Application of sulfonyl chlorides and chiral amines in the efficient synthesis of nonracemic sulfinamides

Article abstract of DOI:10.1016/j.tetasy.2017.03.004

A simple protocol that allows the preparation of separable epimeric sulfinamides from chiral amines and sulfonyl chlorides reduced in situ with triphenylphosphine in the presence of KOH is described. Using this method, tosyl chloride and nosyl chloride were successfully reacted with α-substituted primary amines to give five diastereomeric pairs, in certain cases accompanied by a small amount of the corresponding sulfonamide. Enantiopure products were isolated by column chromatography. The obtained enantiomerically pure sulfinamides were tested as organocatalysts in the asymmetric epoxide ring opening.

Full text of DOI:10.1016/j.tetasy.2017.03.004

Tetrahedron: Asymmetry xxx (2017) xxx–xxx
Contents lists available at ScienceDirect
Tetrahedron: Asymmetry
journal homepage: www.elsevier.com/locate/tetasy
Application of sulfonyl chlorides and chiral amines in the efficient
synthesis of nonracemic sulfinamides
a
a,
⇑
a
b
b
Karolina Kami n´ ska , El z_ bieta Wojaczy n´ ska , Jacek Skar z_ ewski , Andrzej Kochel , Jacek Wojaczy n´ ski
a
Department of Organic Chemistry, Faculty of Chemistry, Wrocław University of Science and Technology, Wybrze z_ e Wyspia n´ skiego 27, 50 370 Wrocław, Poland
Faculty of Chemistry, University of Wrocław, 14 F. Joliot-Curie St., 50 383 Wrocław, Poland
b
a r t i c l e i n f o
a b s t r a c t
Article history:
A simple protocol that allows the preparation of separable epimeric sulfinamides from chiral amines and
sulfonyl chlorides reduced in situ with triphenylphosphine in the presence of KOH is described. Using this
method, tosyl chloride and nosyl chloride were successfully reacted with a-substituted primary amines
to give five diastereomeric pairs, in certain cases accompanied by a small amount of the corresponding
sulfonamide. Enantiopure products were isolated by column chromatography. The obtained enantiomer-
ically pure sulfinamides were tested as organocatalysts in the asymmetric epoxide ring opening.
Ó 2017 Elsevier Ltd. All rights reserved.
Received 5 March 2017
Accepted 8 March 2017
Available online xxxx
1
. Introduction
with sulfinyl chlorides generated from the respective sulfonyl chlo-
1
4
rides and triphenylphosphine. However, significant amounts of
the corresponding sulfonamides were often isolated from this reac-
tion. In 2011, Chakravarti et al. described the application of magne-
sium oxide nanoparticles immobilized over mesoporous carbon as
a catalyst for sulfinamide synthesis from various amines, sulfonyl
Sulfinamides play an important role in asymmetric synthesis as
efficient chiral auxiliaries and catalysts in stereoselective transfor-
1
–4
mations.
enantiopure sulfinimines, valuable precursors of structurally
diverse chiral nitrogen-containing molecules, including -branched
amines, and b-amino acids, 1,2- and 1,3-aminoalcohols,
aziridines, aminooxetanes and
They have been used for the preparation of
a
3
chlorides and PPh . According to this report, no sulfonamide for-
a-
mation was observed when aniline derivatives were used as
1
,5,6
15
a
- and b-aminophosphonates.
substrates.
In addition, sulfinamides can be used as masked amines for their
Since we were interested in the simple access to modular chiral
catalysts, we decided to apply a modified Harmata’s procedure for
the transformation of enantiomeric amines into sulfinamides with
newly generated stereogenic centers. Separation of the obtained
diastereomers offers a simple methodology for the preparation of
various interesting enantiopure sulfonamides, useful as chiral cat-
alysts and synthetic intermediates.
easily removable N-sulfinyl protecting group.6
Despite the importance of sulfinamides in organic synthesis,
only a few methods have been developed for their synthesis from
7
8
9
1,10
sulfinates, thiosulfinates, sulfinic acids or other sulfinamides.
Recently, Han et al. introduced aryl N-sulfonyl-1,2,3-oxathiazo-
lidine-2-oxide derivatives as chiral sulfinyl-transfer agents, which
provide access to a range of enantiopure sulfinamides.1
1
Essentially, sulfinamides can also be obtained directly from sul-
finyl chlorides. However, this strategy remains relatively underex-
plored due to the low stability of these air- and moisture-sensitive
2
. Results and discussion
Over the course of our studies on the catalytic applications of
1
2
compounds. As a consequence, they are typically generated
in situ. In 1999, Toru et al. discovered that triphenylphosphine
selectively reduced sulfonyl chlorides to the corresponding sulfinyl
chlorides, which in the presence of alcohols gave the correspond-
chiral bicyclic amines, 2-azabicyclo[2.2.1]heptane (2-azanorbor-
nane) and 2-azabicyclo[3.2.1]octane (bridged azepane), we were
interested in the preparation of various compounds bearing both
nitrogen and sulfur functionalities.
based on a bridged azepane scaffold is available via a stereoselec-
tive route by utilizing ring expansion upon nucleophilic substitu-
tion of 2-azanorbornan-3-yl methanol. In order to introduce a
Brønsted acidity center, we reacted 1 with tosyl chloride and
obtained the sulfonamide 2 in high yield (80%) (Fig. 1). In a
quest for other chiral derivatives, we turned our attention to
1
6–18
The enantiopure amine 1
1
3
ing sulfinate esters. Following this observation, in 2007 Harmata
et al. developed the synthesis of racemic sulfinamides. They
reacted primary or secondary amines with admixed triethylamine
1
7
⇑
Corresponding author. Tel.: +48 71 3202410; fax +48 71 3202427.
