Catalytic enantioselective ethylalumination of terminal alkenes: Substrate effects and absolute configuration assignment

Article abstract of DOI:10.1016/j.tetasy.2014.11.019

The chemo- and enantioselectivity of the reaction of alkenes with AlEt₃ catalyzed by bis(1-neomenthylindenyl)zirconium dichloride has been studied. The reaction with linear alkenes in a chlorinated solvent (CH₂Cl₂) gives m

Full text of DOI:10.1016/j.tetasy.2014.11.019

Tetrahedron: Asymmetry 26 (2015) 124–135
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Tetrahedron: Asymmetry
journal homepage: www.elsevier.com/locate/tetasy
Catalytic enantioselective ethylalumination of terminal alkenes:
substrate effects and absolute configuration assignment
⇑
Lyudmila V. Parfenova , Pavel V. Kovyazin, Tatyana V. Tyumkina, Alyona V. Makrushina,
Leonard M. Khalilov, Usein M. Dzhemilev
Institute of Petrochemistry and Catalysis, Russian Academy of Sciences, Prospect Oktyabrya, 141, 450075 Ufa, Russian Federation
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 19 November 2014
Accepted 27 November 2014
The chemo- and enantioselectivity of the reaction of alkenes with AlEt3 catalyzed by bis(1-neomenthyl-
indenyl)zirconium dichloride has been studied. The reaction with linear alkenes in a chlorinated solvent
(CH2Cl2) gives mainly carbometallation products in 70–80% yield and with enantiomeric purity of 47–
70%ee with an (S)-configuration. In the case of vinylcycloalkanes and styrene, the reaction provides
roughly equal amounts of carbometallation products and substituted alumolanes with enantioselectivi-
ties of 39–69%ee and 40–57%ee, respectively.
(R)-MTPA and (R)-2-phenylselenopropionic acid [(R)-PSPA] were used as the derivatization reagents for
enantiomeric excess estimation and the absolute configuration assignment of b-chiral primary alcohols
and 2-substituted 1,4-butanediols resulting from oxidation and hydrolysis of the organoaluminum
products. It was shown that the specific rotation changes sign in the series of enantiomerically enriched
2-ethyl-1-alkanols when going from b-ethyl-substituted octanol to nonanol. The conformational analysis
of the MTPA and PSPA esters of 2-ethyl-1-alkanols was performed and a dependence of their conforma-
tional composition on the type of substituent at the b-stereogenic center was established. Calculation of
the 77Se NMR chemical shifts of the possible conformers of the PSPA esters demonstrated that the con-
formation of the selenium moiety has the most pronounced effect on the dSe value. The high efficiency
of PSPA application for the enantiomeric purity estimation and the absolute configuration assignment
of 2-ethyl-1-alkanols is shown.
Ó 2014 Elsevier Ltd. All rights reserved.
1. Introduction
The carboalumination of alkenes with trialkylalanes (AlMe3,
AlEt3) catalyzed by bis(1-neomenthylindenyl)zirconium dichloride
Enantiomerically pure zircono- and titanocene complexes have
found wide use as components of catalytic systems for the con-
struction of CAH, CAC, and metalAC bonds with high chemo-
and stereoselectivity. This refers to both enantioselective alkene
poly- and oligomerizations1 and asymmetric alkene carbo- and
cyclometallations to give acyclic and cyclic organometallic com-
pounds,2 which are important synthons for organometallic chemis-
try. The pathway and stereoselectivity of these reactions depend,
as a rule, on the substrate nature. For example, carbomagnesiation
of unsaturated heterocycles or functionally substituted alkenes in
the presence of enantiomerically pure zirconocenes run with high
chemo- and enantioselectivity,2a,3 whereas when this reaction
involves terminal linear alkenes, it affords acyclic and cyclic orga-
nomagnesium compounds with low enantiomeric excess.4
1 proceeded with high substrate conversion, chemo- and enantiose-
lectivity (Scheme 1).6,7 It was shown that the organoaluminum
compound and the solvent have the greatest effect on the reaction
pathway and enantiomeric purity of the organoaluminum products.
Thus, the replacement of AlMe3 with AlEt3 causes a change in the
absolute configuration of the corresponding b-substituted carboalu-
mination product.7 The use of chlorinated solvents provides acyclic
carboalumination products in high yields and enantiomeric purity
(up to 93%ee).6 However, in hydrocarbon solvents the cycloalumina-
tion pathway that starts to predominate under these conditions
results in 3-substituted alumolanes with 23–38% enantiomeric
purity.6b,8 Nevertheless, the influence of the substrate structure on
the chemo- and enantioselectivity of the ethylalumination reaction
has not been sufficiently studied. We have shown previously
that a length increase for the alkyl chain in linear alkenes or the
involvement of sterically hindered alkenes, for example, 4-methyl-
pent-1-ene or vinylcyclohexane, decreases the cycloalumination
enantioselectivity to 23–26%ee.8 The chemo- and enantioselectivity
⇑
Corresponding author. Tel.: +7 347 2843527; fax: +7 347 2842750.
E-mail address: luda_parfenova@mail.ru (L.V. Parfenova).
http://dx.doi.org/10.1016/j.tetasy.2014.11.019
0957-4166/Ó 2014 Elsevier Ltd. All rights reserved.

L. V. Parfenova et al. / Tetrahedron: Asymmetry 26 (2015) 124–135
125
Me
Me
AlMe3
[O]
[O]
OH
AlMe2
AlEt2
chlorinated solvents
R
R
R
H
68-92%, 65-85%ee
H
Et
Et
H
AlEt3
Zr
R
OH
R
Cl
chlorinated solvents
H
56-88%, 68-93%ee
H
H
[O]
OH
1
AlEt3
AlEt
OH
R
hydrocarbon solvents
R
50-86%, 23-38%ee
Scheme 1.
of the carboalumination of terminal alkenes by AlEt3 in chlorinated
solvents were found to slightly depend on the substrate structure if
unsaturated compounds containing non-substituted allyl group
were used. Herein we decided to expand the range of substrates
involved in the reaction and compare the effect of alkenes with an
allyl and vinyl bond on the reaction direction and enantioselectivity.
Moreover, an important objective of this research was to deter-
mine the enantiomeric excess and absolute configurations of the
stereogenic centers in the resulting acyclic and cyclic organoalumi-
2. Results and discussion
2.1. Reaction of terminal alkenes with AlEt3 catalyzed by bis(1-
neomenthylindenyl)zirconium dichloride 1
The reaction of 1-alkenes with triethylaluminum in CH2Cl2 at
room temperature in the presence of 8 mol % of bis(1-neomenthyl-
indenyl)zirconium dichloride 1 proceeded over 24 h with high
alkene conversion of 84–99% according to Scheme 2.
Et
1
AlEt2
+
AlEt2
+
AlEt
R
AlEt3
+
R
CH2Cl2, 22oC
R
R
R
5a-j
2a-j
3a-j
O2, H3O+
4a-j
a
b
c
;
R = n-C4H9 ; n-C5H11 ; n-C6H13
O2, H3O+
n-C7H15 d; n-C8H17 e; i-C4H9 f;
g
h
i
j
Cy6 ; Cy8 ; Ph ; Bn
Et
OH
OH
OH
R
7a-j
6a-j
Scheme 2.
num compound. For this purpose, the products were subjected to
oxidation and hydrolysis, resulting in the isolation of mono- and
dihydric alcohols for which the specific rotation was determined.
The enantioselectivity of the reaction of alkenes with
triethylaluminum was determined in relation to the oxidation
and hydrolysis products, b-ethyl-substituted alcohols 6a–j and
1,4-butanediols 7a–j.
Comparison of the experimental [a]D value with the published data
allows for the assumption of the absolute configuration of the ste-
reogenic center in the obtained products. Various derivatizing
reagents, often MTPA, or chromatographic methods with optically
active columns were used for the estimation of the enantiomeric
purity of the products. However, the assignment of the absolute
configuration based on the specific rotation for non-crystalline
mono- and dihydric alcohols is difficult because the data presented
in the literature are often contradictory. Furthermore, the effi-
ciency of the application of one or another derivatizing agent to
determine the enantiomeric excess and the absolute configuration
can depend on the substrate nature. In some cases, diastereomeric
effects sufficient for the determination of these parameters cannot
be observed for the products. Therefore, an investigation into
which shift reagent is correct is often a problem.
Herein we report new results on the enantioselective ethylalu-
mination of alkenes with different structures, and results on the
use of MTPA9 and a selenium-containing compound, (R)-2-phe-
nylselenopropionic acid (PSPA),10 as derivatizing reagents to assign
the absolute configuration of the stereogenic centers and the
enantiomeric excess of the products.
It was found that lengthening the hydrocarbon chain in linear
alkenes 2a–f had almost no influence on the alkene conversion
or the yield of the ethylalumination products. The conversion in
the series of alkenes 2a–f was more than 90%; the yield of the
carbometallation products 3a–f was 70–80% and the enantiomeric
excess was in the 47–70% range with the (S)-enantiomers predom-
inating. Previously it was shown that a decrease in the reaction
temperature resulted in an increase in the enantiomeric excess of
the carboalumination products of up to 92%.6b However, in our
experiments, carrying out the reaction at a reduced temperature
(5 °C) led to a decrease in the enantioselectivity from 68%ee to
62%ee (entries 1 and 2, Table 1).
The use of more sterically hindered substrates, such as alkenes
containing a vinyl group such as vinylcycloalkanes 2g,h or styrene
2i gave noteworthy results. In these cases, the fraction of cycloalu-
mination products markedly increased, while the enantioselectivity
of this pathway was also significantly improved when compared to
linear alkenes. Thus, the enantiomeric purity of 4g reached 57%ee for
the (S)-enantiomer. In the case of vinylcyclooctane, the enantio-
meric excess of the carboalumination product substantially

126
L. V. Parfenova et al. / Tetrahedron: Asymmetry 26 (2015) 124–135
Table 1
Reaction of alkenes 2a–j with AlEt3 catalyzed by complex 1 (molar ratio [Zr]/alkene/AlEt3 = 4:50:60, reaction time 24 h, 20 °C)
25
25
Entry
Alkene
Solvent
Alkene conversion (%)
Product yielda % (ee%, R/S)
[a
]
6 (CH2Cl2)
[a
]
7 (CH2Cl2)
D
D
3
4
1
2
1-Hexene 2a
CH2Cl2
CH2Cl2
99b
35c
75 (68) (S)
25 (62) (S)
21 (5) (S)
10
+2.6 (c 0.3)
+0.3 (c 0.8)
3
4
5
6
7
8
9
1-Heptene 2b
1-Octene 2c
1-Nonene 2d
1-Decene 2e
4-Methyl-1-pentene 2f
Vinylcyclohexane 2g
Vinylcyclo-octane 2h
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
99
99
99
94
99
85
84
79 (60) (S)
78 (47) (S)
80 (70) (S)
77 (69) (S)
70 (60) (S)
34 (62) (S)
35 (39) (S)
18
13
15
15
+1.7 (c 1.9)d
+1.2 (c 4.6)e
ꢀ1.5 (c 4.7)
ꢀ1.3 (c 4.7)
+2.7 (c 0.9)
+4.5 (c 0.4)
+2.5 (c 1.0)
15
42 (57) (S)
49 (45) (S)
ꢀ5.3 (c 1.6)f
ꢀ7.5 (c 1.3)
10
11
12
Styrene 2i
CH2Cl2
—
C6H6
68
96
68
28 (69) (S)
44 (33) (S)
15
30 (31) (R)
39 (40) (R)
39 (6) (R)
ꢀ8.7 (c 0.4)
ꢀ4.3 (c 0.8)
ꢀ11.7 (c 1.2)g
ꢀ2.0 (c 1.0)
13
14
15
Allylbenzene 2j
CH2Cl2
—
C6H6
19
20
24
8 (52) (S)
10 (16) (S)
10 (14) (S)
6
+1.1 (c 0.7)
5 (11) (S)
5
a
b
c
d
e
f
Determined by GC of deuterolysis products.
