Reactions of quadricyclane with fluorinated nitrogen-containing compounds. Synthesis of 3-aza-4-perfluoroalkyl-tricyclo[4.2.1.02,5]non-3,7- dienes

Article abstract of DOI:10.1016/j.jfluchem.2004.09.003

The cycloaddition reactions of quadricyclane (1) and polyfluorinated imines and nitriles were studied. Both (CF₃)₂CNH and (CF ₃)₂CN(2-FC₆H₄) were found to have low reactivity towards 1, giving the corresponding [2 + 2 + 2] cycloadducts in a low yield. C₂F₅NCFCF₃ however, reacts with 1 rapidly, giving a mixture of two isomeric cycloadducts in a high yield. Perfluoroalkyl nitriles R_fCN (R_f = CF₃, C ₂F₅, n-C₃F₇) were found to have surprisingly high reactivity to 1 producing exo-3-aza-4-(fluoroalkyl)- tricyclo[4.2.1.0^2,5]non-3,7-dienes in 56-81% yields at elevated temperature. Exo-3-aza-4-(perfluoroalkyl)-tricyclo[4.2.1.0^2,5]non-3, 7-dienes rapidly react with CF₃Si(CH₃)₃ in the presence of CsF catalyst. The reaction results in addition of CF ₃Si(CH₃)₃ across the CN bond of the azadienes with selective formation of only one stereoisomer of exo-3-aza-3- (trimethylsilyl)-4,4-bis(perfluoroalkyl)-tricyclo[4.2.1.0^2,5]non-7- enes. Silyl group in this compounds can be removed either by the action of tetrabutylammonium fluoride hydrate, leading to the formation of the corresponding amine after hydrolysis, or by reaction with HCl resulting in the formation of the corresponding amine hydrochloride. The reaction of quadricyclane with perfluoroazaalkenes and perfluorinated nitriles leads to high yield formation of the corresponding cycloadducts.

Full text of DOI:10.1016/j.jfluchem.2004.09.003

Journal of Fluorine Chemistry 125 (2004) 1621–1628
www.elsevier.com/locate/fluor
Reactions of quadricyclane with fluorinated nitrogen-containing
compounds. Synthesis of 3-aza-4-perfluoroalkyl-tricyclo
2
,5
[
4.2.1.0 ]non-3,7-dienes
*
Viacheslav A. Petrov , Frederic Davidson, Will Marshall
1
DuPont Central Research and Development , Experimental Station, P.O. Box 80328, Wilmington, DE 19880-0328, USA
Available online 11 November 2004
Abstract
The cycloaddition reactions of quadricyclane (1) and polyfluorinated imines and nitriles were studied. Both (CF
3 2 3 2
) C=NH and (CF ) C=N–
(
2-F–C H ) were found to have low reactivity towards 1, giving the corresponding [2 + 2 + 2] cycloadducts in a low yield. C F N=CFCF
6
4
2
5
3
however, reacts with 1 rapidly, giving a mixture of two isomeric cycloadducts in a high yield. Perfluoroalkyl nitriles R
f
CN (R
f
= CF
3
, C
2
F
5
, n-
2
,5
3 7
C F ) were found to have surprisingly high reactivity to 1 producing exo-3-aza-4-(fluoroalkyl)-tricyclo[4.2.1.0 ]non-3,7-dienes in 56–81%
2
yields at elevated temperature. Exo-3-aza-4-(perfluoroalkyl)-tricyclo[4.2.1.0 ]non-3,7-dienes rapidly react with CF Si(CH ) in the
,5
3
3 3
3 3 3
presence of CsF catalyst. The reaction results in addition of CF Si(CH ) across the C=N bond of the azadienes with selective formation
2
,5
of only one stereoisomer of exo-3-aza-3-(trimethylsilyl)-4,4-bis(perfluoroalkyl)-tricyclo[4.2.1.0 ]non-7-enes. Silyl group in this compounds
can be removed either by the action of tetrabutylammonium fluoride hydrate, leading to the formation of the corresponding amine after
hydrolysis, or by reaction with HCl resulting in the formation of the corresponding amine hydrochloride.
#
2004 Elsevier B.V. All rights reserved.
Keywords: Quadricyclane; Imine of hexafluoroacetone; Perfluoro-3-azapentene-2; Trifluoroacetonitrile; Pentafluoropropionitrile; Perfluorobutyronitrile;
Trifluoromethyltrimethylsilane
1
. Introduction
since due to high stereoselectivity these reactions often
result in selective formation of exo-tricyclononene deriva-
tives, containing a four-membered fragment in exo-position
relative to one carbon bridge of the norbornene system [1,5–
11]. In search for new monomers for preparation of
functional polymers for the next generation microlithogra-
phy [12,13], we started investigation of the reactivity of
quadricyclane towards fluorinated substrates. Recently, we
have demonstrated that fluorinated carbonyl compounds
rapidly react with 1 with the formation of a variety of
norbonenoxetanes [14]. In this study an investigation of the
reactivity of nitrogen-containing substrates towards 1 was
attempted.
