Reactions of 1-haloadamantanes and ethylmercury chloride with nitronate anions by the SRN1 mechanism

Article abstract of DOI:10.1039/b418305c

Secondary or tertiary nitro compounds can be easily obtained by photostimulated reaction of the anions corresponding to primary or secondary nitroalkanes with either 1-iodoadamantane (1-AdI) or ethylmercury chloride (EtHgCl) by the S_RN1 mechani

Full text of DOI:10.1039/b418305c

View Article Online / Journal Homepage / Table of Contents for this issue
P A P E R
Reactions of 1-haloadamantanes and ethylmercury chloride with
nitronate anions by the SRN1 mechanism
Ana N. Santiago,* Silvana M. Basso, Carlos A. Toledo and Roberto A. Rossi*
´ ´ ´
INFIQC, Departamento de Quımica Organica, Facultad de Ciencias Quımicas, Universidad
´
´
Nacional de Cordoba, Ciudad Universitaria, 5000 Cordoba, Argentina.
E-mail: rossi@dqo.fcq.unc.edu.ar, santiago@dqo.fcq.unc.edu.ar;
Fax: +54 351 433 3030; Tel: +54 351 4334170
Received (in Montpellier, France) 3rd December 2004, Accepted 2nd February 2005
First published as an Advance Article on the web 6th May 2005
Secondary or tertiary nitro compounds can be easily obtained by photostimulated reaction of the anions
corresponding to primary or secondary nitroalkanes with either 1-iodoadamantane (1-AdI) or ethylmercury
chloride (EtHgCl) by the SRN1 mechanism. Only 1-AdI requires the presence of the enolate anion of acetone
as an entrainment reagent. The procedure works well with the nitroanions derived from 1-nitropentane,
nitroethane or 6-nitrohex-1-ene, but with 2-nitropropane ion the outcome depends on the substrate and
solvent.
achieved under irradiation or in the presence of FeBr2 in
DMSO.7
Even though no reaction has been observed under irradia-
Introduction
It has been observed that the reactivity of bridgehead halides
with different nucleophiles depends on the strain energy, the
nature of the leaving group, the nucleophile, and the solvent.
Bridgehead halides have a high-energy barrier for a polar
mechanism due to strain factors, and some of these halides
have been found to react by the SRN1 mechanism.1 This
mechanism is a chain process with radicals and radical anions
as intermediates through which a bridgehead substitution is
easily obtained. The initiation step [eqn. (1)] is an electron
transfer (ET) from the nucleophile or from a suitable electron
source to give the radical and the halide ion by a dissociative
ET.2 The propagation steps consist in the coupling of the
radical with the nucleophile to give a radical anion [eqn. (2)],
which by ET to the substrate [eqn. (3)] forms the intermediates
necessary to continue the propagation cycle.
tion of 1-AdI with nitromethane ion, this anion gave the
substitution product in the presence of acetophenone (58%
yield) or acetone enolate anions (87% yield) as entrainment
nucleophiles under irradiation4,5 or in the presence of FeBr26 in
DMSO. The 1-Add radicals are formed under photostimula-
tion with acetone enolate ion [eqn. (1)], but they do not couple
with the nucleophile to follow the SRN1 mechanism, at least at
a rate to compete with other reactions (reduction or dimeriza-
tion). The nitromethane ion is unable to initiate the photo-
stimulated SRN1 reaction, but it does propagate the chain cycle
very efficiently.5
In order to synthesize adamantylnitromethanes in good
yields we decided to investigate the reaction of 1-bromo-,
2-bromo-, 1,3-dibromo- and 1,4-dibromoadamantanes with
nitromethane ions in DMSO and in liquid ammonia.8 The
photostimulated reaction of 1-AdX (X = Br, I) or 2-AdBr with
nitromethane ions gave good yields of the substitution product
Electron Donor
RX ꢀ! Rꢁ þꢀ
X
ð1Þ
9
1-AdCH2NO2 or 2-AdCH2NO2 , respectively, in the presence
ꢀ
Rd + Nuꢀ - (RNu)d
(2)
(3)
of the enolate anions of acetone (entrainment conditions) in
liquid ammonia. Although these reactions can be useful for
preparing other nitroadamantyl derivates, a more thorough
study is necessary so as to determine the scope of these
reactions.
(RNu)d + RX - RNu + Rd + Xꢀ1
ꢀ
It is known that in liquid ammonia solution, the photostimu-
lated reaction of 1-iodoadamantane (1-AdI) with several car-
banions, such as those derived from acetone, N-acetylmor-
pholine, acetylacetone or acetonitrile, afforded the reduction
product adamantane (AdH) and the dimeric product 1,10-
biadamantane,3 as the only products. In these cases substitu-
tion products are not formed.