Data from Ref. 7.
Reaction time 48 h, 5 °C.
Lit. data: [
Lit. data: [
Lit. data: [
Lit. data: [
a
a
a
a
]
D
]
D
]
D
]
D
(S)-6b = +1.3 (62%ee).11
(S)-6c = +2.4 (c 2.0, CHCl3) 74%ee.12
(S)-7g = ꢀ17.5 (c 0.49, EtOH).13
(R)-7i = ꢀ30.7 (c 0.2, acetone).14
g
decreased to 39%ee, whereas the enantioselectivity of the cycloalu-
mination was 45%ee for the (S)-enantiomer. The reaction of styrene
with AlEt3 in CH2Cl2 catalyzed by complex 1 proceeded with 68%
conversion, while the enantioselectivity along the carboalumination
pathway was 69%ee. At the same time the enantioselectivity of the
cycloalumination reaction reached only 31%ee for the (R)-enantio-
mer. Carrying out the reaction without a solvent increases the
conversion to 96% but almost did not change the ratio of the carbo-
and cycloalumination products. The enantioselectivity for the
carboalumination pathways decreased to 33%ee (Table 1). The use
of benzene as the solvent significantly reduced the enantiomeric
purity of the cyclic product 4i (6%ee). In the case of linear alkenes,
the yield and the enantiomeric purity of the cycloalumination
products in the reaction under the same conditions did not exceed
18% and 7%ee, respectively.8 It should be noted that in hydrocarbon
solvents in the presence of catalyst 1, the maximum enantiomeric
excess of the cycloalumination products for linear alkenes did not
exceed 38%ee and the (R)-enantiomer predominated.8
alkene functioning as the key and the catalytically active site acting
as the lock. As a consequence, the chemo- and enantioselectivity of
these reactions are determined by kinetic factors, that is, the key–
lock interaction rate. Provided that the components perfectly
match, the high rate and high stereoselectivity are attained for a
particular reaction pathway.
2.2. Estimation of the enantiomeric excess and absolute
configuration assignment for the alkene carbo- and
cycloalumination products
In order to determine the enantiomeric excess and the absolute
configuration of the reaction products, the obtained alcohols 6a–j,
7g–j were reacted with derivatizing reagents (R)-MTPA [(S)-MTPA-
Cl]9 and (R)-2-phenylselenopropionic acid [(R)-PSPA]10 to give the
corresponding esters 8a–j, 9a–j, 10g–j, 11g–j (Scheme 3, Figs. 1
and 2). Previously, we demonstrated the applicability of MTPA to
assign the absolute configuration of b-stereogenic centers of 2-
ethyl-1-hexanol 6a and 2-n-butyl-1,4-butanediol 7a7 and showed
that (R)-2-phenylselenopropionic acid [(R)-PSPA] can be
The reaction of AlEt3 with allylbenzene in the presence of
catalyst 1 led to the lowest conversion among all of the olefins
used irrespective of the solvent (19–24%). The carboalumination
product (up to 52%ee) slightly predominated among the reaction
products in dichloromethane.
4
Ph
3
2
(R)-MTPA
(R)-PSPA
The overall yield, the chemo- and enantioselectivity of the reac-
tion of AlEt3 with terminal alkenes catalyzed by bis(1-neomenthyl-
indenyl)zirconium dichloride are largely determined by the
substrate structure. Currently, we cannot fully explain the
observed phenomena basing on our knowledge of the reaction
mechanism. This is the subject of additional investigations, which
we plan to perform in the future. However, it should be noted that
CF3
8a-j
9a-j
O
O
(R)
R
R
OMe
1
Et
O
O
OH
R
4
SePh
3
2
6a-j
(R)
1
O
the intramolecular mobility of
g
5-ligands within the zirconium
(R)
MeO
F3C
3
2
catalyst plays an important role in the enantioselective carbo-
and cycloalumination of the alkenes being discussed. Apparently,
for the conformationally non-rigid complex 1,5 the lability of
4
(R)-MTPA
(R)-PSPA
O
Ph
10g-j
11g-j
CF3
Ph
O
O
R
(R)
OMe
1
OH
OH
O
5-ligands gives rise to a set of bimetallic catalytically active sites
O
O
g
R
with different geometries7,8 sufficient for the chemo- and enantio-
selective transformation of terminal alkenes as substrates. In this
case, the solvent serves for the adjustment of the concentrations
of particular conformers of intermediates reactive toward the
alkene. Here the lock–key principle can be implemented with the
3
2
4
O
SePh
7g-j
SePh
R
1
Scheme 3.

L. V. Parfenova et al. / Tetrahedron: Asymmetry 26 (2015) 124–135
127
Figure 1. (a) 1H NMR triplet signals of methyl groups in b-ethyl substituents of diastereomers (R,R)-8b and (R,S)-8b; (b) 77Se NMR signals of diastereomers (R,R)-8b and (R,S)-
8b.
Figure 2. (a) 13C NMR signals of diastereomers (R,R,R)-10h and (R,R,S)-10h; (b) 77Se NMR signals of diastereomers (R,R,R)-11h and (R,R,S)-11h.
successfully used to estimate the enantiomeric excess of 2-alkyl-
1,4-butanediols as well.8 In the present work, we verified whether
it is legitimate to use (R)-MTPA and (R)-PSPA to determine the enan-
tiomeric excess and absolute configuration of 2-ethyl-substituted
primary alcohols 6a–j and 1,4-butanediols 7g–j.
It is noteworthy that upon going from octanol to nonanol in the
series of b-ethyl-substituted alkanols, the sign of the specific rota-
tion changes. Therefore, caution is needed when assigning the
absolute configurations of compounds of this series with long
hydrocarbon groups by comparing the [a]D with the published val-
ues for smaller-size homologs and vice versa. In our case, it turned
out that the isolated alcohols should have high purity because at
low concentrations and expected small rotation values, even minor
amounts of the catalyst or the ligand present (detectable in the
NMR spectra) distort the result. More accurate data can be
extracted from the diastereomeric splitting of the 13C NMR signals
of the carbon skeleton of MTPA esters and diastereomeric effects in
the 77Se NMR spectra of PSPA esters as well (Table 2).

128
L. V. Parfenova et al. / Tetrahedron: Asymmetry 26 (2015) 124–135
Table 2
1H and 13C NMR chemical shifts of MTPA esters 8a–j and 77Se NMR of PSPA esters 9a–j
R
(R)-MTPA esters 8a–j
(R)-PSPA esters 9a–j
dH (CH3)
(R,R)
dC
dSe
C3
C5
a
a
(R,S)
D
dR,S
(R,S)
(R,R)
D
dR,S
D
dR,S
(R,S)
30.20
(R,R)
30.12
D
dR,S
D
dR,S
(R,S)
(R,R)
D
dR,S
calcd
calcd
n-Bu a
0.80
0.81
0.01
23.54
23.47
23.49
23.53
23.54
24.30
20.87
20.78
24.96
23.26
23.63
23.57
23.59
23.63
23.65
24.38
20.89
20.78
24.98
23.49
0.09
0.10
0.10
0.10
0.11
0.08
0.02
0
ꢀ0.08
ꢀ0.08
ꢀ0.08
ꢀ0.09
ꢀ0.10
ꢀ0.18
ꢀ0.06
ꢀ0.03
0.27
452.13
452.14
452.31
452.15
452.22
452.10
451.77
452.02
453.81
451.92
452.22
452.24
452.42
452.26
452.33
452.57
451.43
451.45
453.08
452.60
0.09
0.10
0.11
0.11
0.11
0.47
ꢀ0.34
ꢀ0.57
ꢀ0.73
0.68
n-Pent b
n-Hex c
n-Hept d
n-Oct e
i-Bu f
0.691
0.694
0.760
0.760
0.692
0.705
0.726
0.643
0.784
0.700
0.703
0.771
0.771
0.705
0.719
0.735
0.624
0.788
0.009
0.009
0.011
0.011
0.013
0.014
0.009
30.43
30.49
30.58
30.59
40.48
38.37
36.88
30.35
30.41
30.49
30.49
40.30
38.31
36.85
141.38
37.07
0.25
0.64
ꢀ0.29
Cy6
Cy8
Ph i
Bn j
g
h
ꢀ0.019
0.02
0.23
141.11
37.13
0.58
0.004
ꢀ0.06
a
Values of
D
dR,S
are calculated for the predominant conformers.
calcd
For any of the esters 8b–j studied, the 1H NMR spectra exhibited
diastereomeric splitting of the triplet signal for the methyl group of
the ethyl substituent (Fig. 1a), so that
R,S > 0, except for 8i
(Table 3). The 13C NMR spectra of compounds 8b–h,j contained
doubled signals for the C3 dR,S >0 to 0.23 ppm) and C5 dR,S <0
the (R,S)-diastereomer exists mainly as sp/ap/ꢀsc and sp/ap/+sc
conformers (Table 3, Scheme 4). In the predominant ꢀsc conformer
of (R,R)-8i, the ethyl group can experience the shielding effect of
the phenyl group of the MTPA fragment, whereas in the ꢀsc and
+sc rotamers of (R,S)-8i, the ethyl group is outside the sphere of this
action. This is why the proton signals of the methyl group of the
ethyl substituent in (R,R)-8i are located at a higher field than those
in (R,S)-8i. The upfield shift of the signal for the ipso-carbon atom
(C5) in (R,S)-8i may be caused by the close position of the MTPA
phenyl group in one of the predominant conformers (ꢀsc). Thus,
we observed the corresponding signs of the theoretical and exper-
D
d
(D
(D
to ꢀ0.18 ppm) atoms, which are influenced by the MTPA phenyl
ring anisotropy in the most populated conformers sp/ap/ap and,
hence, they are characteristic.7 In the case of 8i, the difference in
the chemical shifts
phenyl group was above zero. For the same compound, the oppo-
site
dR,S effect was found for the 77Se NMR chemical shift. This
brought about the natural question of whether the observed oppo-
site
dR,S effects for (2RS)-phenyl-1-butanol follow from inversion
D
dR,S for the ipso-carbon atom (C5) of the
D
imental values of
predominant conformers of 8f and 8i. This illustrates the eligibility
D
dR,S for C3and C5, which were estimated for the
D
of the absolute configuration of the b-stereogenic center during
of the approach used.
carboalumination.