The unique reactivity of saturated strained hydrocar-
2
bon—tetracyclo[3.2.0.0. .0 ]heptane
,7 4.6
(quadricyclane,
)—has been of considerable experimental and theoretical
1
interest to organic chemists in the last 40 years [1]. Despite
the fact that numerous examples of [2s + 2s + 2p]
cycloaddition reactions of 1 with a variety of dienophiles [2–
11] have been reported, data on the reactions of 1 with
nitrogen-containing compounds are limited to a few
examples including cycloaddition of 1 to R–N=N–R
[
5,6], bis(phenylsulfonyl)-o-benzoquinondiimine [11],
RN=CHP(O)(OEt)2 [10] and several fluorinated azines
7–9]. Most of reported [2 + 2 + 2] reactions of 1 are quite
interesting from the point of view of synthetic chemistry,
[
2. Results and discussion
*
Corresponding author. Tel.: +1 302 695 1958; fax: +1 302 695 8281.
E-mail address: viacheslav.a.petrov@usa.dupont.com (V.A. Petrov).
Publication No. 8527.
In sharp contrast to hexafluoroacetone, which reacts with
1 exothermally [14], the reaction of imine of hexaflu-
1
0022-1139/$ – see front matter # 2004 Elsevier B.V. All rights reserved.
doi:10.1016/j.jfluchem.2004.09.003

1622
V.A. Petrov et al. / Journal of Fluorine Chemistry 125 (2004) 1621–1628
oroacetone (2) with 1 is very slow even at elevated
temperature (110 8C, 16 h) leading to formation of trace of
the cycloadduct 3.
The value of coupling constant J3
¼ 4:9 Hz is
H-2ꢁH-5
indicative of cis-orientation of these two protons and is
in a good agreement with exo-orientation of azacyclo-
butane ring [1]. In minor isomer 7b the value of coupling
N-(2-Fluorophenyl)imine of hexafluoroacetone (4) in reac-
tion with 1 showed slightly higher reactivity, giving cycload-
duct 5 in low yield after prolonged heating of the reaction
mixture [15].
constant H-2/H-5 is slightly higher (J3
¼ 5:7 Hz). It
H-2ꢁH-5
should be pointed out that stereoselective formation of exo-
2
,5
3
-aza-tricyclo[4.2.1.0 ]non-7-enes was also previously
reported in the reactions of fluorinated azines and 1
7–9].
The formation of two isomers in the reaction of 1 and 6
[
is probably, the result of different orientation of substituents
at C-4 relative to the methylene bridge of norbornene
system. It is reasonable to believe that in major isomer (7a)
smaller substituent, fluorine, is in syn- and the bulkiest
Detailed analysis of the isolated product by NMR
spectroscopy revealed the presence of a small amount
substituent, CF group is in anti-position relative to the
3
(
ꢀ3%) of second isomer 5b. Formation of isomers in this
norbornene methylene bridge. The stereochemistry of 7a
1
19
reaction is the result of syn- versus anti- orientation of aryl
group at nitrogen relative to the methylene bridge of the
norbornene fragment and it is indicative of relatively high
barrier of nitrogen inversion in 5a,b. Although unequivocal
assignment structures of 5a,b has not been attempted in this
work, it is reasonable to postulate on steric grounds that
major isomer has the substituent at nitrogen in anti-position
to the norbornene methylene bridge.
and 7b was confirmed by data of 2D H– F HOESY
(Heteronuclear proton-fluorine 2D NOE) experiment
carried out for mixture of isomers. Since in major isomer
0
large NOE was observed between F-4 and H-9 (CF -4
3
showed a large NOE to H-5 and a smaller NOE to H-2, see
Fig. 1), major isomer indeed has structure 7a with F-4 and
0
1
19
H-9 located in syn-position. Therefore, observed in H,
NMR spectra of 7a four-bond coupling constant
F
4
anti-Perfluoro-3-azapentene-2 (6) [16,17] is significantly
more reactive towards 1. The reaction rapidly proceeds in
a closed system (100 8C, 12 h, a significant pressure
drop was observed in first 2 h of the reaction) with the
formation of two isomers of exo-3-aza-3-pentafluoroethyl-
J ¼ 14:5 Hz is ‘‘trans’’-coupling constant between
H-2ꢁF-4
H-2 and F-4, since two substituents are located on different
sides of azacyclobutane ring. It should be pointed out, that
similar coupling constant (J4
¼ 12:5 Hz) previously
H-2ꢁF-4
reported for major isomer of cycloadduct 1 and CF CF=N–
3
2
,5
4
-trifluoromethyl-4-fluorotricyclo[4.2.1.0 ]non-7-ene
N=CFCF3 was interpreted as four-bond cis-coupling
constant between hydrogen and fluorine [9], however, this
statement was not supported by other spectroscopic
evidences.
(
7a,b).
