Synthesis of 6,7-benzo-3-borabicyclo[3.3.1]nonane and its 3-aza analog from 2-allylphenyl(diallyl)borane. Intramolecular arylboration of the C=C bond

Article abstract of DOI:10.1007/s11172-005-0305-5

A method was developed for the synthesis of 6,7-benzo-3-borabicyclo[3.3.1] nonane and 6,7-benzo-3-azabicyclo[3.3.1]nonane derivatives based on intramolecular cyclization of 2-allylphenyl(diallyl)borane. Intramolecular arylboration of the double bond in 1,

Full text of DOI:10.1007/s11172-005-0305-5

678
Russian Chemical Bulletin, International Edition, Vol. 54, No. 3, pp. 678—683, March, 2005
Synthesis of 6,7ꢀbenzoꢀ3ꢀborabicyclo[3.3.1]nonane and
its 3ꢀaza analog from 2ꢀallylphenyl(diallyl)borane.
Intramolecular arylboration of the C=C bond
ꢀ
N. Yu. Kuznetsov, Z. A. Starikova, B. B. Averkiev, and Yu. N. Bubnov
A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences,
28 ul. Vavilova, 119991 Moscow, Russian Federation.
Fax: +7 (095) 135 5085. Eꢀmail: bubnov@ineos.ac.ru
A method was developed for the synthesis of 6,7ꢀbenzoꢀ3ꢀborabicyclo[3.3.1]nonane
and 6,7ꢀbenzoꢀ3ꢀazabicyclo[3.3.1]nonane derivatives based on intramolecular cyclization
of 2ꢀallylphenyl(diallyl)borane. Intramolecular arylboration of the double bond in 1,5ꢀdiallylꢀ
2,3ꢀbenzoꢀ1ꢀboracyclohexane was carried out for the first time. Conventional oxiꢀ
dation (H2O2—OH–) of 6,7ꢀbenzoꢀ3ꢀmethoxyꢀ3ꢀborabicyclo[3.3.1]nonane afforded
cisꢀ1,3ꢀdi(hydroxymethyl)tetralin. The structure of the latter was established by Xꢀray diffracꢀ
tion analysis.
Key words: triallylborane, allylboranes, allylboration, intramolecular arylboration, dimethyl
2ꢀallylphenylboronate, benzoazocine, 3ꢀborabicyclo[3.3.1]nonane, 3ꢀazabicyclo[3.3.1]nonane.
Triallylborane and various β,γꢀunsaturated boron deꢀ
three successive steps, which in some cases are clearly
rivatives possess high reactivity and are widely used in orꢀ
ganic synthesis.1—3 Due to specific structural features, these
reagents can add to organic compounds containing mulꢀ
tiple bonds (C=O, C=S, C=N, C=C, N=O, C≡C, C≡N).
All these reactions involve the allylic rearrangement and
proceed, apparently, via the sixꢀmembered chairꢀlike tranꢀ
sition state accompanied by cyclic electron transfer.3—5
Allylboron—acetylene condensation, which is the therꢀ
mal reaction of triallyl derivatives of boron with acetyꢀ
lenes giving rise to 3ꢀborabicyclo[3.3.1]nonꢀ6ꢀene derivaꢀ
tives in yields up to 97%, is one of the most important and
promising reactions in organoboron chemistry.3—6 Earꢀ
lier, it has been demonstrated that condensation involves
separated by temperature ranges (Scheme 1). The first
two steps are, respectively, cisꢀallylboration of the triple
and terminal carbon—carbon double bonds in adduct 1.
The temperatures of these steps vary from –70 °C to
+80 °C depending on the nature of the substituent R in
the starting acetylene compound. The third step, viz.,
vinylboration of the terminal double bond in boracycle 2,
occurs at 125—160 °C (2a) and also depends on the naꢀ
ture of R. The products generated in each step were isoꢀ
lated and used as the starting compounds for the synthesis
of 1,4ꢀdienes, unsaturated aldehydes and ketones, acyclic
alcohols, diols, amines, and cage compounds, such as
1ꢀboraꢀ and 1ꢀazaadamantane.3,6,7
Scheme 1
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 668—672, March, 2005.
1066ꢀ5285/05/5403ꢀ0678 © 2005 Springer Science+Business Media, Inc.

