Unusual pathway of the tantalum-catalyzed carboalumination reaction of alkenes with triethylaluminum

Article abstract of DOI:10.1016/j.tetlet.2013.09.121

Carboalumination of 1-alkenes (1-hexene, 1-octene, 1-decene) with Et ₃Al in the presence of catalytic amounts of TaCl₅ results in a mixture of 2-(R-substituted)- and 3-(R-substituted)-n-butylaluminums (1:1 ratio) in total yields of 75-85%. The TaCl₅-catalyzed reaction of bicyclo[2.2.1]hept-2-ene, endo-tricyclo[5.2.1.0^2,6]deca-3,8-diene, and (exo/endo)-5-methylbicyclo[2.1.1]hept-2-ene with Et₃Al leads to the formation of diethyl[2-exo-(2′-norbornylethyl)]aluminums in high yields. DFT calculations confirm the thermodynamic preference of the final exo product. The multistep reaction mechanisms for the formation of the resultant organoaluminums through tantalacyclopentanes as key intermediates are also discussed.

Full text of DOI:10.1016/j.tetlet.2013.09.121

Accepted Manuscript
Unusual pathway of the tantalum-catalyzed carboalumination reaction of al-
kenes with triethylaluminum
Rifkat M. Sultanov, Elena V. Samoilova, Natal’ya R. Popod’ko, Artur R.
Tulyabaev, Denis Sh. Sabirov, Usein M. Dzhemilev
PII:
S0040-4039(13)01696-1
DOI:
http://dx.doi.org/10.1016/j.tetlet.2013.09.121
TETL 43621
Reference:
Tetrahedron Letters
To appear in:
Received Date:
Revised Date:
Accepted Date:
4 February 2013
9 September 2013
25 September 2013
Please cite this article as: Sultanov, R.M., Samoilova, E.V., Popod’ko, N.R., Tulyabaev, A.R., Sabirov, D.S.,
Dzhemilev, U.M., Unusual pathway of the tantalum-catalyzed carboalumination reaction of alkenes with
triethylaluminum, Tetrahedron Letters (2013), doi: http://dx.doi.org/10.1016/j.tetlet.2013.09.121
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Unusual pathway of the tantalum-catalyzed
carboalumination reaction of alkenes
with triethylaluminum
Leave this area blank for abstract info.
R
R
Rifkat M. Sultanov, Elena V. Samoilova,
Natal’ya R. Popod’ko, Artur R. Tulyabaev,
Denis Sh. Sabirov, Usein M. Dzhemilev
AlEt2
+
Et2Al
R = Bun, Hexn, Octn
R
Et3Al, TaCl5
hexane,
20 oC
AlEt2
Unusual pathway of the tantalum-catalyzed carboalumination
reaction of alkenes with triethylaluminum
Rifkat M. Sultanov, Elena V. Samoilova, Natal’ya R. Popod’ko, Artur R. Tulyabaev,
Denis Sh. Sabirov, Usein M. Dzhemilev
Institute of Petrochemistry and Catalysis, Russian Academy of Sciences,
141 Prosp. Oktyabrya, 450075 Ufa, Russian Federation.
Fax: +7 (347) 284 2750. E_mail: ink@anrb.ru
Abstract
Carboalumination of 1-alkenes (1-hexene, 1-octene, 1-decene) with Et3Al in the presence of
catalytic amounts of TaCl5 results in a mixture of 2-(R-substituted)- and 3-(R-substituted)-n-
butylaluminates (1:1 ratio) in total yields of 75–85%. The TaCl5-catalyzed reaction of
bicyclo[2.2.1]hept-2-ene,
endo-tricyclo[5.2.1.02,6]deca-3,8-diene,
and
(exo/endo)-5-
methylbicyclo[2.1.1]hept-2-ene with Et3Al leads to the formation of diethyl[2-exo-(2-
norbornylethyl)]aluminates in high yields. DFT calculations confirm the thermodynamic preference
of the final exo product. The multistep reaction mechanisms for the formation of the resultant
organoaluminates through tantalacyclopentanes as key intermediates are also discussed.
Keywords: 1-Alkenes; Norbornenes;
Organoaluminates; Catalysis; Tantalum complexes;
Tantalacyclopentanes; Carboalumination; DFT calculations.
The carboalumination reaction is widely used as an efficient procedure for the construction
of the metal–carbon and carbon–carbon bonds giving rise to new types of higher organoaluminum
compounds (OACs). The catalytic systems for this reaction based upon titanium and zirconium
compounds or complexes are recognized to be the most active and well studied (Scheme 1).1
Scheme 1. Carboalumination of 1-alkenes in the presence of Ti and Zr catalysts.
 Corresponding author. Tel./fax: +7 347 2842750.
E-mail address: Sultanov55@mail.ru (R.M. Sultanov).

2
However, there is practically no data in the literature regarding the catalytic behavior of Ta
complexes and compounds in the reaction between OACs and unsaturated hydrocarbons, though Ta
and Nb complexes are reported to catalyze dimerization, codimerization, and oligomerization of 1-
alkenes,2 as well as metathesis3 and polymerization of ethylene.4
In this paper, we report the first use of TaCl5 as a catalyst for the carboalumination of linear
alkenes and norbornenes with Et3Al.
Our preliminary experiments showed that TaCl5 catalyzed the reaction between 1-alkenes
and Et3Al. But, in this case, the major products differed from those obtained with Ti and Zr
complexes as shown in Scheme 1. We continued our investigations by studying the Ta-catalyzed
carboalumination reaction of 1-alkenes with Et3Al (see Supporting Information). 1-Hexene, 1-
octene and 1-decene were selected as the starting reactants.
The model reaction of 1-octene with Et3Al (1:1 ratio) in the presence of 5 mol% of the TaCl5
catalyst (1-octene:[Ta] = 100:5) in hexane at r.t. for seven hours resulted mainly in a mixture of two
OACs, 1b and 2b, in 75% yield relative to the starting 1-octene. Together with the
carboalumination products, 1b (classic) and 2b (with an unusual structure), small amounts of the
hydroalumination products 3b (10–15%) derived initial 1-octene, were also detected in the reaction
mixture (Scheme 2) (see Supporting Information).
Scheme 2. The Ta-catalyzed carboalumination of 1-alkenes.
The structures of the synthesized compounds 4, 5, 6a, 6c, 8, and 11 were confirmed by
1
recording IR, H and 13C NMR spectra, mass measurements and elemental analysis of their
derivatives generated upon deuterolysis and oxidation with molecular oxygen.5
The only hydrolysis product, 4b (3-methylnonane)5b was obtained upon treatment of 1b and
2b with dilute hydrochloric acid (8%), while their deuterolysis led to two monodeuterated
hydrocarbons, 6b and 7b (1:1 ratio). The yield and molar ratio of the resulting regioisomers were
determined by calculating their GLC peak area ratios (see Supporting Information).
Oxidation of these reaction products with anhydrous oxygen afforded regioisomeric alcohols
9b and 10b, in which the hydroxyl groups were attached to different carbon atoms (see Supporting
Information).
The observations described above confirmed unambiguously the structures of the reaction
products 1b and 2b as 2-(R-substituted)- and 3-(R-substituted)-n-butylaluminates.
To gain a more detailed insight into this unusual tantalum-catalyzed alkene
carboalumination with Et3Al, we have studied the influence of the solvent, the temperature, the
molar ratio of reactants, the ligand environment of tantalum, the concentration of the catalyst as
well as the duration of the reaction on the yield and composition of the OACs 1b and 2b in the
model reaction with 1-octene (Table 1).
Table 1. The effect of the molar ratio of reactants, the solvent, the ligand environment of tantalum,
and the concentration of the catalyst on the yield and composition of the carboalumination products
of 1-octene.
Reaction conditions: concentration of Et3Al 2 mmol/mL, [Ta]:[L] = 1:1, 20 oC, 7 h.
As seen in Table 1, the carboalumination reaction of 1-octene with Et3Al in the presence of
TaCl5 occurred in hydrocarbon solvents such as hexane, benzene, and toluene (entries 1–4, 6, and 7)
over 7 hours to afford the OACs 1b and 2b (1:1 ratio) in good yields. In dichloroethane (entry 5),
this reaction produced predominantly the classic carboalumination product 1b (2:1). It should be
noted that we could not obtain the desired result when ethereal solvents such as the diethyl ether,
tetrahydrofuran or methyl tert-butyl ether were employed.