8i
(R,R)-
8i
(R,S)-
O
H
H
O
H
H
Table 3
H
O
H
MeO
F3C
MeO
F3C
MeO
F3C
Calculated relative energies and populations of 8a,f,i conformers
Ph
Et
2
O
Ph
O
1
O
Et
H
H
Compound
Diastereomer
Conformer
D
E (kcal/mol)
P (%)
H
Ph
3
8a7
(R,R)
sp/ap/ap
sp/ap/ꢀsc
sp/ap/+sc
sp/ap/ap
sp/ap/ꢀsc
sp/ap/+sc
0
99.3
0.4
0.3
97.9
1.4
0.7
4
sp/ap/-sc
sp/ap/-sc
sp/ap/+sc
1.4
1.5
0
1.2
1.4
Scheme 4.
(R,S)
Analogous studies of the conformational composition were
carried out for the PSPA esters as well. We determined the confor-
mational composition of the PSPA esters by DFT (PBE/3f)15 similar
to MTPA.7 The search for conformers was performed by rotating
molecules around two bonds, HCASePh and HCACO. The rotation
around the HCACO bond gave rise to two possible minima corre-
sponding to syn- (sp) and anti-periplanar (ap) positions of the
CAH bond with respect to the C@O group (Fig. 3).
In these conformers, the SeAPh and HAC bonds have the sp-
configuration. An additional rotation around the HCASePh bond
in each of these minima revealed two more conformers with an
anti-periplanar orientation of the SeAPh and HAC bonds. Thus,
four minima were found: ap/ap, ap/sp, sp/ap, and sp/sp, where the
first abbreviation corresponds to the HCASePh bond, while the sec-
ond one corresponds to the HCACO bond. The ap/ap conformer was
found to have the lowest energy among these structures (Fig. 1).
The sp/sp and sp/ap conformers are located at a higher energy level.
The molecule with the ap/sp bond orientation has the highest
energy. It is worth noting that in each pair of conformers, going
from the ap to sp configuration of the SeAPh and HAC bonds, the
calculated chemical shift dSe decreased by more than 10 ppm. Thus,
it can be stated that the 77Se chemical shift of PSPA may be affected
8f
8i
(R,R)
(R,S)
sp/ap/ap
sp/ap/ꢀsc
sp/ap/+sc
sp/ap/ap
sp/ap/ꢀsc
sp/ap/+sc
0
95.6
0.4
4.0
93.8
0.0
6.2
1.6
0.9
0
3.9
0.8
(R,R)
(R,S)
sp/ap/ap
sp/ap/ꢀsc
sp/ap/+sc
sp/ap/ap
sp/ap/ꢀsc
sp/ap/+sc
0.8
0
1.1
4.0
0.1
0
4.8
93.0
2.2
0
42.6
57.4
To answer the above question, we investigated the conforma-
tional composition of the MTPA and PSPA esters with the phenyl
group by a reported procedure.7 For the sake of comparison,
calculation for the MTPA ester with the isobutyl substituent 8f
was carried out. It was found that in the case of 8f, the conformer
populations were nearly the same as in 8a (Table 3). Furthermore,
calculation of the relative energy of conformers of the phenyl-
substituted MTPA ester 8i demonstrated that in the case of the
(R,R)-diastereomer, the sp/ap/ꢀsc conformer predominates, while

L. V. Parfenova et al. / Tetrahedron: Asymmetry 26 (2015) 124–135
129
became the most populated. However, the conformational compo-
sition of the alkoxide moiety has a much lower effect on the 77Se
chemical shift than the conformational composition of the second
part of the molecule, the PSPA moiety. It follows from analysis of
the relative conformer energy that the least population of the ap/
sp conformer along the SeAPh and HAC bonds of the initial PSPA
is responsible for the minor population of the corresponding ester
conformers, whereas the greatest population of the ap/ap con-
former ensures the highest fraction of molecules with the same
configuration of the selenium moiety in the esters. As in the PSPA,
transition from the ap- to sp-configuration of the SeAPh and HAC
bonds in esters results in a substantial decrease in the calculated
dSe. Moreover, the ap/ap to ap/sp or sp/sp to sp/ap transformation
of the PSPA moiety of the ester molecule leads to an increase in
the Se77 chemical shift.
ap/ap (Erel= 0 kcal/mol)
Se calc= 539.5 ppm
sp/sp (Erel= 0.2 kcal/mol)
Se calc= 482.6 ppm
δ
δ
It should be noted that the presence of a phenyl substituent in
the alkoxide moiety of the ester leads to an increase in the fraction
of conformers with the sp/ap configuration of the selenium moiety.
Thus, the nature of the substituent at the b-stereogenic center of
the PSPA ester and the absolute configuration of this center influ-
ences the distribution of conformers, the geometry of which is ini-
tially dictated by the selenium moiety of the whole molecule. It is
this part of the molecule that has a more pronounced effect on the
Se77 chemical shift. With the assumption that the real NMR spec-
trum exhibits the line resulting from fast exchange of conformers
sp/ap (Erel= 0.3 kcal/mol)
Se calc= 523.8 ppm
ap/sp (Erel= 1.1 kcal/mol)
Se calc= 538.6 ppm
δ
δ
presented in definite proportions, the chemical shift dSe = R
diPi.16
Figure 3. Relative energies and calculated chemical shifts dSe of PSPA conformers.
According to this, we determined the averaged chemical shifts
for each of the diastereomers of esters 9a and 9i. As follows from
Table 4, in the case of 9a, the calculated value
D
dR,SSe = 1.5 ppm,
by both the electronic and steric factors of the whole molecule.
Hence, we considered conformers 9a and 9i containing PSPA
moieties in four above-indicated variants. This resulted in 12 local
minima in the PES of diastereomer molecules, which are presented
in Scheme 5.
The conformer relative energies, populations, and calculated
77Se NMR chemical shifts are summarized in Table 4. In the case
of butyl-substituted product 9a, the conformers with an ap-config-
whereas for 9i,
D
dR,SSe = ꢀ1.3 ppm. As a result, the signs of the
calculated and experimental diastereomeric effects coincided. It
follows from the foregoing that the proposed approach to determi-
nation of the averaged dSe of the possible conformers of PSPA ester
diastereomers can be used to assign the absolute configuration of
the b-stereogenic center of 2-ethyl-1-alkanols provided that as
many as possible potential conformers are analyzed.
In conclusion, comparing MTPA and PSPA with regard to their
efficiency in the estimation of the enantiomeric excess of
2-ethyl-1-alkanols and 2-substituted 1,4-butanediols, PSPA is
favorable because in this case, the 77Se NMR spectra exhibit more
uration of the C AO and CbAH bonds were found to predominate
a
for both diastereomers. Furthermore, for the phenyl-substituted
product 9i, as in the case of MTPA esters, the gauche-conformers
O
H
H
O
H
H
O
H
H
Me
Ph
Me
Me
Ph
Ph
L1
H
O
L2
Se
O
O
Se
Se
L2
L1
H
H
L1
H
H
L2
H
ap/ap/ap/+sc
ap/ap/ap/-sc
ap/ap/ap/ap
O
H
H
O
H
H
O
H
H
H
H
H
L2
H
L1
O
O
O
Me
Me
L1
Me
L2
H
Se
L2
Se
Se
L1
H
Ph
Ph
Ph
ap/sp/ap/ap
ap/sp/ap/+sc
ap/sp/ap/-sc
H
O
H
H
H
O
H
H
O
Me
Me
Me
L1
L2
H
O
O
O
Se
Ph
Se
Ph
Se
Ph
L2
L1
H
H
L1
H
L2
H
H
H
sp/ap/ap/+sc
sp/ap/ap/ap
sp/ap/ap/-sc
O
H
H
O
H
O
H
H
H
H
H
L1
L2
H
O
O
O
Me
Ph
L2
Me
Me
L1
H
Se
L1
Se
L2
Se
H
Ph
Ph
sp/sp/ap/ap
sp/sp/ap/-sc
sp/sp/ap/+sc
Scheme 5. Conformer composition of the (R,S)- and (R,R)-diastereomers of (R)-PSPA esters 9a,j: (R,S)-L1 = Et, L2 = Bu (Ph); (R,R)-L1 = Bu (Ph), L2 = Et.

130
L. V. Parfenova et al. / Tetrahedron: Asymmetry 26 (2015) 124–135
Table 4
Calculated relative energies, populations and 77Se NMR chemical shifts of 9a,i conformers
Compound
Diastereomer
Conformer
D
E (kcal/mol)
P (%)
dSe
calcd
9a
(R,R)
ap/ap/ap/ap
ap/ap/ap/ꢀsc
ap/ap/ap/+sc
ap/sp/ap/ap
ap/sp/ap/ꢀsc
ap/sp/ap/+sc
sp/ap/ap/ap
sp/ap/ap/ꢀsc
sp/ap/ap/+sc
sp/sp/ap/ap
sp/sp/ap/ꢀsc
sp/sp/ap/+sc
0.00
0.55
0.11
1.46
2.13
1.47
0.43
0.92
0.68
0.13
0.67
0.35
31.2
4.5
21.2
0.2
0.0
0.2
6.8
1.3
2.9
19.6
3.0
517.79
511.91
510.63
534.23
534.49
542.54
497.44
500.71
502.04
467.58
464.18
466.59
dSe av = 497.94
510.93
512.75
507.38
535.63
549.94
529.79
497.98
498.44
492.44
467.28
459.15
466.18
dSe av = 496.39
504.79
516.03
513.92
553.15
550.49
530.22
486.59
498.47
515.81
488.07
461.23
462.18
dSe av = 498.37
517.51
511.93
510.05
538.14
531.87
543.00
502.51
493.77
492.92
455.36
474.80
466.18
dSe av = 499.67
9.0
(R,S)
(R,R)
(R,S)
ap/ap/ap/ap
ap/ap/ap/ꢀsc
ap/ap/ap/+sc
ap/sp/ap/ap
ap/sp/ap/ꢀsc
ap/sp/ap/+sc
sp/ap/ap/ap
sp/ap/ap/ꢀsc
sp/ap/ap/+sc
sp/sp/ap/ap
sp/sp/ap/ꢀsc
sp/sp/ap/+sc
0.00
0.24
0.55
1.66
1.76
1.97
0.58
0.53
1.04
0.25
0.37
0.83
38.0
16.3
5.6
0.1
0.1
0.0
5.0
5.9
1.0
15.6
10.3
2.1
9i
ap/ap/ap/ap
ap/ap/ap/ꢀsc
ap/ap/ap/+sc
ap/sp/ap/ap
ap/sp/ap/ꢀsc
ap/sp/ap/+sc
sp/ap/ap/ap
sp/ap/ap/ꢀsc
sp/ap/ap/+sc
sp/sp/ap/ap
sp/sp/ap/ꢀsc
sp/sp/ap/+sc
0.7
0.0
4.0
46.7
1.2
0.0
0.2
0.0
2.1
15.7
4.4
0.6
22.8
2.2
1.04
2.31
1.60
1.99
0.89
0.31
0.68
1.23
0.20
0.87
ap/ap/ap/ap
ap/ap/ap/ꢀsc
ap/ap/ap/+sc
ap/sp/ap/ap
ap/sp/ap/ꢀsc
ap/sp/ap/+sc
sp/ap/ap/ap
sp/ap/ap/ꢀsc
sp/ap/ap/+sc
sp/sp/ap/ap
sp/sp/ap/ꢀsc
sp/sp/ap/+sc
0.90
0.01
0.00
2.16
1.42
1.33
1.20
0.15
0.44
1.28
0.48
0.26
1.2
27.8
29.2
0.0
0.2
0.3
0.4
17.0
6.2
0.3
5.55
11.7
pronounced diastereomeric effects, which in turn minimizes the
errors of signal integration (Figs. 1b and 2b).
intramolecular mobility of the g
5-ligands in the zirconium cata-
lyst. As a result, the chemo- and enantioselectivity are determined
by the kinetic factor, that is, by the rate of reaction in the alkene–
catalytically active site, which can be represented by conformers of
3. Conclusion
Zr,Al–complexes formed through mutual rotation of
g
5-ligands.