1
9
F NMR spectrum of minor isomer 7b is distinctly
different. First of all, substantial downfield shift is observed
for resonance of F-4 (d = ꢁ129.05 for 7b versus d = ꢁ141.70
for 7a; similar downfield shift for F-4 was previously
1
9
observed in
F NMR spectra of minor isomers of
cycloadducts of 1 and CF C(O)F or FSO CF C(O)F, also
3
2
2
having anti-orientation of F-4 in an oxetane ring relative to
1
CH bridge [14]). In H NMR spectrum of 7b the signal of
2
H-5 (d = 2.22, dd, J = 21.5, 5.7 Hz), coupled to H-2 (d = 3.87,
d, J = 5.7 Hz) has also a substantial three-bond coupling
Based on NMR data the ratio of two isomers 7a,b in isolated
product is 75:25. The H NMR spectrum of mixture 7a,b
1
constant to F-4 (J3
syn-orientation of CF -4 and H-9 (anti-orientation of both
H-5 and F-4, respectively) for minor isomer once again was
¼ 21:5 Hz). The confirmation of
exhibit two sets of signals, containing seven resonances for
each isomer with relative intensities 1:1:1:2:1:1:1. Two
signals of vinyl protons at ꢀ6 ppm are indicative of presence
of the double bond in the norbornene fragment. In
major isomer (7a, see structure below) H-2 (d = 3.48, dd,
J = 14.7, 4.9 Hz) is coupled to H-5 (d = 2.31, ddt, J = 6.3, 4.9,
H-5ꢁF-4
0
3
1
obtained in 2D H– F HOESY experiment, where large
19
0
NOE’s between H-9 /CF -4 and F-4/H-5 (and smaller NOE
3
for F-4/H-2) were observed. So, the minor isomer has
structure 7b with H-2, H-5 and F-4 located on the same side
1
.0 Hz).

V.A. Petrov et al. / Journal of Fluorine Chemistry 125 (2004) 1621–1628
1623
1
9
1
Fig. 1. Phase-sensitive 2D F– H HOESY NMR expanded spectrum of a mixture of 7a and 7b isomers in dichloromethane-d
2
at 30 8C (only major NOE’s are
shown).
of azacyclobutane ring. Therefore, observed constant
3
J
¼ 21:5 Hz is cis-coupling constant between H-5
H-5ꢁF-4
and F-4. Unusually high value of this constant probably
results from combination of small dihedral angle F-4/C-4/C-
5
/H-5 and short distance between F-4 and H-5.
It should be pointed out, that NMR data however, were
not sufficient to define the position N–CF CF group in 7a or
2
3
7
7
b. In HOESY experiment N–CF -group in both isomers
a,b showed small NOE to protons on both sides of
2
norbornene fragment, indicating that nitrogen either is
inverting rapidly on NMR time scale or is planar. The
Transition state A (with F substituent of azaalkene 6 pointed
towards CH bridge of norbornene system) is responsible for
1
absence of major changes in H and F NMR spectra of
19
2
7
broadening of the signals of N–CF group of major isomer)
a,b at ꢁ70 8C in CD Cl solvent (except for slight
the formation of major isomer 7a. Less favorable, due to
stronger steric interaction between bulkier CF group and
2
2
2
3
may be used as an argument in favor of planar nitrogen.
However, at this point experimental data are not sufficient to
exclude rapid nitrogen inversion process.
CH bridge, transition state B leads to minor isomer 7b.
However, the formation of biradical intermediate in this
reaction cannot be excluded either.
2
Assuming concerted mechanism of cycloaddition of 6 to
, the formation of isomers 7a,b in this reaction can be
explained as the result of different orientation of F and CF3
substituents of 6 in transition state (A and B, Eq. 4) resulting
in the formation of two isomers, 7a and 7b.
Nitriles, in general, are not active towards 1 and there are
no reported examples of cycloaddition between 1 and
nitriles [1]. In this study it was found that perfluorinated
nitriles have surprisingly high reactivity towards 1. In sharp
contrast to acetonitrile, which is totally inert towards 1
1

1
624
V.A. Petrov et al. / Journal of Fluorine Chemistry 125 (2004) 1621–1628
19 13
1
IR, H, F, C NMR, and mass spectroscopy. IR spectra of
(100 8C, 16 h), CF CN (8) and nitriles 9, 10 rapidly react
with quadricyclane at elevated temperature producing exo-
3
ꢁ
1
11–13 exhibit weak absorption ꢀ1600–1615 cm assigned
2
-aza-4-perfluoroalkyltricyclo[4.2.1.0 ]non-3,7-dienes
,5
ꢁ1
3
to C=N (cf. 1590 cm
for endo-3-aza-2,4,5-tris(tert-
2
,5
1
(11–13).
butyl)tricyclo[4.2.1.0 ]non-3,7-diene [18]). Each H spec-
trum of compounds 11–13 containing eight well-separated
signals of equal intensity, exhibits resonance of vinyl
protons at 6.2–6.3 ppm (H-7, H-8, see Eq. (5)) having small
but distinct difference in chemical shifts (ꢀ0.1 ppm); the
3
value of coupling constants J
in 11–13 (determined
H-2ꢁH-5
1
in selective H homodecoupling experiments) are smaller
than similar coupling constant in 3, 7a,b [J3
¼ 2:6 for
H-2ꢁH-5
1
1–13 versus 4.9 (7a) and 5.7 (7b) Hz; see Table 2] or 15–19.
1
3
Despite the fact that cycloadducts of 1 with both
acetylenes [1–3] and azocompounds [5,6] are known for
over 30 years, the only reported representative of 3-aza-
Each {H} C NMR spectrum of 11–13 along with other
required resonances, exhibits two singlets at ꢀ134 and
ꢀ137 ppm (C-7, C-8) and multiplet at ꢀ180 ppm (C-4)
coupled to a-fluorines of the corresponding perfluoroalkyl
group (quartet, J = 38 Hz for 11 and triplets J = 29 and 30 Hz
for 12, 13, respectively).