E-mail address: elzbieta.wojaczynska@pwr.edu.pl (E. Wojaczy n´ ska).
http://dx.doi.org/10.1016/j.tetasy.2017.03.004
957-4166/Ó 2017 Elsevier Ltd. All rights reserved.
0
Please cite this article in press as: Kami n´ ska, K.; et al. Tetrahedron: Asymmetry (2017), http://dx.doi.org/10.1016/j.tetasy.2017.03.004

2
K. Kami n´ ska et al. / Tetrahedron: Asymmetry xxx (2017) xxx–xxx
SO
2
R
amine 1 can react with both generated sulfinyl chloride and non-
reduced sulfonyl chloride. As expected, compound 2 remained
unchanged when subjected to the reaction with phosphine and
KOH, both in the presence and in the absence of tosyl chloride.
The addition of an extra base (potassium hydroxide) to the reaction
mixture is essential since our diamine 1 was recovered, when it
RSO
KOH
2
Cl
NH
N
2
HN
N
Ph
Ph
CH
2
Cl , RT
2
1
2
6
R = p-Tol (80%)
R = Me (60%)
was mixed solely with tosyl chloride and PPh
Amine 1 was also reacted with other sulfonyl chlorides reduced
by PPh . Nosyl (p-nitrobenzenesulfonyl) chloride performed well,
3
.
Figure 1. Synthesis of sulfonamides.
3
yielding a mixture of sulfinamides 4a (23%) and 4b (25%;
dr = 1:1.1), accompanied by sulfonamide 5 (20%; Fig. 2). On the
other hand, mesyl chloride led to a complete recovery of amine
sulfonamides, since their formation would result in the introduc-
tion of an additional stereogenic center.
We decided to treat 1 with tosyl chloride, triphenylphosphine
14
3 2
1. When the reaction of 1 with CH SO Cl was conducted in the
and triethylamine as described by Harmata. Under these condi-
tions we obtained a mixture of sulfinamides 3a and 3b (30%),
and sulfonamide 2 (10%). However, when amine 1 was reacted
with 1 equivalent of tosyl chloride in the presence of triph-
enylphosphine (1 equiv), followed by powdered KOH (1.8 equiv),
a mixture of epimers 3a and 3b (56%) and side-product 2 (15%)
were formed (Fig. 2). Sulfinamides 3a and 3b were produced in
absence of phosphine, sulfonamide 6 was produced in 60% yield
Fig. 1). The failure of our attempt to generate the respective sulfi-
namides must be thus connected with the particular instability of
(
1
2
methanesulfinyl chloride
which decomposes before reaction
with the amine 1.
Epimeric sulfinamides 3a, 3b and sulfonamide 2, as well as
compounds 4a, 4b and 5, were successfully separated by column
chromatography followed by recrystallization from petroleum
1
4
1
S S
:1.4 ratio (S ):(R ) within 2 hours. Contrary to Harmata’s results,
our reaction run under slow reagents addition (syringe pump)
resulted in a lower yield. The proposed sequence for the addition
of reactants (solution of amine and phosphine + sulfonyl chloride
1
ether. All new derivatives were fully characterized by H NMR,
1
3
C NMR, IR and HRMS techniques. The configuration of the sulfinyl
stereocenter in the sulfinamides was determined by the X-ray
diffraction study of 3a and 4b (Fig. 3). Since four of the five stere-
ocenters have defined configurations (identical to those in starting
amine 1), the determination of the remaining one as (S) in 3a and
+
KOH) was found to be optimal. The preliminary mixing of TolSO
2
-
Cl and PPh led to the generation of excessive amounts of unstable
sulfinyl chloride, part of which decomposes before the reaction
with the added amine.
3
(R) in 4b was straightforward. In both structures, two independent
Additional experiments showed that the in situ reduction of
molecules are present in the cell exhibiting slight differences of
bond angles and torsion angles; oxygen atoms of sulfinyl groups
are engaged in intermolecular hydrogen bonds with sulfinamide
NH.