When the pair components perfectly match, high rate and
stereoselectivity for a particular reaction pathway are attained.
It was found that in the series of enantiomerically enriched 2-
ethyl-1-alkanols isolated after oxidation and hydrolysis of the
alkene carboalumination products, the sign of the specific rotation
changes when going from b-ethyl-substituted octanol to substi-
tuted nonanol. Conformational analysis of the MTPA and PSPA
esters of 2-ethyl-1-alkanols showed the dependence of their con-
formational composition on the type of substituent at the b-stere-
ogenic center. Calculation of the 77Se chemical shifts of the possible
conformers of the PSPA esters demonstrated that the conformation
of the selenium moiety had the most pronounced influence on
The effect of the substrate structure on the chemo- and
enantioselectivity of the bis(1-neomenthylindenyl)zirconium
dichloride-catalyzed reaction of alkenes with AlEt3 was studied.
The reactions of linear alkenes in a chlorinated solvent (CH2Cl2)
were found to afford carboalumination products in high yields
with the (S)-enantiomers predominating (47–70%ee). The involve-
ment of more sterically hindered alkenes containing a vinyl bond,
such as vinylcycloalkanes or styrene, into the reaction results in
higher yields of cyclic organoaluminum compound—substituted
alumolanes with an enantiomeric purity of 40–57%. It was pro-
posed that the dependence of the reaction pathway and enantiose-
lectivity on the alkene structure can be related, in particular, to the

L. V. Parfenova et al. / Tetrahedron: Asymmetry 26 (2015) 124–135
131
dSe. The applicability of (R)-2-phenylselenopropionic acid [(R)-
PSPA] for the estimation of the enantiomeric excess and determi-
nation of the absolute configuration of the stereogenic centers of
b-chiral primary alcohols has been demonstrated for the first time.
pound 6; then the column was then washed with acetone to give
7 as a colorless oils.
4.2.1. (2RS)-Ethyl-1-heptanol 6b
1H NMR (CDCl3) d 0.91 (t, 6H, 3J = 7.2 Hz, CH3), 0.92 (t,
3J = 7.6 Hz, CH3CH2CH), 1.21–1.48 (m, 10H, CH2), 1.38–1.50 (m,
1H, CH), 3.57 (d, 2H, 3J = 5.2 Hz, CH2OH). 13C NMR (CD3Cl) d 11.0
(C9), 14.1 (C7), 22.6 (C6), 23.4 (C8), 26.9 (C4), 30.5 (C3), 32.1 (C5),
41.9 (C2), 65.2 (C1).
4. Experimental
4.1. General
All operations for organoaluminum compounds were performed
under argon according to Schlenk procedures. The complex (ꢀ)-
bis(1-neomenthylindenyl)zirconium dichloride was prepared by a
known procedure5 from ZrCl4 (99.5%, Aldrich) and (+)-3-
[(10S,20S,50R)-20-isopropyl-50-methylcyclohexyl]indene (3-neomen-
thylindene).5,8 Terminal alkenes 1-hexene (97%, Acros), 1-heptene
(98%, Acros), 1-octene (99%, Acros), 1-nonene (96%, Aldrich),
1-decene (97%, Aldrich), 4-methyl-1-pentene (97%, Acros), vinylcy-
clohexane (98%, Aldrich), vinylcyclooctane (99%, Aldrich), styrene
(99%, Acros), allylbenzene (98%, Aldrich) were used. The solvents
(hexane, benzene, toluene) were distilled from triisobutylalumi-
num immediately prior to use; THF and diethyl ether were dried
with sodium and distilled from LiAlH4 before use. Commercially
available 98% AlEt3 was involved in the reactions. The 1H, 13C, and
77Se NMR spectra were recorded on a Bruker AVANCE-400 spec-
trometer (400.13 MHz (1H), 100.62 MHz (13C), and 76.35 MHz
4.2.2. (2RS)-Ethyl-1-octanol 6c
1H NMR (CDCl3) d 0.90 (t, 3H, 3J = 6.8 Hz, CH3), 0.91 (t, 3H,
3J = 7.2 Hz, CH3CH2CH), 1.22–1.35 (m, 10H, CH2), 1.31–1.43 (m,
2H, CHCH2CH3), 1.35–1.47 (m, 1H, CH), 3.56 (d, 2H, 3J = 4.8 Hz, CH2-
OH). 13C NMR (CD3Cl) d 11.1 (C10), 14.1 (C8), 22.8 (C7), 23.35 (C9),
26.9 (C4), 29.7 (C5), 30.5 (C3), 31.9 (C6), 42.0 (C2), 65.3 (C1).
4.2.3. (2RS)-Ethyl-1-nonanol 6d
1H NMR (CDCl3) d 0.90 (t, 3H, 3J = 7.2 Hz, CH3), 0.91 (t, 3H,
3J = 7.2 Hz, CH3CH2CH), 1.22–1.45 (m, 12H, CH2), 1.30–1.45 (m,
2H, CHCH2CH3), 1.36–1.46 (m, 1H, CH), 3.55 (d, 2H, 3J = 4.8 Hz, CH2-
OH). 13C NMR (CD3Cl) d 11.1 (C11), 14.1 (C9), 22.7 (C8), 23.4 (C10),
26.9 (C4), 29.3 (C5), 30.0 (C6), 30.5 (C3), 31.9 (C7), 42.0 (C2), 65.3
(C1).
(
77Se)). As the solvent and the internal standard, CDCl3, toluene-
4.2.4. (2RS)-Ethyl-1-decanol 6e
1H NMR (CDCl3) d 0.90 (t, 6H, 3J = 7.2 Hz, CH3), 1.20–1.46 (m,
14H, CH2), 1.29–1.46 (m, 2H, CHCH2CH3), 1.34–1.46 (m, 1H, CH),
3.56 (d, 2H, 3J = 5.2 Hz, CH2OH). 13C NMR (CD3Cl) d 11.1 (C12),
14.1 (C10), 22.7 (C9), 23.4 (C11), 26.9 (C4), 29.6 (C5), 29.3 (C6), 30.1
(C7), 30.5 (C3), 31.9 (C8), 42.0 (C2), 65.3 (C1).
d8, and benzene-d6 were employed. The 77Se chemical shifts are
referred to Me2Se. 1D, and 2D NMR spectra (COSY HH, HSQC, HMBC)
were recorded using standard Bruker pulse sequences. The optical
20
rotation [
a
]
was measured on a Perkin Elmer-341 polarimeter.
D
Chromatographic analysis was carried out on a CARLO ERBA 1150
instrument in a helium flow, a 50,000 ꢁ 0.32 mm column, ULTRA-
1 stationary phase, and a flame ionization detector. The deuterated
products were analyzed by GC/MS on an automated QP 2010 Ultra
GC/MS assembled with a TD-20 Shimadzu thermal desorber. The
enantioselectivity of 1-alkene carbo- and cyclometallation was esti-
mated from the optical purity of the alcohols resulting from oxida-
tion and hydrolysis of the reaction products. The alcohols isolated in
4.2.5. (2RS)-Ethyl-4-methyl-1-pentanol 6f
1H NMR (CDCl3) d 0.89 (d, 3H, 3J = 6.4 Hz, CH3CH), 0.90 (d, 3H,
3J = 5.2 Hz, CH3CH), 0.91 (t, 3H, 3J = 6.0 Hz, CH3CH2), 1.08–1.22
(m, 2H, CHCH2CH), 1.28–1.49 (m, 2H, CH2CH3), 1.50 (sept, 1H,
3J = 6.4 Hz, CHCH2OH), 1.65 (non, 1H, 3J = 6.8 Hz, CHCH3), 3.52
(dd, 1H, 3J = 10.8 Hz, 2J = 5.6 Hz, CHHOH), 3.56 (dd, 1H,
3J = 10.8 Hz, 2J = 5.2 Hz, CHHOH). 13C NMR (CD3Cl) d 10.9 (C7),
22.90 (C5), 22.93 (C8), 23.6 (C6), 25.4 (C4), 39.5 (C2), 40.1 (C3),
65.4 (C1).
a pure state were involved in the reaction with (R)-(+)-
a
a-methoxy-
-trifluoromethylphenylacetic acid (S-MTPACl)9,6b and with (R)-
(+)-phenylselenopropionic acid [(R)-PSPA]10 to give diastereomeric
esters, which were then analyzed by 1H, 13C, and 77Se NMR.
The geometric parameters of the MTPA and PSPA esters were
optimized by DFT calculations using Priroda-08 software developed
by Laikov.15a The generalized gradient approximation (GGA) for the
exchange-correlation functional by Perdew, Burke, and Ernzerhof
was employed (PBE/3z).15b NMR chemical shifts were calculated
using the GIAO method, which is implemented in the program.15c
4.2.6. (2RS)-Cyclohexyl-1-butanol 6g
1H NMR (CDCl3) d 0.94 (t, 3H, 3J = 7.2 Hz, CH3), 0.99–1.12 (m, 2H,
CHCHax(Cy)), 1.09–1.21 (m, 1H, CHCH2CH2CHax(Cy)), 1.18–1.32 (m,
2H, CHCH2CHax(Cy)), 1.20–1.29 (m, 1H, CHCH2OH), 1.26–1.36 (m,
1H, CH3CHHCH), 1.39–1.49 (m, 2H, CH3CHHCH, CH(Cy)), 1.63–
1.72 (m, 3H, CHCHeq(Cy), CHCH2CH2CHeq(Cy)), 1.72–1.81 (m, 2H,
CHCH2CHeq(Cy)), 3.60 (dd, 1H, 2J = 10.4 Hz, 3J = 5.6 Hz), 3.66 (dd,
1H, 2J = 10.4 Hz, 3J = 5.2 Hz). 13C NMR (CD3Cl) d 12.3 (C4), 20.7
(C3), 26.78, 26.87, 26.91, 30.12, 30.27 (Cy), 38.3 (C5, Cy), 47.9
(C2), 63.3 (C1).