Synthesis of borabicyclo[3.3.1]nonane
Russ.Chem.Bull., Int.Ed., Vol. 54, No. 3, March, 2005
679
Scheme 2
Reagents and conditions: i. 1) Mg; 2) B(OMe)3, –78 °C; 3) TMSCl; ii. 60 °C (60 Torr); iii. 140 °C, 8 h; iv. 1) TsCl, Py;
2) BnNH2, PhCH3, 110 °C.
As part of continuing studies, we carried out thermal
cyclization of 2ꢀallylphenyl(diallyl)borane (6) and thus
performed the previously unknown intramolecular arylꢀ
boration of the terminal double bond 7 → 8 (Scheme 2).
earlier for arylboranes. Therefore, this is the first example
of intramolecular arylboration of the C=C bond. It should
be noted that the intermolecular addition of arylboranes
to olefins and acetylenes is also untypical of arylboranes.
To our knowledge, only two reactions of this type were
described in the literature: the addition of phenyl(diꢀ
chloro)borane to norbornadiene10 and butylacetylene.11
Compound 8 was not isolated in pure form and was
immediately treated with methanol to prepare methoxyꢀ
organoborane 9. Conventional oxidation (H2O2—OH–)
of compound 9 produced bicyclic diol 10 (88%), which
was purified by chromatography on silica gel. The cis arꢀ
rangement of the hydroxymethyl groups in compound 10
was unambiguously established by Xꢀray diffraction analyꢀ
sis (Fig. 1).
Results and Discussion
The reaction of 2ꢀallylphenylmagnesium bromide 4
with trimethyl borate at –78 °C followed by treatment of
the resulting ateꢀcomplex with trimethylchlorosilane afꢀ
forded dimethyl 2ꢀallylphenylboronate 5 (81%) (see
Scheme 2). The methoxy groups in 5 were replaced with
the allyl groups by the reaction with triallylborane. These
exchange reactions are equilibrium processes, and the
equilibrium can be shifted in the desired direction, for
example, by removing lowꢀboiling products.8,9 Thus, heatꢀ
ing of a mixture of 5 and triallylborane (1 : 2) under
reduced pressure (60 °C, 60 Torr) is accompanied by the
removal of lowꢀboiling AllB(OMe)2 to form unsymmetriꢀ
cal aryldiallylborane 6. Under the reaction conditions,
the latter undergoes cyclization through intramolecular
allylboration of the terminal double bond to give benzoꢀ
borinane 7 (91%), which is the 2,3ꢀbenzo analog of the
product that is generated in the second step of allylboronꢀ
acetylene condensation (2) (see Scheme 1). Heating
(140 °C, 8 h) of compound 7 results in its smooth reꢀ
arrangement into 6,7ꢀbenzoꢀ3ꢀborabicyclo[3.3.1]noꢀ
nane (8). This cyclization is similar to the third step of
allylboronꢀacetylene condensation, viz., the rearrangeꢀ
ment of vinylic borane 2 into bicyclic compound 3 (see
Scheme 1). However, this reaction has not been known
The sixꢀmembered ring adopts a halfꢀchair conformaꢀ
tion with the C(8) and C(9) atoms deviating from the
C(10)C(1)C(6)C(7) plane by 0.51 and –0.22 Å, respecꢀ
tively. In the crystal, the hydroxymethyl groups occupy
the equatorial (C(12)) and pseudoequatorial (C(11)) poꢀ
O(1)
C(11)
O(2)
C(9)
C(2)
C(5)
C(10)
C(1)
C(3)
C(4)
C(12)
C(8)
C(6)
C(7)
Fig. 1. Overall view of compound 10.

680
Russ.Chem.Bull., Int.Ed., Vol. 54, No. 3, March, 2005
Kuznetsov et al.