We also examined our successful procedure with commercially
available chiral amines: (S)-1-phenylethylamine 7 and (R)-1-(2-
3
sulfonyl chloride with PPh is a key step for the effective formation
of sulfinamides. After addition of phosphine to tosyl chloride dis-
solved in chloroform-d, we observed an appearance of new signals
in the upfield region of 1H NMR spectrum, attributed to methyl
groups of the formed reduction products which however could
not be isolated. The formation of sulfonamide by-product 2 in
our synthesis results from the competition between two processes:
naphthyl)ethylamine
8
(Fig. 4). Both reactions proceeded
Ar
Ar
SO
HN
2
Ar
S
O
S
O
ArSO
KOH, PPh
2
Cl
NH
N
2
HN
HN
3
+
+
Ph
N
N
N
Ph
Ph
Ph
CH Cl , RT
2
2
1
3a (23%)
a (23%)
3b (33%)
4b (25%)
2 (15%)
5 (20%)
4
2
4
, 3a, 3b Ar = p-Tol
a, 4b, 5: Ar = p-NO
2 6 4
C H
Figure 2. Conversion of amine 1 into sulfinamides.
Figure 3. Crystal structure of 3a (left) and 4b (in each case one of two independent molecules is shown).
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K. Kami n´ ska et al. / Tetrahedron: Asymmetry xxx (2017) xxx–xxx
3
smoothly, resulting in the corresponding sulfinamides in 57% and
8% overall yield, respectively. The diastereoselectivity was mod-
est (9a:9b 1:1.4; 10a:10b 1:1.3). Moreover, in both cases, the for-
sulfinamides 12a and 12b in excellent yield (87%; dr = 1:1.2),
accompanied with trace amounts of the corresponding sulfon-
amide 13. Chromatographic separation allowed for the isolation
of fractions containing particular epimers 12a (major, less polar,
contained 15% of sulfonamide 13) and 12b, which differed in the
sign of the specific rotation and the signs of the respective Cotton
effects in their CD spectra (Supporting Information, Fig. S1). On this
base we tentatively assign an (S)-configuration for the sulfur stere-
ocenter 12a and an (R)-configuration for 12b. Their NMR spectra
measured in chloroform-d at 300 K showed complicated patterns,
which could be explained by the presence of rotamers (atropiso-
mers). It is known that certain modifications of Cinchona alkaloids
6
mation of sulfonamides was not observed.
TolSO2Cl
O
O
KOH, PPh3
S
S
Ar
*
NH2
*
+
Ar
N
Tol
Ar
*
N
Tol
CH2Cl2, RT
H
H
(
(
S)-7
R)-8
9
a (24%)
9b (33%)
10b (38%)
1
0a (30%)
7
, 9a, 9b: Ar = phenyl
8
, 10a, 10b: Ar = 2-naphthyl
2
1,22
1
lead to the formation of such atropisomers.
Here, the H NMR
Figure 4. Preparation of diastereomeric sulfinamides.
spectrum of epimer 12b shows two sets of signals in a 2:1 intensity
ratio, and the NOESY spectrum clearly reveals EXSY peaks due to
the chemical exchange between the two forms (Supporting Infor-
mation, Fig. S8).
Sulfinamides 9a and 9b could be separated by a simple crystal-
lization from petroleum ether. Their identity was confirmed by the
comparison of their spectroscopic characteristics with the litera-
ture data of products of two-step reaction from enantiomerically
Sulfonamide 13, which could be obtained via the reaction of
amine 11 with tosyl chloride and KOH, was identified by compar-
2
3
1
9
ison with the literature data.
pure sulfinate. In the case of naphthyl derivatives, pure diastere-
omer 10b was isolated by crystallization, and its (R,R )-configura-
Under the conditions used, (1R,2R)-diaminocyclohexane, (S)-
pyrrolidin-2-yl)methanol, and bicyclic [(1S,3R,4R)-2-azanorbor-
S
(
tion was established by X-ray studies (Fig. 5). When amine 7 was
replaced with benzylamine, we were unable to detect the desired
sulfinylated products. Apparently, the steric hindrance introduced
nan-3-yl)]methanol were found to be unreactive.
For the sake of comparison, alkyl sulfinamide based on a bicyc-
lic backbone was also prepared. Enantiomerically pure tert-butane
sulfinamide bearing the 2-azabicyclo[2.2.1]heptane skeleton 15
was obtained using a different synthetic route. The reaction of
aldehyde 14 and Ellmann’s reagent [(R)-tert-butane sulfonamide]
by the
a-methyl group seemed to be a key factor for the efficient
sulfinamidation.
4 4
in the presence of Ti(OEt) followed by reduction with NaBH gave
3
compound 15 in 59% overall yield (Fig. 7). Due to both enantiop-
ure reactants being used, this procedure leads to a particular
stereoisomer, although chromatographic purification is still neces-
sary. It is noteworthy that since this method based on achiral
sulfonyl chlorides and chiral amines provides a much simpler
one-step preparation of two easily separable epimers.
O
1.
S
, Ti(OEt)
4
NH
2
N
Ph
N
Ph
CHO
S
2
. NaBH
4
N
H
O
14
15 (59%)
Figure 7. Synthesis of sulfinamide 15.
Our preliminary catalytic experiments showed that the applica-
tion of the isolated enantiopure sulfinamides (20 mol %) in the ring
Figure 5. X-ray structure of sulfoxide 10b.
2
4
opening of cyclohexene oxide with aniline resulted in an enan-
tiomerically enriched product in low yield (up to 30%) (Fig. 8). Both
sulfonamides and compound 15 gave only trace amounts of the
desired product. Further catalytic tests are currently underway in
our laboratory.