However, later it was observed that in DMSO the photo-
stimulated reaction of 1-AdI with acetone enolate anions gave
the substitution product 1-adamantylacetone (20%), together
with AdH (17%). The substitution product was also obtained
with acetophenone enolate anions, which gave 48% of
1-adamantylacetophenone under irradiation4,5 or 85% in the
reaction induced by FeBr2.6 The photostimulated reaction of 1-
AdI with anthrone anion also gave good yields (75%) of the
substitution product in DMSO.5 The reaction of 1-AdI with
the anion from N-acetylthiomorpholine has been successfully
Recently, it has been reported that cyanide ions also reacted
by the SRN1 mechanism with 1,3,5,7-tetrabromoadamantane
in DMSO, affording the tetrasubstituted product in good yields
(72%) in a photostimulated reaction (l = 254 in quartz).10
On the other hand, alkylmercury halides (RHgX) are easily
reduced to Rd, Hg0 and Xꢀ and can initiate a chain reaction by
addition to an appropriate nucleophile.1,11 Furthermore, the
RHgX are reagents that have moderate reactivity in electro-
philic substitution and low reactivity in SN2 substitution at
carbon because of the unfavorable polarity of the C–Hg bond
(
ꢀdR–Hgd+Cl).12 Thus, RHgX has been proposed to react with
primary or secondary nitronate ions by the SRN1 mechanism
[eqns. (4) and (5)]:13
ꢀ
d
Rd + ꢀCR1R2NO2 - RR1R2CNO2
(4)
T h i s j o u r n a l i s & T h e R o y a l S o c i e t y o f C h e m i s t r y a n d t h e
C e n t r e N a t i o n a l d e l a R e c h e r c h e S c i e n t i f i q u e 2 0 0 5
N e w J . C h e m . , 2 0 0 5 , 2 9 , 8 7 5 – 8 8 0
875

View Article Online
Table 1 Reaction of 1-AdX with 1 and acetone enolate ions in DMSOa
Entry
1-AdX
Conditions
% Xꢀb
Products (%)c
1
2e
3
1-AdBr
1-AdBr
1-AdI
hn
hn
Dark
37
77
30
98
28
2 (0), 1-AdOH (30)d
2 (75), 1-AdH (traces)f
2 (0), 1-AdOH (15)
2 (85), 1-AdOH (8)
2 (15), 1-AdOH (17)
4
5g
1-AdI
1-AdI
hn
hn
a
The concentration of substrate was 3.33 ꢂ 10ꢀ3 M. The concentration of 1 was 1 ꢂ 10ꢀ2 M and that of acetone enolate ion 6.67 ꢂ 10ꢀ3 M. The
b
c
d
reaction time was 6 h. Determined potentiometrically. Quantified by GLC by the internal standard method with Ph3As as reference. Substrate
e
recovered in 56%. The solvent was liquid ammonia. Substrate recovered in 15%. p-DNB (20 mol %) was added.
f
g
ꢀ
RR1R2CNO2 + RHgX - RR1R2CNO2
d
a double bond are not easy to synthesize by the standard
procedures.
+ Rd + Hg0 + Xꢀ (5)
The synthesis of these nitro derivatives is of great interest
since a nitro group is readily transformed into a number of
other useful functional groups,17 increasing the synthetic value
of the reaction.
The procedure works well with alkylmercury chloride, bromide
and iodide, even in the presence of other functionalities, with-
out formation of alkyl nitrites. Tertiary nitro alkanes can be
easily obtained by this method.
Results
It was suggested that the ET to RHgX is dissociative, on the
basis that the reactivity of RHgX in competitive reactions with
2-nitropropane ions is determined by the stability of the Rd
radical.14 This reaction is initiated by light and inhibited by
radical scavengers or oxygen. Another piece of mechanistic
evidence is the observation of products from the cyclization of
the 5-hexenyl radical in the reaction of 5-hexenylmercury
chloride with 2-nitropropane ions.15 The nature of the photo-
initiation appears not to involve homolysis, since simple RHgX
do not absorb light above 310 nm. Russell et al. proposed an
ET to RHgX from a photoexcited nitronate anion for the
initiation path, due to the fact that no charge transfer complex
was detected.16
Reactions of 1-AdX with the anion of 1-nitropentane (1)
1-AdBr reacts with the anion of 1-nitropentane (1), in the
presence of acetone enolate ion, in DMSO under irradiation to
afford 1-AdOH and only a trace of the substitution product 1-
(1-nitropentyl)adamantane (2). It was suggested that 1-AdOH
is formed by a polar bromophilic type mechanism within a
solvent cage reaction to furnish the observed product.8 How-
ever, in liquid ammonia this bromophilic reaction did not
occur, and 1-AdBr reacted with 1 under photostimulation in
the presence of acetone enolate anion to give the substitution
product 2 in 75% yield [eqn. (6), Table 1, experiments 1 and 2].