2
tricyclo[4.2.1.0 ]non-3,7-dienes is endo-3-aza-2,4,5-tris
,5
2
tert-butyl)tricyclo[4.2.1.0 ]non-3,7-diene, prepared by
,5
(
reaction of tri-tert-butylazete and cyclopentadiene [18].
The activation of the nitrile functionality by strong
electron-withdrawing group, such as perfluoroalkyl is
essential, since no formation of the corresponding cycload-
ducts was observed in the reaction of 1 with either
pentafluorobenzonitrile or acetonitrile under similar condi-
tions. Observed order of reactivity on nitriles
+
Mass spectra (EI) of 11–13 exhibit an [M ꢁ 1] peak of
relatively high intensity. Fragmentation of the molecule
involves loss of fluoroalkyl group with generation of
+
C H N (m/z = 118) ion transforming into C H (m/z = 91),
þ
8
8
7
7
probably, through the extrusion of HCN.
The C=N bond in compounds 11–13 is highly reactive
towards nucleophiles. For example, the reaction with
CF Si(CH ) (14) in the presence of CsF catalyst proceeds
(
s-constants for the corresponding substituents (s /s ) CF :
R CN ꢂ C F CN, CH CN) correlates well with Hammet
m p 3
f
6
5
3
3
3 3
0
.43/0.54, C F : 0.47/0.52 versus C F : 0.26/0.27, CH :
2
exothermally in THF, giving products 15–17 in high
yield.
5
6
5
3
ꢁ
0.07/ꢁ0.17 [19].
Isomer of 1, norbornadiene, has quite different reactivity.
In reaction with CF CN, which proceeds at higher
3
temperature (180–190 8C) it was reported to give exclu-
sively homo-Diels–Alder cycloadduct isolated in moderate
yield (34%) after 40 h [20].
Azadienes 11–13 are colorless liquids, which can be
isolated by vacuum distillation and stored at ambient
temperature under inert atmosphere without decomposition
for a long time. However, being exposed to air, these
materials rapidly develop yellow-brown coloration, prob-
ably, due to oxidation. Air sensitivity and relatively high
vapor pressure of materials (11–13) prevented obtaining
satisfactory elemental analysis however, the proposed
structures of 11–13 are in good agreement with data of
According to NMR data (see Table 2), addition of
CF Si(CH ) to compounds 11–13 is stereoselective, and
leads to the formation of only one isomer in each reaction.
Silanes 15–17 are surprisingly stable to the action of dry
CsF at ambient temperature. For example, no reaction was
observed between 16 and CsF in THF (25 8C, 2 d, NMR).
3
3 3
Table 1
Ratio of reactants and reaction conditions
a
Entry Reagents (mol)
no.
Method Temperature (8C) Time (h) Product
Boiling point Analysis or MS
(yield %) (8C/mmHg)
+
+
1
2
3
4
1 (0.21), 2 (0.25)
1 (0.05), 4 (0.01)
1 (0.2), 6 (0.18)
1 (0.34), 8 (0.25)
A
B
A
A
100
90
16
50
12
12
3 (<2)
5a,b (14) 76–78/0.1
7a,b (80) 69–72/18
11 (78)
12 (56)
13 (81)
9 6
257 (M , C10H F N )
C, 54.41 (54.71); H, 3.34 (3.44); F, 37.30 (37.86)
C, 40.68 (40.63); H, 2.61 (2.48); F, 52.47 (52.58)
90
+
+
+
100
54–55/13
63–64/15
72–73/13
181 [(M ꢁ 1) , C
9
H
7
F
3
N , 80], 118 [(M ꢁ CF
3
) ,
+
N , 80], 91 (C
+
C
8
H
8
7
H
7
, 100)
+
+
+
) ,
5
6
1 (0.3), 9 (0.17)
1 (0.2), 10 (0.15)
A
A
100
100
12
12
236 [(M ꢁ 1) , C10
H
7
F
5
N , 80], 118 [(M ꢁ C
2
F
5
+
N , 95], 91 (C
+
C
8
H
8
7
H
7
, 100)
+
+
+
) ,
236 [(M ꢁ 1) , C10
H
7
F
5
N , 80], 118 [(M ꢁ C
2
F
5
+
N , 95], 91 (C
+
C
8
H
8
7
H
7
, 100)
a
m/z, electronic ionization.

V.A. Petrov et al. / Journal of Fluorine Chemistry 125 (2004) 1621–1628
1625
Fig. 2. ORTEP drawing of 19. Thermal ellipsoids are drawn to the 50% probability level.
However, under the action of terabutylammonium fluoride
hydrate compound 15 was converted into amine 3.
azabutane fragment and thus the addition of C F CN to 1
2 5
proceeds exclusively from exo-side.
The values of coupling constant between H-2/H-5,
1
observed in
3
H
NMR of compounds 3, 15–19
(
J
¼ 6:1, 5.7, 5.5, 5.3, 6.1, 6.0 Hz, respectively;
H-2ꢁH-5
see Table 2) are typical for tricyclononene systems with exo-
orientation of the four-member fragment [1,14]. It should be
also emphasized that, the value of coupling constant
The N–Si bond in 15–16 is sensitive to the action of acids.