Cinchona alkaloids offer privileged chiral moieties for a range of
organocatalysts and ligands.20 For this reason, we also submitted
enantiopure 9-amino-epi-quinine 11 to the sulfinamidation reac-
tion (Fig. 6). The reaction led to a mixture of diastereomeric
O
O
(
S)
(R)
S
S
TolO2S
H
Tol
Tol
H2N
H
H
HN
H
H
H
HN
HN
H
N
TolSO Cl
2
N
N
N
H
PPh3, KOH
MeO
3HCl
MeO
MeO
MeO
+
+
CH2Cl2, RT
N
N
N
N
11
12a (39%)
12b (48%)
13 (5%)
Figure 6. Synthesis of sulfinamides derived from quinine.
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4
K. Kami n´ ska et al. / Tetrahedron: Asymmetry xxx (2017) xxx–xxx
NH
2
O
HO
HN
HO
HN
(R)
(R)
(S)
(S)
L* (20 mol%)
CH Cl
+
+
2
2
L*: 3a: (R,R):(S,S) = 20:80
3
4
4
9
9
b: (R,R):(S,S) = 85:15
a: (R,R):(S,S) = 20:80
b: (R,R):(S,S) = 52:48
a: (R,R):(S,S) = 22:78
b: (R,R):(S,S) = 50:50
12b: (R,R):(S,S) = 43:57
Figure 8. Catalytic ring opening of cyclohexene oxide with aniline (1.1 equiv) in dichloromethane with the prepared sulfinamides (20 mol %). The results were determined by
chiral HPLC of a crude reaction mixture obtained after 3 days at room temperature (Chiralpak OD column, mobile phase: hexane/i-PrOH 90/10).
3
. Conclusion
ccdc.cam.ac.uk/conts/retrieving.html (or from the Cambridge Crys-
tallographic Data Centre, 12 Union Road, Cambridge CB2 1EZ, UK;
Tel: +44 1223 336408; fax: +44 1223 336033; E-mail: deposit@
ccdc.cam.ac.uk).
In conclusion, a simple procedure for the synthesis of enan-
tiomerically pure sulfinamides from chiral amines under mild con-
ditions has been developed. Due to in situ generation of sulfinyl
chlorides, handling and purification of these troublesome reagents
4.3. Preparation of compounds
1
2
is avoided. The described method offers the possibility of prepar-
ing both epimeric products. In our hands, the obtained separable
sulfinyl derivatives appeared both chemically and configura-
tionally stable and can be further applied as chiral catalysts or
building blocks in asymmetric synthesis. Preliminary experiments
have already demonstrated their usefulness in the catalytic epox-
ide ring opening.
The bicyclic amine, (1S,4S,5R)-2-[(S)-1-phenylethyl]-4-amine-
2-azabicyclo[3.2.1]octane 1 was prepared as described previously.16
(9R)-Amino-deoxyquinine 11 was obtained from 9-epi-quinine as
2
7
described in the literature. Aldehyde (1S,3R,4R)-2-[(S)-1-pheny-
lethyl]-2-azabicyclo[2.2.1]heptan-3-al 14 was synthesized accord-
2
8,29
ing to the literature.
4
2
.3.1. Synthesis of sulfinamides 3, 4, 9, 10, 12 and sulfonamides
, 5, 6, 13
4
4
. Experimental section
.1. General
To
a solution of amine 1, 7, 8 or 11 (3.0 mmol) and
triphenylphosphine (0.81 g, 3.0 mmol, 1.0 equiv) in a dry dichloro-
methane (10.0 mL), stirred at room temperature, the appropriate
sulfonyl chloride (3.0 mmol, 1.0 equiv) and potassium hydroxide
3
CD spectra were recorded for CH CN solutions at 25 °C in 0.1 or
0
.2 cm cells with 100 nm/min scan speed at 0.1 nm step and
(
0.30 g, 5.4 mmol, 1.8 equiv) were added in a 5 min gap. The reac-
1
.00 nm bandwidth. IR spectra were recorded on a 2000 FTIR spec-
1
13
tion was monitored by TLC for the complete conversion of the sul-
fonyl chloride. The reaction mixture was then washed several
times with water and brine. The organic phase were dried over
sodium sulfate, filtered, and evaporated under a reduced pressure.
Reaction products were separated by column chromatography.
Sulfonamides 2, 6 were prepared in an analogous manner from
amine 1 and tosyl chloride or mesyl chloride, respectively, but
triphenylphosphine was not added to the reaction mixture. Simi-
larly, sulfonamide 13 was obtained from amine 11 and tosyl chlo-
ride in the presence of KOH.
trophotometer. H NMR and C NMR spectra were measured on a
00 MHz spectrometer using solvent residual peak (chloroform-d,
5
1
13
d( H) = 7.28 ppm, d( C) = 77.0 ppm as a reference. The reported J
values are those observed from the splitting patterns in the spec-
trum and may not reflect the true coupling constant values. High
resolution mass spectra were recorded utilizing electrospray ion-
ization mode. Chromatographic separations were performed on sil-
ica gel 60 (70–230 mesh). Thin layer chromatography was carried
out using silica gel 60 precoated plates. HPLC analyses were per-
formed on Chiracel OD-H or Chiralpak AD-H chiral columns (flow
rate of 1.0 mL/min).