In order to synthesize secondary or tertiary nitro compounds
we decided to investigate the unreported reaction of 1-AdX
(X = I, Br) and EtHgCl with some nitronate anions in DMSO
and in liquid ammonia by the SRN1 mechanism. This approach
provides a facile preparation of 1-adamantyl compounds bear-
ing a nitro group. Herein, we report on results that were
obtained upon extension of our investigations on nitronate
anions, different from nitromethane, so as to determine the
scope and limitations of these reactions. Unfortunately, the
classic substitution reactions of nitranions are impractical for
the preparation of substituted nitroalkanes due to the forma-
tion of the O-alkylation product. The procedure we report here
can be of great interest due to the absence of unwanted
product. Also, we studied nitronate anions that can contain a
double bond. In these cases, the substitution products bearing
ð6Þ
In the same way, under dark conditions 1-AdI reacted with 1 to
afford 1-AdOH, but under photostimulation in the presence of
acetone enolate anion, it affords the substitution product 2 in
85% yield [eqn. (6)]. No products derived from acetone enolate
anion were found, and 1-AdOH was observed in 8% yield. The
photostimulated reaction in the presence of acetone enolate
ions was inhibited by p-dinitrobenzene (p-DNB), a well-known
inhibitor of SRN1 reactions1 (Table 1, experiments 3–5).
Table 2 Reaction of 1-AdI and EtHgCl with nitranions in DMSO
Entry
Substratea
Nucleophileb
Conditions
Time/min
% Xꢀc
Products (%)d
1e
2e
1-IAd
1-IAd
3a
3a
3b
3b
3a
3a
3b
3b
3c
3c
3c
3c
3c
3d
Dark
hn
Dark
hn
Dark
hn
Dark
hn
Dark
hn
hn
hn
hn
360
360
360
360
180
180
180
180
360
360
360
360
180
360
22
99
24
94
nq
nq
nq
nq
32
87
37
85
nq
85
4a (0)f, 1-AdOH (17%)
4a (84), 1-AdOH (5%)
4b (0), 1-AdOH (13%)
4b (77), 1-AdOH (4%)
5a (0)
3e
1-IAd
1-IAd
4e
5
EtHgCl
EtHgCl
EtHgCl
EtHgCl
1-IAd
6
5a (68)
5b (0)
5b (50)
7
8
9e
1-AdOH (25)
6 (17), 7 (13), AdH (14)
8 (21)
10e
11eg
12egh
13
14e
a
1-IAd
1-IAd
1-IAd
EtHgCl
1-IAd
8 (50), AdH (3)
9 (65)
AdH (55)
hn
The concentration of substrate was 3.33 ꢂ 10ꢀ3 M. The concentration of nucleophile was 1.0 ꢂ 10ꢀ2 M. Determined potentiometrically;
b
c
nq = not quantified. Quantified by GLC and the internal standard method. Acetone enolate ions (6.67 ꢂ 10ꢀ3 M). 1-AdI was recovered
d
e
f
in 95%. The solvent was liquid ammonia The concentration of nucleophile was 1.67 ꢂ 10ꢀ2 M.
g
h
876
N e w J . C h e m . , 2 0 0 5 , 2 9 , 8 7 5 – 8 8 0

View Article Online
in good yields in DMSO. The presence of acetone enolate ion
as entrainment reagent is necessary for these reactions to occur.
A reaction between a nucleophile and a substrate may be rather
unreactive at initiation, but quite reactive at propagation. The
addition of small amounts of another nucleophile that is more
reactive at initiation increases the generation of the reactive
intermediates and allows the less reactive nucleophile to start
its own propagation (entrainment reaction).
Reactions of 1-AdI and EtHgCl with nitranions in DMSO
1-AdI reacted under photostimulation with nitroethane (3a) or
6-nitrohex-1-ene (3b) ions in the presence of acetone enolate
anion to give the substitution products 4a and 4b in 84% and
77% yields, respectively [eqn. (7)]. These nucleophiles afford
1-AdOH in the dark (Table 2, experiments 1–4).
The facts that these reactions did not occur in the dark and
were inhibited by p-DNB are indicative that 1-AdI reacts with
these nitranions by the SRN1 mechanism.
The dark reaction of 1-AdI with nitranions only afforded
1-AdOH, whereas under irradiation, the substitution products
were formed in high yields, along with small amounts of
1-AdOH. These results indicate that in dark conditions
1-AdI only reacts by a polar mechanism to furnish 1-AdOH;
however, under irradiation the SRN1 mechanism takes over the
polar reaction to give mainly the substitution products.