3
The search for an efficient catalytic system revealed that the binary TaCl5–P(OPri)3 (1:1)
catalytic system produced the highest yield of the unusual carboalumination product 2b (Table 1,
entry 9). Our experiments also showed that ligand-modified Ta catalysts (Table 1, entries 8, 11, 12,
and 13) reduced the total yield of the carboalumination products but, at the same time, favored
predominant formation of the OAC 1b. As can be seen from Table 1, the above reaction did not
produce 1b and 2b when a bidentate ligand (entry 10), or a two-fold excess of other ligands (L/Ta =
2) listed in the Table were used in the carboalumination.
The temperature also played an important role in the reaction of 1-alkenes with Et3Al,
significantly influencing the product yield and the 1b:2b ratio. Thus, at elevated temperature (60
oC), the yield of 2b decreased (1b:2b = 70:30), while over five hours the total yield of 1b and 2b
reached 78%. At a lower temperature (~0 ºC), the total yield did not exceed 20% at a molar ratio of
1b:2b = 4:5.
Taking into account our own experimental findings, as well as published data on the
synthesis and transformations of substituted tantalacyclopentanes,3,6 we can suggest possible routes
for the simultaneous formation of OACs 1 and 2 via the carboalumination reaction (Scheme 3).
Scheme 3. The catalytic cycle for the TaCl5-catalyzed carboalumination reaction of 1-alkenes with
Et3Al.
In accordance with Scheme 3, the reaction between TaCl5 and Et3Al afforded unstable
diethyl tantalum complex 12, which eliminates an ethane molecule to produce the alkene complex
13 as a result of β-hydride transfer. The latter transforms into complex 14 containing molecules of
ethylene and the initial 1-alkene in the coordination sphere. Intramolecular oxidative cyclization of
complex 14 afforded labile β-alkyl-substituted tantalacyclopentane 15, of which further reaction
with excess Et3Al may proceed along two possible parallel routes.
The first route involves the formation of a bimetallic complex via transmetallation of 15
with Et3Al at the C1–Ta bond. The subsequent conversion of 16 leads to the OAC 1 as a result of β-
hydride transfer. The second route can be realized through the stepwise transmetallation reaction of
intermediate 15 with Et3Al at the C4–Ta bond to give bimetallic complex 17, followed by its
transformation into the unusual carboalumination product 2 after β-hydride transfer.
As shown in all our experiments the hydroalumination products of the original 1-alkene
were also detected in the reaction mixture. This can be explained by the fact that the tantalum alkyl
derivatives are easily converted into hydrides,7 which can serve as promoters for the
hydrometallation process.
1-Hexene and 1-decene also reacted with Et3Al giving rise to the OACs 1a and 2a, as well as
1c and 2c, respectively. We found that these reactions proceeded in a similar way. They retain all
the regularities described above for 1-octene, resulting in deuterated 6a, 6c, 7a, and 7c, as well as
the oxidation products 9a, 9c and 10a, 10c, respectively (see Supporting Information). In all these
experiments, the carboalumination reaction was also accompanied by small amounts of
hydroalumination products 3 (10–15%).
For more detailed investigations of the carboalumination reaction and its regio- and
stereoselectivity in order to synthesize new classes of organoaluminum compounds, we have
studied the reaction of norbornenes with Et3Al under the reaction conditions described above (5
о
mol% TaCl5, hexane, 20 С). Bicyclo[2.2.1]hept-2-ene (norbornene), endo-tricyclo[5.2.1.02.6]deca-
3,8-diene (endo-dicyclopentadiene) and exo-endo-5-methylbicyclo[2.2.1]hept-2-ene (exo/endo =
2:1) were selected for this study. The structures of the resulting organoaluminates were deduced
from 1D and 2D NMR,8 and IR spectra and chromatography-mass spectrometry data of their
hydrolysis, deuterolysis, and oxidation products.
Our experiments revealed that norbornene reacted with an equimolar amount of Et3Al in the
o
presence of 5 mol% TaCl5 as the catalyst (hexane, 20 C, 6 h) giving rise, exclusively, to an

4
organoaluminate compound (exo-adduct) 18 (85% yield) as the product of an unusual
carboalumination pathway of the reaction (Scheme 4).
Scheme 4. The TaCl5-catalyzed carboalumination reaction of norbornene with triethylaluminum
The chemical structure of adduct 18 was elucidated by standard chemical transformations.
Thus, hydrolysis of 18 with dilute hydrochloric acid (~5% aq. HCl) gave 2-exo-
ethylbicyclo[2.2.1]heptane (19),9 whereas deuterolysis of the reaction mixture led to exo-
monodeuteroethylnorbornane (20). Oxidation of 18 resulted in the appropriate alcohol 21 (see
Supporting Information). The yields of the end products were estimated from the GLC peak areas
of their hydrolysis and deuterolysis products.
To clarify the influence of the norbornene structure on the pathway and stereochemistry of
the carboalumination reaction we studied endo-dicyclopentadiene and exo-endo-5-
methylbicyclo[2.2.1]hept-2-ene in the reaction with Et3Al under the optimized conditions.
Dicyclopentadiene took part in the reaction with Et3Al to give a mixture of two
regioisomeric organoaluminates 22 and 23, which differed from one another in the position of the
aluminum-containing substituent relative to the double bond (Scheme 5). The total yield of 22 and
23 (1:1 ratio) reached 88%.
Scheme 5. The reaction of dicyclopentadiene with triethylaluminum in the presence of TaCl5.
Deuterolysis of 22 and 23 resulted in a mixture of exo-8-(1-deuteroethyl)-endo-
tricyclo[5.2.1.02.6]-dec-3-ene (24) and exo-9-(1-deuteroethyl)-endo-tricyclo[5.2.1.02.6]-dec-3-ene
(25), respectively.10 The formation of only 24 and 25 from four possible dicyclopentene isomers
was clearly confirmed by the 13C NMR assignments (see Supporting Information).
The reaction between exo-endo-5-methylbicyclo[2.2.1]-hept-2-ene and Et3Al in the presence
of TaCl5 as the catalyst under the above reaction conditions resulted in a more complex product
mixture (Scheme 6).
Scheme 6. The reaction of exo-endo-5-methylbicyclo[2.2.1]-hept-2-enes with triethylaluminum in
the presence of TaCl5.
Deuterolysis of the reaction mixture (compounds 26–29), in this case, led to
methyl(deuteroethyl)norbornanes 30, 31, 32, and 33 [(30+31):(32+33) = 2:1] in a total yield of
86%.11
According to the 13C NMR spectral data, products 30, 31, 32, and 33 differed from each
other in the positions of their monodeuteroethyl substituents relative to the methyl substituent, and
were epimers of each other at the C2 position (see Supporting Information).
Based on our current and earlier experimental data, and taking into account the published
data dealing with the synthesis, application and transformations of tantalum complexes,2,6 we
suggest possible pathways for the reaction under discussion.
The catalytic cycle of the TaCl5-catalyzed reaction involving norbornenes and Et3Al is
represented by the example of bicyclo[2.2.1]hept-2-ene (Scheme 7).
In accordance with the Scheme, the reaction between TaCl5 and Et3Al affords unstable
dialkyl tantalum complex 34, which eliminates an ethane molecule to produce the ethylene complex
35 as a result of β-hydride transfer. The latter transforms into bis-alkene complex 36 containing the
ethylene and initial norbornene molecules in the coordination sphere. Intramolecular oxidative
cyclization in complex 36 affords labile tantalacyclopentane 37. Transmetallation reaction of the
latter with an additional Et3Al molecule results in Al,Ta-bimetallic complex 38, which undergoes
transformation into the carboaluminate product 18 after β-hydride transfer.