The reaction of 15 or 16 with a solution of hydrogen chloride
in ether at ambient temperature results in rapid formation of
the corresponding hydrochlorides 18 and 19.
3
1
J
¼ 6:0 Hz observed in H spectrum of 19 correlates
H-2ꢁH-5
well with the value of dihedral angle H–C(2)–C(5)–H
(11.98) obtained from X-ray diffraction experiment, since
the value of H–H coupling constant is well known to be
sensitive to dihedral angle, reaching the maximum value at
0
8 [21].
3. Conclusion
The structure of 19 was determined by single crystal X-ray
diffraction. The nitrogen-containing cycle in 19 indeed has
exo-geometry and pentafluoroethyl substituent pointed
Reactivity of polyfluorinated imines and nitriles towards
quadricyclane strongly depends on electron deficiency of
carbon–nitrogen multiple bonds. Introduction of perfluor-
oalkyl groups into the molecule of imine or nitrile drastically
increases the reactivity of fluorinated substrate towards 1.
Addition of polyfluorinated imines and perfluoroalkylni-
triles to 1 is stereoselective and leads to products with exo-
orientation of the azacyclobutane (azacyclobutene) rings.
Based on isolated yields of products, the reactivity of the
nitrogen-containing substrates studied decreases in the
following order: CF CF¼NC F ꢃ R CN > ðCF Þ C¼Nꢁ
towards the CH bridge (see Fig. 2). The molecules pack
2
in hydrogen bonded pairs with two molecules and two
chloride ions forming around a crystallographic center of
symmetry.
The formation of 19 as a single isomer and syn-
orientation of C F group are both indicative of the addition
2
5
of 14 to C=N bond occurring stereoselectively from the less
hindered side of the molecule. Since only the C=N bond is
involved in this reaction, it is reasonable to assume that
precursor of 19 (compound 12) also has exo-orientation of
3
2
5
f
3 2
ð2-FꢁC H Þ > ðCF Þ C¼NH
6
4
3 2

Table 2
NMR and IR data for new compounds
1
a
Compound no. H NMR (d, ppm, J, Hz)
19 a
F NMR (d, ppm, J, Hz)
13 b
C NMR (d, ppm, J, Hz)
c
IR (cm )
ꢁ1
d
3
1.45(1H, d, 9.1), 2.35(1H, d, 6.1), 2.51(1H, d, 9.1),
ꢁ70.30(3F, q, 9.8), ꢁ77.47(3F, q, 9.8)
40.6, 41.7(m), 45.3, 58.9,
3372, 3311, 1459(w),
1370, 1318, 1259,
1138, 1100, 1014, 946,
803, 714
2
3
6
.60(1H, br s, NH), 2.88(1H, m), 3.10(1H, m),
.77(1H, dm, 6.1), 5.95(1H, dd, 5.7, 3.0),
.18(1H, dd, 5.7, 3.0)
64.0(sept, 31), 123.6(q, 286.0),
125.4(q, 286.0), 134.2, 138.7
e
5a,b
Major: 1.49(1H, d, 9.9), 2.38(2H, m), 3.18(1H, m),
Major: ꢁ64.18(3F, hex. 9.0),
–
–
–
–
3
6
.25(1H, m), 4.28(1H, t, 3.9), 6.01(1H, dd), 6.25(1H, dd),
.87(2H, m), 7.05(2H, m)
ꢁ72.95(3F, dq, 9.0, 4.1), ꢁ128.55(1F, m)
Minor: 1.59(1H, d, 10.0), 2.38(2H, m), 3.11(1H, m),
Minor: ꢁ64.81(3F, hex. 9.0),
ꢁ79.95, ꢁ133.93(1F, m)
–
3
6
.30(1H, m), 4.81(1H, d, 5.5), 6.01(1H, dd),
.25(1H, dd), 6.87(2H, m), 7.49(2H, m)
f
7
7
1
1
a
1.55(1H, dm, 9.8), 1.95(1H, d, 9.8),
ꢁ83.15(3F, qq, 9.7, 1.7), ꢁ84.80(3F, s),
ꢁ94.65(1F,d pent. 213.0, 10.4),
1789(w), 1465(w)
2
2
6
.31(1H, dd, 6.3, 4.9, 1.0),
h
.84(2H, s), 3.48(1H, dd, 14.7, 4.9), 5.92(1H, dd, 5.7, 3.3), ꢁ98.00(1F, d pent. 213.0, 10.4),
h
.19(1H, dd, 5.7, 3.0)
ꢁ141.70(1F br.s, J
d
= 14.7)
f
g
b
1.35(1H, d), 1.80(1H, d, 9.8), 2.22(1H, dd, 21.5, 5.7),
ꢁ77.32(3F, dd, 14.3, 3.0), ꢁ85.15(3F, s),
ꢁ93.75(1F, d pent., 215.0, 15.0),
2
6
.80(2H, s), 3.87(1H, d, 5.7), 5.93(1H, dd, 5.7, 3.0),
.21(1H, dd, 5.7, 3.0)
ꢁ105.60(1F, dqdd, 215.0, 14.3, 6.7, 1.0),
g
ꢁ129.05(1F br.t, J
t
ꢀ18)
1
2
1.28(1H, d, 10.5), 1.53(1H, d, 10.5), 2.70(1H, oct.,
h
J = 1.3, 2.6 Hz), 2.92(1H, s), 3.00(1H), 3.82(1H, d oct.,
h
J = 1.3, 2.6 Hz), 6.20(1H, dd, 3.2, 5.2),
ꢁ73.81(d, 2.0)
36.7, 39.8, 40.1, 47.7, 66.4,
118.4(q, 276.0), 134.5, 137.0,
180.0(q, 38.0)
2978, 1615(w), 1460(w),