On the other hand, the reaction of 1 with 1-AdBr, which is a
less reactive substrate than the iodo derivative in ET reactions,
only yielded 1-AdOH in the photostimulated reaction in
DMSO. This result indicates that the polar reaction is faster
than the radical one. Conversely, a different product distribu-
tion was observed in the reaction of 1-AdBr with 1 in liquid
ammonia. Thus, the photostimulated reaction affords the
substitution product in high yield, and no 1-AdOH is found.
In these experimental conditions, the SRN1 mechanism is faster
than the polar one.
ð7Þ
On the other hand, EtHgCl did not react with 3a or 3b in the
dark; however, under irradiation the substitution products
were found in 68% and 50% yields, respectively [eqn. (8);
Table 2, experiments 5–8].
ð8Þ
5b was synthesized in order to be used later as a precursor of
another nitroanion.
1-AdI reacts with 2-nitropropane (3c) and acetone enolate
anions in the dark in DMSO to afford 1-AdOH; however,
under irradiation, it affords the hydrocarbon 6 (17%) and the
olefin 7 (13%), together with AdH (14%) (Table 2, experiments
9 and 10). No substitution product with the nitro group was
found [eqn. (9)].
As regards the anions of a secondary nitro compound, such
as 3c, the photostimulated reaction in DMSO gave the hydro-
carbon 6, the olefin 7 and the reduction product AdH. The
formation of these products is depicted in eqns. (13)–(15).
ð13Þ
ð9Þ
Conversely, in liquid ammonia as solvent, 1-AdI reacted with
3c, under photostimulation in the presence of acetone enolate
anion, to give the substitution product 8 in 21% yield and only
a trace of AdH was found [eqn. (10)]. When the concentration
of the nucleophile was increased, 8 was obtained in 50% yield
(Table 2, experiments 11 and 12).
ð14Þ
ð15Þ
ð10Þ
In contrast, the photostimulated reaction of 3c with EtHgCl
afforded the tertiary substitution product 2-methyl-2-nitro-
butane (9) in 65% yield in DMSO [eqn. (11); Table 2, experi-
ment 13].
Once the 1-Add radical is formed in the initiation step, it
couples with 3c to give the radical anion 10 [eqn. (13)]. This
radical anion, instead of transferring the odd electron to the
substrate in the sense of eqn. (3) of the propagation cycle,
fragments faster to give the radical 11 and nitrite ions [eqn.
(14)]. Radical 11 does not couple with 3c, but by a dispropor-
tion reaction it affords the products 6 and 7 [eqn. (15)].
The fact that the main product is the reduction product AdH
indicates that the coupling reaction of 1-Add radical with the
secondary anion 3c is not efficient, probably due to steric
reasons, and 1-Add radicals are reduced to AdH.
The driving force of radical anion 10 fragmentation is the
formation of the tertiary radical 11 and nitrite ions. There are
precedents in the literature of fragmentation process of radical
anions during the SRN1 cycle. Thus, nitromethane anion and
other nitranions react with aryl radicals [eqn. (16)],18,19 or vinyl
radicals [eqn. (17)],20 and the radical anions formed fragment
to give radicals and nitrite ions faster than ET to the substrates
can occur. The driving force of these fragmentation reactions is
the formation of the stable benzylic 12 and allylic 13 radicals
and nitrite ions.
ð11Þ
Finally, a new nitroanion, 6-nitrooct-1-ene (3d), reacted
under irradiation with 1-AdI in the presence of acetone enolate
anion, affording AdH in 55% yield [eqn. (12)] and only traces
of different substitution products (Table 2, experiment 14).
ð12Þ
Discussion
The photostimulated reactions of 1-AdI with primary nitra-
nions, such as 1, 3a and 3b, afforded the substitution products
N e w J . C h e m . , 2 0 0 5 , 2 9 , 8 7 5 – 8 8 0
877

View Article Online
ions, which indicates that EtHgCl is easier to reduce (peak
potential ꢀ0.6 V vs. SCE)26 than 1-AdI (peak potential ꢀ2.20
vs. SCE27 or ꢀ2.01 vs. SHE28). The radical anion formed in the
coupling of Etd radical with 3c did not fragment in DMSO,
which indicates that intermolecular ET to the substrate was
faster than its fragmentation. The higher rate for intermole-
cular ET is due to the fact that EtHgCl is easier to reduce
than 1-AdI.
ð16Þ
ð17Þ
On the other hand, straightforward substitution is achieved
by reaction of nitromethane ions with 1-AdX,4,5,8, 2-IAd,8,9
neopentyl21 and neophyl22 iodides, and 7-iodonorcarane,6 in
liquid ammonia or DMSO. In these cases, the fragmentation
would give a primary radical and the ET reactions to the
substrates are faster than the fragmentation rates [eqn. (18)].
