Preparation, X-ray crystal structure, and chemistry of stable azidoiodinanes-derivatives of benziodoxole

Article abstract of DOI:10.1021/ja954119x

Azidoiodinanes 2 and 4a,b can be prepared from the appropriate benziodoxoles 1 and 3a,b and trimethylsilyl azide in the form of stable, crystalline compounds. A single-crystal X-ray analysis for azide 4b revealed the expected hypervalent iodine distorted

Full text of DOI:10.1021/ja954119x

5
192
J. Am. Chem. Soc. 1996, 118, 5192-5197
Preparation, X-ray Crystal Structure, and Chemistry of Stable
AzidoiodinanessDerivatives of Benziodoxole
Viktor V. Zhdankin,* Alexei P. Krasutsky, Chris J. Kuehl, Angela J. Simonsen,
Jessica K. Woodward, Brian Mismash, and Jason T. Bolz
Contribution from the Department of Chemistry, UniVersity of Minnesota-Duluth,
Duluth, Minnesota 55812
X
ReceiVed December 7, 1995
Abstract: Azidoiodinanes 2 and 4a,b can be prepared from the appropriate benziodoxoles 1 and 3a,b and trimethylsilyl
azide in the form of stable, crystalline compounds. A single-crystal X-ray analysis for azide 4b revealed the expected
hypervalent iodine distorted T-shaped geometry with the N1-I-O bond angle of 169.5 (2) degrees. The lengths of
the bonds to the iodine atom, I-N (2.18 Å), I-O (2.13 Å), and I-C (2.11 Å), are within the range of typical single
covalent bonds in organic derivatives of polyvalent iodine, while the previously reported benziodoxoles generally
have an elongated I-O bond. The geometry of the I( NNN fragment in 4b is similar to the literature electron
diffraction data on monomeric iodine azide, IN3, in gas phase. Azidobenziodoxoles 2,4 are potentially useful reagents
for direct azidation of organic substrates, such as dimethylanilines, alkanes, and alkenes. Reaction of 2 with
dimethylanilines proceeds under mild conditions to afford the respective N-azidomethyl-N-methylanilines in excellent
yield. Alkanes, cycloalkanes, and adamantanes react with azidobenziodoxoles 2 or 4b in the presence of radical
initiators at 80-132 °C with the formation of tertiary alkylazides, while reaction of norbornane leads to exo-2-
azidonorbornane. Under similar conditions cyclohexene is selectively azidated at the allylic position.
III)
Introduction
decomposition at -25 °C to 0 °C with the formation of
5
iodobenzene and dinitrogen; however, low temperature
Covalent inorganic azides have attracted considerable current
interest in both theoretical and practical aspects.1 Iodine azide,
IN3, the first and the most important member of the family of
6a
spectroscopy and the subsequent chemical reactions in situ
provided some experimental evidence toward the existence of
6-9
these species.
The first systematic study of the structure and
2
halogen azides, was first prepared about 100 years ago and
reactivity of the unstable, acyclic azidoiodinanes was attempted
found wide practical application in both organic and inorganic
syntheses.1 In pure form iodine azide is thermally unstable
and highly explosive, which makes its structural identification
6
by Zbiral and co-workers in the early 1970s. In particular,
,3
the IR spectroscopic measurements at -60 to 0 °C indicated
the existence of PhI(OAc)2-n(N3)n species in the mixture of PhI-
1
-4
difficult.
Despite significant interest in iodine azide for
6a
(OAc)2 with trimethylsilyl azide.
almost a century, it was only in 1993 that Klap o¨ tke, Schleyer,
White, and co-workers succeeded in its X-ray structure
characterization.4 In particular, it was found that in solid state
IN3 has polymeric structure with the average I-N distance of
The unstable and highly reactive azidoiodinanes generated
in situ from PhIO/TMSN3, PhI(OAc)2/NaN3, or PhI(OAc)2/
TMSN3 have found some practical application as efficient
a
reagents for the introduction of the azido function into organic
4
a
2
.3 Å. In gas phase, however, it has monomeric structure as
6-9
molecules.
For example, reaction of the PhI(OAc)2/TMSN3
4b
determined by electron diffraction analysis.
or PhIO/NaN3 systems with alkenes lead to diazides, R-azi-
Much less is known about the structure of azides of polyvalent
iodine. Azidoiodinanes, PhI(N3)X (X ) OAc, Cl, OTMS, etc.)
or PhI(N3)2, were proposed as reactive intermediates in the
widely used azidation reactions involving the combination of
PhIO or PhI(OAc)2 with trimethylsilyl azide or NaN3.
Attempts to isolate these intermediates always resulted in fast
6,7
doketones, or nitriles. Treatment of â-dicarbonyl compounds
with PhIO/TMSN3 in chloroform affords the respective azides
7a
in moderate to good yield. Under similar conditions, 2-(tri-
5
-9
(7) (a) Moriarty, R. M.; Vaid, R. K.; Ravikumar, V. T.; Vaid, B. K.;
Hopkins, T. E. Tetrahedron 1988, 44, 1603. (b) Moriarty, R. M.; Vaid, R.
K.; Hopkins, T. E.; Vaid, B. K.; Tuncay, A. Tetrahedron Lett. 1989, 30,
3
019. (c) Moriarty, R. M.; Khosrowshahi, J. S. Tetrahedron Lett. 1986,
X
Abstract published in AdVance ACS Abstracts, May 15, 1996.
27, 2809. Moriarty, R. M.; Khosrowshahi, J. S. Synth. Comm. 1987, 17,
89.
(1) Review: Tornieporth-Oetting, I. C.; Klap o¨ tke, T. M. Angew. Chem.,
Int. Ed. Engl. 1995, 34, 511.
(8) (a) Arimoto, M.; Yamaguchi, H.; Fujita, E.; Ochiai, M.; Nagao, Y.
Tetrahedron Lett. 1987, 28, 6289. (b) Tingoli, M.; Tiecco, M.; Chianelli,
D.; Balducci, R.; Temperini, A. J. Org. Chem. 1991, 56, 6809. Czernecki,
S.; Randriamandimby, D. Tetrahedron Lett. 1993, 34, 7915. (c) Kirschning,
A.; Domann, S.; Dr a¨ ger, G.; Rose, L. Synlett 1995, 767. (d) Kita, Y.;
Tohma, H.; Inagaki, M.; Hatanaka, K.; Yakura, T. Tetrahedron Lett. 1991,
32, 4321. Kita, Y.; Tohma, H.; Hatanaka, K.; Takada, T.; Fujita, S.; Mitoh,
S.; Sakurai, H.; Oka, S. J. Am. Chem. Soc. 1994, 116, 3684. Kita, Y.;
Tohma, H.; Takada, T.; Mitoh, S.; Fujita, S.; Gyoten, M. Synlett 1994, 427.