5
Scheme 7. Catalytic cycle for the reaction of norbornene
with Et3Al in the presence of TaCl5.
To estimate the thermodynamic probability of the elementary steps of the proposed
mechanism for the TaCl5-mediated norbornene reaction with organoaluminate compounds, we
carried out density functional theory (DFT) calculations using the PBE functional12 and Stevens–
Basch–Krauss pseudopotential13 implemented in the Priroda 6 program.14 Density functional
methods are efficient tools for the understanding of chemical transformations of palladium,15
organomagnesium, organoaluminium and zirconium coordination compounds.16 The calculated
harmonic vibrational frequencies characterize the optimized structures as minima of potential
energy surfaces. The Gibbs energies of the reactions were calculated as differences between the
total energies of products and reactants taking into account thermal corrections (T = 293, all Gibbs
energies ΔG are in kJ/mol).
Scheme 8 shows a sequence of elementary steps of the catalytic cycle. Accordingly, the
reaction of Et3Al with TaCl5 results in the formation of organotantalum compound Cl3TaEt2 34,
which then converts into a π-complex of ethylene and tantalum chloride 35 (reaction 2). Complex
formation is endothermic and can occur due to the very high exothermicity of the previous step.
Formation of key intermediate 37 (reaction 3) is also an exothermic process.
As we have shown earlier, the reaction between norbornene and Et3Al in the presence of
TaCl5 leads to the only product 18, which is characterized by the exo-location of the ethylaluminum
moiety. To understand the reasons for such chemical behavior of norbornene, we investigated two
paths for the reaction between 37 and Et3Al: a) without breaking the chemical bond between Ta and
the norbornyl moiety resulting in 38 (reaction 4), and b) with breaking leading to 39 (reaction 5).
DFT calculations showed that both pathways were exothermic and characterized with
approximately equal Gibbs energies. The calculated lengths of the non-equivalent Ta–C bonds,
being 2.152 and 2.122 Å (Figure 1), confirmed the equal probability of the two possible routes for
the reaction between tantalacyclopentane 37 and Et3Al.
Scheme 8. Elementary steps of the catalytic cycle for the norbornene carboalumination and their
calculated Gibbs energies (PBE/SBK, in kJ/mol).
Figure 1. Calculated bond lengths of the tantalacyclopentane moiety in the intermediate 22 (Å).
Hydrogen atoms are omitted for clarity.
The greatest differences in the thermodynamic parameters were observed during further
transformations of 38 and 39. According to the proposed Scheme, regeneration of active π-complex
35 occurs in the final steps of the catalytic cycle resulting in 18 and 40. According to PBE/SBK
calculations, these compounds differ in thermodynamic stability, so the Gibbs energies of their
formations differ by sign. The formation of 40 (reaction 7) is endothermic in contrast to the
exothermic formation of 18 (reaction 6). Therefore, the identification of the only product 18 from
the reaction between norbornene and Et3Al in the chemical experiment is the result of its higher
thermodynamic stability.
In conclusion, we have demonstrated a new route to organoaluminate compounds through
the carbalumination reaction between 1-alkenes and Et3Al in the presence of TaCl5 as the catalyst.
In contrast to the known zirconium- and titanium-catalyzed procedures, the elaborated method
allows synthesis of unusual 3-(R-substituted)-n-butylaluminates, thus opening up new possibilities
for applications in organic and organometallic chemistry. The stereoselective TaCl5-catalyzed
reaction of bicyclo[2.2.1]hept-2-ene, endo-tricyclo[5.2.1.02,6]dec-3,8-diene, and exo-endo-5-

6
methylbicyclo[2.1.1]hept-2-ene with Et3Al affords diethyl[2-exo-(2’-norbornylethyl)]aluminates in
high yields. The quantitative evaluation of the Gibbs energy ΔG (293K) for elementary reactions of
the proposed catalytic cycle through intermediate tantalacyclopentanes has been carried out by
using DFT calculations, which confirmed the thermodynamic preference of the unusual pathway of
the carboalumination reaction and the final exo product linking it with steric hindrance in the bulky
norbornane moiety. The elaborated method represents a convenient opportunity for
functionalization of norbornene-type cyclic olefins.
Acknowledgement
This work was supported financially by the Russian Foundation for Basic Research (Grant No.10-
03-00046).
References and notes
1. (a) Dzhemilev, U. M.; Ibragimov, A. G. Russ. Chem. Rev. 2000, 69, 121.
(b) Kondakov, D. Y.; Negishi, E. J. Am. Chem. Soc. 1996, 118, 1577.
(c) Dzhemilev, U. M.; Ibragimov, A. G.; Zolotarev, A. P.; Muslukhov, R. R.; Tolstikov, G. A.
Bull. Acad. Sci. USSR, Div. Chem. Sci. 1989, 38, 194.
(d) Dzhemilev, U. M.; Ibragimov, A. G.; Vostrikova, O. S.; Tolstikov, G. A. Bull. Akad. Sci.
USSR, Div. Chem. Sci. 1985, 34, 196.
2. (a) McLain, S. J.; Sancho, J.; Schrock, R. R. J. Am. Chem. Soc. 1980, 102, 5610.
(b) McLain, S. J.; Sancho, J.; Schrock, R. R. J. Am. Chem. Soc. 1979, 101, 5451.
(c) McLain, S .J.; Schrock, R. R.; Wood, C. D. J. Am. Chem. Soc. 1977, 99, 3519.
(d) Schrock, R. R.; McLain, S. J.; Sancho, J. Pure Appl. Chem. 1980, 52, 729.
(e) McLain, S. J.; Schrock, R. R. J. Am. Chem. Soc. 1978, 100, 1315.
(f) Fellmann, J. D.; Rupprecht, G. A., Schrock, R. R. J. Am. Chem. Soc. 1979, 101, 5099.
(g) Andes, C.; Harkins, S. B.; Murtuza, S.; Oyler, K.; Sen, A. J. Am. Chem. Soc. 2001, 123,
7423.
(h) Mueller, R. A.; Tsurugi, H.; Saito, T.; Yanagawa, M.; Oda, S.; Mashima, K. J. Am. Chem.
Soc. 2009, 131, 5370.
(i) Yu, Z. X.; Houk, K. N. Angew. Chem. Int. Ed. 2003, 42, 808.
3. (a) Rocklage, S. M.; Fellmann, J. D.; Messerle, L. W.; Schrock, R. R. J. Am. Chem. Soc. 1980,
103, 1440.
(b) Mauri, O.; Lefort, L.; Vidal, V.; Thivolle-Cazat, J.; Basset, J.-M. Organometallics, 2010, 29,
6612
(c) Wallance, K. C.; Liu, A. H.; Dewan, J. C.; Schrock, R. R. J. Am. Chem. Soc. 1988, 110,
4964.
(d) Roux, E. L.; Chabanas, M.; Baundonin, A.; de Mallman, A.; Coperet, C.; Quadrelli, E. A.;
Thivolle-Cazat, J.; Basset, J.-M.; Lukens, W.; Lesage, A.; Emsley, L.; Sunley, G. J.; J. Am.
Chem. Soc. 2004, 126, 13391.
4. Mashima, K.; Fujikama, S.; Tanaka, Y.; Urata, H.; Oshiki, T.; Tanaka, E.; Nakamura, A.
Organometallics, 1995, 14, 2633.
5. Compounds 4, 5, 6a, 6c, 8, and 11 were identified by comparison with authentic samples as
described in the following:
(a) Gubaidullin, L. Yu.; Sultanov, R. M.; Dzhemilev, U. M. Bull. Akad. Sci. USSR, Div. Chem.
Sci. 1982, 31, 638.
(b) Dzhemilev, U. M.; Vostrikova, O. S.; Sultanov, R. M. Bull. Akad. Sci. USSR, Div. Chem.
Sci. 1983, 32, 193.