Table 1. Selected bond lengths (d) and bond angles (ω) in comꢀ
pound 10
Scheme 3
Parameter
Value
Parameter
Value
Bond
d/Å
Bond
d/Å
O(1)—C(11)
O(2)—C(12)
C(1)—C(2)
C(1)—C(6)
C(1)—C(10)
Angle
1.430(2)
1.417(2)
1.394(2)
1.395(2)
1.525(2)
ω/deg
C(2)—C(3)
C(3)—C(4)
C(4)—C(5)
C(5)—C(6)
1.385(3)
1.369(3)
1.376(3)
1.399(2)
Angle
ω/deg
C(2)—C(1)—C(6) 118.3(1)
C(2)—C(1)—C(10) 120.0(1)
C(6)—C(1)—C(10) 121.7(1)
C(1)—C(6)—C(5) 119.0(1)
C(1)—C(6)—C(7) 121.4(1)
C(5)—C(6)—C(7) 119.6(2)
C(9)—C(8)—C(12) 112.0(1)
C(9)—C(8)—C(7)
108.7(1)
C(12)—C(8)—C(7) 112.7(1)
C(11)—C(10)—C(9) 110.0(1)
C(11)—C(10)—C(1) 111.1(1)
C(9)—C(10)—C(1) 112.8(1)
O(1)—C(11)—C(10) 111.6(1)
O(2)—C(12)—C(8) 112.6(1)
sitions in the benzocyclohexane fragment. The bond
lengths and bond angles have standard values (Table 1).
A slight difference between the O(1)—C(11) and
O(2)—C(12) bond lengths is, apparently, attributable to
the crystal packing effects. Actually, the molecules of
diol 10 in the crystal are linked to each other by strong
hydrogen bonds to form chains along the crystallographic
b axis (Fig. 2).
Reagents and conditions: i. 1) BuLi, –95 °C; 2) B(OMe)3,
–78 °C; 3) TMSCl; ii. 60 °C (60 Torr).
tosylate with benzylamine in toluene produced tricyclic
amine, viz., benzoazocine 11,12 which is a carbocyclic
analog of alkaloid cytisine, in 86% yield (see Scheme 2).
With the aim of extending the scope of application of
intramolecular arylboration, we synthesized borane 14
containing the methoxy group in the side chain
(Scheme 3). Iodide 12 was metallated with BuLi to preꢀ
Treatment of diol 10 with TsCl in pyridine afforded
the ditosyl derivative in quantitative yield. The latter was
used without additional purification. Refluxing of diꢀ
b
0
H(2O″)
O(2″)
H(10)
O(1)
H(10´)
O(1´)
H(2O)
O(2)
a
Fig. 2. The O—H...Oꢀbonded chains in the crystal structure of diol 10.
Parameters of H bonds:
Fragment
Symmetry transformation
Bond
d/Å
Angle
ω/deg
O(1)—H(1O)...O(2)
1.5 – x, y – 0.5, 0.5 – z
O(1)...O(2″)
H(1O)...O(2″)
O(2)...O(1´)
H(2O)...O(1´)
2.653(2)
1.77
2.625(2)
1.82
O(1)—H(1O)—O(2″)
173
O(2)—H(2O)...O(1)
x, y + 1, z
O(2)—H(2O)—O(2´)
168

Synthesis of borabicyclo[3.3.1]nonane
Russ.Chem.Bull., Int.Ed., Vol. 54, No. 3, March, 2005
681
a colorless liquid. C11H15BO2. M = 190.5. 1H NMR (200 MHz),
δ: 3.47 (d, 2 H, J = 6.7 Hz); 3.64 (s, 6 H); 5.07 (s, 1 H); 5.16 (dd,
1 H, J = 1.6 Hz, J = 7.6 Hz); 5.90—6.10 (m, 1 H); 7.23—7.37
(m, 4 H). Upon storage in air for one day, boronate 5 was
transformed into solid 2ꢀallylphenylboronic acid, whose idenꢀ
tity was confirmed by comparing with the 1H NMR spectrum
published in the literature.15
pare the aryllithium derivative, which was successively
treated with trimethyl borate and trimethylchlorosilane.
The further replacement of the methoxy groups in 13 with
the allyl groups in the presence of triallylborane afforded
exclusively compound 14, which, however, was not subꢀ
jected to further cyclization even at 100 °C.
This is, apparently, caused by the intramolecular O→B
coordination, which blocks the unoccupied orbital of the
boron atom. The occurrence of this coordination in comꢀ
pound 14 is evidenced by the fact that the 11B NMR
spectrum shows a signal at δ 14.8, which corresponds to
the fourꢀcoordinate boron atom, whereas the correspondꢀ
ing signal in the 11B NMR spectrum of compound 7 is
observed at δ 69.8. We also failed to perform cyclization
of borane 14 in the presence of strong Lewis acids, such as
Sc(OTf)3 or BF3•OEt2 (10 mol.%, CH2Cl2, 20 °C, 2 h),
which should be coordinated to the oxygen atom of the
methoxy group and destroy the O→B coordination. Both
reactions produced (1H and 13C NMR spectroscopic data)
at least three new compounds, whose structures were not
established.