(9) (a) Magnus, P.; Lacour, J. J. Am. Chem. Soc. 1992, 114, 3993.
Magnus, P.; Lacour, J. J. Am. Chem. Soc. 1992, 114, 767; Magnus, P.;
Roe, M. B.; Lynch, V.; Hulme, C. J. Chem. Soc., Chem. Commun. 1995,
1609. (b) Magnus, P.; Roe, M. B.; Hulme, C. J. Chem. Soc., Chem.
Commun. 1995, 263. (c) Magnus, P.; Lacour, J.; Weber, W. J. Am. Chem.
Soc. 1993, 115, 9347. (d) Magnus, P.; Hulme, C.; Weber, W. J. Am. Chem.
Soc. 1994, 116, 4501. Magnus, P.; Hulme, C. Tetrahedron Lett. 1994, 35,
8097.
(
2) Hantzsch, A.; Sch u¨ mann, M. Ber. Dtsch. Chem. Ges. 1900, 33, 522.
(3) For synthetic applications of iodine azide, see reviews: (a) Dehnicke,
K. Angew. Chem., Int. Ed. Engl. 1967, 6, 240. (b) Dehnicke, K. Angew.
Chem., Int. Ed. Engl. 1979, 18, 407. (c) L’abb e´ , G.; Hassner, A. Angew.
Chem., Int. Ed. Engl. 1971, 10, 98. (d) Scriven, E. F. V.; Turnbull, K.
Chem. ReV. 1988, 88, 297.
(4) (a) Buzek, P.; Klap o¨ tke, T. M.; Schleyer, P. v. R.; Tornieporth-
Oetting, I. C.; White, P. S. Angew. Chem., Int. Ed. Engl. 1993, 32, 275. (b)
Hargittai, M.; Moln a´ r, J.; Klap o¨ tke, T. M.; Tornieporth-Oetting, I. C.;
Kolonits, M.; Hargittai, I. J. Phys. Chem. 1994, 98, 10095.
(
5) Zefirov, N. S.; Zhdankin, V. V.; Safronov, S. O.; Kaznacheev, A.
A. Zh. Org. Khim. 1989, 25, 1807.
6) (a) Cech, F.; Zbiral, E. Tetrahedron 1975, 31, 605. (b) Zbiral, E.;
(
Ehrenfreund, J. Tetrahedron 1971, 27, 4125. Zbiral, E.; Nestler, G.
Tetrahedron 1970, 26, 2945. Ehrenfreund, J.; Zbiral, E. Liebigs Ann. Chem.
1
973, 290.
S0002-7863(95)04119-9 CCC: $12.00 © 1996 American Chemical Society

DeriVatiVes of 1,2-Benziodoxole
J. Am. Chem. Soc., Vol. 118, No. 22, 1996 5193
methylsiloxy)furan gives azidofuranone as the main product.7b
Allyl azides can be prepared from alkyltrimethylsilanes utilizing
the PhIO/TMSN3/BF3‚Et2O combination.8 Alkenes react with
PhI(OAc)2/TMSN3 in the presence of diphenyl diselenide to
a
8b
produce vicinal azidoselenides in good yield. 3-Deoxyglycals
can be converted into azidoglycals upon treatment with PhIO/
8
c
TMSN3. Aromatic compounds, such as anisoles and alkyl-
benzenes, can be azidated in the ring by treatment with
8d
PhI(OCOCF3)2/TMSN3.
Recently Magnus and co-workers reported several new,
synthetically useful azidations with the PhIO/MSN3 combina-
tion, which serves presumably as the source of nonisolable
azidoiodinanes PhI(N3)2 or PhI(N3)OTMS.9 Various triisopro-
pylsilyl enol ethers react with this reagent at -15 to -18 °C to
give the â-azido adducts in excellent yields.9 Likewise, N,N-
dimethylarylamines are cleanly converted into azidomethylene
derivatives with the PhIO/TmSN3 reagent combination.9 Amides,
carbamates, and ureas also can be R-azidated under similar
conditions; however, the yields of azides in this case are
a,b
c
Figure 1. ORTEP representation of the molecular structure of
azidobenziodoxole 4b.
9
d
generally lower.
It should be emphasized that the low thermal stability of the
reported PhIO/TMSN3 reagent combination restricts its practical
application only to low temperature reactions with the most
reactive organic substrates.
Table 1. Selected Bond Distances for 6
a
distance (Å)
distance (Å)
I-O
2.130 (5)
2.182 (7)
2.109 (7)
1.378 (9)
1.26 (1)
N2-N3
C6-C7
C1-C6
C7-C8
C7-C9
1.12 (1)
1.52 (1)
1.38 (1)
1.57 (1)
1.50 (1)
I-N1
I-C1
O-C7
N1-N2
In this paper we wish to report the preparation, X-ray
structure, and chemical reactivity of novel, stable azidoiodinanes
2
and 4a,b.10 The higher thermal stability of these compounds
is achieved due to incorporation of polyvalent iodine into a five-
a
Numbers in parentheses are estimated standard deviations in the
membered heterocycle.11
least significant digits.
Table 2. Selected Bond Angles for 6a
Results and Discussion
Azidoiodinanes 2 and 4a,b were synthesized in one step by
the reaction of benziodoxoles 1 and 3a,b with trimethylsilyl
azide in acetonitrile. All three azidoiodinanes (2,4a,b) were
isolated as thermally stable, yellow, crystalline solids. Azides
angle (deg)
angle (deg)
O-I-N1
O-I-Cl
169.5 (2)
78.9 (2)
90.6 (3)
116.1 (4)
109.5 (6)
174.0 (9)
I-C1-C2
I-C1-C6
C1-C6-C7
O-C7-C6
O-C7-C8
O-C7-C9
122.2 (6)
114.3 (5)
117.5 (7)
112.9 (6)
105.3 (7)
107.1 (8)
N1-I-C1
I-O-C7
2
and 4b have melting/decomposition points at 140-150 °C
I-N1-N2
N1-N2-N3
and can be stored at room temperature for several months
without noticeable decomposition. Azide 4a has lower thermal
stability; however, it can be stored for several months in a
refrigerator. Specially performed thermal and shock tests did
not reveal any explosive properties for crystalline products 4;
however, azidoiodinane 2 decomposed with explosion upon
heating to 138-140 °C.
a
Numbers in parentheses are estimated standard deviations in the
least significant digits.
respectively. These IR data are in good agreement with the
previously reported stretching vibrations of the azido-group in
12
-1
6a
-1
IN3 at 2045 cm and in PhI(OAc)2-n(N3)n at 2040 cm .