4
.3.1.1.
4-Methyl-N-((1S,4S,5R)-2-((S)-1-phenylethyl)-2-azabi-
Yellow solid-
= À32.2 (c 0.51, CH Cl ) R 0.4
OH 95/5 v/v). H NMR (500 MHz, CDCl ): d
.19–1.35 (m, 3H), 1.22 (d, 3H, J = 6.6 Hz), 1.57–1.62 (m, 2H),
.81–1.85 (m, 2H), 1.96–1.99 (part of ABX system, 1H,
= 12.6 Hz, J = 3.6 Hz), 2.26 (q, 1H, J = 4.8 Hz), 2.33 (s, 3H),
.97–2.99 (m, 1H), 3.19 (q, 1H, J = 6.6 Hz), 3.51 (t, 1H, J = 4.8 Hz),
cyclo[3.2.1]octan-4-yl)benzenesulfonamide 2.
4
.2. X-ray crystallography
2
0
ifying oil. Yield 0.92 g (80%) [
silica, CHCl /CH
a]
D
2
2
f
1
(
1
1
3
3
3
Single crystal data for 3a, 4b and 10b were collected using Xcal-
ibur Ruby diffractometer equipped with a two-dimensional CCD
Sapphire area detector. The graphite monochromatized MoK radi-
ation (k = 0.71073 Å) was used. Data collection and reduction,
a
J
1
2
2
along with absorption correction, were performed using CrysAlis
2
5
4.98 (d, 1H, J = 8.8 Hz, NH), 7.06 (d, 2H, J = 8.0 Hz, ArH), 7.14–7.17
m, 2H, ArH), 7.23–7.28 (m, 3H, ArH), 7.50 (d, 2H, J = 8.2 Hz,
software package. The structure was solved by direct methods
using SHELXT2014 revealing the positions of almost all non-hydro-
gen atoms. The remaining atoms were located from subsequent
difference Fourier syntheses. The structure was refined using
SHELXL2014 with the anisotropic thermal displacement parame-
(
1
3
ArH). C NMR (125 MHz, CDCl
3
): d 21.2, 21.5, 21.7, 27.1, 34.3,
3
1
9.9, 49.0, 52.6, 55.6, 62.2, 126.7, 126.9, 127.1, 128.4, 129.6,
37.7, 142.8, 145.2. IR (KBr): 3287, 2951, 2862, 2802, 1448, 1323,
1162, 1091, 703, 545 cm . HRMS (ESI-TOF): m/z [M+H]+ calcd
À1
2
6
ters. Aromatic C-bonded H and CH
in their calculated positions and a riding model was used with
eq = 1.2 or 1.5 Ueq(parent C atom). The H atom of NH group was
found from difference maps and constrained with N–H = 0.90
2
, CH atoms were generated
+
for [C22
H
29
N
2
O
2
S] 385.1950; found 385.1953.
U
4
.3.1.2.
4-Methyl-N-((1S,4S,5R)-2-((S)-1-phenylethyl)-2-azabi-
cyclo[3.2.1]octan-4-yl)benzene-(S)-sulfinamide 3a.
solid, Mp 155–156 °C Yield 0.24 g (23%). [
CH Cl 0.24 (silica, CHCl /CH
White
= +33.7 (c 0.36,
(
1) Å and Uiso(H) = 1.5Ueq(N). CCDCÀ1492186, CCDCÀ1530091
2
0
a
]
D
and CCDC-1530090 contain the supplementary crystallographic
data. These data can be obtained free of charge via www.
1
2
2
)
R
f
3
3
OH 95/5 v/v).
H NMR
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K. Kami n´ ska et al. / Tetrahedron: Asymmetry xxx (2017) xxx–xxx
5
(
1
2
500 MHz, CDCl
3
): d 1.25–1.35 (m, 3H), 1.28 (d, 3H, J = 6.6 Hz),
.58–1.67 (m, 2H), 1.97 (d, 1H, J = 11.7 Hz), 2.19–2.21 (m, 2H),
.37 (s, 3H), 2.44–2.46 (m, 1H), 3.04–3.06 (m, 1H), 3.30 (q, 1H,
34.2, 40.0, 49.2, 52.9, 55.4, 62.2, 124.3, 127.0, 127.1, 127.8, 128.5,
145.0, 146.7, 149.6. IR (KBr): 3426, 3326, 2969, 1608, 1532, 1349,
À1
+
1170, 740, 731 cm . HRMS (ESI-TOF): m/z [M+H] calcd for [C21
H N O S] 416.1644; found 416.1632.
26 3 4
-
+
J = 6.6 Hz), 3.50 (t, 1H, J = 4.7 Hz), 4.61 (d, 1H, J = 7.9 Hz), 7.18–
7
(
5
IR (KBr): 3435, 3240, 2966, 2929, 1491, 1453, 1091, 1046, 812,
7
1
3
.30 (m, 7H, ArH), 7.48 (d, 2H, J = 8.2 Hz, ArH).