1366(s), 1180, 1140,
1080, 939, 707(s)
6.28(1H, dd, 3.2, 5.2)
1.34(1H, d, 10.3), 1.63(1H, d pent., 10.3, 1.2),
ꢁ83.40(3F, t, 2.5), ꢁ112.30(1F, dm, 272.0),
ꢁ122.70 (1F, dm, 272.0)
36.7, 39.4, 39.8, 48.3, 67.1,
108.3(tq, 212.0, 39.0),
118.5(qt, 286.0, 35.0), 134.2,
136.7, 180.3(t, 29)
2978, 1605(w), 1565(w)
h
.80(1H, sept., J = 1.3, 2.6 Hz), 3.22(1H, m),
2
3
6
6
h
.75(1H, d sept., J = 1.3, 2.6 Hz),
.28(1H, dd, 5.5, 3.2),
.35(1H, dd, 5.5, 3.0)
13
1.13(1H, d, 10.0), 1.42(1H, d pent., 10.0, 1.1),
ꢁ80.80(3F, t, 6.0), ꢁ120.00(1F, dqd, 297.0,
36.8, 39.4, 39.8, 48.5, 67.0,
1460(w)
h
.58(1H, s), 2.75(1H, m), 2.83(1H, sept, J = 1.3, 2.6 Hz),
2
3
6
10.0, 2.0), ꢁ120.52(1F, dqd, 297.0, 10.0, 2.0), 109.4(tm, 268.0, 39.0),
h
.70(1H, sept., J = 1.3, 2.6 Hz), 6.08(1H, dd, 5.5, 3.2),
ꢁ127.22(1F, d, 294.0), ꢁ127.32(1Fd, 294.0)
110.2(tt, 254.0, 33.0),
118.5(qt, 286.0, 33.0),
.13(1H, dd, 5.5, 3.0)
1
34.2, 136.7, 180.41(t, 30.0)
15
16
17
0.13(9H, s), 1.36(1H, d, 9.4), 2.22(1H, d, 5.7),
ꢁ66.40(3F, q, 10.3), ꢁ70.03(3F, q, 10.3)
1456, 1409(w)
1455, 1410(w)
1455, 1411(w)
2
3
6
.38(1H, d, 9.4), 2.91(1H, m), 3.05(1H, m),
.59 (1H, d, 5.7), 5.89(1H, dd, 6.4, 3.4),
.17(1H, dd, 6.4, 3.4)
0.19(9H, s), 1.35(1H, d, 9.7),
ꢁ74.10(3F, qd, 10.3, 5.2),
ꢁ0.63, 41.02, 41.30(d, 15.5),
2
2
5
.35(1H, d, 5.5), 2.50(1H, d, 9.7),
ꢁ80.10(3F, qd, 10.3),
43.00, 46.09, 61.82, 67.50(m, 38.0),
114.11(tm, 263.0), 118.93(qt, 288.0, 35.0),
125.48(qd, 288.0, 9.7), 133.71, 138.60
ꢁ0.8, 41.00(d, 15.0), 41.36,
.95(1H, m), 3.05(1H, m), 3.69 (1H, d, 5.5),
.91(1H, dd, 5.6, 3.4), 6.19(1H, dd, 5.6, 3.4)
ꢁ112.20(1F, dq, 289.0, 5.2),
ꢁ113.00(1F, dq, 289.0, 10.8)
ꢁ73.65(3F, m), ꢁ81.34(3F, dd, 15.6, 7.8),
ꢁ109.50(2F, AB quart., 296.0),
ꢁ124.00(2F, AB quart., 296.0)
0.16(9H, s), 1.35(1H, d, 9.5), 2.21(1H, d, 5.3),
2
3
6
.47(1H, d m, 9.5), 2.95(1H, m), 2.99(1H, s),
.71 (1H, d, 5.3), 5.91(1H, dd, 5.6, 3.1),
.19(1H, dd, 5.6, 3.1)
42.90, 46.00, 62.01, 68.12(m, 29.0),
110.11(tq, 271.0, 38.0), 115.90(tm, 262.0, 38.0),
118.00(qt, 289.0, 35.0), 125.30(qd, 288.0, 10.0),
1
33.61, 138.64

V.A. Petrov et al. / Journal of Fluorine Chemistry 125 (2004) 1621–1628
1627
4. Experimental
1
19
H and F NMR spectra were recorded on a Brucker
DRX-400 (400.5524 and 376.8485 MHz, respectively)
instruments using CFCl as an internal standard and CDCl
3
3
1
as a lock solvent. H COSY experiments for compounds
1–13 were carried out in Brucker DRX-500
1
(
a
499.8731 MHz). The 2D H– F HOESY ( F observed)
1
19
19
spectrum [22] of 7a,b was obtained on a 500 MHz Bruker
1
9
Avance DRX spectrometer, where
70.712 MHz in CD Cl solvent. The pulse sequence
F appears at
4
2
2
use was Hoesyph found in their pulse sequence library. The
spectrum was obtained at 30 8C using a 500 ms mixing
time, 10 s recycle time (due to the long relaxation times of
the fluorine), 2048 t points, 64 scan averages, and 128 t
2
1
with a 51282.051 Hz t and a 3369.59 Hz t spectral width
2
1
1
and with H decoupling during the acquisitions time. The
spectrum was processed using a Gaussian function in t2
with 2049 points and a Gaussian function in t with 1024
1
points. The spectra are displayed in a phase-sensitive
mode and linear prediction was used, backward in t and
2
forward in t dimensions. IR spectra were recorded in a
1
Perkin-Elmer 1600 FT spectrometer. Moisture sensitive
materials were handled inside a glove box under inert
atmosphere. GC and GC/MS analyses were carried out with
an HP-6890 instrument using an HP FFAP capillary
column and either a TCD (GC) or mass selective detector
(
GS/MS, EI), respectively. The crystal structure for 19
has been deposited at the Cambridge Crystallographic
Data Center and allocated the deposition number CCDC
2
36156.