1
13
The H and C NMR spectra of compounds 2,4a,b showed
signals and splitting patterns typical of o-substituted benzene
rings and consistent with the proposed structures.
The structure of azide 4b was unambiguously established by
a single-crystal X-ray analysis. The ORTEP diagram is shown
in Figure 1, and selected bond distances and bond angles are
listed in Tables 1 and 2. The structural data revealed the
expected hypervalent iodine distorted T-shaped geometry with
the N1-I-O bond angle of 169.5 (2) degrees. The lengths of
the bonds to the iodine atom, I-N (2.18 Å), I-O (2.13 Å), and
I-C (2.11 Å), all have similar values, and generally are within
the range of typical single covalent bonds in organic derivatives
Azidoiodinanes 2,4a,b were identified by spectral data,
elemental analyses, and X-ray data (for 4b). Specifically, IR
spectra of all three compounds (2,4a,b) displayed a very intense
1
1a
of polyvalent iodine.
However, the endocyclic I-O bond in
b is significantly shorter than usual in iodine heterocycles,
while the I-C and the I-N bonds are slightly longer. For
4
-
1
peak of the azido function at 2048, 2034, and 2046 cm ,
1
3
example, the I-N bond length in benziodazoles is 2.06-2.14
Å, while the endocyclic I-O bond in 1-alkynyl-1,2-benziodo-
(10) Preliminary communications: (a) Zhdankin, V. V.; Kuehl, C. J.;
Krasutsky, A. P.; Formaneck, M. S.; Bolz, J. T. Tetrahedron Lett. 1994,
14a
3
1
5, 9677. (a) Krasutsky, A. P.; Kuehl, C. J.; Zhdankin, V. V. Synlett 1995,
081.
xole-3(1H)-one has a distance of 2.34 Å and the I-C(1) bond
length of 2.03 Å. An even greater difference in I-O (2.478
(11) For general reviews on the chemistry of benziodoxoles and other
iodine heterocycles, see: (a) Varvoglis A. The Organic Chemistry of
Polycoordinated Iodine; VCH Publishers, Inc.: New York, 1992; pp 169-
(12) Dehnicke, K. Angew. Chem., Int. Ed. Engl. 1976, 15, 553.
(13) Balthazar, T. M.; Godaz, D. E.; Stults, B. R. J. Org. Chem. 1979,
44, 1447. Naae, D. G.; Gougoutas, J. Z. J. Org. Chem. 1975, 40, 2129.
Prout, K.; Stevens, N. M.; Coda, A.; Tazzoli, V.; Shaw, R. A.; Demir, T.
Z. Naturforsch. 1976, 31b, 687.
1
80. (b) Koser, G. F. In The Chemistry of Functional Groups, Suppl. D;
Patai, S., Rappoport, Z., Eds; Wiley-Interscience: Chichester, 1983; Chapter
8, pp 721-811.
1

5
194 J. Am. Chem. Soc., Vol. 118, No. 22, 1996
Zhdankin et al.
Table 3. Direct Azidation of Organic Substrates by
Å) and I-C (2.105 Å) bond distances is observed in 1-phenyl-
1
,2-benziodoxole-3(1H)-one,1 which is more consistent with
4b
Azidobenziodoxoles
an open zwitterionic structure for this compound in contrast
with cyclic structure of 4b.
A comparison of our data on the geometry of the I(III)NNN
fragment in 4b with the literature X-ray data on iodine azide
reveals significant structural differences between these two
4a
compounds in solid state. In particular, in the solid state IN3
forms zigzag polymeric -I-N(1)-I-(N1)- chains with the
I-N(1) distance at 2.26-2.30 Å, the N(1)-I-N(1) bond angle
4a
of 177°, and the I-N(1)-N(2) bond angle of 114-117°, while
azidoiodinane 4b has a monomeric structure. However, the
4b
structure of the free IN3 molecule determined by gas-phase
electron diffraction analysis is in better agreement with our data
on 4b. According to the literature data,4b the monomeric IN3
has the I-N(1) distance of 2.12 Å, the I-N(1)-N(2) bond angle
of 106°, and the N-N-N bond angle of 169°, which is close
to the respective calculated parameters4
1
a,15
of 2.12-2.13 Å,
10°, and 171°. Compared to the monomeric IN3, azidoiodinane
4
b has a slightly elongated I-N bond, while the rest of the
structural parameters are very similar. The relatively long I-N
bond in 4b can be ascribed to the stronger polarity of this bond
in comparison with the monomeric IN3.
Further perusal of X-ray structural data on 4b reveals the
presence of secondary bonding between the oxygen atom of
the five-membered ring and the iodine atom of another molecule
of 4b with the I‚‚‚O distance 3.030 Å. In addition to the I‚‚‚O
interaction, there exists a weaker intermolecular I‚‚‚F interaction
with the distance of 3.284 Å. A similar secondary bonding was
14
observed in the previously reported benziodoxoles.
Similarly to the unstable azidoiodinanes,6-9 azidobenziodo-
xoles 2 and 4 can be used as efficient azidating reagents toward
various organic substrates (Table 3). In a typical example,
reagent 2 reacts with N,N-dimethylanilines 5 in dichloromethane
at reflux in 30 min to afford the respective N-azidomethyl-N-
methylanilines 6 in excellent yield. The analogous reaction of
N,N-dimethylanilines with the PhIO/TMSN3 system9c proceeds
smoothly at -20 °C, which indicates lower reactivity of reagent
2
in comparison with the unstable PhI(N3)2 and PhI(N3)OTMS.
Azidoiodinanes 4a and 4b are even less reactive in this azidation
reaction. Thus, the reaction of 4b requires 3 h of reflux in
dichloromethane, while reagent 4a reacts with N,N-dimethyl-
anilines only at relatively high temperature, upon reflux in 1,2-
dichloroethane (bp 83 °C), to afford the respective products 6
in a moderate yield. Azidation of N,N-dialkylanilines by the
2
-iodosylbenzoic acid/TMSN3 system was previously reported
9b
by Magnus.
Plausible mechanism for azidation of N,N-
dimethylanilines with azidoiodinanes involves iminium cations
as key intermediates.9
c
The main advantage of reagents 2 and 4 over the known,
unstable PhIO/TMSN3 reagent combination is high thermal
stability allowing its use at higher temperatures. We have found
that the most stable azidoiodinanes 2 and 4b can even be used
for direct azidation of hydrocarbons at high temperatures and
in the presence of radical initiators (Table 3). Azidoiodinane
a
Isolated yields. b Additionally identified by reduction with LiAlH
to the respective amine 11. c Additionally identified by reduction with
LiAlH to the respective amine 14.
