−31 μmol of
aminopentene, 10 mol % of catalyst 2, hexamethylbenzene as the
internal standard (3 mg, 18 μmol), fluorobenzene (0.8 mL), and a
C D -filled narrow tube for NMR lock. The samples, which were clear
2
1
complexes with the tridentate ambiphilic ligand B(C H PPh -2) .
A
6
4
2
3
complex of AgCl with the related ligand B(C H PiPr -2) has been
6
4
2
3
isolated, and its 31P NMR spectrum shows two characteristic doublets
107
due to Ag−P coupling with both common silver isotopes, Ag and
6
6
1
09
22
Ag. Solid B(C H PPh -2) (21 mg, 27 μmol) was added to a
solutions initially, were placed in a temperature-controlled oil bath (T
6
4
2
3
1
solution of Ag[CHB Cl ] in C D Br (0.4 mL) in an NMR tube
= 130(2) °C), and the progress of the reaction was monitored by H
11
11
6
5
inside a glovebox, and after brief shaking of the tube, a clear yellow
NMR spectroscopy. During the reactions, a small amount of a dark
1
solution was obtained. H NMR (400.13 MHz, C D Br): δ 7.4−6.8
powder precipitated. The aminopentenes A−C (Scheme 1 and Table
6
5
11
23−25
(
m, br, aromatic H), 2.85 (s, CHB ). B NMR (128.38 MHz,
1) were prepared according to literature procedures,
and the
11
31
1
23−25
C D Br): δ −1.8 (s, 1B), −9.2 (s, 5B), −12.3 (s, 5B). P{ H} NMR
products were identified by comparison with reported spectra.
6
5
109
107
(
161.97 MHz, C D F): δ 14.2 (2d, J( Ag−P) = 300 Hz, J( Ag−P)
6
5
=
345 Hz). The addition of B(C H PPh -2) to solutions of 1 and 2 in
6 4 2 3
Scheme 1
fluorobenzene resulted in the immediate precipitation of an as-yet-
unidentified orange precipitate, and the 31P NMR spectrum of the
mother liquor only showed the signal of the uncomplexed ligand.
Thus, a significant contamination of compounds 1 and 2 with silver
can be ruled out.
[
Ph PH][CHB Cl ] (3). A solution of 1 (0.09 g, 0.09 mmol) in
3 11 11
fluorobenzene (10 mL) was added to a solution of PPh (0.06 g, 0.23
3
Table 1. Catalytic Conversion of Aminopentenes A−C
mmol) in fluorobenzene (10 mL) at room temperature. After the
addition, a black precipitate began to form. The supernatant liquid was
filtered twice through a medium-porosity glass frit to give a clear
solution. The solution was concentrated under reduced pressure to 5−
amount
(μmol)
time
(h)
conversion
(%)
yield
(%)
compound
R
A
B
C
31
27
20
25
11
94
95
98
97
96
95
90
1
0 mL, and cooling at −20 °C for 14 days afforded small yellow
H
31 1
crystals. P { H} NMR (161.97 MHz, C D F): δ 5.8 (s, br, w
∼
6
5
1/2
CH3
+
1
10 Hz, [HPPh ] ), −5.5 (s, br, w ∼ 184 Hz, PPh ), relative
3
1/2
3
3
1
1
intensity ∼ 1:0.39. P NMR (161.97 MHz, C D F): δ 5.8 (d, br, J
=
6
5
PH
501 Hz). 11B NMR (128.38 MHz, C D Br): δ −1.9 (s, 1B), −9.3 (s,
X-ray Crystallography. Crystals of compounds 1, 2, and 4−6
were grown as described above (Table 2). The data were collected
using a diffractometer with a Bruker APEX CCD area detector and
graphite-monochromated Mo Kα radiation (λ = 0.71073 Å) at 100(2)
6
5
5
B), −12.4 (s, 5B).
[
IPr·H][CHB Cl ] (4). To a mixture of IPr (0.01 g, 0.03 mmol) and
1
1
11
2
(0.03 g, 0.03 mmol) in a small grease-free Schlenk flask was added
26
fluorobenzene (2 mL) at room temperature. A small amount of a black
precipitate formed immediately. The reaction mixture was briefly
heated with a heat gun (ca. 10 s), whereupon more precipitate formed.
The mixture was filtered through a medium-porosity sintered-glass frit
K. The data were corrected for absorption by the empirical method,
and the structures were solved and refined using the SHELXS and
2
7
SHELXL packages.
In the structure of 1, the metal and two of the three toluenes were
disordered. The occupancies of In1 and C1B−C7C were refined to
0.587(2) and 0.413(2) for the unprimed and primed atoms. Restraints
on the positional and displacement parameters of the disordered
1
and cooled at −20 °C for 9 days to afford yellowish crystals of 4. H
NMR (400.13 MHz, CDCl ): δ 8.37 (s, NCHN, 1H), 7.75 (s, CH,
3
2
H), 7.67 (t, J = 7.8 Hz, p-H, 2H), 7.43 (d, J = 7.8 Hz, m-H, 4H), 3.12
B
Inorg. Chem. XXXX, XXX, XXX−XXX