4.2. Reaction of terminal alkenes with AlEt3 in the presence of
complex 1
A 10 ml flask equipped with a magnetic stirrer and filled with
argon was loaded with 0.4 mmol of complex 1, 1.5 ml of CH2Cl2,
5 mmol of alkenes 2a–k and 6 mmol of AlEt3. The reaction mixture
was stirred for 24 h at room temperature (20–25 °C). Next, a part of
the reaction mixture was decomposed with 10% HCl or DCl at 0 °C.
The products were extracted with benzene, after which the organic
layer was dried over Na2SO4, and analyzed by GC or GC–MS.
Another part of the reaction mixture was cooled to 0 °C and dry
oxygen was passed through for 2 h. The resultant mixture was then
stirred under an oxygen atmosphere for 24 h, and then treated
with 10% HCl and extracted with Et2O. The organic layer was dried
over Na2SO4, filtered, and concentrated. Chromatography of the
mixture 6 and 7 on silica gel (hexane/Et2O 5:1) provided com-
4.2.7. (2RS)-Cyclooctyl-1-butanol 6h
1H NMR (CDCl3) d 0.94 (t, 3H, 3J = 7.2 Hz, CH3), 1.22–1.38 (m,
2H, CHCHax(Cy)), 1.26–1.33 (m, 1H, CHCH2OH), 1.27–1.41 (m, 2H,
CH3CH2CH), 1.44–1.58 (m, 2H, CHCHeq(Cy)), 1.34–1.76 (m, 10H,
Cy), 1.67–1.76 (m, 1H, CH(Cy)), 3.57 (dd, 1H, 2J = 10.8 Hz,
3J = 5.6 Hz), 3.62 (dd, 1H, 2J = 10.8 Hz, 3J = 5.6 Hz). 13C NMR (CD3Cl)
d 12.6 (C4), 20.9 (C3), 26.4, 26.6, 26.7, 30. 2, 30.7 (Cy), 36.8 (C5, Cy),
50.0 (C2), 63.6 (C1).
4.2.8. (2RS)-Phenyl-1-butanol 6i
1H NMR (CDCl3) d 0.87 (t, 3H, 3J = 7.6 Hz), 1.52–1.69 (m, 1H,
CH3CHHCH), 1.72–1.85 (m, 1H, CH3CHHCH), 2.65–2.75 (m, 1H,

132
L. V. Parfenova et al. / Tetrahedron: Asymmetry 26 (2015) 124–135
CHCH2OH), 3.74 (dd, 1H, 2J = 10.8 Hz, 3J = 8.0 Hz, CHHOH), 3.79 (dd,
1H, 2J = 10.8 Hz, 3J = 6.0 Hz, CHHOH), 7.19–7.30 (m, 3H, Ph), 7.32–
7.40 (m, 2H, Ph). 13C NMR (CD3Cl) d 11.9 (C4), 25.0 (C3), 50.5 (C2),
67.3 (C1), 128.6, 128.1, 126.7, 142.3 (Ph).
30.41 (S,R), 30.49 (R,R) (C5), 31.7 (C8), 38.6 (C2), 55.0 (OCH3),
67.98 (R,R), 68.01 (S,R) (C1), 84.9 (q, JC-F = 26.4 Hz, CCF3), 124.0
(q, JC-F = 288.6 Hz, CF3), 127.4, 128.6, 128.8, 129.3 (Ph), 166.4
(C@O).
2
4.2.9. (2RS)-Benzyl-1-butanol 6j
4.2.15. (2RS)-Ethylnonyl-(R)-a-methoxy-a-trifluoromethylphen-
ylacetate 8d
1H NMR (CDCl3) d 0.97 (t, 3H, 3J = 7.6 Hz, CH3), 1.33–1.50 (m, 2H,
CH3CH2CH), 1.76 (sept, 1H, 3J = 6.0 Hz, CH2CH), 2.66 (d, 2H,
3J = 6.8 Hz, CCH2CH), 3.57 (d, 2H, 3J = 5.2 Hz, CH2OH), 7.15–7.26
(m, 3H, Ph), 7.26–7.36 (m, 2H, Ph). 13C NMR (CDCl3) d 11.3 (C4),
23.3 (C3), 37.3 (C5), 44.2 (C2), 64.5 (C1), 125.9, 128.3, 129.2, 140.9
(Ph).
1H NMR (C7D8) d 0.760 [t, 3H, 3J = 7.6 Hz, CHCH2CH3, (S,R)],
0.771 [t, 3H, 3J = 7.2 Hz, CHCH2CH3, (R,R)], 0.94 (t, 3H, 3J = 7.2 Hz,
CH3), 1.09–1.27 (m, 12H, CH2), 1.25–1.37 (m, 2H, CH3CH2CH),
1.37–1.47 (m, 1H, CH), 3.45 (s, 3H, OCH3), 4.02 (dd, 1H,
3J = 10.8 Hz, 2J = 5.6 Hz, CHHO), 4.15 (dd, 1H, 3J = 10.8 Hz,
2J = 5.6 Hz, CHHO), 6.75–7.32 (m, 3H, Ph), 7.62 (d, 2H, 3J = 7.2 Hz,
o-H(Ph)). 13C NMR (C7D8) d 10.6 (C4), 14.0 (C11), 22.8 (C10), 23.53
(S,R), 23.63 (R,R) (C3), 26.6 (C6), 29.3 (C7), 29.9 (C8), 30.49 (R,R),
30.58 (S,R) (C5), 31.9 (C9), 38.7 (C2), 54.9 (OCH3), 67.9 (C1), 84.8
4.2.10. (2RS)-Cyclooctyl-1,4-butanediol 7h
1H NMR (CDCl3) d 1.27–1.39 (m, 2H, CHax2CH(Cy)), 1.37–1.73
(m, 10H, Cy), 1.48–1.56 (m, 2H, CHeq2CH(Cy)), 1.50–1.57 (m, 1H,
CHCH2OH), 1.54–1.62 (m, 1H, CHCHHCH2OH), 1.60–1.67 (m, 1H,
CH(Cy)), 1.67–1.73 (m, 1H, CHCHHCH2OH), 3.51 (dd, 1H,
2J = 10.4 Hz, 3J = 8.2 Hz, CH2CHHOH), 3.53 (ddd, 1H, 2J = 10.6 Hz,
3J = 8.2 Hz, 4J = 4.1 Hz, CHCHHOH), 3.68 (dd, 1H, 2J = 10.4 Hz,
3J = 3.6 Hz, CH2CHHOH), 3.79 (ddd, 1H, 2J = 10.6 Hz, 3J = 5.7 Hz,
4J = 4.3 Hz, CHCHHOH). 13C NMR (CD3Cl) d 26.29, 26.48, 26.54,
26.60, 26.66, 30.34, 30.93 (Cy), 33.6 (C3), 39.7 (C5, Cy), 47.3 (C2),
62.2 (C4), 65.2 (C1).
2
(q, JC-F = 26 Hz, CCF3), 123.5 (q, CF3, JC-F = 288 Hz), 125.9, 130.2,
132.8, 134.0 (Ph), 166.3 (C@O).
4.2.16. (2RS)-Ethyldecyl-(R)-a-methoxy-a-trifluoromethylphen-
ylacetate 8e
1H NMR (C7D8) d 0.760 [t, 3H, 3J = 7.6 Hz, CHCH2CH3, (S,R)],
0.771 [t, 3H, 3J = 7.4 Hz, CHCH2CH3, (R,R)], 0.94 (t, 3H, 3J = 7.2 Hz,
CH3), 1.11–1.36 (m, 14H, CH2), 1.29–1.46 (m, 2H, CH3CH2CH),
1.34–1.46 (m, 1H, CH), 3.45 (s, 3H, OCH3), 4.02 (dd, 3J = 11.0 Hz,
3J = 5.4 Hz, 1H, CHHO), 4.15 (dd, 3J = 10.9 Hz, 3J = 5.4 Hz, 1H,
CHHO), 6.74–7.35 (m, 3H, Ph), 7.62 (d, 2H, 3J = 7.6 Hz, o-H(Ph)).
13C NMR (C7D8) d 10.59 (C4) 13.98 (C12), 22.76 (C11), 31.98 (C10),
29.61 (C9), 29.43 (C8), 26.6 (C7); 23.54 (S,R), 23.65 (R,R) (C3), 29.9
(C6), 30.59 (S,R), 30.49 (R,R) (C5), 38.7 (C2), 54.9 (OCH3), 67.9 (C1),
4.2.11. (2RS)-Phenyl-1,4-butanediol 7i
1H NMR (CDCl3) d 1.81–1.94 (m, 1H, CHCHHCH2OH), 1.96–2.11
(m, 1H, CHCHHCH2OH), 2.95 (q, 1H, 3J = 6.8 Hz, CHCH2OH), 3.50–
3.61 (m, 1H, CH2CHHOH), 3.61–3.72 (m, 1H, CH2CHHOH), 3.75
(dd, 2H, 3J = 6.4 Hz, 3J = 4.0 Hz, CHCH2OH), 7.15–7.28 (m, 3H, Ph),
7.29–7.40 (m, 2H, Ph). 13C NMR (CDCl3) d 35.9 (C3), 45.9 (C2),
61.0 (C4), 67.5 (C1), 126.8, 127.8, 128.7, 142.4 (Ph).
2
84.8 (q, JC-F = 26.5 Hz, CCF3,), 123.7 (q, JC-F = 287 Hz, CF3), 127.5,
128.7, 132.8, 134.0 (Ph), 166.3 (C@O).
4.2.12. (2RS)-Benzyl-1,4-butanediol 7j
1H NMR (CDCl3) d 1.55–1.68 (m, 1H, CHHCH2OH), 1.68–1.81 (m,
1H, CHHCH2OH), 1.95–2.08 (m, 1H, CH2CH), 2.58 (dd, 1H,
3J = 13.6 Hz, 3J = 7.2 Hz, CCHHCH), 2.70 (dd, 1H, 3J = 13.6 Hz,
3J = 7.6 Hz, CCHHCH), 3.52 (dd, 1H, 3J = 10.8 Hz, 3J = 6.8 Hz, CH2-
CHHOH), 3.62–3.74 (m, 2H, CH2CHHOH, CHCHHOH), 3.74–3.84
(m, 1H, CHCHHOH), 7.15–7.25 (m, 3H, Ph), 7.25–7.35 (m, 2H, Ph).
13C NMR (CDCl3) d 35.3 (C3), 38.2 (C5), 41.2 (C2), 61.1 (C4), 65.6
(C1), 126.1, 128.4, 129.1, 140.3 (Ph).