The fact that EtHgCl does not react with nitranions in the
dark, but that it does under irradiation, suggests that these
reactions occur by the SRN1 mechanism. This synthetic ap-
proach is important to obtain secondary or tertiary nitro
compounds from primary ones. Tertiary nitro alkanes can be
easily obtained by this method. These reactions are compatible
with many functional groups, as compared to the drastic
experimental conditions of other C-alkylation processes such
as the reaction of alkyl halides with the dianion of the primary
nitro compound.29
ð18Þ
In our study, in the reaction of 1-IAd with secondary nitra-
nions, the fragmentation reaction led to a stable tertiary
radical, such as 11. Under these conditions this reaction
prevails over the ET to the substrate. The reaction of second-
ary nitronate anions with aliphatic substrates bearing electron-
withdrawing groups, such as 2-bromo-2-nitropropane23 or
4-nitrobenzylbromide,17b afforded the substitution products
(90% and 92% yields, respectively) in the reaction with
2-nitropropane anion. No fragmentation was observed due
to the formation of stabilized radical anions.1
Conclusion
We have reported the conversion of EtHgCl and 1-AdX to
nitroalkanes by reaction with nitranions under irradiation
(SRN1 reactions). These results can be of great interest to
obtain aliphatic nitro compounds as precursors in organic
synthesis.
Compared with the standard procedures, our method offers
a series of important advantages, such as better yields, reac-
tions compatible with some functional groups, less drastic
experimental conditions, and the absence of formation of
unwanted alkyl nitrites.
On the other hand, in liquid ammonia the photostimulated
reaction of 1-IAd with 3c gave only the straightforward sub-
stitution product. In this case the ET reaction is faster than the
fragmentation reaction.
Experimental
There are precedents that changing the solvent from DMSO
to liquid ammonia modifies the product distribution in SRN1
reactions.24 This behavior is attributed to differences in the ratꢀe
constant of intra-ET vs. inter-ET of the radical anion 14d
[eqn. (19)].
Methods and materials
Irradiation was conducted in a reactor equipped with two
400 W UV lamps emitting with a maximum at 350 nm (Philips
Model HPT, water-refrigerated). The HRMS were recorded at
Santiago of Compostela University (RIAIDT), Spain.
1-AdBr, 1-AdI, ethyl chloride, magnesium, acetone, nitro-
ethane, nitropropane, 6-nitrohex-1-ene, 1-nitropentane and
potassium t-butoxide were commercially available and were
used as received. DMSO was distilled under vacuum and
stored under molecular sieves (4 A).
ð19Þ
While disꢀsociative intra-ET is the main reaction of radical
Preparation of ethyl mercury chloride
anion 14d in DMSO to yield radical 15, the main reaction of
ꢀ
14d in liquid ammonia is intermolecular ET to afford 14. It
The ethyl mercury chloride (EtHgCl) was obtained by a
modification of the Marvel30 method. The Grignard com-
pound was prepared from 2.7 g (77 mmol) of magnesium
turnings and EtCl in excess. The Grignard solution was added
to 18.7 g (69 mmol) of powdered HgCl2 suspended in 30 mL of
dry THF. After all the Grignard solution had been added, the
mixture was stirred and refluxed for 24 h. EtHgCl could not be
recrystallized by conventional methods, since it decomposes
readily. Acetone was added to the solid at room temperature
and the suspension was filtered. The acetone was then evapo-
rated under vacuum at room temperature. The EtHgCl was
obtained as long needles crystals, mp 192–193 1C (lit.31 mp
192.5 1C).
has been reported that unsubstituted benzyl halides do not
form radical anions in acetonitrile and follow a concerted
dissociative pathway.25 The fact that the main product isꢀthe
substitution one, 14, indicates that the radical anion 14d is
indeed an intermediate in liquid ammonia and survives to
transfer its odd electron to the substrate. We do not know if
it is formed in DMSO or if the ET reaction follows a concerted
dissociative pathway.
The coupling reaction of 1-Add radical with 3c afforded
radical anion 10. In DMSO as solvent, it fragmented in the
sense of eqn. (14) faster than intermolecular ET to the sub-
strate; however, in liquid ammonia as solvent, the intermole-
cular ET was faster than its fragmentation. In order to trap the
radical formed in the sense of eqn. (14), we performed the
reaction of 1-IAd with the secondary nitronate anion 3d,
prepared from 5b. But this nucleophile did not couple with
the 1-Add radical, probably for steric reasons; AdH was the
main product obtained and only traces of different products
were observed by GC-MS. Thus, we can conclude that 3c gives
the substitution product in liquid ammonia.