7
(c) Ibragimov, A. G.; Khafizova, L. O.; Zagrebel’naya, I. V.; Parfenova, L. V.; Sultanov, R. M.;
Khalilov, L. M., Dzhemilev, U. M. Russ. Chem. Bull. Int. Ed. 2001, 50, 292.
6. McLain, S. J.; Wood, C. D.; Schrock, R. R. J. Am. Chem. Soc. 1979, 101, 4558.
7. Chirik, P. J.; Zubris, D. L.; Ackerman, L. J.; Henling, L. M.; Doy, M. W.; Bercaw, J. E.
Organometallics, 2003, 22, 172.
8. K.Whitesell and M.A.Minton. Stereochemical Analysis of Alicyclic Compounds by C-13 NMR
Spectroscopy. Eds. Chapman & Hall. London-New York. 1985. 275 p.
9. Dzhemilev, U. M.; Vostrikova, O. S.; Sultanov, R. M. Bull. Acad. Sci. USSR, Div. Chem. Sci.
1985, 34, 1310.
10.Compounds 24 and 25 were synthesized via the TaCl5-catalyzed carboalumination reaction of
endo-dicyclopentadiene with Et3Al according to the general procedure (see Supporting
Information).
11.Compounds 30, 31, 32, and 33 were synthesized according to the general procedure (see
Supporting Information).
12.Perdew, J.P.; Burke, K.; Ernzerhof, M. Phys. Rev. Lett. 1996, 77, 3865.
13.Giordan, M.; Custodio, R.; Morgon, N.H. Chem. Phys. Lett. 1997, 279, 396.
14.Laikov, D.N.; Ustynyuk, Yu.A. Russ. Chem. Bull. 2005, 54, 820.
15.Shamsiyev, R.S.; Perepelkova, T.I.; Mal'kov, A.A.; Romm I.P; Belov A.P. Russ. J. Coord.
Chem. 2002, 28, 104.
16.(a) Pankratyev, E.Yu.; Tyumkina, T.V.; Parfenova, L.V.; Khalilov, L.M.; Khursan, S.L.;
Dzhemilev U.M. Organometallics 2009, 28, 968.
(b) Pankratyev, E.Yu.; Tyumkina, T.V.; Parfenova, L.V.; Khursan, S.L.; Khalilov, L.M.;
Dzhemilev, U.M. Organometallics 2011, 30, 6078.

Figure(s) (use if uploading high quality figure files)
R
Cp2ZrCl2
[Ti] or [Zr]
Et3Al (Et2AlCl)
+
R
R
AlEt2
Al
Et
Scheme 1.

Figure(s) (use if uploading high quality figure files)
Et3Al
+
R
20 oC [Ta]
7 h
AlEt2
AlEt2
R
+
+
AlEt2
3a,b,c
R
R
1a,b,c
H3O+
2a,b,c
D3O+
O2
R
R
D
R
OH
R
4a,b,c
6a,b,c
9a,b,c
OH
D
+
+
+
R
R
10a,b,c
5a,b,c
7a,b,c
+
+
R = Bun (a)
R
OH
R
D
Hexn (b)
Octn (c)
8a,b,c
11a,b,c
Scheme 2.

Figure(s) (use if uploading high quality figure files)
TaCl5
2Et3Al
[Ta] = TaCl3
2Et2AlCl
[Ta]
12
C2H6
[Ta]
13
R
R
[Ta]
R
14
R
[Ta]
15
route 1
route 2
R
R
Et3Al
AlEt2
H
Et2Al
H
[Ta]
[Ta]
16
17
R
R
Et2Al
AlEt2
2
1
Scheme 3.

Figure(s) (use if uploading high quality figure files)
+
Et3Al
(5 mol%)
20 oC
TaCl5
6 h hexane
AlEt2
18
H3O+
D3O+
O2
D
OH
19
Scheme 4.
20
21

Figure(s) (use if uploading high quality figure files)
+ Et3Al
20 oC
6 h
TaCl5 (5 mol%)
hexane
AlEt2
+
AlEt2
22
23
D3O+
D
+
D
1 : 1
24
25
Scheme 5.

Figure(s) (use if uploading high quality figure files)
Et3Al
+
20 oC
TaCl5 (5 mol%)
6 h hexane
+
+
+
+
AlEt2
AlEt2
AlEt2
AlEt2
26
27
28
D3O+
29
7
7
7
7
1
1
1
1
6
6
2
2
6
2
2
6
4
+
+
4
D
D
4
4
3
3
D
5
D
3
5
3
5
5
30
31
32
(30+31) : (32+33) = 2 :1
33
Scheme 6.

Figure(s) (use if uploading high quality figure files)
TaCl5
2Et3Al
2Et2AlCl
[Ta] = TaCl3
H
[Ta]
Et
34
C2H6
Et2Al
[Ta]
18
35
[Ta]
Et2Al
[Ta]
36
H
38
[Ta]
Et3Al
Scheme 7.
37

Figure(s) (use if uploading high quality figure files)
G kJ/mol
(1)
(2)
TaCl5
+
2Et3Al
Cl3TaEt2
+
+
2Et2AlCl
C2H6
543.4
34
Cl3TaEt2
+13.9
TaCl3
35
(3)
(4)
35
+
41.0
TaCl3
37
Et2Al
113.0
100.0
Cl3EtTa
38
Et3Al
+
37
Cl3EtTa
Et2Al
(5)
39
18
40
(6)
(7)
Et2Al
+
+
10.2
38
39
35
35
H
Et
+ 8.1
Et2Al
Scheme 8.

Figure(s) (use if uploading high quality figure files)
Figure 1.