4.2.17. (2RS)-Ethyl-4-methylpentyl-(R)-a-methoxy-a-trifluoro-
methylphenylacetate 8f
1H NMR (C7D8) d 0.692 [t, 3H, 3J = 7.2 Hz, CHCH2CH3, (S,R)],
0.705 [t, 3H, 3J = 7.2 Hz, CHCH2CH3, (R,R)], 0.735 (d, 3H,
3J = 6.4 Hz, CH3CH), 0.737 (d, 3H, 3J = 6.4 Hz, CH3CH), 0.89–1.03
(m, 2H, CHCH2CH), 1.07–1.18 (m, 2H, CH2CH3), 1.35–1.43 (m, 1H,
(CH3)2CH), 1.40–1.48 (m, 1H, CHCH2O), 3.92 (dd, 1H, 3J = 11.0 Hz,
3J = 5.6 Hz, CHHO), 4.08 (dd, 1H, 3J = 11.0 Hz, 3J = 4.8 Hz, CHHO),
3.39 (s, 3H, OCH3), 6.71–7.32 (m, 3H, Ph), 7.57 (d, 2H, 3J = 7.5 Hz,
o-H(Ph)). 13C NMR (C7D8) d 10.9 (C4), 22.7 (C6), 23.0 (C7), 24.30
(S,R), 24.38 (R,R) (C6), 25.4 (C5), 36.7 (C2), 40.30 (R,R), 40.48 (S,R)
4.2.13. (2RS)-Ethylheptyl-(R)-a-methoxy-a-trifluoromethylphen-
ylacetate 8b
1H NMR (C6D6) d 0.691 [t, 3H, 3J = 7.6 Hz, CHCH2CH3, (S,R)],
0.700 [t, 3H, 3J = 7.2 Hz, CHCH2CH3, (R,R)], 0.85 (t, 3H, 3J = 7.2 Hz,
CH3), 1.07–1.20 (m, 2H, CH2), 1.13–1.31 (m, 8H, CH3CH2CH),
1.31–1.39 (m, 1H, CH), 3.41 (s, 3H, OCH3), 3.99 (dd, 1H,
3J = 10.8 Hz, 3J = 5.6 Hz, CHHO), 4.12 (dd, 1H, 3J = 10.8 Hz,
3J = 5.2 Hz, CHHO), 7.07–7.13 (m, 3H, Ph), 7.65 (d, 2H, 3J = 7.6 Hz,
o-H(Ph)). 13C NMR (C6D6) d 10.6 (C4), 13.9 (C9), 22.5 (C8), 23.47
(S,R), 23.57 (R,R) (C3), 26.2 (C6), 30.35 (R,R), 30.43 (S,R) (C5), 32.0
(C7), 38.6 (C2), 54.9 (OCH3), 67.97 (R,R), 67.99 (S,R) (C1), 84.8 (q,
2JC-F = 27 Hz, CCF3), 124.0 (q, JC-F = 287 Hz, CF3), 127.4, 127.5,
129.3, 132.8 (Ph), 166.4 (C@O).
2
(C3), 55.3 (OCH3), 68.27 (R,R), 68.34 (S,R) (C1), 85.2 (q, JC-
F = 26 Hz, CCF3), 124.8 (q, CF3, JC-F = 288 Hz), 127.7, 128.9, 129.7,
133.2 (Ph), 166.7 (C@O).
4.2.18. (2RS)-Cyclohexylbutyl-(R)-a-methoxy-a-trifluoromethyl-
phenylacetate 8g
1H NMR (C6D6) d 0.705 (t, 3H, 3J = 7.2 Hz, CH2CH3, (S,R)], 0.719
(t, 3H, 3J = 7.2 Hz, CH2CH3, (R,R)], 0.71–0.82 (m, 2H, CHCHax(Cy)),
1.12–1.26 (m, 3H, CHCH2CH2CHax(Cy), CHCH2CHax(Cy)), 1.17–1.27
(m, 2H, CH2CH3), 1.16–1.24 (m, 2H, CHCH), 1.29–1.49 (m, 2H,
CHCHeq(Cy)), 1.53–1.72 (m, 3H, CHCH2CH2CHeq(Cy), CHCH2CHeq(-
Cy)), 3.42 (s, 3H, OCH3), 4.04 [dd, 1H, 3J = 11.0 Hz, 3J = 4.6 Hz,
CHHO, (S,R)], 4.10 [dd, 1H, 3J = 11.2 Hz, 3J = 4.8 Hz, CHHO, (R,R)],
4.17 [dd, 1H, 3J = 11.2 Hz, 3J = 5.2 Hz, CHHO, (R,R)], 4.24 [dd, 1H,
3J = 11.0 Hz, 3J = 4.6 Hz, CHHO (S,R)], 6.93–7.24 (m, 3H, Ph), 7.62–
7.76 (m, 2H, o-H(Ph)). 13C NMR (C6D6) d 11.5 (C4), 20.87 (S,R),
20.89 (R,R) (C3), 25.4, 26.4, 26.5, 29.7, 29.9 (Cy), 38.31 (Cy, R,R),
38.37 (Cy, SR) (C5), 44.1 (C2), 66.43 (R,R), 66.49 (S,R) (C1), 54.9
(OCH3), 86.3 (q, 2JC-F = 26.2 Hz, CCF3), 124.0 (q, CF3,
JC-F = 278.7 Hz), 126.30–130.62, 133.1, 134.4 (Ph), 166.4 (C@O).
4.2.14. (2RS)-Ethyloctyl-(R)-a-methoxy-a-trifluoromethylphen-
ylacetate 8c
1H NMR (C6D6) d 0.694 [t, 3H, 3J = 7.4 Hz, CHCH2CH3, (S,R)],
0.703 [t, 3H, 3J = 7.4 Hz, CHCH2CH3, (R,R)], 0.89 (t, 3H, 3J = 6.8 Hz,
CH3), 1.20–1.38 (m, 12H, CH2), 1.32–1.41 (m, 1H, CH), 3.41 (s,
3H, OCH3), 3.99 (dd, 1H, 3J = 10.9 Hz, 2J = 5.6 Hz, CHHO), 4.13 (dd,
1H, 3J = 10.9 Hz, 2J = 5.4 Hz, CHHO), 6.96–7.28 (m, 3H, Ph), 7.64
(d, 2H, 3J = 7.5 Hz, o-H(Ph)). 13C NMR (C7D8) d 10.6 (C4), 14.0
(C10), 22.7 (C9), 23.49 (S,R), 23.59 (R,R) (C3), 26.5 (C6), 29.5 (C7),

L. V. Parfenova et al. / Tetrahedron: Asymmetry 26 (2015) 124–135
133
4.2.19. (2RS)-Cyclooctylbutyl-(R)-
phenylacetate 8h
a
-methoxy-
a
-trifluoromethyl-
3H, OCH3), 3.65–3.78 (m, 1H, CH2CHHO), 3.88–4.01 (m, 2H, CH2-
CHHO, CHCHHO), 4.16 (dd, 1H, 3J = 10.8 Hz, 3J = 7.4 Hz, CHCHHO),
6.73–7.60 (m, 15H, Ph). 13C NMR (C7D8) d 30.37 (R,R,R), 30.59
(R,R,S) (C3); 40.88 (R,R,R), 41.00 (R,R,S) (C2); 54.8 (OCH3); 63.4
(C4); 69.3 (C1); 84.7 (q, JC-F = 26.9 Uw, CCF3); 124.2 (q,
JC-F = 288.4 Hz, CF3); 139.2 (C5, Ph); 127.3-130.2 (Ph); 166.0,
166.1 (C@O).
1H NMR (C7D8) d 0.726 [t, 3H, 3J = 7.4 Hz, CHCH2CH3, (S,R)],
0.735 [t, 3H, 3J = 7.4 Hz, CHCH2CH3, (R,R)], 0.99–1.28 (m, 2H, CH3-
CH2), 1.04–1.14 (m, 2H, CHax2CH(Cy)), 1.24–1.37 (m, 1H, CH),
1.25–1.35 (m, 2H, CHeq2CH(Cy)), 1.23–1.68 (m, 10H, Cy), 1.49–
1.58 (m, 1H, CH(Cy)), 3.43 (s, 3H, OCH3), 4.03 [dd, 1H,
3J = 11.2 Hz, 3J = 5.8 Hz, CHHO, (S,R)], 4.09 [dd, 1H, 3J = 11.2 Hz,
3J = 6.1 Hz, CHHO, (R,R)], 4.16 [dd, 1H, 3J = 11.2 Hz, 3J = 5.8 Hz,
CHHO, (R,R)], 4.22 [dd, 1H, 3J = 11.2 Hz, 3J = 6.2 Hz, CHHO, (S,R)],
6.94–7.26 (m, 3H, Ph), 7.67 (d, 2H, 3J = 7.4 Hz, o-H(Ph)). 13C NMR
(C7D8) d 11.9 (C4), 20.8 (C3), 25.33, 25.39, 25.42, 26.06, 26.40
(Cy), 30.29 (C6, Cy), 29.67 (R,R), 29.73 (R,S) (C6, Cy), 36.85 (R,R),
36.88 (S,R) (C5, Cy), 46.05 (C2), 66.84 (R,R), 66.91 (S,R) (C1), 54.9
(OCH3), 85.7 (q, 2JC-F = 24.3 Hz, CCF3), 125.8 (q, CF3,
JC-F = 288.3 Hz), 129.30 (R,S), 129.36 [(R,R), ipso-C(Ph)], 126.9,
128.0, 128.6 (Ph), 166.4 (C@O).
2
4.2.24. (R)-MTPA ester of (2RS)-benzyl-1,4-butanediol 10j
1H NMR (C7D8) d 1.31–1.53 (m, 2H, CH2CH2O), 1.81–1.93 (m,
1H, CH), 2.30–2.43 (m, 2H, CHCH2C), 3.47 (s, 6H, OCH3), 3.85–
4.04 (m, 1H, CHCHHO), 3.97–4.14 (m, 2H, CH2CH2O), 4.06–4.15
(m, 1H, CHCHHO), 6.78–7.65 (m, 11H, Ph), 7.73 (d, 4H, 3J = 6.8 Hz,
o-H(Ph)). 13C NMR (C7D8) d 29.48 (R,R,S), 29.75 (R,R,R) (C3); 36.01
(R,R,S), 36.22 (R,R,R) (C2); 36.81 (R,R,R), 36.95 (R,R,S) (C5); 63.52
(R,R,S), 63.59 (R,R,R) (C4); 66.86 (R,R,S), 66.92 (R,R,R) (C1); 55.1
2
(OCH3), 85.1 (q, JC-F = 26 Hz, CCF3), 124.7 (q, JC-F = 287 Hz, CF3),
138.78 (R,R,S), 138.81 (R,R,R) (C6, Ph), 125.0-130.2 (Ph), 166.3
(C@O).