125 MHz, CDCl ): d 20.9, 21.3, 22.0, 27.5, 34.4, 41.1, 50.4, 52.5,
6.1, 62.4, 125.9, 126.9, 127.4, 128.3, 129.5, 140.9, 141.7, 145.1.
C NMR
3
4.3.1.7. N-((1S,4S,5R)-2-((S)-1-Phenylethyl)-2-azabicyclo[3.2.1]
octan-4-yl)methanesulfonamide 6. White solid, Mp 139–
= À90.7 (c 0.13, CH Cl ) R 0.22 (sil-
OH 95/5 v/v). H NMR (500 MHz, CDCl ): d 1.25–1.41
2
0
140 °C. Yield 0.34 g (60%). [
a
]
D
2
2
f
À1
+
+
1
00 cm . HRMS (ESI-TOF): m/z [M+H] calcd for [C22
H
29
N
2
OS]
ica, CHCl
3
/CH
3
3
3
69.2001; found 369.1996.
(m, 4H), 1.31 (d, 3H, J = 6.6 Hz), 1.67–1.74 (m, 2H), 1.87 (d, 1H,
J = 12.0 Hz), 2.33 (d, 2H, J = 2.7 Hz), 2.39 (q, 1H, J = 4.6 Hz), 2.74
(s, 3H), 3.21 (bs, 1H), 3.33 (q, 1H, J = 6.6 Hz), 3.58 (t, 1H,
4
.3.1.3. 4-Methyl-N-((1S,4S,5R)-2-((S)-1-phenylethyl)-2-azabi-
3b. Pale
= À147.5 (c 0.97,
cyclo[3.2.1]octan-4-yl)benzene-(R)-sulfinamide
J = 4.6 Hz), 4.86 (d, 1H, J = 6.8 Hz), 7.20–7.23 (m, 1H, ArH), 7.25–
2
0
13
yellow solidifying oil. Yield 0.34 g (33%). [
CH Cl 0.33 (silica, CHCl /CH OH 95/5 v/v).
500 MHz, CDCl ): d 1.21–1.33 (m, 3H), 1.28 (d, 3H, J = 6.7 Hz),
.51–1.60 (m, 2H), 1.92 (d, 1H, J = 11.7 Hz), 1.98–2.01 (m, 1H);
.35 and 2.53 (ABX system, 2H, J = 12.4 Hz, J = 3.6 Hz), 2.41 (s,
H), 3.09–3.13 (m, 1H), 3.40 (q, 1H, J = 6.7 Hz), 3.48 (t, 1H,
a]
D
3
7.31 (m, 4H, ArH). C NMR (125 MHz, CDCl ): d 21.1, 21.8, 27.3,
1
2
2
)
R
f
3
3
H
NMR
34.3, 40.0, 41.7, 49.8, 52.9, 55.9, 62.3, 127.1, 127.3, 128.5, 145.1.
IR (KBr): 3436, 3277, 2988, 2967, 2937, 2807, 1452, 1425, 1309,
(
3
À1
+
1
2
3
1155, 1134, 772 cm . HRMS (ESI-TOF): m/z [M+H] calcd for [C16-
+
1
2
25 2 2
H N O S] 309.1637; found 309.1638.
J = 4.7 Hz), 4.65 (d, 1H, J = 7.9 Hz), 7.28–7.31 (m, 7H, ArH), 7.55
d, 2H, J = 8.2 Hz, ArH). 13C NMR (125 MHz, CDCl
): d 20.8, 21.4,
2.2, 27.5, 34.4, 40.8, 50.8, 51.9, 56.1, 62.4, 126.2, 126.9, 127.3,
4.3.1.8. (R,S
S
)-N-a-Methylbenzyl-p-tolylsulfinamide 9a. White
1
(
3
solid. Yield 0.19 g (24%). H NMR (500 MHz, CDCl ): d 1.47
(d, 3H, J = 6.8 Hz); 2.41 (s, 3H); 4.13 (d, 1H, J = 4.6 Hz); 4.65–4.71
(m, 1H); 7.28–7.45 (m, 7H, ArH), 7.60 (d, 2H, J = 8.4 Hz). 13C NMR
3
2
1
1
28.3, 129.4, 140.9, 142.2, 145.0. IR (KBr): 3435, 3255, 2932,
À1
491, 1452, 1088, 1066, 811, 701 cm . HRMS (ESI-TOF): m/z [M
(125 MHz, CDCl
3
): d 21.4, 24.7, 53.6, 125.5, 127.0, 127.7, 128.7,
+
+
+
29 2
H] calcd for [C22H N OS] 369.2001; found 369.1999.
129.5, 141.4, 142.5, 143.3. Physicochemical characteristics is in
agreement with literature data.
1
1
4
.3.1.4. 4-Nitro-N-((1S,4S,5R)-2-((S)-1-phenylethyl)-2-azabicyclo
White solid.
[
3.2.1]octan-4-yl)benzene-(S)-sulfinamide 4a.