Table(s)
Et3Al :
1-octene
molar
Total
yield
1b+2b
(%)
1b:2b
molar
ratio
1-Octene:
TaCl5
molar ratio
Entry
1
Solvent
Ligand
ratio
hexane
hexane
1 : 1
1 : 1
2 : 1
1 : 1
1 : 1
1 : 1
1 : 1
1 : 1
1 : 1
100 : 5
100 : 3
100 : 5
100 : 10
100 : 5
100 : 5
100 : 5
100 : 5
100 : 5
―
―
75
53
85
81
74
70
71
70
72
1 : 1
1 : 1
1 : 1
1 : 1
2 : 1
1 : 1
1 : 1
5 :4
2
3
hexane
―
hexane
4
5
6
7
8
9
―
dichloroethane
benzene
toluene
―
―
―
hexane
Ph3P
(PriO)3P
hexane
1 : 6
hexane
10
1 : 1
100 : 5
–
–
PPh2
Ph2P
hexane
hexane
11
12
1 : 1
1 : 1
100 : 5
100 : 5
P(NMe2)3
Et3N
59
66
1 : 1
3 :2
hexane
13
1 : 1
100 : 5
65
5 : 1
N
Table 1.

Supporting Information
Unusual pathway of the tantalum-catalyzed carboalumination reaction of
alkenes with triethylaluminum
Rifkat M. Sultanov, Elena V. Samoilova, Natal’ya R. Popod’ko, Artur R. Tulyabaev, Denis Sh.
Sabirov, Usein M. Dzhemilev
Experimental section
All manipulations of oxygen- and moisture-sensitive materials were conducted with using a
standard Schlenk technique or in a dry glove box under an argon atmosphere. Alkenes having a
purity of no less than 99,.8% were distilled over Bui3Al in under a stream of argon prior to use.
Commercially available norbornene and dicyclopentadiene (purity 99,5 %) were purchased from
Aldrich. Unavailable commercially exo-endo-5-methylnorbornene (exo/endo = 2:1) used in
experiments was prepared in the laboratory of Prof. R.I. Khusnutdinov. Commercially available
TaCl5 (purity 99,8 %) was purchased from Aldrich. Dry solvents (toluene, benzene, dichloroethane,
and hexane) were prepared according to procedures as described in the following: Gordon, A.;
Ford, R. Sputnik khimika, Mir, Moscow, 1976. (Russian translation from A. Gordon, R. Ford, The
chemist’s companion. A handbook of practical data, techniques and references, John Wiley & Sons,
1972). Chromatographic analysis of the hydrolysis and deuterolysis products was performed on
SHIMADZU GC-2014 instrument (column 2 m x 3 mm, 5% SE-30 on Chromaton N-AW-HMDS
(0.125−0.160 mm) as the stationary phase, helium as a carrier gas (30 mL min–1), temperature
o
o
13
programming from 50 to 300 C at a rate of 8 C min–1. The one-dimensional (1H, C) and two
dimensional homo- (COSY) and heteronuclear (HSQC, HMBC) NMR spectra were recorded in
CDCl3 on a spectrometer Bruker Avance 400 [400.13 MHz (1H) and 100.62 MHz (13C)] at 298 K in
accordance with standard Bruker pulse sequences. Chemical shifts were reported in parts per
million (ppm) relative to tetramethylsilane (TMS) as an internal standard. Infrared spectra (IR) were
recorded using FT-IR spectrometer Bruker Vertex 70 v (liquid film). Chromato-mass spectrometric
analysis of compounds was performed on SHIMADZU GCMS-QP 2010 instrument (SUPELCO
SLBTM-5 ms, 60000 mm x 0.25 mm x 0.25 μm, helium as the carrier gas, temperature programming
o
o
260 C at a rate of 5 C min–1, the temperature of the ion source 260 ° C [EI, 70 eV]). Elemental
analysis of the samples was carried out using Carlo Erba Elemental Analyzer model 1106.
The carboalumination reaction of 1-alkenes with Et3Al catalyzed by TaCl5 catalyst (general
procedure). A glass reactor, under a dry argon atmosphere at 0 ºC, was charged under stirring with
TaCl5 (2.5 mmol, ~ 0,9 g), 1-alkene (50 mmol) and Et3Al (50 mmol, 2 M solution in hexane).
Temperature was raised to 20 ºC, and the mixture of reactants was stirred for additional 7 h. Then,
the reaction mixture was quenched by a 8% DCl in D2O to identify OACs obtained. The organic
layer was separated, washed with NaHCO3 (until neutral) and dried over MgSO4. The mixture of
products was separated by fractional distillation. Additional separation of compounds from the
mixtures was performed by preparative GC.
o
1
1-Deutero-3-ethyloctane (6b): B.p. 75 C (30 mm Hg). IR: 2175 (C–D) cm–1. H NMR (400.13
MHz, CDCl3): δ 1.12–1.45 (m, 13Н, CH2, СН), 0.86–0.97 (m, 8Н, CH3, СН2D). 13C NMR (100.62
MHz, CDCl3): δ 36.8 (C4), 34.5 (C3), 32.1 (C7), 29.8 (C6), 29.6 (C2), 27.2 (C5), 22.8 (C8), 18.9 (C10,