Photostimulated reactions
1-Adx with nitronate anions in liquid ammonia. The following
procedure is representative. The reactions were carried out in a
500 mL three-neck round-bottomed flask equipped with nitro-
gen inlet and magnetic stirrer. To 300 mL of distilled ammonia
were added t-BuOK (5.1 mmol), the nitroalkane (3 mmol), and
acetone (2 mmol). The 1-AdX (1 mmol) dissolved in 1 mL of
anhydrous ether was added to the solution and the reaction
In the photostimulated reaction of EtHgCl with 3a and 3b it
was not necessary to entrain the reactions with acetone enolate
878
N e w J . C h e m . , 2 0 0 5 , 2 9 , 8 7 5 – 8 8 0

View Article Online
mixture was irradiated. The reaction was quenched with an
excess of ammonium nitrate and the ammonia was allowed to
evaporate. The residue was dissolved with water and then
extracted with diethyl ether. The products were isolated by
column chromatography. In other similar experiments the
products were quantified by GC using the internal standard
method.
pentane–ethyl ether (98 : 2). 1H-NMR (DCCl3) d: 1.25–2.12
(21H, m); 4.10 (1H, dd, J = 12, 2.3 Hz); 4.96–5.06 (2H, m);
5.65–5.85 (1H, m). 13C-NMR (DCCl3) d: 25.60, 26.17, 28.24,
32.93, 36.57, 38.51, 99.05, 115.35, 137.59. MS (EI+) m/z (%):
175 (1), 135 (100), 119 (2), 107 (10), 93 (14), 91 (8), 79 (18), 67
(13), 55 (19), 41 (37). HRMS (CI) exact mass calcd for
C16H25NO2: 263.1885, found 263.1874.
1-Adx with nitronate anions in DMSO. The following pro-
cedure is representative. The reactions were carried out in a
250 mL three-neck round-bottomed flask equipped with nitro-
gen inlet and magnetic stirrer. To 100 mL of dry and degassed
DMSO under nitrogen were added t-BuOK (5.1 mmol), the
nitroalkane (3 mmol), and acetone (2 mmol). After 15 min
1-AdX (1.0 mmol) was added and the reaction mixture was
irradiated. The reaction was quenched with an excess of
ammonium nitrate. The residue was dissolved with water and
then extracted with diethyl ether. The products were isolated
by column chromatography. In similar experiments the pro-
ducts were quantified by GC using the internal standard
method.
2-Nitrobutane (5a). Isolated as a colorless oil after column
chromatography on silica gel, eluted with pentane–ethyl ether
(98 : 2). MS (EI+) m/z (%): 58(3), 57 (64), 56 (8), 55 (6), 42 (6),
41 (100), 40 (6), 39 (23), 30 (9), 29 (99), 28 (16), 27 (38).
Identified by comparison with literature data.33
6-Nitrooct-1-ene (5b). Isolated as a solid after column chro-
matography on silica gel, eluted with pentane–ethyl ether
1
(99 : 1). H-NMR (DCCl3) d: 0.95 (3H, t, J = 7.6); 1.38–2.09
(8H, m); 4.32–4.46 (1H, m); 4.96–5.07 (2H, m); 5.65–5.85 (1H,
m). 13C-NMR (DCCl3) d:. 10.21, 24.95 (m), 27.16, 29.67, 32.80,
90.23, 115.41, 137.45. MS (EI+) m/z (%): 109 (2), 95 (4), 90
(7), 81 (18), 69 (100), 68 (18), 55 (91). HRMS (CI) exact mass
calcd for C8H15NO2: 157.1103, found 157.1108.
EtHgCl with nitronate anions in DMSO. The following
procedure is representative. The reactions were carried out in
a 25 mL three-neck round-bottomed flask equipped with
nitrogen inlet and magnetic stirrer. To 12 mL of dry and
degassed DMSO under nitrogen were added t-BuOK (2.1
mmol) and the nitroalkane (2 mmol). EtHgCl (1 mmol) was
added and the reaction mixture was irradiated. The reaction
was quenched with an excess of ammonium nitrate. The
residue was dissolved with water and then extracted with
diethyl ether. The products were isolated by column chroma-
tography. In similar experiments the products were quantified
by GC using the internal standard method.
1-Isopropyladamantane (6). Isolated as an oil after column
chromatography on silica gel, eluted with petroleum ether
(100) and identified by comparison with literature data.34
13C-NMR (DCCl3) d: 16.27, 28.84, 34.33, 37.49, 39.27. MS
(EI+) m/z (%): 178 (3), 135 (100), 107 (9), 93 (15), 79 (20), 67
(8), 55 (5), 41 (11).
1-Isopropenyladamantane (7). Isolated as an oil after column
chromatography on silica gel, eluted with petroleum ether
(100) and identified by comparison with literature data.34
13C-NMR (DCCl3) d: 18.51, 28.76, 37.06, 41.04, 107.37,
154.73. MS (EI+) m/z (%): 176 (100), 161 (21), 147 (8), 133
(25), 119 (45), 105 (26), 93 (43), 91 (60), 79 (54), 55 (18), 41 (43).