4
2
selectively reacts with isooctane 7 upon reflux in 1,2-
4
dichloroethane in the presence of catalytic amounts of benzoyl
peroxide to afford tertiary azide 8 and 2-iodobenzoic acid as
the only products according to NMR spectra of the reaction
mixture. The individual azide 8 can be easily isolated in a good
preparative yield by filtration of the reaction mixture through a
short silica gel column using hexane as the eluent. Azido-
iodinane 4b can also react with isooctane 7 under these
conditions, but the yield of azide 8 is substantially lower, and
the unreacted 4b can be recovered from reaction mixture even
after several hours of reflux.
To demonstrate the general character of azidation of hydro-
carbons, we studied reaction of azidoiodinanes 2,4b with
bicyclic and tricyclic hydrocarbons 9, 12, 15, 17, and 19 (Table
3
), all of which are known to be reactive in the free-radical
(
14) (a) Ochiai, M.; Y. Masaki, Y.; Shiro, M. J. Org. Chem. 1991, 56,
16
hydrogen abstraction reactions. The azidations were carried
out in 1,2-dichloroethane or chlorobenzene at 83-132 °C in
the presence of a catalytic amount of benzoyl peroxide. The
5
2
511. (b) Batchelor, R. J.; T. Birchall, T.; Sawyer, J. F. Inorg. Chem. 1986,
5, 1415.
(15) Otto, M.; Lotz, S. D.; Frenking, G. Inorg. Chem. 1992, 31, 3647.

DeriVatiVes of 1,2-Benziodoxole
J. Am. Chem. Soc., Vol. 118, No. 22, 1996 5195
process can be conveniently monitored by disappearance of the
Scheme 1
-
1
azide peak of the starting reagent at 2050 cm and emergence
-
1
of the product’s peak at about 2090-2100 cm in the IR
spectrum of the reaction mixture. The reaction was generally
complete in 3-4 h and, according to NMR and GC-MS data,
the major products in each case were the respective azides 10,
1
3, 16, 18, and 20 and 2-iodobenzoic acid. Pure azides can be
isolated in good yield by column chromatography on silica gel.
The best yields of azides 16, 18, and 20 were obtained in
chlorobenzene solution at temperatures 100-105 °C for reagent
components of the reaction mixture are exo-2-azidonorbornane
0, 2-iodobenzoic acid, and unreacted norbornane. Pure 2-azi-
donorbornane was isolated from the reaction mixture by column
2
and under reflux conditions (132 °C) for the less reactive
2
azidoiodinane 4b. Similar reactions of hydrocarbons with 2
generated from 2-iodosylbenzoic acid and TMSN3 in situ usually
gave lower yields of products. The presence of benzoyl
peroxide is essential for the reaction; employment of a mixture
azobis(isobutyronitrile)/benzoyl peroxide as radical initiator in
some cases leads to a slight yield improvement.
1
13
chromatography and identified by comparison of H NMR,
C
2
0
NMR and IR spectra with the literature data. Relatively low
yields of 2-azidonorbornane (15-45%) are explained by a
considerable decomposition of the starting reagent and the
product at higher temperatures, required for the reaction. As a
possible variation, iodinane 4b can be used in this reaction as
an azidating reagent, or reagent 2 can be generated in situ from
the commercially available 2-iodosobenzoic acid and azidotri-
methylsilane; however, the yields of 20 under these conditions
are even lower. Formation of 2-azidonorbornane instead of the
alternative 1-azidonorbornane is in agreement with the literature
data on the predominant formation of exo-2-substituted products
Reaction of cis-decalin 9 under these conditions selectively
afforded tertiary azide 10 in good preparative yield. Product
1
0 was identified by its spectra and by reduction to the known
17
amine 11.
2,6
Likewise, tricyclo[5.2.1.0 ]decane 12 was azidated with 2
at C-2 to give azide 13 as a yellow oil. For additional
identification azide 13 was reduced to the respective amine 14
by treatment with LiAlH4 in ether according to standard
procedure.3d The structure of amine 14 was elucidated by
21
in radical substitution reactions of norbornane.
It should be emphaszied that these reactions of azidoiodinanes
1
13
comparison of its H and C NMR with the previously reported
spectra of 2-substituted tricyclo[5.2.1.0 ]decanes.
2
and 4b represent a first experimental procedure for the direct
2,6
16b,c
azidation of alkanes. Recently, azides of polycyclic bridgehead
compounds have attracted an intense interest and research
activity due to their high reactivity and some useful properties.
For example, secondary azidonorbornenes are potentially im-
Adamantane 15 is known to be reactive in the hydrogen
1
6
abstraction reactions because of the relatively high stability
of the intermediate bridgehead free-radical.1 However, it is
generally less reactive than acyclic alkanes bearing tertiary
8
2
2
portant as energetic fuel additives, and azidoadamantanes are
1
8
19,23
hydrogens. We found that azidations of adamantane 15 and
,3-dimethyladamantane 17 required higher temperatures com-
pared to hydrocarbons 7, 9, and 12. The best yield of
-azidoadamantane 16 was obtained in the reaction of adaman-
used as precursors to various aza-bridged polycyclic systems.
1
To our knowledge, no direct preparation of azides from
bridgehead hydrocarbons was reported in the literature. In
particular, 2-azidonorbornane is usually synthesized by addition
1
2
0
tane with reagent 2 at 100-105 °C using chlorobenzene as the
solvent. Azidation of 1,3-dimethyladamantane 17 by reagent
of HN to norbornene, while azidoadamantanes are prepared
3
from the respective adamantanols or bromoadamantanes.19
2
under similar conditions afforded azide 18 in only 30-45%
The mechanism for azidation of alkanes with reagents 2 and
4b clearly has a free-radical origin which is consistent with the
literature data on radical mechanism for azidations by the
yield. However, the use of reagent 4b instead of 2 and carrying
out azidation at higher temperatures led to a substantial
improvement of the product 18 yield. Azides 16 and 18 were
isolated from the reaction mixture by column chromatography
and identified by comparison of their spectra with the literature
8c,9,24
unstable iodinanes, PhI(N ) and PhI(N )OTMS.
3
2
3
However,
in contrast with the previously reported reactions of the unstable
iodinanes, azidations by azidobenziodoxoles 2 and 4b require
the presence of radical initiators and higher temperature.