2
1
t, JC–D = 19 Hz), 14.1 (C9), 11.3 (C1). MS, m/z 143 [M]+. Elemental Anal. Calc. for: C, 83.92; H,
19.68; D, 1.40. Found: C, 84.20; H+D, 15.49%.
o
1
1-Deutero-3-methylnonane (7b): B.p. 75 C (30 mm Hg). IR: 2175 (C–D) cm–1. H NMR (400.13
MHz, CDCl3): δ 1.12–1.45 (m, 13Н, CH2, СН), 0.86–0.97 (m, 8Н, CH3, СН2D). 13C NMR (100.62
MHz, CDCl3): δ 36.8 (C4), 34.5 (C3), 32.1 (C7), 29.8 (C6), 29.5 (C2), 27.2 (C5), 22.8 (C8), 19.2
1
(C10), 14.1 (C9), 11.0 (C1, t, JC–D = 19.0 Hz). MS, m/z 143 [M]+. Elemental Anal. Calc. for: C,
83.92; H, 14.68; D, 1.40. Found: C, 83.79; H+D, 15.97%.
The 13С NMR spectrum of regioisomer 6b exhibits a signal at δ(С10) 18.9 with a
characteristic coupling constant (1JС–D = 19.0 Hz) and a diagnostic signal at δ(С1) 11.3 ppm. The
1
deuterium isotope effect on the H chemical shift of the C10-methyl group caused its shielding
compared to that of compound 7b. This shielding effect results in the chemical shift of δ 0.31 ppm.
13
The С NMR spectrum of regioisomer 7b also contained the characteristic triplet signal at δ(С1)
11.0 ppm (1JС–D = 19.0 Hz).
In an analogous fashion, the deuterium isotope effect in compound 7b caused shielding of
the C1-methyl group, which resulted in a chemical shift of δ 0.30 ppm. We also noted the presence
of β-isotope effects in both compounds 6b (∆ δβ-isotope С3 = 0.06 ppm) and 7b (∆ δβ-isotope С2 = 0.07
ppm).
Oxidation of OACs from the reaction of 1-alkenes with Et3Al catalyzed by TaCl5 (general
procedure). Oxidation of the OMCs 1b and 2b, obtained by the reaction of 1-alkenes with Et3Al in
hexane or benzene in the presence TaCl5, was carried out in a thermostated glass reactor (100 mL)
by passing bubbles of pure dry oxygen through the solution. The temperature of solution was
o
maintained at 5–8 °C. After 120 minutes, a 5% HCl solution was added dropwise (0 C) to the
reaction mixture. The resultant mixture was extracted with diethyl ether (3 x 20 mL), dried over
MgSO4. After removal of ether, the residue was analyzed by GLC and then distilled in vacuo.
Individual alcohols 9 and 10 were separated by preparative GLC.
2-Ethyloctane-1-ol (9b): Bp 76–77 ºC (3 mm Hg). IR (thin film): 3420 (O–H), 1045 (C–O), 1465,
1
3
1375 cm–1. H NMR (400.13 MHz, CDCl3): δ 3.51 (d, JH–H = 5 Hz, 2Н, СН2O), 1.12–1.41 (m,
13H, CH2, CH), 0.87–0.89 (m, 6H, CH3). C NMR (100.62 MHz, CDCl3): δ 65.2 (C1), 31.9 (C6),
13
30.5 (C2), 29.8 (C3), 29.7 (C5), 30.0 (C4), 23.4 (C9), 22.7 (C7), 14.1 (C8), 11.1 (C10). MS, m/z 158
[M]+. Elemental Anal. Calc. for: C, 75.95; H, 13.92; O, 10.13. Found: C, 75.91; H, 13.69%.
3-Methylnonane-1-ol (10b): Bp 76–77 ºC (3 mm Hg). IR (thin film): 3420 (O–H), 1045 (C–O),
1465, 1375 cm–1. H NMR (400.13 MHz, CDCl3): δ 3.64 (m, 2Н, СН2O), 1.59 and 1.35 (m, 2H,
1
H2C2), 1.57 (m, 1H, HC3), 1.18–1.31 (m, 10H, CH2), 0.87–0.89 (m, 6H, CH3). C NMR (100.62
13
MHz, CDCl3): δ 61.1 (C1), 40.0 (C2), 37.2 (C4), 31.9 (C7), 29.8 (C6), 29.6 (C3), 26.9 (C5), 22.7 (C8),
19.7 (C10), 14.1 (C9). MS, m/z 158 [M]+. Elemental Anal. Calc. for: C, 75.95; H, 13.92; O, 10.13.
Found: C, 75.91; H, 13.69%.
13
In the С NMR spectrum of regioisomeric alcohol 10b the carbinol signal appeared at a
higher field (δС1 61.1) compared to the corresponding signal in the spectrum of regioisomeric
alcohol 9b (δС10 65.2).
Significant differences between the positions of the low field methyl carbon resonance
(δС10 9.7) and the shielded methyl carbon resonance (δС1 11.1) were observed in the spectra of
compounds 10b and 9b, respectively. The 1:1 ratio of 9b and 10b was calculated through 1H NMR
experiments from integration of unambiguously different proton signals belonging to the
hydroxymethylene groups (δС1Н2 3.51 and δС1Н2 3.64 for alcohols 9b and 10b, respectively).
o
1
1-Deutero-3-methylheptane (7a): B.p. 56 C (80 mm Hg). IR: 2180 (C–D) cm–1. H NMR (400.13
MHz, CDCl3): δ 1.45 (m, 1Н, СН), 1.29 (m, 2Н, СН2), 1.20 (m, 2Н, СН2), 1.16 (m, 2Н, CН2), 1.12
3
(m, 2H, СН2), 0.87 (t, 3H, CH3, 3J = 7.2 Hz), 0.86 (m, 2Н, СН2D), 0.83 (q, 3H, CH3, J = 6.4 Hz).
13C NMR (100.62 MHz, CDCl3): δ 36.6 (C4), 34.7 (C3), 29.4 (C2), 28.6 (C5), 22.8 (C6), 18.6 (C8),

3
14.1 (C9), 10.8 (C1, t, 1JC–D = 19.0 Hz). MS, m/z 115 [M]+. Elemental Anal. Calc. for: C, 83.48; H,
14.78; D, 1.74. Found: C, 83.41; H+D, 16.49%.
o
1
1-Deutero-3-methylundecane (7c): B.p. 110 C (30 mm Hg). IR: 2175 (C–D) cm–1. H NMR
13
(400.13 MHz, CDCl3): δ 1.43 (m, 1Н, СН), 1.35 (m, 16Н, СН2), 0.93 (m, 8H, СН3, CH2D). C
NMR (100.62 MHz, CDCl3): δ 34.4 (C2), 34.4 (C4), 32.0 (C5), 30.2 (C6), 29.8 (C7), 29.5 (C3), 29.5
(C8), 27.2 (C9), 22.7 (C10), 19.1 (C12), 18,8 (C1, t, JC–D = 19.0 Hz), 14.0 (C11). MS, m/z 171 [M]+.
1
Elemental Anal. Calc. for: C, 84.21; H, 14.62; D, 1.17. Found: C, 84.18; H+D, 15.71%.
2-Ethylhexane-1-ol (9a): B.p. 101 oC (30 mm Hg). IR: 1375, 1465, 1045 (C–O), 3430 (O–H) cm–1.
1H NMR (400.13 MHz, CDCl3): δ 3.52 (q, 3JH–H = 4.8 Hz, 2Н, СН2O), 1.39 (m, 2Н, СН2), 1.37 (m,
1H, СН), 1.32 (m, 2H, CH2), 1.28 (m, 4H, CH2), 0.89 (m, 6H, CH3). 13C NMR (100.62 MHz,
CDCl3): δ 65.1 (C1), 41.9 (C2), 30.1 (C3), 29.2 (C4), 23.3 (C7), 23.1 (C5), 14.1 (C6), 11.1 (C8). MS,
m/z 130 [M]+. Elemental Anal. Calc. for: C, 73.85; H, 13.84; O, 12.31. Found: C, 73.63; H, 13.75%.
2-Ethyldecane-1-ol (9c): Bp 151 ºC (30 mm Hg). IR (thin film): 3425 (O–H), 1045 (C–O), 1465,
1375 cm–1. 1H NMR (400.13 MHz, CDCl3): δ 3.35 (m, 2Н, СН2O), 1.76 (m, 3H, CH3), 1.45 (m, 1H,
13
CH), 1.17 (m, 16H, CH2), 0.76 (m, 3H, CH3). C NMR (100.62 MHz, CDCl3): δ 64.3 (C1), 41.8
(C2), 37.2 (C3), 31.9 (C4), 30.4 (C5), 29.6 (C6), 29.3 (C7), 26.9 (C8), 23.2 (C11), 22.3 (C9), 13.8 (C10),
10.8 (C12). MS, m/z 186 [M]+. Elemental Anal. Calc. for: C, 77.42; H, 13.98; O, 8.60. Found: C,
77.39; H, 13.89%.
3-Methylheptane-1-ol (10a): B.p. 97 oC (30 mm Hg). IR: 1375, 1465, 1045 (C–O), 3425 (O–H) cm–
1
1. H NMR (400.13 MHz, CDCl3): δ 3.65 (m, 2Н, СН2O), 1.59 (m, 2H, CH2), 1.52 (m, 1H, CH),
1.28 (m, 6H, CH2), 0.89 (m, 6H, CH3). 13C NMR (100.62 MHz, CDCl3): δ 61.1 (C1), 39.9 (C2), 36.8
(C4), 29.5 (C3), 29.1 (C5), 22.9 (C6), 19.6 (C8), 14.0 (C7). MS, m/z 130 [M]+. Elemental Anal. Calc.
for: C, 73.85; H, 13.84; O, 12.31. Found: C, 73.71; H, 13.80%.
3-Methylundecane-1-ol (10c): Bp 156 ºC (30 mm Hg). IR (thin film): 3425 (O–H), 1045 (C–O),
1
1465, 1375 cm–1. H NMR (400.13 MHz, CDCl3): δ 3.47 (m, 2Н, СН2O), 1.45 (m, 1H, CH), 1.17
13
(m, 16H, CH2), 0.76 (m, 6H, CH3). C NMR (100.62 MHz, CDCl3): δ 60.2 (C1), 39.7 (C2), 31.9
(C4), 30.1 (C5), 30.0 (C6), 29.6 (C7), 29.4 (C3), 29.3 (C8), 26.9 (C9), 22.3 (C10), 19.4 (C12), 13.8
(C11). MS, m/z 186 [M]+. Elemental Anal. Calc. for: C, 77.42; H, 13.98; O, 8.60. Found: C, 77.43;
H, 13.85%.
The carboalumination reaction of norbornene with Et3Al catalyzed by TaCl5 catalyst (general
o
procedure). A glass reactor, under a dry argon atmosphere at 0 C, was sequentially charged under
stirring with hexane (20 mL), norbornene (30 mmol, 2.8 g), triethylaluminum (30 mmol, 4.5 mL),
o
and TaCl5 (1,5 mmol, 0.54 g). The temperature was raised to 20 C and the mixture was stirred for
additional 6 h. Then, the reaction mixture was quenched by a 8% DCl in D2O to identify the OAC
obtained. The organic layer was separated. The aqueous layer was extracted with diethyl ether (3 x
50 mL). The combined organics were washed with NaHCO3 (until neutral) and dried over MgSO4.
The target product 20 was separated by fractional distillation.
2-exo-(2-deuteroethyl)bicyclo[2.2.1]heptane (20): Bp = 64 ºС (30 mm Hg.). IR ν (сm−1 in thin film):
1
2180 (C−D). Н NMR (CDCl3, in ppm, 400.13 MHz): δ = 2.19 (m, 1Н, СН), 1.98 (m, 1Н, СН),
1.48 (m, 1Н, СН), 1.43 (m, 1Н, СН), 1.41 (m, 1Н, СН), 1.33 (m, 2Н, СН2), 1.31−1.33 (m, 1Н,
СН), 1.28 (m, 1Н, СН), 1.24 (m, 1Н, СН), 1.16 (m, 1Н, СН), 1.10 (m, 1Н, СН), 1.04 (m, 1Н, СН),
0.83−0.88 (m, 2Н, CH2D). 13С NMR (CDCl3, in ppm, 100.62 MHz): δ = 44.4 (С2), 40.8 (С1), 38.0
1
(С3), 36.5 (С4), 35.2 (С7), 30.2 (С6), 29.5 (С8), 28.9 (С5), 12.1 (С9, JC−D = 19 Hz). MS, m/z: 125
(M+). Elemental Anal. Calc. for: С, 86.4; Н, 12.00; D, 1.60. Found: С, 86.35; Н+D, 13.61%.
Oxidation of OACs from the reaction of norbornenes with Et3Al catalyzed by TaCl5 (general
procedure). Oxidation of the OAC 18, obtained by the reaction of bicycle[2.2.1]-hept-2-ene with
Et3Al in hexane in the presence TaCl5, was carried out in a thermostated glass reactor (100 mL) by
passing bubbles of pure dry oxygen through the solution. The temperature of solution was
maintained at 5–8 °C. After 120 minutes, the reaction mixture was poured into a 5% aq. HCl