Reactions with nitronate anions in the dark. The procedure
was similar to that for the previous reactions, except that the
reaction flask was wrapped with aluminum foil.
1-(1-Methyl-1-nitroethyl)adamantane (8). Isolated as a white
solid after column chromatography on silica gel, eluted with
petroleum ether–ethyl ether (98 : 2). The product was recrys-
Inhibited reactions with nitronate anions. The procedure was
similar to that for the previous reactions, except that 20 mol %
of p-DNB was added to the solution of nucleophile prior to
substrate addition.
1
tallized from pentane. Mp: 136–139 1C. H-NMR (DCCl3) d:
1.52 (6H, s); 1.56–1.73 (12H, m); 1.97–2.11 (3H, m). 13C-NMR
(DCCl3) d: 21.40, 28.54, 36.52, 95.22. MS (EI+) m/z (%): 177
(36), 176 (21), 135 (100), 107 (17), 93 (35), 91 (21), 81 (15), 79
(43), 67 (18), 55 (11), 41 (20). HRMS (CI) exact mass calcd for
C13H21NO2: 223.1572, found 223.1577.
Isolation and identification of the products32
1-(1-Nitropentyl)adamantane (2). Isolated as a yellow oil
after column chromatography on silica gel, eluted with petro-
1
leum ether–ethyl ether (98 : 2). H-NMR (DCCl3) d: 0.89 (3H,
Acknowledgements
t, J = 6.9 Hz); 1.45–2.02 (21H, m); 4.09 (1H, dd, J = 12.1, 2.2
Hz). 13C-NMR (DCCl3) d: 13.74, 22.13, 26.54, 28.24, 28.62,
35.90, 36.60, 38.51, 99.26. MS (EI+) m/z (%): 204 (2), 136
(11), 135 (100), 107 (6), 93 (12), 91 (9), 79 (16), 67 (8), 55 (4), 41
(6). HRMS (EI) exact mass calcd for C15H25NO2: 251.1885,
found 251.1878.
This work was supported in part by Agencia Co
(ACC), Consejo Nacional de Investigaciones Cientı
Tecnicas (CONICET), Antorchas Foundation, SECYT,
Universidad Nacional de Cordoba and FONCYT. C.A.T.
´
rdoba Ciencia
´
ficas y
´
´
gratefully acknowledges receipt of a fellowship from FONCYT
and S.M.B. gratefully acknowledges receipt of a fellowship
from the Council of the Province of Neuquen and Repsol-
´
1-(1-Nitroethyl)adamantane (4a). Isolated as a white solid
after column chromatography on silica gel, eluted with hex-
YPF.
1
ane–ethyl ether (98 : 2). Mp: 46–47.5 1C. H-NMR (DCCl3) d:
1.42–1.46 (3H, d, J = 6.9 Hz); 1.49–2.04 (15H, m); 4.21–4.31
(1H, q, J = 6.9 Hz). 13C-NMR (DCCl3) d:12.80; 28.22; 36.54;
38.16; 92.93. MS (EI+) m/z (%): 163 (100), 135 (33), 121 (15),
107 (33), 93 (46), 91 (30), 79 (55), 67 (29), 55 (27). Anal. found:
C, 68.7; H, 8.9; N, 6.5%; calcd for C12H19NO2: C, 68.87; H,
9.15; N, 6.69%.
References
1
2
(a) R. A. Rossi, A. B. Pierini and A. B. Penenory, in The
´
Chemistry of Functional Groups, eds. S. Patai and Z. Rappoport,
Wiley, Chichester, 1995, Suppl. D2, ch. 24, pp. 1395–1485; (b) R.
A. Rossi and A. Postigo, Curr. Org. Chem., 2003, 7, 747–769; (c)
R. A. Rossi, A. B. Pierini and S. M. Palacios, Adv. Free Radical
Chem., 1990, 1, 193–252; (d) R. A. Rossi, A. B. Pierini and A. B.
Pene
(a) J. M. Save
(b) J. M. Save
´
nory, Chem. Rev., 2003, 103, 71–167.
1-(1-Nitrohex-5-enyl)adamantane (4b). Isolated as an oil
after column chromatography on silica gel, eluted with
´
ant, Adv. Electron Transfer Chem., 1994, 4, 53–116;
ant, J. Am. Chem. Soc., 1992, 114, 10595–10602; (c)
´
N e w J . C h e m . , 2 0 0 5 , 2 9 , 8 7 5 – 8 8 0
879

View Article Online
J. M. Save
´
references cited therein.
R. A. Rossi, S. M. Palacios and A. N. Santiago, J. Org. Chem.,
1982, 47, 4654–4657.