Specially performed experiments demonstrated that radical
initiators did not catalyze decomposition of azidobenziodoxoles
at 80-100 °C in the absence of the alkane. This result indicates
that the presence of alkane is essential to initiate the radical
chain process. A plausible mechanism for azidation of alkanes
is shown in Scheme 1. The reaction is initiated by benzoyl
radicals 23 generated by thermal decomposition of benzoyl
peroxide. Radical 23 (or phenyl radical, product of its decar-
boxylation) can serve as the initial hydrogen abstractor from
alkane. The propagation steps in this process involve the azide
abstraction by alkyl radicals and the hydrogen abstraction by
the 2-iodobenzoate radical 24. In full agreement with this
mechanistic scheme, the final isolated products are alkyl azide,
RN3, and 2-iodobenzoic acid.
1
9
data.
Norbornane 19 reacts with azidoiodinane 2 in the presence
of a radical initiator to afford exo-2-azidonorbornane 20 as the
principal product, without any detectable amounts of the
alternative 1-azidonorbornane as the product of azidation at the
bridgehead position. In a typical procedure, a mixture of
azidoiodinane 2, norbornane 19 (1-2 mol-equiv), and a catalytic
amount of benzoyl peroxide is heated to 100-105 °C in a
chlorobenzene solution. According to NMR spectra, the major
(
16) (a) Olah, G. A.; Faroog, O.; Prakash, G. K. In ActiVation and
Functionalization of Alkanes; John Wiley and Sons, Inc.: 1989; Chapter
. (b) Fokin, A. A.; Gunchenko, P. A.; Yaroshinsky, A. I.; Yurchenko, A.
2
G.; Krasutsky, P. A. Tetrahedron Lett. 1995, 36, 4479. (c) Krasutsky, P.
A.; Likhotvorik, I. R.; Dubinina, T. V.; Nesterenko, V. V.; Jones, M.
Tetrahedron Lett. 1995, 36, 3079. (d) Koch, V. R.; Gleicher, G. J. J. Am.
Chem. Soc. 1971, 93, 1657.
(
17) Feltkamp, v. H.; Thomas, K. D. Liebigs Ann. Chem. 1965, 683, 49.
Wylde, p. R.; Vidal, J.-P.; Bival, A.-M. Bull. Soc. Chim. Fr. 1970, 1174.
18) Lorand, J. P.; Chodroff, S. D.; Wallace, R. W. J. Am. Chem. Soc.
968, 90, 5266. Danen, W. C.; Tipton, T. J.; Saunders, D. G. J. Am. Chem.
(20) Breton, G. W.; Daus, K. A.; Kropp, P. J. J. Org. Chem. 1992, 57,
6646.
(21) Kooyman, E. C.; Vegter, G. C. Tetrahedron 1958, 4, 382. Fujimoto,
H.; Fukui, K. Tetrahedron Lett. 1966, 5551.
(
1
Soc. 1971, 93, 5186. Fort, R. C.; Hiti, J. J. Org. Chem. 1977, 42, 3968;
Lomas, J. S. J. Org. Chem. 1987, 52, 2629.
(22) Marchand, A. P.; Sorokin, V. D.; Rajagopal, D.; Bott, S. G. Synth.
Commun. 1994, 24, 3141.
(23) Margosian, D.; Speier, J.; Kovacic, P. J. Org. Chem. 1981, 46, 1346.
(24) Fontana, F.; Minisci, F.; Yan, Y. M.; Zhao, L. Tetrahedron Lett.
1993, 34, 2517.
(19) (a) Prakash, G. K. S.; Stephenson, M. A.; Shih, J. S.; Olah, G. A.
J. Org. Chem. 1986, 51, 3215. (b) Sasaki, T.; Eguchi, S.; Katada, T.;
Hiroaki, O. J. Org. Chem. 1977, 42, 3741.

5
196 J. Am. Chem. Soc., Vol. 118, No. 22, 1996
Zhdankin et al.
It is interesting to compare our results with the literature data
Materials. All commercial reagents were ACS reagent grade and
used without further purification. 1-Hydroxy-3,3-dimethyl-3-(1H)-1,2-
benziodoxole 3a was prepared from 2-iodobenzoic acid by a known
method.25 Benziodoxole 3b was prepared by oxidation of 2-(2-
on azidations by the unstable iodinanes, PhI(N3)2 and PhI(N3)-
OTMS. Recently, Magnus and co-workers have found that the
reaction of PhIO/TMSN3 with cyclohexene and triisopropylsilyl
26
iodophenyl)-1,1,1,3,3,3-hexafluoro-2-propanol with peracetic acid.
Methylene chloride and acetonitrile were distilled from CaH im-
9
b
enol ethers proceeds Via an azido-radical addition process. In
particular, cyclohexene reacts with PhIO/TMSN3 at -45 °C in
the presence of the stable radical TEMPO to afford a mixture
of cis- and trans-1,2-diazidocyclohexanes in 80% yield. A
plausible mechanism of this reaction involves the initial
generation of azido-radicals from PhI(N3)2 and their subsequent
addition to the double bond.9b In contrast with these data,
azidobenziodoxoles 2,4 in the presence of TEMPO or benzoyl
peroxide do not react with cyclohexene at temperatures below
2
mediately prior to use. Other solvents were of commercial quality from
freshly opened containers. The reaction flasks were flame-dried and
flushed with nitrogen.
1
-Azido-1,2-benziodoxole-3-(1H)-one (2). To a stirred mixture of
2
-iodosobenzoic acid 3 (0.53 g, 2 mmol) in dry acetonitrile (20 mL)
9b
was added trimethylsilylazide (0.53 mL, 4 mmol) under nitrogen at
room temperature. The reaction mixture was stirred for 10-15 h until
the formation of a clear, pale yellow solution. The resulting solution
was evaporated in vacuum to give slightly yellow microcrystalline
residue of azide 2, which was washed with anhydrous ether and dried
0
°C, or at room temperature, even after several hours of stirring.
The reaction of cyclohexene with reagent 2 proceeds only upon
reflux in 1,2-dichloroethane (bp 83 °C) in the presence of
catalytic amounts of benzoyl peroxide to afford the allylic azide
in vacuum: yield 0.54 g (94%); mp 138-140 °C (dec; from CH
3
CN);
), 1643 (CdO) cm ; H NMR (CDCl
COOH, 20:1) δ 8.32 (d, 1H, J ) 8 Hz), 8.05 (m, 2H, J ) 8 Hz),
-
1 1
IR (CCl
CF
.85 (t, 1H, J ) 8 Hz); C NMR (CDCl
CdO), 137.28, 128.69, 126.69, 126.57, 118.84, 117.66 (Ar). Anal.