4.2.20. (2RS)-Phenylbutyl-(R)-a-methoxy-a-trifluoromethylphen-
ylacetate 8i
1H NMR (C7D8) d 0.624 [t, 3H, 3J = 8.0 Hz, CH3, (R,R)], 0.643 [t,
3H, 3J = 7.6 Hz, CH3, (S,R)], 1.26–1.42 (m, 1H, CH3CHH), 1.43–1.56
(m, 1H, CH3CHH), 2.55–2.67 (m, 1H, CH), 3.26 [s, 3H, OCH3, (S,R)],
3.29 [s, 3H, OCH3, (R,R)], 4.09 (dd, 1H, 3J = 10.8 Hz, 3J = 7.2 Hz,
CHHO), 4.29 (dd, 1H, 3J = 10.8 Hz, 3J = 7.2 Hz, CHHO), 6.76–7.38
(m, 8H, Ph), 7.40–7.55 (m, 2H, Ph). 13C NMR (C7D8) d 12.1 (C4),
25.16 (S,R), 25.18 (R,R) (C3), 46.43 (S,R), 46.46 (R,R) (C2), 55.1
(OCH3), 69.70 (S,R), 69.88 (R,R) (C1), 84.8 (q, JC-F = 26.0 Hz, CCF3),
124.6 (q, CF3, JC-F = 284.4 Hz), 126.5, 127.1, 130.4, 132.7, 134.2
(Ph), 141.11 (R,S), 141.38 (R,R) (C5, Ph), 166.0 (C@O).
4.2.25. (R)-PSPA ester of (2RS)-ethyl-1-hexanol 9a
1H NMR (CDCl3) d 0.86 (t, 3H, 3J = 7.5 Hz, CH3CH2CH), 0.91 (t, 3H,
3J = 6.5 Hz, CH3), 1.21–1.41 (m, 8H, CH2), 1.45–1.54 (m, 1H, CH2CH),
1.56 (d, 3H, 3J = 7.0 Hz, CH3CH), 3.80 (q, 1H, 3J = 7.0 Hz, CHSe), 3.95
(dd, 1H, 2J = 10.8 Hz, 3J = 5.8 Hz, CHHO), 4.00 (dd, 1H, 2J = 10.8 Hz,
3J = 5.8 Hz, CHHO), 7.24–7.36 (m, 3H, Ph), 7.60 (d, 2H, 3J = 7.0 Hz,
o-H(Ph)). 13C NMR (CDCl3) d 11.0 (C4), 14.1 (C8), 17.8 (CH3CHSe),
22.9 (C7), 23.7 (C3), 28.9 (C5), 30.3 (C6), 38.7 (C2), 37.5 (CHSe),
67.4 (C1), 128.1, 128.4, 129.0, 135.4 (Ph), 173.7 (C@O). 77Se NMR
(CDCl3) d 452.13 (S,R), 452.22 (R,R).
2
4.2.21. (2RS)-Benzylbutyl-(R)-
ylacetate 8j
a
-methoxy-
a
-trifluoromethylphen-
4.2.26. (R)-PSPA ester of (2RS)-ethyl-1-heptanol 9b
1H NMR (CDCl3) d 0.86 (t, 3H, 3J = 7.6 Hz, CH3CH2CH), 0.89 (t, 3H,
3J = 6.8 Hz, CH3), 1.20–1.42 (m, 10H, CH2), 1.45–1.55 (m, 1H, CH2-
CH), 1.56 (d, 3H, 3J = 7.2 Hz, CH3CH), 3.79 (q, 1H, 3J = 7.2 Hz, CHSe),
3.95 (dd, 1H, 2J = 10.9 Hz, 3J = 6.0 Hz, CHHO), 3.99 (dd, 1H,
3J = 10.9 Hz, 3J = 5.8 Hz, CHHO), 7.19–7.39 (m, 3H, Ph), 7.55–7.63
(m, 2H, Ph). 13C NMR (CDCl3) d 11.0 (C4), 14.1 (C9), 17.8 (CH3CHSe),
22.6 (C8), 23.7 (C3), 26.4 (C6), 30.6 (C5), 32.1 (C7), 38.7 (C2), 37.6
(CHSe), 67.4 (C1), 128.1, 128.4, 129.0, 135.4 (Ph), 173.7 (C@O).
77Se NMR (CDCl3) d 452.14 (S,R), 452.24 (R,R).
1H NMR (C6D6) d 0.784 [t, 3H, 3J = 7.2 Hz, CH3, (S,R)], 0.788 [t,
3H, 3J = 7.2 Hz, CH3, (R,R)], 1.16–1.37 (m, 2H, CH3CH2), 1.67–1.81
(m, 1H, CH), 2.41–2.59 (m, 2H, CH2Ph), 3.52 (s, 3H, OCH3), 4.03
[dd, 1H, 2J = 11.0 Hz, 3J = 6.0 Hz, CHHO, (S,R)], 4.07 [dd, 1H,
2J = 11.0 Hz, 3J = 4.8 Hz, CHHO, (R,R)], 4.15 [dd, 1H, 2J = 11.0 Hz,
3J = 4.8 Hz, CHHO, (R,R)], 4.24 [dd, 1H, 2J = 11.0 Hz, 3J = 5.2 Hz,
CHHO, (S,R)], 6.80–7.70 (m, 8H, Ph), 7.77 (d, 2H, 3J = 7.2 Hz, o-
H(Ph)). 13C NMR (C6D6) d 10.9 (C4), 23.26 (S,R), 23.49 (R,R) (C3),
37.07 (R,R), 37.13 (S,R) (C5), 40.80 (S,R), 40.91 (R,R) (C2), 55.1
2
(OCH3), 67.0 (C1), 85.1 (q, JC-F = 26.8 Hz, CCF3), 124.6 (q, JC-
F = 289 Hz, CF3), 126.2-133.9 (Ph), 146.7 (Ph), 166.4 (C@O).
4.2.27. (R)-PSPA ester of (2RS)-ethyl-1-octanol 9c
1H NMR (CDCl3) d 0.86 (t, 3H, 3J = 7.2 Hz, CH3CH2CH), 0.91 (t, 3H,
3J = 7.4 Hz, CH3), 1.21–1.36 (m, 12H, CH2), 1.45–1.55 (m, 1H, CH2-
CH), 1.56 (d, 3H, 3J = 7.1 Hz, CH3CH), 3.80 (q, 1H, 3J = 7.1 Hz, CHSe),
3.95 (dd, 1H, 2J = 10.9 Hz, 3J = 6.0 Hz, CHHO), 3.97–4.02 (m, 1H,
CHHO), 7.23–7.41 (m, 3H, Ph), 7.56–7.67 (m, 2H, Ph). 13C NMR
(CDCl3) d 11.0 (C4), 14.1 (C10), 17.8 (CH3CHSe), 22.6 (C9), 23.7
(C3), 26.7 (C7), 29.6 (C6), 30.6 (C5), 31.8 (C8), 38.7 (C2), 37.5 (CHSe),
67.4 (C1), 128.1, 128.3, 129.0, 135.4 (Ph), 173.7 (C@O). 77Se NMR
(CDCl3) d 452.31 (S,R), 452.42 (R,R).
4.2.22. (R)-MTPA ester of (2RS)-cyclooctyl-1,4-butanediol 10h
1H NMR (C7D8) d 0.88–1.01 (m, 2H, CHax2CH(Cy)), 1.07–1.24 (m,
2H, CHeq2CH(Cy)), 1.10–1.55 (m, 10H, Cy), 1.14–1.30 (m, 1H, OCH2-
CHH), 1.33–1.48 (m, 1H, OCH2CHH), 1.35–1.46 (m, 1H, CH), 1.37–
1.48 (m, 1H, CH(Cy)), 3.40 (s, 3H, OCH3), 3.41 (s, 3H, OCH3),
3.92–4.09 (m, 2H, CH2CH2O), 3.90 (dd, 1H, 3J = 11.4 Hz,
3J = 5.1 Hz, CHCHHO), 4.08 (dd, 1H, 3J = 11.4 Hz, 3J = 5.7 Hz,
CHCHHO), 6.97–7.18 (m, 6H, Ph), 7.64 (d, 4H, 3J = 7.6 Hz, o-
H(Ph)). 13C NMR (C7D8) d 25.80, 26.14, 26.32, 26.36, 26.51 (Cy),
26.98 (R,R,S), 27.04 [(R,R,R), C3], 29.34 (R,R,R), 29.28 (R,R,S) (C6,
Cy), 30.29 (R,R,R), 30.39 (R,R,S) (C6, Cy), 36.96 (R,R,R), 37.02 (R,R,S)
(C5, Cy), 40.95 (C2), 64.36 (R,R,R), 64.39 (R,R,S) (C4), 66.8 (C1), 55.0
4.2.28. (R)-PSPA ester of (2RS)-ethyl-1-nonanol 9d
1H NMR (CDCl3) d 0.84 (t, 3H, 3J = 7.5 Hz, CH3CH2CH), 0.87 (t, 3H,
3J = 6.0 Hz, CH3), 1.17–1.38 (m, 14H, CH2), 1.43–1.53 (m, 1H, CH2-
CH), 1.54 (d, 3H, 3J = 6.8 Hz, CH3CH), 3.78 (q, 1H, 3J = 7.2 Hz, CHSe),
3.93 (dd, 1H, 3J = 10.9 Hz, 3J = 6.0 Hz, CHHO), 3.98 (dd, 1H,
2J = 10.9 Hz, 3J = 5.8 Hz, CHHO), 7.17–7.37 (m, 3H, Ph), 7.58 (d,
2H, 3J = 6.4 Hz, o-H(Ph)). 13C NMR (CDCl3) d 11.0 (C4), 14.1 (C11),
17.8 (CH3CHSe), 23.0 (C10), 23.7 (C3), 26.7 (C6), 29.3 (C8), 29.9
(C7), 30.6 (C5), 31.9 (C9), 38.7 (C2), 37.5 (CHSe), 67.4 (C1), 128.1,
128.3, 129.0, 135.4 (Ph), 173.7 (C@O). 77Se NMR (CDCl3) d 452.16
(S,R), 452.26 (R,R).
2
(OCH3), 55.04 (OCH3), 84.77 (q, JC-F = 27.5 Hz, CCF3), 84.79 (q,
2JC-F = 27.5 Hz, CCF3), 123.89 (q, CF3, JC-F = 287.9 Hz) (R,R,S),
125.85 (CF3, q, JC-F = 287.9 Hz) (R,R,R), 127.4, 128.32, 128.36,
129.46, 132.59 (Ph), 166.24 (C@O), 166.32 (C@O).
4.2.23. (R)-MTPA ester of (2RS)-phenyl-1,4-butanediol 10i
1H NMR (C6D6) d 1.42–1.55 (m, 1H, CHHCH2O), 1.63–1.78 (m,
1H, CHHCH2O), 2.68–2.81 (m, 1H, CH), 3.25 (s, 3H, OCH3), 3.34 (s,

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L. V. Parfenova et al. / Tetrahedron: Asymmetry 26 (2015) 124–135
4.2.29. (R)-PSPA ester of (2RS)-ethyl-1-decanol 9e
40.99 (S,R), 40.96 (R,R) (C2), 66.5 (C1), 125.9, 128.3, 128.9, 129.0,
129.2, 131.5, 140.1 (Ph), 173.6 (C@O). 77Se NMR (CDCl3) d 451.92
(S,R), 452.60 (R,R).