4
solution. The resultant alcohol was extracted with diethyl ether (3 x 50 mL), dried over MgSO4,
and, after removal of ether, was analyzed by GLC. The alcohol 21 was separated by vacuum
distillation.
2-exo-(2-hydroxyethyl)bicyclo[2.2.1]heptane (21): Bp = 135 ºС (30 mm Hg). IR ν (сm−1 in thin
film): 3435 (О−Н), 1045 (С−О). 1Н NMR (CDCl3, in ppm, 400.13 MHz): δ = 3.64 (t, 3J = 7.2 Hz,
2H, CH2O), 2.21 (m, 1Н, СН), 1.98 (m, 1Н, СН), 1.59 (m, 1Н, СН), 1.50 (m, 1Н, СН), 1.49 (m,
1Н, СН), 1.47 (m, 1Н, СН), 1.45 (m, 1Н, СН), 1.38 (m, 1Н, СН), 1.31 (m, 1Н, СН), 1.15 (m, 1Н,
13
СН), 1.10 (m, 3Н, СН). С NMR (CDCl3, in ppm, 100.62 MHz): δ = 61.7 (С9), 41.1 (С1), 40.0
(С8), 38.4 (С2), 38.1 (С3), 36.6 (С4), 35.3 (С7), 30.1 (С5), 28.8 (С6). MS, m/z: 122 (M+−H2O).
Elemental Anal. Calc. for: С, 77.14; Н, 11.43; O, 11.43. Found: С, 77.21; Н, 11.39%.
The 13C NMR spectra of products 20 and 21 contain seven resonances assigned to
magnetically nonequivalent carbon atoms of the norbornane skeleton. This indicates the effect of
the methylene hydrogen substitution at the C2 position. The crosspeaks due to long-range couplings
between the norbornane C2 and the protons of the substituent is the further convincing evidence of
the structures.
The HMBC spectrum of 20 contains crosspeaks between δС2 44.4 and δН 1.35 and
0.80−0.88, whereas, in the spectrum of 21, δС2 38.4 provides crosspeaks with δН 1.38, 1.59 and
3.64. The resonances δС 44.4, 28.9, and 35.2 for 20 and δС 38.4, 30.1, and 35.3 for 21 of the
characteristic С2, С5, and С7 clearly indicate the formation of both 20 and 21 having exo-
substituents, that is, these groups are cis to the bridge.
The product mixture of 24 and 25 was isolated by distillation. Bp = 118 ºС (30 mm Hg). IR
ν (сm−1 in thin film): 1370, 1480, 1620, 2190 (C-D), 2860, 2960, 3060. MS, m/z: 163 (M+).
Elemental Anal. Calc. for: С, 88.34; Н, 10.43; D, 1.23. Found: С, 88.41; Н+ D, 11.60%.
The GC retention times for components of a given mixture were determined as 15.89 and
13
16.05 min. Two sets of the characteristic carbons in the C NMR spectra (according to reference
data from [10]) clearly indicate the presence of two isomers that are hard to chromatographically
separate.
1
8-exo-(1-deuteroethyl)-endo-tricyclo[5.2.1.02.6]dec-3-ene (24): Н NMR (CDCl3, in ppm, 400.13
MHz): δ = 5.66 (m, 1Н, СН), 5.54 (m, 1Н, СН), 2.52 (m, 1Н, СН), 2.21 (m, 2Н, СН2), 2.11 (m, 1Н,
СН), 1.88 (m, 1Н, СН), 1.54 (m, 1Н, СН), 1.49 (m, 1Н, СН), 1.48 (m, 1Н, СН), 1.29 (m, 2Н,
2СН), 1.23 (m, 2Н, СН2), 0.82 (t, 2Н, СН2D), 0.77 (m, 1Н, CH). 13С NMR (CDCl3, in ppm, 100.62
MHz): δ = 132.6 (С4), 130.8 (С3), 53.7 (С2), 45.7 (С6), 42.5 (С7), 41.1 (С1), 38.4 (С10), 35.6 (С8),
33.6 (С9), 32.0 (С5), 29.6 (С11), 12.3 (С12, t, 1JC−D = 19 Hz).
1
9-exo(1-deuteroethyl)-endo-tricyclo[5.2.1.02.6]dec-3-ene (25): Н NMR (CDCl3, in ppm, 400.13
MHz): δ = 5.66 (m, 1Н, СН), 5.54 (m, 1Н, СН), 2.52 (m, 1Н, СН), 2.27 (m, 1Н, СН), 2.21 (m, 1Н,
СН), 2.07 (m, 1Н, СН), 1.54 (m, 1Н, СН), 1.52 (m, 1Н, СН), 1.48 (m, 1Н, СН), 1.46 (m, 1Н, СН),
13
1.29 (m, 1Н, СН), 1.12 (t, 2Н, СН2), 0.83 (m, 1Н, CH), 0.82 (t, 2Н, СН2D). С NMR (CDCl3, in
ppm, 100.62 MHz): δ = 132.6 (С4), 130.4 (С3), 52.4 (С2), 44.1 (С6), 41.8 (С7), 40.0 (С1), 38.6 (С9),
38.4 (С10), 32.4 (С5), 30.3 (С8), 29.2 (С11), 11.9 (С12, t, 1JC−D = 19 Hz).
The 13C NMR spectrum of the mixture of compounds 24 and 25 contains two resonances at
δС 11.9 and 12.3 (1:1 intensity ratio) assigned to C12 indicating the formation of only 24 and 25
from four possible dicyclopentene isomers. The 2C intensity signal at δC 38.4 belonging to both
bridging C10 carbons is indicative of the exo-orientation of monodeuterated fragments. The
crosspeak between the C12 methylene proton resonance at δН 0.82 and the resonance at δС 38.6 in
the HMBC spectrum of 25 clearly indicate the substitution in the carcass at C9 position, whereas 24
is the C8 substituted isomer due to the correlation between δН 0.82 and δС 35.6.
The product mixture of 30, 31, 32, and 33 was isolated by distillation. Bp = 78 ºС (30 mm Hg).
IR ν (сm−1 in thin film): 2180 (C−D). MS, m/z: 139 (M+). Elemental Anal. Calc. for: С, 86.33; Н,
12.23; D, 1.44. Found: С, 86.21; Н+D, 13.61%.