Calcd for C IO : C, 29.09; H, 1.39. Found: C, 29.40; H, 1.48.
4
) 3065 (Ar), 2048 (N
3
3
/
3
2
2 (Table 3) and 2-iodobenzoic acid as major products according
13
7
3 3
/CF COOH, 20:1) δ 171.11
to NMR spectra of the reaction mixture. No 1,2-diazidocyclo-
hexane is formed under these conditions. The isolated yield of
azide 22 is relatively low (23%) due to a substantial decomposi-
tion of the product under reaction conditions and during aqueous
workup. Reagent 4b reacts with cyclohexene only at higher
temperature, upon reflux in chlorobenzene (bp 132 °C), to afford
the respective azide 22 in a low preparative yield. These results
are all consistent with the free radical chain mechanism shown
in Scheme 1 and exclude the alternative pathway involving the
azido-radicals as key intermediates.
(
H
7 4
2 3
N
CAUTION: Azidoiodinane 2 decomposes with an explosion upon
heating to 130-140 °C and should be handled with care.
1-Azido-3,3-dimethyl-3-(1H)-1,2-benziodoxole (4a). To a stirred
solution of 1-hydroxy-3,3-dimethyl-3-(1H)-1,2-benziodoxole 3a (0.200
g, 0.72 mmol) in dry CH
3
CN (15 ml) was added azidotrimethylsilane
(0.144 mL, 1.09 mmol) under nitrogen at room temperature. After
stirring 2 h reaction mixture was cooled to -15 °C, and the resulting
yellow precipitate of 4a was filtered under nitrogen and dried in
vacuum: yield 0.189 g (87%); mp 114-117 °C (from CH
CCl ) 2977 (Ar), 2921, 2034 (N ), 1558, 1458, 1435, 1241, 1154, 1110,
002, 948 cm ; H NMR (CDCl ) δ 7.78 (m, 1H), 7.55 (m, 2H), 7.26
m, 1H), 1.53 (s, 6H); 13C NMR (CDCl
) δ 149.12, 130.78, 130.17,
27.70, 126.60, 113.91 (Ar), 83.03 (C(CH , 29.44 (C(CH ). Anal.
Calcd for C : C, 35.66; H, 3.33; N, 13.86. Found: C, 35.73;
H, 3.31; N, 13.96.
-Azido-3,3-bis(trifluoromethyl)-3-(1H)-1,2-benziodoxole (4b).
To a stirred mixture of 1-hydroxy-3,3-bis(trifluoromethyl)-3-(1H)-1,2-
benziodoxole 3b (0.5 g, 1.3 mmol) in dry CH CN (20 mL) was added
3
CN); IR
(
1
4
3
Conclusions
-1 1
3
(
3
In summary, we prepared first stable azidoiodinanes 2,4a and
b from readily available benziodoxoles. The X-ray crystal
structure establishes molecule 4b as a five-membered iodine
1
)
3 2
3 2
)
4
9 3
H10ION
heterocycle with a weak covalent iodine-azide bond. The
1
(III)
geometry of the I NNN fragment in 4b is similar to the
literature electron diffraction data on monomeric iodine azide,
IN3, in gas phase.
3
trimethylsilylazide (0.35 mL, 2.6 mmol) under nitrogen at room
temperature. The reaction mixture was stirred for 18 h, and then the
resulting yellow solution was evaporated in vacuum to give a pale
yellow microcrystalline residue of azide 4b: yield 0.49 g (92%); mp
The scope of azidations with compounds 2 and 4 demonstrate
their usefulness as reagents for organic chemistry. It should
be emphasized that their reactivity is generally different from
the known reagent combinations PhIO/TMSN3 or PhI(OAc)2/
TMSN3, in which the unstable species PhI(N3)X or PhI(N3)2
serve as reactive intermediates in azidation reactions. In
particular, the low stability of PhI(N3)X or PhI(N3)2 restricts
its practical application only to low temperature reactions with
the most reactive, nucleophilic organic substrates, such as
alkenes, amines, and enol ethers, while stable azidoiodinanes 2
and 4b can be applied even to hydrocarbons at higher temper-
atures. The mechanism of azidation of hydrocarbons with
reagents 2 and 4 clearly has a free-radical origin which is
indicated by the reaction conditions and the product composition.
1
47-150 °C (from CH
3
CN); IR (KBr) 3082 (Ar), 2046 (N
3
), 1266,
CN, 10:1)
CN, 10:1) δ 134.04,
-1
1
1
186, 1141, 1111, 1041 (CF
3
) cm ; H NMR (CDCl
3 3
/CD
13
δ 7.9-7.65 (m, C
131.79, 131.48, 130.33, 128.30 (Ar), 123.42 (q, J ) 290 Hz, C(CF ) ),
6
H
4
); C NMR (CDCl /CD
3
3
3
2
114.26, 84.40 (septet, J ) 30.5 Hz, C(CF
IF ON : C, 26.30; H, 0.98. Found: C, 27.04; H, 1.14. X-ray quality
single crystals were obtained by slowly evaporating a solution of 4b
in CH CN in an open air container.
Crystallographic Data for 4b. Empirical formula: C
M ) 411.046, monoclinic, space group P2 /n (no. 14); cell constants
a ) 11.850 (3) Å, b ) 6.993 (2) Å, c ) 15.188 (2) Å, â ) 99.61 (2)
3 2 9 4
) ). Anal. Calcd for C H -
6
3
3
9 4 6 3
H F IN 0,
1
3
-3
deg, V ) 1240.79 Å , Z ) 4.0, D ) 2.200 g‚cm . Crystal dimensions
c
0
.21 × 0.20 × 0.16 mm. Data were collected at 291 K on an Enraf-
Nonius CAD-4 diffractometer, MoKR radiation, λ ) 0.71073 Å. The
intensities of 2497 nonzero reflections were measured; 2183 of unique
reflections in the range 4.0 < 2Θ < 50.0° were used for the structure
analysis (scan technique Θ/2Θ, scan width 0.800 + 0.340(tan Θ) deg,
data collection position: bisecting with ω ) 0). No decay correction
was applied [absorption correction, empirical; minimum % transmission,
Experimental Section
General Methods. All melting points were determined in an open
capillary tube with a Gallenkamp melting point apparatus and are
uncorrected. Infrared spectra were recorded on a Perkin-Elmer 1600
series FT-IR spectrophotometer. NMR spectra were recorded on a
7
6.31; maximum % transmission, 99.96; average % transmission, 88.81;
1
Varian VXR-300 spectrometer at 300 MHz ( H NMR) and 75 MHz
3
highest peak in final difference Fourier 1.138 e/Å ; summary of final
1
3
1
13
(
C NMR). Chemical shifts for H and C NMR are reported in parts
least squares refinement: weighting scheme-non-Poisson contribution;
1
per million (ppm). H chemical shifts are referenced relative to the
residual nondeuteriated solvent of chloroform at δ 7.24 or acetonitrile
(25) Amey, R. L.; Martin, J. C. J. Org. Chem. 1979, 44, 1779.