G. L Borosky, A. B. Pierini and R. A. Rossi, J. Org. Chem., 1990,
55, 3705–3707.
ant, Adv. Phys. Org. Chem., 2000, 35, 117–192, and
20 A. N. Santiago, R. A. Rossi, G. Lassaga and Z. Rappoport,
J. Org. Chem., 1996, 61, 1125–1128.
21 A. B. Penenory and R. A. Rossi, Gazz. Chim. Ital., 1995, 125,
´
3
4
5
6
7
8
9
605–609.
22 J. E. Arguello, A. B. Pene
´
nory and R. A. Rossi, J. Org. Chem.,
¨
2000, 65, 775–7182.
R. A. Rossi, A. B. Pierini and G. L. Borosky, J. Chem. Soc.,
Perkin Trans. 2, 1994, 2577–2581.
M. A. Nazareno and R. A. Rossi, J. Org. Chem., 1996, 61, 1645–
1649.
´
M. C. Murguıa and R. A. Rossi, Tetrahedron Lett., 1997, 38,
23 G. A. Russell and W. C. Danen, J. Am. Chem. Soc., 1966, 88,
5663–5665.
24 M. H. Gallego, Ph.D. Thesis, National University of Co
Cordoba, Argentina, 2000.
25 C. P. Andrieux, A. L. Le Gorande and J. M. Save
Chem. Soc., 1992, 114, 6892–6904.
´
rdoba,
´
´
ant, J. Am.
1355–1358.
A. N. Santiago, C. A. Toledo and R. A. Rossi, J. Phys. Org.
Chem., 2003, 16, 413–419.
A. E. Lukach and R. A. Rossi, J. Org. Chem., 1999, 64, 5826–5831.
26 (a) H. Kurosawa, H. Okada and T. Hattori, Tetrahedron Lett.,
1981, 22, 4495–4498; (b) N. S. Hush and K. B. Oldham,
J. Electroanal. Chem., 1963, 6, 34–45.
10 G. S. Lee, J. N. Bashara, G. Sabih, A. Oganesyan, H. M. Duong,
G. Godjoian, E. R. Martinez and C. G. Gutierrez, Org. Lett.,
2004, 6, 1705–1707.
27 M. Ahbala, P. Hapiot, A. Houmam, M. Jouini, J. Pinson and
´
J. M. Save
¨
´
ant, J. Am. Chem. Soc., 1995, 117, 11488–11498.
nory, J. Org. Chem., 2003, 68, 2362–
28 J. E. Arguello and A. B. Pene
´
2368.
11 G. A. Russell, Acc. Chem. Res., 1989, 22, 1–8.
12 R. C. Larock, Organomercury Compounds in Organic Synthesis,
Springer-Verlag, Heidelberg and New York, 1985.
13 G. A. Russell, J. Hershberger and K. Owens, J. Am. Chem. Soc.,
1979, 101, 1312–1313.
14 G. A. Russell and R. K. Khanna, Tetrahedron, 1985, 41,
4133–4145.
15 G. A. Russell and D. Guo, Tetrahedron Lett., 1984, 25, 5239–5242.
16 G. A. Russell, J. Hershberger and K. Owens, J. Organomet.
Chem., 1982, 225, 43–56.
17 (a) N. Kornblum, Aldrichim. Acta, 1990, 23, 71–78; (b) N.
Kornblum, Angew. Chem., Int. Ed. Engl., 1975, 14, 734–745.
18 G. L. Borosky, A. B. Pierini and R. A. Rossi, J. Org. Chem., 1992,
57, 247–252.
29 (a) D. Seebach and F. Lehr, Angew. Chem., Int. Ed. Engl., 1976,
15, 505–505; (b) D. Seebach, R. Henning, F. Lehr and J. Gonner-
mann, Tetrahedron Lett., 1977, 18, 1161–1164.
30 C. S. Marvel, C. G. Gauerke and E. L. Hill, J. Am. Chem. Soc.,
1925, 47, 3009.
31 Dictionary of Organic Compounds, E.&F.N. Spon Ltd., Oxford
University Press, New York, 1965, vol. 4, p. 2082.
32 All new compounds were purified by column chromatography and
were determined to be 495% pure by GLC and NMR.
33 ‘‘Mass Spectra’’, in NIST Chemistry WebBook, NIST Standard
Reference Database Number 69, eds. P. J. Linstrom and W. G.
Mallard, NIST Mass Spec Data Center, director S. E. Stein,
National Institute of Standards and Technology, Gaithersburg,
MD, March 2003, 20899 (http://webbook.nist.gov).
19 C. Amatore, M. Gareil, M. A. Oturan, J. Pinson, J. M. Save
and A. Thiebault, J. Org. Chem., 1986, 51, 3757–3761.
´
ant
34 R. C. Fort, Jr. and P. V. R. Schleyer, J. Org. Chem., 1965, 30, 789.
880
N e w J . C h e m . , 2 0 0 5 , 2 9 , 8 7 5 – 8 8 0