1H NMR (CDCl3) d 0.86 (t, 3H, 3J = 7.6 Hz, CH3CH2CH), 0.89 (t, 3H,
3J = 6.0 Hz, CH3), 1.18–1.40 (m, 16H, CH2), 1.45–1.55 (m, 1H, CH2-
CH), 1.55 (d, 3H, 3J = 6.8 Hz, CH3CH), 3.79 (q, 1H, 3J = 6.8 Hz, CHSe),
3.94 (dd, 1H, 2J = 11.0 Hz, 3J = 6.2 Hz, CHHO), 3.99 (dd, 1H,
2J = 11.0 Hz, 3J = 6.0 Hz, CHHO), 7.23–7.36 (m, 3H, Ph), 7.59 (d,
2H, 3J = 6.4 Hz, o-H(Ph)). 13C NMR (CDCl3) d 11.0 (C4), 14.1 (C12),
17.8 (CH3CHSe), 22.7 (C11), 23.7 (C3), 26.7 (C6), 29.3 (C9), 29.6
(C8), 29.9 (C7), 30.6 (C5), 31.9 (C10), 38.7 (C2), 37.5 (CHSe), 67.4
(C1), 128.1, 128.3, 128.9, 135.4 (Ph), 173.6 (C@O). 77Se NMR (CDCl3)
d 452.22 (S,R), 452.33 (R,R).
4.2.35. (R)-PSPA ester of (2RS)-cyclooctyl-1,4-butanediol 11h
1H NMR (CDCl3) d 1.21–1.36 (m, 2H, CHax2CH(Cy)), 1.42–1.55
(m, 2H, CH2eqCH (CyOct)), 1.37–1.59 (m, 2H, CH2CH2O), 1.35–1.79
(m, 10H, Cy), 1.46–1.58 (m, 1H, CH), 1.55 (d, 6H, 3J = 7.2 Hz, CH3-
CH),1.57–1.70 (m, 1H, CH(Cy)), 3.77 (q, 2H, 3J = 7.2 Hz, CHSe),
3.92–4.11 (m, 3H, CH2CH2O, CHCHHO), 3.90 (dd, 1H, 3J = 6.2 Hz,
3J = 11.0 Hz, CHCHHO), 7.23–7.38 (m, 6H, Ph), 7.54–7.61 (m, 4H,
Ph). 13C NMR (CDCl3) d 17.68, 17.74 (CH3), 26.10, 26.37, 26.48,
26.55, 26.64 (Cy), 27.73 (R,R,R), 27.69 (R,R,S) (C3), 29.98 (R,R,S),
30.05 (R,R,R) (C6, (Cy)), 30.42 (R,R,R), 30.52 (R,R,S) (C6, (Cy)),
37.37, 37.39 (CHSe), 37.71 (C5, (Cy)), 41.3 (C2), 63.9 (C4), 66.2
(C1), 127.89, 127.95, 128.44, 128.48, 129.00, 129.04, 135.70,
135.44 (R,R,S), 135.48 (R,R,R) (Ph), 173.46 (R,R,R), 173.41, 173.49
(R,R,S) (C@O). 77Se NMR (CDCl3) d 453.50 (R,R,R), 454.26 (R,R,R);
453.56 (R,R,S), 453.84 (R,R,S).
4.2.30. (R)-PSPA ester of (2RS)-ethyl-4-methyl-1-pentanol 9f
1H NMR (CDCl3) d 0.81–0.94 (m, 9H, CH3), 1.09 (t, 2H, 3J = 6.8 Hz,
CHCH2CH), 1.21–1.35 (m, 2H, CH2CH3), 1.51–1.61 (m, 1H, CHCH2-
CH3), 1.57–1.64 (m, 1H, CH(CH3)2), 3.79 (q, 1H, 3J = 7.0 Hz, CHSe),
3.91 (dd, 1H, 2J = 10.8 Hz, 3J = 6.0 Hz, CHHO), 3.98 (dd, 1H,
2J = 10.8 Hz, 3J = 5.2 Hz, CHHO), 7.24–7.37 (m, 3H, Ph), 7.59 (d,
2H, 3J = 6.4 Hz, o-H(Ph)). 13C NMR (CDCl3) d 10.9 (C4), 17.8 (CH3-
CHSe), 22.7, 22.9 (C7), 24.0 (C3), 25.2 (C6), 40.3 (C5), 36.4 (C2),
37.6 (CHSe), 67.5 (C1), 128.1, 128.4, 129.0, 135.4 (Ph), 173.7
(C@O). 77Se NMR (CDCl3) d 452.10 (S,R), 452.57 (R,R).
4.2.36. (R)-PSPA ester of (2RS)-phenyl-1,4-butanediol 11i
1H NMR (CDCl3) d 1.49 (d, 6H, 3J = 7.6 Hz, CH3CH), 1.70–2.07 (m,
8H, CH2CH2O), 2.86–3.01 (m, 1H, CHCH2O), 3.69–3.79 (m, 2H,
CHSe), 3.82–4.03 (m, 2H, CHCH2O), 4.08–4.27 (m, 2H, CH2CH2O),
7.08–7.39 (m, 9H, Ph), 7.48–7.70 (m, 6H, Ph). 13C NMR (CDCl3) d
17.59, 17.65, 17.71 (CH3), 30.98 (R,R,R), 31.08 (R,R,S) (C3), 37.3
(CHSe), 41.50 (R,R,R), 41.59 (R,R,S) (C2), 62.8 (C4), 68.52 (R,R,S),
68.46 (R,R,R) (C1), 127.1, 127.3, 127.9, 127.9, 128.5, 128.7, 128.8,
129.2, 130.0, 140.3 (Ph), 173.3 (C@O). 77Se NMR (CDCl3) d 452.94
(R,R,R), 454.08 (R,R,S), 454.57 (R,R,R), 454.91 (R,R,S).
4.2.31. (R)-PSPA ester of (2RS)-cyclohexyl-1-butanol 9g
1H NMR (CDCl3) d 0.87 (t, 3H, 3J = 7.6 Hz, CH3), 0.94–1.07 (m, 2H,
CHax2CH(Cy)), 1.14–1.26 (m, 3H, CHCH2CHaxCHax(Cy)), 1.19–1.28
(m, 1H, CHHCH3), 1.29–1.41 (m, 1H, CH(Cy)), 1.34–1.43 (m, 1H,
CHHCH3), 1.55–1.65 (m, 2H, CHeq2CH(Cy)), 1.54 (d, 3H, 3J = 7.2 Hz,
CH3CH), 1.61–1.69 (m, 3H, CHCH2CHeqCHeq(Cy)), 3.77 (q, 1H,
3J = 7.2 Hz, CHSe), 4.02–4.11 (m, 2H, CH2O), 7.21–7.36 (m, 3H,
Ph), 7.54–7.62 (m, 2H, o-H(Ph)). 13C NMR (CDCl3) d 12.0 (C4),
17.8 (CH3CHSe), 21.1 (C3), 26.66, 26.77, 29.79, 30.21 (Cy), 38.49
(R,R), 38.57 (S,R) (C5), 44.3 (C2), 37.6 (CHSe), 65.7 (C1), 128.3,
128.9, 129.2, 135.7 (Ph), 173.7 (C@O). 77Se NMR (CDCl3) d 451.43
(R,R), 451.77 (S,R).
4.2.37. (R)-PSPA ester of (2R,S)-benzyl-1,4-butanediol 11j
1H NMR (CDCl3) d 1.50–1.61 (m, 8H, CH2CH2O, CH3), 1.91–2.06
(m, 1H, CHCH2O), 2.52–2.61 (m, 2H, CHCH2C), 3.73–3.79 (m, 2H,
CHSe), 3.86–4.00 (m, 2H, CHCH2O), 4.00–4.12 (m, 2H, CH2CH2O),
7.07–7.37 (m, 9H, Ph), 7.53–7.69 (m, 6H, Ph). 13C NMR (CDCl3) d
17.8 (CH3), 29.79, 29.89 [(R,R,S), (R,R,R), C3], 36.42, 36.51 [(R,R,S),
(R,R,R), C2], 37.5 (CHSe), 37.3 (C5), 62.82, 62.84 [(R,R,S), (R,R,R),
C4], 66.2 (C1), 126.2, 127.7, 128.2, 128.4, 128.9, 129.0, 129.1,
129.2, 135.2, 135.5 (Ph), 173.4 (C@O). 77Se NMR (CDCl3) d 452.50
[(R,R,R)], 453.77 [(R,R,R)], 454.19 [(R,R,S)], 454.65 [(R,R,S)].
4.2.32. (R)-PSPA ester of (2RS)-cycloctyl-1-butanol 9h
1H NMR (CDCl3) d 0.88 (t, 3H, 3J = 7.2 Hz, CH3), 1.04–1.80 (m,
10H, Cy), 1.17–1.26 (m, 1H, CHHCH3), 1.29–1.39 (m, 1H, CHHCH3),
1.22–1.33 (m, 2H, CHax2CH(Cy)), 1.32–1.42 (m, 1H, CH), 1.45–1.53
(m, 2H, CHeq2CH(Cy)), 1.56 (d, 3H, 3J = 7.2 Hz, CH3CH), 1.61–1.71
(m, 1H, CH(Cy)), 3.78 (q, 1H, 3J = 7.2 Hz, CHSe), 3.96 (dd, 1H,
3J = 11.2 Hz, 3J = 6.0 Hz, CHHO), 4.07 (dd, 1H, 3J = 11.2 Hz,
3J = 6.0 Hz, CHHO), 7.21–7.43 (m, 3H, Ph), 7.60 (d, 2H, 3J = 6.0 Hz,
o-H(Ph)). 13C NMR (CDCl3) d 12.3 (C4), 17.9 (CH3CHSe), 21.2 (C3),
24.68, 25.44, 25.66, 26.27, 26.64, 26.73, 30.21, 30.28 (Cy), 37.03
(R,R), 37.08 (S,R) (C5), 46.2 (C2), 37.7 (CHSe), 66.2 (C1), 128.1,
128.3, 129.0, 135.4 (Ph), 173.7 (C@O). 77Se NMR (CDCl3) d 452.02
(S,R), 451.45 (R,R).
Acknowledgements
The authors thank the Russian Ministry of Education and
Science (Grant No. 8426) and the Russian Foundation of Basic
Research (Grant Nos. 11-03-00210a, 12-03-00363a) for financial
support.
References
4.2.33. (R)-PSPA ester of (2RS)-phenyl-1-butanol 9i
1H NMR (CDCl3) d 0.81 (t, 3H, 3J = 7.4 Hz, CH3CH2CH), 1.54–1.64
(m, 2H, CH2), 1.49 (d, 3H, 3J = 7.3 Hz, CH3CH), 2.67–2.80 (m, 1H,
CHCH2O), 3.73 (q, 1H, 3J = 7.1 Hz, CHSe), 4.14–4.25 (m, 2H, CH2O),
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173.5 (C@O). 77Se NMR (CDCl3) d 453.08 (R,R), 453.81 (S,R).
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