4.3.1.9. (R,R
solid. Yield 0.26 g (33%). H NMR (500 MHz, CDCl
(d, 3H, J = 6.6 Hz); 2.38 (s, 3H); 4.21 (d, 1H, J = 4.4 Hz); 4.54–4.59
(m, 1H); 7.19–7.28 (m, 7H, ArH), 7.56 (d, 2H, J = 8.3 Hz, ArH). 13
NMR (125 MHz, CDCl ): d 21.3, 23.7, 52.4, 125.8, 126.4, 127.5,
128.5, 129.4, 141.3, 141.5, 143.7. Physicochemical characteristics
is in agreement with literature data for (S, S
)-enantiomer.19
S
)-N-a-Methylbenzyl-p-tolylsulfinamide 9b. White
20
1
Mp 155–156 °C Yield 0.28 g (23%). [
a
]
D
= +81 (c 0.06, CH
2
Cl
2
) R
): d
f
3
): d 1.63
3 3
.15 (silica, CHCl /CH
OH 95/5 v/v). 1H NMR (500 MHz, CDCl
3
0
1
1
.18–1.38 (m, 3H), 1.28 (d, 3H, J = 6.1 Hz), 1.61–1.75 (m, 2H),
.92–1.95 (m, 1H); 2.05 and 2.12 (ABX system, 2H, J = 12.5 Hz,
= 3.5 Hz), 2.41–2.44 (m, 1H), 2.98–3.01 (m, 1H), 3.26 (q, 1H,
J = 6.0 Hz), 3.56 (s, 1H), 4.84 (bs, 1H), 7.22–7.32 (m, 5H, ArH),
C
1
3
J
2
S
1
3
7
.74 (d, 2H, J = 8.8 Hz, ArH), 8.18 (d, 2H, J = 8.8 Hz, ArH). C NMR
(
6
125 MHz, CDCl ): d 21.0, 21.7, 27.5, 34.3, 41.1, 50.4, 52.4, 56.0,
3
4.3.1.10.
namides 10a and 10b (mixture of epimers).
solid. Yield 0.63 g (68%); dr = 1:1.3. (R,R )-N-4-Methyl-N-(1-(naph-
thalen-2-yl)ethyl)benzenesulfinamide 10b. Mp 135–136 °C. Yield
4-Methyl-N-(1-(naphthalen-2-yl)ethyl)benzenesulfi-
2.4, 123.9, 127.1, 127.3, 127.4, 128.4, 145.0, 149.3, 151.5. IR
Pale yellow
À1
(
KBr): 3435, 2924, 1632, 1526, 1070, 722 cm . HRMS (ESI-TOF):
S
+
+
26 3 3
m/z [M+H] calcd for [C21H N O S] 400.1695; found 400.1696.
2
0
1
0
.35 g (38%). [
a]
D
= +50.0 (c 0.32, CH
2
Cl
2
)
H NMR (500 MHz,
4
[
.3.1.5. 4-Nitro-N-((1S,4S,5R)-2-((S)-1-phenylethyl)-2-azabicyclo
3.2.1]octan-4-yl)benzene-(R)-sulfinamide 4b. White solid,
= À106.3 (c 0.32, CH Cl
CDCl
3
) d 1.70 (d, 3H, J = 6.6 Hz), 2.29 (s, 3H), 4.34 (d, 1H,
J = 4.5 Hz), 4.71–4.76 (m, 1H), 7.16 (d, 2H, J = 8.0 Hz), 7.34 (dd,
1H, J = 8.5 Hz, J = 1.8 Hz), 7.42–7.47 (m, 2H), 7.54–7.56 (m, 3H),
7.72–7.79 (m, 3H). C NMR (125 MHz, CDCl
2
0
Mp 159–160 °C. Yield 0.30 g (25%). [
a
]
D
1
2
2
)
):
1
2
13
R
f
0.18 (silica, CHCl
3
/CH
3
OH 95/5 v/v). H NMR (500 MHz, CDCl
3
3
): d 21.2, 23.7, 52.1,
d 1.16–1.35 (m, 3H), 1.32 (d, 3H, J = 6.7 Hz), 1.50–1.62 (m, 2H),
.88–1.92 (m, 2H), 2.37 and 2.50 (ABX system, 2H, J = 12.4 Hz,
= 3.6 Hz), 3.06–3.08 (m, 1H), 3.40 (q, 1H, J = 6.7 Hz), 3.51 (t, 1H,
J = 4.7 Hz), 4.88 (d, 1H, J = 8.2 Hz), 7.21–7.31 (m, 5H, ArH), 7.86
124.6, 125.2, 125.8, 125.9, 126.2, 127.6, 127.9, 128.4, 129.4,
+
1
1
132.7, 133.2, 141.0, 141.27, 141.31. HRMS (ESI-TOF): m/z [M+H]
+
J
2
calcd for [C19
H
20NOS] 310.1266; found 310.1255.