Compounds 8–10, 14 (SyQuest), tetrabutylammo-
nium fluoride hydrate (Aldrich) and other starting materials
were purchased and used without further purification.
Quadricyclane (1) was prepared by photochemical iso-
merization of norbornadiene [23] using t-butyl methyl ether
as a solvent. For all reactions, material of a 90–95%
purity was used [the remainder: norbornadiene (5–8%)
and solvent (2–3%)]. Molar ratios of reagent are calcu-
lated based on pure 1 (Table 1). Compounds 2 [24], 4 [25]
and 6 [16,17] were prepared according to the literature
procedures.
4.1. Reactions of 1 with polyfluorinated nitrogen-
containing compounds
4.1.1. Method A
Solution of 20–35 g (0.2–0.37 mol) of 1 in 100 mL of dry
ether was placed in a 400 mL Hastelloy shaker tube. The
reactor was cooled down, evacuated, charged with 20–42 g
(0.17–0.27 mol) of fluorinated substrate and kept under
autogenic pressure at 90–110 8C for 12–16 h. The reaction
vessel was unloaded. The solvent was removed under a
vacuum and the liquid residue was distilled under reduced
pressure. Reaction conditions and ratio of reactants are given
in Table 1.

1628
V.A. Petrov et al. / Journal of Fluorine Chemistry 125 (2004) 1621–1628
4
.1.2. Method B
A 20 mL glass sample vial was charged with a mixture of
(0.05–0.1 mol, 10–20% excess) and the corresponding
Compound 19: yield 45%, m.p. 106–109 8C (dec.). Anal.
Calc. for C H ClF N: C, 38.45; H, 2.93; F, 44.23. Found:
C, 38.19; H, 2.89; F, 44.27. Spectral data for 3 are given in
Table 2.
1
1
10
8
1
substrate (0.03–0.08 mol), sealed and kept at 90–100 8C for
a period of time indicated in Table 1. The product was
isolated by vacuum distillation of the crude reaction mixture.
Reaction conditions and ratio of reactants are given in
Table 1.
The sample of 19 for single crystal X-ray analysis was
obtained by recrystallization of crude material from hexane.
Acknowledgements
4
.2. Preparation of compound 15 (typical experiment)
VAP thanks Prof. N.V. Vasil’ev for providing the copy of
manuscript on the reactions of norbornadiene with
fluorinated carbonyl and nitrogen compounds, R. Smith
Jr. for technical assistance and B. Vekker for the help with
manuscript preparation.
To an agitated mixture of 50 mL of dry THF and 0.5 g
0.003 mol) of dry CsF was slowly added a mixture of 15 g
(
(
0.08 mol) of 11 and 12 g (0.084 mol) of 14 at 0–10 8C over
a 40-min period. The reaction mixture was agitated for
0 min and poured in 400 mL of water. The mixture was
3
extracted with CH Cl (50 mL ꢄ 3), extract was washed
2
2
References
with water (200 mL ꢄ 2), the solvent was removed under a
vacuum and the residue was distilled under reduced pressure
to give 15 (21 g, 85%), b.p. 56–57 8C/1 mmHg. MS (m/e):
[
1] V.A. Petrov, N.V. Vasil’ev, Curr. Org. Synth., submited for publication.
[2] C.D. Smith, J. Am. Chem. Soc. (1966) 88.
+
+
+
3
29 (M , C H F NSi , 10%), 263(C H F NSi , 100%).
[3] I. Tabushi, K. Yamamura, Z. Yoshida, J. Am. Chem. Soc. 94 (1972)
1
3
17
6
8 11 6
7
87–792.
Compounds 16 and 17 were prepared similarly.
[
4] I. Tabushi, K. Yamamura, Z. Yoshida, A. Togashi, Bull. Chem. Soc.
Compound 16: yield 73%, b.p. 79–81 8C/2 mmHg. Anal.
Jpn. 48 (1975) 2922–2926.