2,3ꢀBenzoꢀ1,5ꢀdiallylborinane (7). A mixture of compound 5
(2.0 g, 10.5 mmol) and triallylborane (2.97 g, 3.86 mL, 22 mmol)
was heated at 55—60 °C for 6 h under reduced pressure (60 Torr).
Simultaneously, argon was passed through the reaction mixture
using a thin capillary tube to remove volatile reaction products.
The reaction was monitored by NMR spectroscopy based on the
disappearance of the signals of the methoxy group. Subsequent
vacuum distillation (95—96 °C; 0.5 Torr) afforded product 7.
The yield was 2 g (91%). Found (%): C, 85.61; H, 9.05; B, 5.06.
C15H19B. M = 210.12. Calculated (%): C, 85.74; H, 9.11; B, 5.15.
1H NMR (400 MHz), δ: 1.10 (dd, 1 H, J = 11.8 Hz, J =
18.7 Hz); 2.00 (m, 2 H); 2.22 (t, 2 H, J = 6.6 Hz); 2.55—2.66
(m, 3 H); 2.94 (dt, 1 H, J = 2.8 Hz, J = 15.6 Hz); 5.03—5.14
(m, 4 H); 5.93 (m, 1 H); 6.13 (m, 1 H); 7.29 (d, 1 H, J =
7.5 Hz); 7.35 (t, 1 H, J = 7.2 Hz); 7.51 (td, 1 H, J = 1.2 Hz, J =
7.5 Hz); 7.95 (d, 1 H, J = 6.8 Hz). 13C NMR (127 MHz), δ:
31.08 (CH2B); 31.93 (CH2B); 35.30 (CH); 39.74 (CH2); 43.04
(CH2); 114.41 (CH2=); 115.87 (CH2=); 125.59 (CH=); 128.69
(CH=); 133.23 (CH); 134.15 (CH); 136.09 (CH); 137.34 (CH);
150.17 (C). 11B NMR (128 MHz), δ: 69.83.
6,7ꢀBenzoꢀ3ꢀmethoxyꢀ3ꢀborabicyclo[3.3.1]nonane (9).
Borinane 7 (1.30 g, 6.14 mmol) was heated at 140—150 °C
for 8 h. The reaction was monitored by NMR spectroscopy.
Heating was performed until the ratio of the integral intensities
of the signals for the aromatic to allylic (CH=) protons became
ca 4 : 1. The reaction mixture was treated with an excess of
MeOH, and methyl ether 9 was distilled off in vacuo, b.p.
114—116 °C (1 Torr). The yield was 1.18 g (96%). C13H17BO.
M = 200.08. The product contained ca 8% of the methanolysis
product of compound 7 (1H NMR spectroscopic data). 1H NMR
(400 MHz), δ: 1.03 (br.d, 1 H, J = 17.4 Hz); 1.12—1.20 (m, 2 H);
1.29 (br.d, 1 H, J = 16.3 Hz); 1.91 (br.d, 1 H, J = 12.6 Hz); 2.07
(br.d, 1 H, J = 12.4 Hz); 2.59 (d, 1 H, J = 17.0 Hz); 2.66
(br.s, 1 H); 3.14 (dd, 1 H, J = 6.0 Hz, J = 17.0 Hz); 3.28
(br.s, 1 H); 3.53 (s, 3 H); 7.14—7.06 (m, 4 H). 13C NMR
(50 MHz), δ: 25.43 (CH2B); 27.23 (CH); 28.94 (br, CH2B);
32.60 (CH2); 33.48 (CH); 38.20 (CH2); 52.96 (OCH3); 125.57
(CH); 125.79 (CH); 129.05 (CH); 129.68 (CH); 133.47 (C);
143.03 (C). 11B NMR (128 MHz), δ: 54.81.
To summarize, we developed a procedure for the
preparation of 6,7ꢀbenzoꢀ3ꢀborabicyclo[3.3.1]nonane and
6,7ꢀbenzoꢀ3ꢀazabicyclo[3.3.1]nonane derivatives based on
intramolecular allylꢀ and arylboration of carbon—carbon
double bonds. It was found that heating of 2ꢀallylꢀ
phenyl(diallyl)borane leads to its cyclization (isomerizaꢀ
tion) by the mechanism of allylboronꢀacetylene condenꢀ
sation.