(26) Perozzi, E. F.; Michalak, R. S.; Figuly, G. D.; Stevenson III, W.
H.; Dess, D. B.; Ross, M. R.; Martin, J. C. J. Org. Chem. 1981, 46, 1049.
1
3
δ 1.93. The C chemical shifts are referenced relative to CDCl
7.0 or CD CN δ 1.3. Mass spectra were obtained with a Hewlet-
Packard 5970A GC-mass spectrometer (electron impact, 70 eV).
3
at δ
7
3
(
27) Alender, J.; Morgan, P.; Timberlake, J. J. Org. Chem. 1983, 48,
55.
(28) Murahashi, S.-I.; Imada, Y.; Tanigawa, Y. J. Org. Chem. 1989, 54,
3292.
7
Microanalyses for stable products were carried out by Atlantic
Microlab, Inc., Norcross, Georgia.

DeriVatiVes of 1,2-Benziodoxole
J. Am. Chem. Soc., Vol. 118, No. 22, 1996 5197
ignorance factor, P ) 0.05; data rejected if I < 3.00 σ(I) and sin Θ/λ
NMR (CDCl
3
) δ 1.1-2.2 (m); 13C NMR (CDCl
3
) δ 69.0, 56.67, 49.85,
+
<
0.0500; 1943 observations; 172 variables; data-to-parameter ratio
41.65, 40.93, 36.88, 28.74, 26.41, 21.62; m/z (%) 151 (100), M . Anal.
for 14‚HCl: Calcd for C10H18ClN: C, 63.99; H, 9.67; N, 7.46.
Found: C, 63.94; H 9.45; N, 7.17. H and C NMR of 14 are in
1
1
0.06; shift to error ratio 0.004; error in an observation of unit weight
.9166; R factor 0.0363; weighted R factor 0.0484]. All hydrogen atoms
1
13
were calculated and included in the final least-squares refinements. All
calculations were carried out using the MOLEN software distributed
by Enraf-Nonius.
Typical Procedure for Azidation of N,N-Dimethylarylamines with
Azidobenziodoxole 2. To a stirred mixture of azidobenziodoxole 2
good agreement with previously reported spectra of 2-substituted
tricyclo[5.2.1.02 ]decanes.
,6
16b,c
Typical Experimental Procedure for the Azidation of Bridgehead
Hydrocarbons (15, 17, and 19) with Azidoiodinane 2. To a stirred
mixture of azidobenziodoxole 2 (0.14 g, 0.48 mmol) and adamantane
15 (0.07 g, 0.47 mmol) in dry chlorobenzene (20 mL) was added a
catalytic amount of benzoyl peroxide (5 mg) under nitrogen at room
temperature. The reaction mixture was then stirred at 100-105 °C
for 3-4 h, and the resulting dark orange solution was evaporated in
vacuum to give a residual brown oil which was passed through a short
silica gel column with hexane to give 1-azidoadamantane 16 as a clear,
(0.075 g, 0.26 mmol) in dry dichloromethane (10 mL) was added
4
-bromo-(N,N-dimethylaniline) (0.057 g, 0.29 mmol) under nitrogen
at room temperature. The reaction mixture was then refluxed for 0.5
h. The reaction can be monitored by disappearance of the azide peak
-
1
of the starting reagent at 2048 cm and emergence of the product’s
-1
peak at about 2100 cm in the IR spectrum of the mixture. According
to NMR spectra, 4-bromo-(N-azidomethyl-N-methyl)aniline 6a and
partially crystalline oil: R
f
(hexane) ) 0.72, yield 0.057 g (68%); mp
77-80 °C (from CH
3
OH) (lit.1 mp 76-77 °C).
9a
2
-iodobenzoic acid were the only reaction products. Pure 6a can be
isolated by column chromatography on silica gel: yield 0.115 g (91%);
1-Azido-3,5-dimethyladamantane 18 and exo-2-azidonorbornane 20
were prepared similarly. For 18: 45% yield; colorless oil; IR (neat)
-
1 1
IR (neat) 2102 (N
3
) cm ; H NMR (CDCl
3
) δ 7.0 (m, 5H, Ph), 4.84
-
1 1
(
s, 2H, CH
2
); 3.09 (s, 3H, CH ); MS (EI, 70 eV) m/z (%) 146 (100),
3
2911, 2844, 2089 (N ), 1450, 1283, 1017, cm ; H NMR (200 MHz,
3
+
M . Products 6b,c were prepared similarly and identified by com-
parison of their IR and NMR spectra with the literature data.9c
N-Azidomethyl-N-methylaniline (6b). According to the above
typical procedure, 2 (0.235 g, 0.813 mmol) was reacted with N,N-
dimethylaniline (0.108 g, 0.894 mmol) to give 0.101 g (77%) of 6b:
CDCl ) δ ) 2.2 (1H, m, CH), 1.1-2.0 (12H, m, 6CH ), 0.87 (6H, s,
3
2
19a
1
2Me); lit. data for 18 mp 25-26 °C; IR (KBr) 2100 (N ); H NMR
3
1
9b
(CDCl ) δ ) 2.0-2.4 (m, 2H), 1.0-1.8 (m, 12H), 0.89 (s, 6H). For
3
20: 45% yield; colorless oil; IR (neat): 2950, 2090 (N ), 1450, 1290,
3
-
1 1
1001, cm ; H NMR (200 MHz, CDCl ) δ ) 3.45 (1H, dd, J ) 7.5
3
-
1
1
13
IR (neat) 2098 (N
3
, s) cm ; H NMR (CDCl
3
) δ 7.0 (m, 5H, Ph), 4.83
and 2.5 Hz, CHN ), 2.28 (2H, m, 2CH), 1.1-1.7 (8H, m); C NMR
3
+
(s, 2H, CH ), 3.05 (s, 3H, CH
2
3
); m/z (%) 162 (100), M .