Calc. for C H F NSi: C, 44.32; H, 4.52, Found: C, 43.86;
H, 4.41.
1
4
17
8
[5] N. Rieber, J. Albert, J.A. Lipsky, D.M. Lemal, J. Am. Chem. Soc.
(1969) 91.
Compound 17: yield 68%, b.p. 53 8C/0.3 mmHg. Anal.
[6] M.E. Landis, J.C. Mitchell, J. Org. Chem. 44 (1979) 2288–2290.
[
7] M.G. Barlow, R.G. Pritchard, N.S. Suliman, A.E. Tipping, Acta
Crystallogr., Sect. C C50 (1994) 553–556.
Calc. for C H F NSi: C, 41.96; H, 3.99; F, 44.25. Found:
C, 41.73; H, 3.75; F, 44.31. Spectral data are given in Table
1
5 17 10
[
8] M.G. Barlow, N.N. Suliman, A.E. Tipping, J. Chem. Soc., Chem.
Commun. (1993) 9–11.
2
.
Spectral data for 15–17 are given in Table 2.
[9] M.G. Barlow, N.N. Suliman, A.E. Tipping, J. Fluorine Chem. 72
1995) 147–156.
(
[
[
10] T. Schrader, W. Steglich, Synthesis (1990) 1153–1156.
4.3. Reaction of 15 with terabutylammonium fluoride
hydrate
11] W. Friedrichsen, E. Bueldt, R. Schmidt, Tetrahedron Lett. (1975)
1
137–1140.
[
[
12] M.K. Crawford, W.B. Farnham, A.E. Feiring, J. Feldman, R.H.
French, K.W. Leffew, V.A. Petrov, F.L. Shadt III, F.C. Zumsteg, J.
Photopolym. Sci. Technol. 15 (2002) 677–687.
Five grams (0.015 mol) of 15 was dissolved in 30 mL
+
of a 1 M solution of (C H ) N F /H O and the reaction
ꢁ
4
9 4
2
13] M.K. Crawford, W.B. Farnham, A.E. Feiring, J. Feldman, R.H.
French, K.W. Leffew, V.A. Petrov, W. Qui, F.L. Shadt III, H.V. Tran,
R.C. Wheland, F.C. Zumsteg, Proc. SPIE-Int. Soc. Opt. Eng. 5039
(2003) 80–92.
mixture was agitated for 3 days at ambient temperature. It
was poured in 400 mL of 10% hydrochloric acid, extracted
with CH Cl (20 mL ꢄ 2), the extract was washed with
2
2
water (200 mL ꢄ 2), the solvent was removed under a
vacuum and the residue was distilled under reduced pressure
to give 3.2 g (85%) of 3, b.p. 85–86 8C/30 mmHg. Anal.
Calc. for C H F N: C, 46.70; H, 3.53; F, 44.32. Found: C,
[14] V.A. Petrov, F. Davidson, B.E. Smart, J. Fluorine Chem. 125 (2004)
1543–1552.
[
[
15] A.E. Feiring, F.L. Schadt III, V.A. Petrov, B.E. Smart, W.B. Farnham
E. I. Du Pont De Nemours and Company, USA). PCT WO 2004/
14960.
(
1
0 9 6
0
46.42; H, 3.52; F, 44.10. Spectral data for 3 are given in
Table 2.
16] V.A. Petrov, G.G. Belen’kii, L.S. German, Izv. Akad. Nauk, Ser. Khim.
(1985) 1934–1935.
[
[
17] V.A. Petrov, G. Resnati, Chem. Rev. 96 (1996) 1809–1823.
18] U.J. Vogelbacher, N. Ledermann, T. Schach, G. Michels, U. Hees, M.
Regitz, Angew. Chem. Int. Ed. Engl. 27 (1988) 272–273.
19] T. Hiyama, Organo Fluorine Compounds. Chemistry and
Applications, Springer-Verlag, New York, 2000.
4
.4. Preparation of 18 and 19
[
To 0.6 g of either 15 (or 16) was added at ambient
temperature 4 mL of 1 M solution of hydrogen chloride in
ether. The reaction mixture was kept for 2–3 h at 25 8C, the
precipitate formed was filtered, washed with a small amount
of cold hexane and dried under a vacuum.
[20] N.V. Vasil’ev, T.D. Truskanova, A.V. Buzaev, D.V. Romanov, G.V.
Zatonskii, Izv. RAN. Ser. Khim., in press.
[
[
21] M.J. Karplus, J. Am. Chem. Soc. 85 (1963) 2870–2871.
22] S. Braun, Kalinowski, H.O.S. Berger, 100 and More Basic NMR
Experiments: A Practical Course, VCH, New York, 1996.
23] C.D. Smith, Org. Synth. 51 (1971) 562.
Compound 18: yield 57%, m.p. 128–131 8C (dec.). Anal.
Calc. for C H ClF N: C, 40.90; H, 3.43. Found: C,
[
1
0
10
10
[24] W.J. Middleton, C.G. Krespan, J. Org. Chem. 30 (1965) 1398–1402.
[25] V.A. Petrov, D.D. Khasnis, Isr. J. Chem. 39 (1999) 147–150.
4
0.72; H, 3.48. Spectral data for 3 are given in Table 2.