Experimental
All operations with organoboron compounds were carried
out under dry argon. The solvents were dried according to
standard procedures. The 1H and 13C NMR spectra were
recorded on Bruker ACꢀ200P and Bruker AMXꢀ400 specꢀ
trometers. The chemical shifts δ in the 1H and 13C NMR
spectra are given relative to the residual signals of the solvent
in CDCl3. The chemical shifts in the 11B NMR spectra are
given relative to BF3•OEt2 as the external standard. 2ꢀAllylꢀ
bromobenzene 4 was prepared according to procedures described
earlier.13,14
Dimethyl 2ꢀallylphenylboronate (5). A solution of 4 (10.23 g,
41 mmol) in THF (50 mL) was added to magnesium chips
(1.1 g, 45 mmol) activated with 1,2ꢀdibromoethane in THF
(20 mL). The addition was carried out at such a rate as to
maintain the temperature of the reaction mixture at no higher
than 40 °C. Then the reaction mixture was stirred at room temꢀ
perature for 30 min. The resulting Grignard reagent was added
dropwise to a solution of trimethyl borate (10.39 g, 11.15 mL,
0.1 mol) in THF (40 mL) cooled to –78 °C. After completion of
the addition, the reaction mixture was stirred until it was warmed
to room temperature, treated with TMSCl (3.24 g, 3.77 mL,
30 mmol), stirred for 30 min, and concentrated in vacuo. The
residue was extracted several times with hexane, filtered off from
salts, and concentrated under reduced pressure. Vacuum distilꢀ
lation (59—60 °C (0.5 Torr)) afforded boronate 5 (6.3 g, 81%) as
cisꢀ1,3ꢀDi(hydroxymethyl)ꢀ1,2,3,4ꢀtetrahydronaphthalene
(10). An excess of 20% NaOH (5 mL) was added to a solution of
borane 9 (1.32 g, 6.6 mmol) in THF (5 mL), and then 30% H2O2
(0.63 g, 1.9 mL, 18.5 mmol) was added dropwise with stirring
and cooling. The reaction mixture was stirred for 1 h, refluxed
for 1 h, and cooled. The organic layer was separated, dried with
K2CO3, and concentrated under reduced pressure. The oil
was purified by passing through a short column (20×2 cm)
with SiO2 in the AcOЕt—nꢀC6H14 system (3 : 2). After reꢀ
moval of the solvents, diol 10 was obtained as white crystals
(1.12 g, 88%), m.p. 92—93 °C (nꢀC6H14—CH2Cl2), Rf = 0.1
(AcOЕt—nꢀC6H14, 1 : 1). Found (%): C, 74.95; H, 8.40.
C
12H16O2. M = 192.25. Calculated (%): C, 74.97; H, 8.39.
1H NMR (400 MHz), δ: 1.38 (dd, 1 H, J = 11.5 Hz, J =
23.6 Hz); 1.95 (m, 1 H); 2.12—2.25 (br.m, 2 H); 2.37 (br.s, 1 H,

682
Russ.Chem.Bull., Int.Ed., Vol. 54, No. 3, March, 2005
Kuznetsov et al.
OH); 2.50 (dd, 1 H, J = 11.8 Hz, J = 15.9 Hz); 2.71 (dd, 1 H,
J = 1.9 Hz, J = 15.9 Hz); 3.07 (m, 1 H); 3.60 (dd, 1 H, J =
6.8 Hz, J = 10.6 Hz); 3.65 (dd, 1 H, J = 6.2 Hz, J = 10.6 Hz);
3.90 (dd, 1 H, J = 5.9 Hz, J = 10.9 Hz); 3.95 (dd, 1 H, J =
4.0 Hz, J = 10.9 Hz); 7.10—7.19 (m, 3 H); 7.31 (d, 1 H, J =
7.5 Hz). 13C NMR (127 MHz), δ: 30.14 (CH2); 33.30 (CH2);
36.69 (CH); 40.48 (CH); 66.90 (CH2OH); 67.60 (CH2OH);
126.09 (2 CH); 126.84 (CH); 129.52 (CH); 136.63 (C);
137.73 (C).