(CDCl ) δ ) 64.0 (d), 41.6 (d), 38.2 (d), 35.5 (t), 34.7 (t), 28.1 (t),
3
+
20
4
-(N-Azidomethyl-N-methylamino)pyridine (6c). By following
25.5 (t). MS (EI, 70 eV) m/z (%) 137 (5), M ; lit. data for exo-2-
1
3
the above typical procedure, reaction of 2 (0.307 g, 1.064 mmol) and
azidonorbornane IR (neat) 2090 (N ); H NMR δ ) 3.45 (1H, ddd, J
) 7.6, 2.6, and 1.3 Hz, CH), 2.28 (2H, s, CH), 1.1 (3H, m), 1.5 (5H,
m).
4
6
7
-dimethylaminopyridine (0.134 g, 1.17 mmol) gave 0.156 g (90%) of
-
1
1
c: IR (neat) 2106 (N
.87 (dd, 2H) 4.91 (s, 2H, CH
Azidation of 4-Bromo-N,N-dimethylaniline with Azidobenz-
iodoxole 4b. According to the above typical procedure, reagent 4b
3
, s) cm ; H NMR (CDCl
3
) δ 8.5 (m, 2H),
2
), 3.24 (s, 3H, CH ).
3
Reactions of Azidoiodinanes with Cyclohexene. To a stirred
mixture of azidobenziodoxole 2 (0.325 g, 1.125 mmol) in dry 1,2-
dichloroethane (15 ml) was added cyclohexene (0.23 mL, 2.25 mmol)
at room temperature under nitrogen. Catalytic amounts of benzoyl
peroxide (0.005 g) and 1,1′-azobis(cyclohexanecarbonitrile) (0.005 g)
were added as radical initiators. The reaction mixture was then refluxed
for 3 h. The resulting solution was evaporated in vacuum. A yellow
oil was dissolved in hexane (20 mL) and filtered through a silica gel
plug to give a colorless solution. It was washed with 10% NaOH (2
× 30 mL) and water (30 mL), dried over Na SO and evaporated in
(0.212 g, 0.516 mmol) was reacted with 4-bromo-(N,N-dimethylaniline)
(0.114 g, 0.567 mmol) in dichloromethane (10 mL) at reflux for 3 h to
give the respective azide 6a as the major product: isolated yield 0.076
g (61%).
2
-Azido-2,4,4-trimethylpentane (8). Typical Procedure. To a
stirred mixture of azidobenziodoxole 2 (0.234 g, 0.81 mmol) in dry
,2-dichloroethane (15 mL) was added 2,2,4-trimethylpentane 7 (0.267
1
2
4
mL, 1.62 mmol). Catalytic amounts of benzoyl peroxide (0.005 g)
and 1,1′-azobis(cyclohexanecarbonitrile) (0.005 g) were added as radical
initiators. The reaction mixture was then refluxed for 3 h. The resulting
solution was evaporated in vacuum. A brownish residue was dissolved
in hexane (20 mL) and filtered through a silica gel plug to give a
colorless solution. It was washed with 10% NaOH (2 × 30 mL) and
vacuum to give the resulting azide 22 as a colorless oil: yield 0.032 g
(23%); IR (neat) 2095 (N ,s) cm-1
; H NMR (CDCl ) δ 5.3-6.0 (m,
1
3
3
2H), 3.7-4.1 (m, 1H), 1.3-2.3 (m, 6H); MS (EI, 70 eV) m/z (%) 123
+
; lit. data28 for 3-azido-1-cyclohexene IR (neat) 2095 (N , s)
(100), M
3
cm-1
1
; H NMR (CCl ) δ 5.43-6.15 (m, 2H), 3.58-4.40 (m, 1H), 1.5-
2.4 (m, 6H).
4
water (30 mL), dried over Na
2 4
SO , and evaporated in vacuum to give
Likewise, azidobenziodoxole 4b (0.247 g, 0.601 mmol) was reacted
with cyclohexene (0.122 mL, 1.202 mmol) in chlorobenzene (10 mL)
at reflux (132 °C) for 1 h to give the respective azide 22 as the major
product; isolated yield 0.015 g (20%).
the resulting azide 8 as a colorless oil: yield 0.095 g (76%); IR (neat)
-
1 1
2
099 (N
C(CH ), 1.02 (s, 9H, C(CH
pentane: IR (neat) ν ) 2100 (N
3
) cm ; H NMR (CDCl
3
2
) δ 1.51 (s, 2H, CH ), 1.32 (s, 6H,
)
3 2
3 3
) ); lit. data for 2-azido-2,4,4-trimethyl-
1
3
); H NMR δ ) 1.52 (s, 2H), 1.31 (s,
2
7
6
H), 1.02 (s, 9H).
-Azido(decahydronaphthalene) (10). By following the above
Acknowledgment. This work was supported by a research
grant from the National Science Foundation (NSF/CHE-
9
typical procedure, reaction of 2 (0.305 g, 1.055 mmol) and cis-
decahydronaphthalene 9 (0.292 g, 2.110 mmol) gave 0.117 g (62%) of
9505868) and by a Cottrell College Science Award of Research
Corporation. Acknowledgement is also made to the Donors of
The Petroleum Research Fund, administered by the ACS, for
partial support of this research. Special thanks are made to Dr.
Atta M. Arif (University of Utah, Salt Lake City) for X-ray
structural analysis of compound 4b. This paper is dedicated to
Professor Nikolai S. Zefirov on the occasion of his 60th birthday.
-
1 1
1
0
0 as a yellow oil: IR (neat) 2093 (N
3
, s) cm ; H NMR (CDCl
3
) δ
+
.75-1.9 (m); MS (EI, 70 eV) m/z (%) 179 (100), M . Treatment of
azide 10 with an excess of LiAlH
4
in ether at room temperature
3d
according to standard procedure afforded the respective, known amine
17
1
1.
2
-Azidotricyclo[5.2.1.02,6]decane (13). According to the above
typical procedure, 2 (0.330 g, 1.142 mmol) was reacted with tricyclo-
2
,6
[
5.2.1.0 ]decane 12 to give the respective azide 13 as a yellow oil:
Supporting Information Available: Tables of positional
parameters and ESD, anisotropic displacement parameters, and
bond lengths and bond angles for compound 4b (9 pages).
Ordering information is given on any current masthead page.
-
1 1
3 3
yield 0.103 g (51%); IR (neat) 2090 (N ) cm ; H NMR (CDCl ) δ
1
.2-2.5 (m).
For additional identification azide 13 was reduced to amine 14 by
3d
4
treatment with LiAlH in ether according to standard procedure. For
amine 14: a colorless oil; IR (neat) 3355, 3276 (NH
-
1
1
2
, s) cm ; H
JA954119X