5
The GC retention times tr for components of a given mixture were determined as 11.34 and
11.52 min with the integral intensity ratio of 2:1, respectively, that agrees with the exo/endo ratio of
2:1 for initial exo-endo-5-methylbicyclo[2.2.1]-hept-2-ene. However, four sets of the characteristic
carbons in the 13C NMR spectra (according to reference data from [10]) clearly indicate the
presence of two exo and two endo isomers that are hard to chromatographically separate.
1
2-exo-methyl-6-exo-(1-deuteroethyl)bicyclo[2.2.1]heptane (30): Н NMR (CDCl3, in ppm, 400.13
MHz): δ = 2.15 (m, 1Н, СН), 1.90 (m, 1Н, СН), 1.64 (m, 1Н, СН), 1.46 (m, 1Н, СН), 1.41 (m, 1Н,
СН), 1.25 (m, 1Н, СН), 1.22−1.25 (m, 1Н, СН), 1.20 (m, 2Н, СН2), 1.15 (m, 1Н, CH), 0.97 (d, 3Н,
СН3, 3J = 7.2 Hz), 0.95 (m, 1Н, СН), 0.93 (m, 1Н, СН), 0.86 (d, 2Н, CH2D, 3J = 7.2 Hz). 13С NMR
(CDCl3, in ppm, 100.62 MHz): δ = 44.8 (С6), 38.9 (С3), 37.0 (С7), 36.9 (С1), 35.3 (С2), 31.7 (С5),
22.3 (С9), 16.7 (С8), 12.3 (С4), 12.1 (С10, t, 1JC−D = 19 Hz).
1
2-exo-methyl-5-exo-(1-deuteroethylbicyclo[2.2.1]heptane (31): Н NMR (CDCl3, in ppm, 400.13
MHz): δ = 2.15 (m, 1Н, СН), 1.81 (m, 1Н, СН), 1.48 (m, 1Н, СН), 1.46 (m, 1Н, СН), 1.37 (m, 1Н,
СН), 1.29 (m, 2Н, 2СН), 1.27 (m, 1Н, СН), 1.20 (m, 1Н, СН), 1.13 (m, 1Н, СН), 1.11 (m, 1Н,
СН), 1.02 (m, 1Н, CH), 0.95 (m, 1Н, СН), 0.93 (d, 3Н, СН3, 3J = 6.8 Hz), 0.86 (d, 2Н, CH2D). 13С
NMR (CDCl3, in ppm, 100.62 MHz): δ = 44.9 (С5), 43.3 (С4), 38.7 (С3), 37.0 (С1), 37.0 (С7), 35.7
(С2), 31.7 (С6), 29.4 (С9), 17.4 (С8), 12.1 (С10).
1-endo-methyl-6-exo-(1-deuteroethyl)bicyclo[2.2.1]heptane (32): 1Н NMR (CDCl3, in ppm, 400.13
MHz): δ = 2.14 (m, 1Н, СН), 1.94 (m, 1Н, СН), 1.90 (m, 1Н, СН), 1.80 (m, 2Н, 2СН), 1.78 (m,
3
1Н, СН), 1.65 (m, 1Н, СН), 1.48 (m, 1Н, СН), 1.41 (m, 1Н, СН), 0.90 (d, 3Н, СН3, J = 7.2 Hz),
0.86 (d, 2Н, СН2D), 0.84 (m, 1Н, CH), 0.57 (m, 1Н, СН), 0.55 (m, 1Н, СН). 13С NMR (CDCl3, in
ppm, 100.62 MHz)): δ = 47.6 (С5), 41.9 (С4), 39.1 (С7), 37.9 (С1), 37.6 (С3), 34.1 (С2), 30.7 (С6),
29.6 (С9), 22.2 (С8), 12.1 (С10).
1-endo-methyl-5-exo-(1-deuteroethyl)bicyclo[2.2.1]heptane, (33): 1Н NMR (CDCl3, in ppm, 400.13
MHz): δ = 1.90 (m, 1Н, СН), 1.80 (m, 1Н, СН), 1.46 (m, 1Н, СН), 1.41 (m, 1Н, СН), 1.40 (m, 1Н,
СН), 1.25 (m, 1Н, СН), 1.15 (m, 1Н, СН), 0.97 (m, 3Н, СН2, СН), 0.90 (d, 3Н, СН3, 3J = 7.2 Hz),
13
0.86 (m, 2Н, СН2D), 0.84 (m, 1Н, CH). С NMR (CDCl3, in ppm, 100.62 MHz): δ = 46.4 (С6),
41.8 (С4), 40.2 (С7), 38.2 (С3), 37.9 (С1), 33.3 (С2), 30.7 (С5), 29.3 (С9), 22.0 (С8), 12.1 (С10).
The 13C DEPT135 NMR spectrum contains two typical resonances δС6 44.8 and δС5 44.9 for
exo epimers 30 and 31 as well as the other two δС6 46.4 and δС5 47.6 for endo isomers 32 and 33.
The bridging C7 carbon atoms in exo isomers 30 and 31 are accidentally isochronous and
manifest themselves at δC 37.0, while the resonances δC7 39.1 and 40.2 are clearly distinguishable
for the endo epimers 32 and 33.