116.85 (CH); 127.84 (CH); 128.58 (CH); 129.31 (CH); 136.87
(CH); 139.32 (CH); 142.62 (C).
Dimethyl 2ꢀ(1ꢀmethoxyꢀ2ꢀpropenyl)phenylboronate (13).
A solution of 12 (7.5 g, 27.4 mmol) in THF (30 mL) was cooled
to –95—–100 °C and BuLi (2.5 mol L–1, 12 mL, 30.0 mmol)
was added with stirring using a syringe. After 1 min, the lithium
derivative precipitated, and the temperature rapidly increased
to –70 °C. Then the mixture was cooled to –90 °C and a soluꢀ
tion of trimethyl borate (4.68 g, 5.1 mL, 45 mmol) in Et2O
(4 mL) was added. The mixture was gradually warmed to 0 °C,
after which TMSCl (3.8 g, 4.4 mL, 35 mmol) was added, the
mixture was stirred for 30 min, and the solvents were removed
under reduced pressure. The residue was treated with hexane
and the clean solution was decanted. Vacuum distillation afꢀ
forded compound 13 in a yield of 4.7 g (79%), b.p. 77—78 °C
(2 Torr). Found (%): C, 65.60; H, 7.80. C12H17BO3. M = 220.07.
Calculated (%): C, 65.49; H, 7.79. 1H NMR (400 MHz), δ: 3.43
(s, 3 H); 3.53 (s, 6 H); 4.69 (d, 1 H, J = 8.1 Hz); 5.40 (m, 2 H);
5.84 (m, 1 H); 7.16—7.35 (m, 4 H). 13C NMR (127 MHz),
δ: 52.05 (2 CH3); 55.76 (CH3); 84.59, 118.92 (CH); 124.98
(CH); 126.68 (CH); 127.80 (CH); 130.54 (CH); 137.41 (CH);
143.49 (C).
Diallylꢀ[2ꢀ(1ꢀmethoxyꢀ2ꢀpropenyl)phenyl]borane (14).
A mixture of compound 13 (1.8 g, 8.2 mmol) and triallylborane
(2.4 g, 3.2 mL, 18 mmol) was heated for 6 h in a flask for
distillation under a stream of Ar at 55—60 °C and 60 Torr.
Vacuum distillation afforded compound 14 in a yield of 1.6 g
(82%), b.p. 109—110 °C (2 Torr). Found (%): C, 80.05; H, 8.74.
C16H21BO. M = 240.15. Calculated (%): C, 80.02; H, 8.81.
1H NMR (400 MHz), δ: 1.60—1.67 (m, 3 H); 1.73—1.79 (m,
1 H); 3.69 (s, 3 H); 4.70 (d, 2 H, J = 9.8 Hz); 4.81 (t, 2 H, J =
17.2 Hz); 5.28 (d, 1 H, J = 8.9 Hz); 5.57—5.62 (m, 2 H);
5.69—5.77 (m, 1 H); 5.77—5.84 (m, 2 H); 6.96 (d, 1 H, J =
1.6 Hz, J = 5.7 Hz); 7.20 (td, 1 H, J = 1.6 Hz, J = 7.6 Hz);
7.28—7.32 (m, 2 H). 13C NMR (127 MHz), δ: 30.58 (br, 2 CH2);
55.12 (CH3); 93.72 (CH); 110.69 (CH2); 111.18 (CH2); 121.06
(CH); 122.65 (CH); 125.57 (CH); 127.55 (CH); 128.09 (CH);
134.84 (CH); 138.26 (C); 141.25 (CH); 141.38 (CH). 11B NMR
(128 MHz), δ: 14.8.
6,7ꢀBenzoꢀ3ꢀbenzylꢀ3ꢀazabicyclo[3.3.1]nonane (11). Tosyl
chloride (1.75 g, 9.2 mmol) was added to a solution of diol 10
(0.8 g, 4.16 mmol) in pyridine (10 mL) at 0 °C and the mixture
was stirred for 2 h. The reaction was monitored by TLC
(AcOEt—nꢀC6H14, 1 : 1). After consumption of the starting
compound 10, pyridine was evaporated under reduced pressure.
The residue was washed successively with water and 3 N HCl,
extracted with CH2Cl2 (10 mL), dried with Na2SO4, and conꢀ
centrated. The ditosyl derivative was dissolved in toluene
(40 mL), benzylamine (1.34 g, 1.36 mL, 12.5 mmol) was added,
and the mixture was refluxed for 14 h. The reaction was moniꢀ
tored by TLC (AcOEt—nꢀC6H14, 1 : 2). After consumption of
the starting ditosylate, an excess of 6 N NaOH was added. The
organic layer was separated, filtered, dried with K2CO3, and
concentrated in vacuo. The product was purified by filtration
through a small layer of SiO2 in the AcOEt—nꢀC6H14 system
(1 : 5), and the nonpolar fraction of amine 11 (yellow oil)
was collected. The yield was 0.93 g (86%), Rf = 0.73
(AcOEt—nꢀC6H14, 1 : 5). Found (%): C, 86.31; H, 8.14; N, 5.09.
C19H21N. M = 263.38. Calculated (%): C, 86.65; H, 8.04;
N, 5.32. 1H NMR (400 MHz), δ: 1.85 (br.d, 1 H, J = 12.1 Hz);
1.95 (br.d, 1 H, J = 12.1 Hz); 2.23 (m, 1 H); 2.35 (dd, 1 H, J =
1.9 Hz, J = 10.3 Hz); 2.43 (dd, 1 H, J = 1.9 Hz, J = 10.6 Hz);
2.79 (br.d, 1 H, J = 10.3 Hz); 2.86—2.92 (m, 3 H); 3.14 (dd,
1 H, J = 7.2 Hz, J = 17.4 Hz); 3.45 (s, 2 H); 6.94 (m, 2 H); 7.04
(d, 1 H, J = 7.5 Hz); 7.12—7.25 (m, 6 H). 13C NMR (127 MHz),
δ: 28.72 (CH2); 29.93 (CH2); 34.97 (CH); 35.82 (CH); 60.14
(CH2); 61.14 (CH2); 62.16 (CH2); 124.55 (CH); 125.52 (CH);
126.31 (CH); 127.35 (CH); 127.85 (3 CH); 128.00 (2 CH);
138.80 (C); 139.25 (C); 141.37 (C).
1ꢀIodoꢀ2ꢀ(1ꢀmethoxyꢀ2ꢀpropenyl)benzene (12). 1ꢀ(2ꢀIodoꢀ
phenyl)ꢀ2ꢀpropenꢀ1ꢀol (15.8 g, 60.8 mmol), which was preꢀ
pared according to a known procedure,16 and MeI (12.95 g,
5.7 mL, 91.2 mmol) were dissolved in THF (120 mL) under
argon and cooled to –40 °C. Then NaH (60%, 3.3 g, 82 mmol)
was added. The reaction mixture was slowly warmed to
–15—–10 °C. At this temperature, the reaction proceeded rather
vigorously. After hydrogen evolution ceased, the reaction mixꢀ
ture was allowed to warm to room temperature. The reaction
was monitored by TLC (AcOEt—nꢀC6H14, 1 : 4). The reaction
mixture was stirred at room temperature for 1 h and then conꢀ
centrated in vacuo. The residue was treated with water and exꢀ
tracted with CH2Cl2. The extracts were dried with K2CO3 and
concentrated. The residue was distilled in vacuo. Iodide 12 was
obtained in a yield of 14 g (84%), b.p. 77—78 °C (2 Torr),
Rf = 0.74 (AcOEt—nꢀC6H14, 1 : 4). Found (%): C, 43.93;
H, 4.10. C10H11IO. M = 274.10. Calculated (%): C, 43.82;
H, 4.05. 1H NMR (400 MHz), δ: 3.35 (s, 3 H); 4.95 (d, 1 H, J =
6.2 Hz); 5.25 (d, 1 H, J = 10.3 Hz); 5.38 (d, 1 H, J = 17.1 Hz);
5.88 (ddd, 1 H, J = 6.2 Hz, J = 10.3 Hz, J = 17.1 Hz); 6.99 (t,
1 H, J = 6.9 Hz); 7.40 (m, 2 H); 7.84 (d, 1 H, J = 8.1 Hz).
13C NMR (127 MHz), δ: 56.57 (CH3); 86.83 (CH); 98.98 (C—I);
Xꢀray diffraction study of compound 10. Crystals of diol 10
at –100 °C are monoclinic, space group P21/n, a = 11.552(2),
b = 7.729(1), c = 11.704(2)Е, β = 99.92(3)°, V = 1029.4(4) Å3,
Z = 4, dcalc = 1.240 g cm–3, µ(MoꢀKα) = 0.83 cm–1
,
F(000) = 416. The intensities of 2360 reflections were measured
at –110 °C on a Syntex P21 diffractometer (λ(MoꢀKα) =
0.71072 Å, θ/2θ scanning technique, 2θ < 54°); 2251 indepenꢀ
dent reflections (Rint = 0.0414) were used in the refinement.
The structure was solved by direct methods using successive
difference electron density maps. All hydrogen atoms were loꢀ
calized from difference electron density maps. The structure was
refined against F 2 with anisotropic displacement parameters
hkl
for nonhydrogen atoms and isotropic displacement parameters
for hydrogen atoms. The final R factors for 10 are R1 = 0.0430
(based on Fhkl for 1393 reflections with I > 2σ(I )), wR2 = 0.1128
(based on F 2hkl for reflections), GOOF = 0.837. All calculations
were carried out using the SHELXTL 5.10 program package.17
This study was financially supported by the Russian
Foundation for Basic Research (Project Nos 05ꢀ03ꢀ33268
and 05ꢀ03ꢀ32953), the Foundation of the President of the
Russian Federation (Grant NSh 1917.2003.2), and the

Synthesis of borabicyclo[3.3.1]nonane
Russ.Chem.Bull., Int.Ed., Vol. 54, No. 3, March, 2005
683
8. B. M. Mikhailov, Yu. N. Bubnov, and A. V. Tsyban´, Izv.
Akad. Nauk SSSR, Ser. Khim., 1978, 1594 [Bull. Acad. Sci.
USSR, Div. Chem. Sci., 1978, 27, 1392 (Engl. Transl.)].
9. B. M. Mikhailov, Yu. N. Bubnov, and A. V. Tsyban´,
J. Organomet. Chem., 1978, 154, 113.
Program of the Presidium of the Russian Academy of
Sciences (coordinator V. A. Tartakovsky).
References
10. F. Joy, M. F. Lappert, and B. Prokai, J. Organomet. Chem.,
1966, 5, 506.
11. M. F. Lappert and B. Prokai, J. Organomet. Chem.,
1964, 1, 384.
12. K. J. Balackall, D. Hendry, R. J. Pryce, and S. M. Roberts,
J. Chem. Soc., Perkin Trans. 1, 1995, 2767.
13. J. Knight and P. J. Parson, J. Chem. Soc., Perkin Trans. 1,
1989, 979.
14. G. Majetich, S. Liu, J. Fang, D. Siesel, and Y. Zhang, J. Org.
Chem., 1997, 62, 6928.
15. J. R. Falck, M. Bondlela, S. K. Venkataraman, and
D. Srinivas, J. Org. Chem., 2001, 66, 7148.
16. E. Negishi, C. Copéret, S. Ma, T. Mita, T. Sugihara, and
J. M. Tour, J. Am. Chem. Soc., 1996, 118, 5904.
17. G. M. Sheldrick, SHELXTLꢀ97, Version 5.10, Bruker AXS,
Inc., Madison (WIꢀ53719, USA), 1998.
1. D. S. Matteson, Stereodirected Synthesis with Organoboranes,
Springer, Berlin, 1995.
2. A. Pelter, K. Smith, and H. C. Brown, Borane Reagents,
Academic Press, London, 1988.
3. B. M. Mikhailov and Yu. N. Bubnov, Organoboron Comꢀ
pounds in Organic Synthesis, Harwood Acad. Sci. Publ., Lonꢀ
don—New York, 1984.
4. Yu. N. Bubnov, Pure Appl. Chem., 1987, 59, 895.
5. Yu. N. Bubnov, Izv. Akad. Nauk, Ser. Khim., 1995, 1203
[Russ. Chem. Bull., 1995, 44, 1156 (Engl. Transl.)].
6. Yu. N. Bubnov, M. E. Gurskii, A. I. Grandberg, and D. G.
Pershin, Tetrahedron, 1986, 42, 1079.
7. Yu. N. Bubnov, M. E. Gurskii, and I. D. Gridnev, in Comꢀ
prehensive Heterocyclic Chemistry — II, Eds A. R. Katritsky,
Ch. W. Rees, and E. F. Seriven, Vol. 8, Ed. G. Jones,
Pergamon, Glasgow, 1996, 889.
Received November 3, 2004