1
3
(
(
6
(
d, 2H, J = 8.8 Hz, ArH), 8.32 (d, 2H, J = 8.8 Hz, ArH). C NMR
125 MHz, CDCl ): d 20.7, 22.1, 27.3, 34.3, 40.7, 50.8, 52.0, 56.1,
2.4, 123.8, 127.1, 127.3, 127.6, 128.4, 144.8, 149.5, 152.2. IR
KBr): 3435, 3297, 2970, 2932, 1606, 1521, 1342, 1087, 1070,
4.3.1.11. (9R)-N-Quinyl-p-tolylsulfinamide 12b.
Colorless
0.53 (silica,
2
0
3
oil. Yield 0.66 g (48%). [
a
]
D
= +89.2 (c 0.90, CH
2
Cl
2
) R
f
1
CHCl
3
/CH
3
OH 95/5 v/v). H NMR (500 MHz, CDCl ), major atropiso-
3
mer d 0.78–0.82 (m, 1H), 1.21–1–25 (m, 1H), 1.60–1.67 (m, 2H),
1.89 (s, 3H), 2.29–2.31 (m, 1H), 2.70–2.78 (m, 2H), 2.97–2.99 (m,
1H), 3.37–3.44 (m, 2H), 3.99 (s, 3H), 4.91–4.88 (m, 2H), 5.20 (d,
À1
+
1
26 3
056, 854 cm . HRMS (ESI-TOF): m/z [M+H] calcd for [C21H N -
+
3
O S] 400.1695; found 400.1698.
1
H, J = 10.8 Hz), 5.65–5.72 (m, 1H), 6.30 (s, 1H, NH), 6.37 (d, 2H,
4
[
.3.1.6. 4-Nitro-N-((1S,4S,5R)-2-((S)-1-phenylethyl)-2-azabicyclo
3.2.1]octan-4-yl)benzenesulfonamide 5. White solid, Mp
= +39.0 (c 0.26, CH Cl ) R
OH 95/5 v/v). H NMR (500 MHz, CDCl ): d
.22 (d, 3H, J = 6.6 Hz), 1.25–1.36 (m, 3H), 1.63–1.71 (m, 3H),
.83 (d, 1H, J = 12.1 Hz), 2.04 (dd, 1H, J = 12.7 Hz, J = 3.7 Hz),
J = 8.0 Hz), 7.01 (d, 2H, J = 8.0 Hz), 7.17 (d, 1H, J = 2.4 Hz), 7.24–
7.30 (m, 2H), 7.77 (d, 1H, J = 9.2 Hz), 8.50 (d, 1H, J = 4.6 Hz); minor
atropisomer d 0.83–0.87 (m, 1H), 1.27–1.32 (m, 1H), 1.60–1.67 (m,
2H), 2.01 (s, 3H), 2.29–2.31 (m, 1H), 2.70–2.78 (m, 2H), 3.27–3.44
(m, 3H), 3.97 (s, 3H), 4.64 (d, 1H, J = 10.9 Hz), 4.84–4.91 (m, 2H),
5.55–5.62 (m, 1H), 6.42 (d, 2H, J = 8.0 Hz), 6.45 (s, 1H, NH), 6.70
(d, 1H, J = 4.3 Hz), 6.99 (d, 2H, J = 8.0 Hz), 7.25–7.28 (m, 1H), 7.73
(d, 1H, J = 2.5 Hz), 7.82 (d, 1H, J = 9.2 Hz), 8.24 (d, 1H, J = 4.3 Hz);
2
0
1
0
1
1
2
3
7
63–165 °C. Yield 0.25 g (20%). [
.22 (silica, CHCl /CH
a]
D
2
2
f
1
3
3
3
1
2
.28–2.29 (m, 1H), 3.09 (bs, 1H), 3.12 (q, 1H, J = 6.6 Hz), 3.55–
.56 (m, 1H), 5.14 (bs, 1H, NH), 7.11–7.13 (m, 2H, ArH), 7.21–
.22 (m, 3H, ArH), 7.78 (d, 2H, J = 8.9 Hz, ArH), 8.09 (d, 2H,
1
3
C NMR (2:1 mixture of atropisomers): d 20.8, 20.9, 25.4, 26.8,
27.6, 27.7, 27.8, 39.5, 39.8, 40.2, 45.2, 55.0, 55.7, 55.9, 56.1, 56.7,
1
3
3
J = 8.8 Hz, ArH). C NMR (125 MHz, CDCl ): d 21.2, 21.4, 27.2,
Please cite this article in press as: Kami n´ ska, K.; et al. Tetrahedron: Asymmetry (2017), http://dx.doi.org/10.1016/j.tetasy.2017.03.004

6
K. Kami n´ ska et al. / Tetrahedron: Asymmetry xxx (2017) xxx–xxx
6
1
1
1
1
1.2, 101.3, 104.1, 114.7, 120.8, 121.0, 121.3, 123.7, 125.2, 125.7,
mobile phase: hexane/i-PrOH 90/10; flow rate 0.8 mL/min, reten-
tion times: (1S,2S): 13.07 min, (1R,2R): 14.94 min).
2
4
27.1, 127.6, 128.0, 131.2, 131.5, 138.4, 138.8, 140.4, 140.8,
41.1, 141.3, 141.9, 143.9, 144.7, 145.8, 146.4, 147.0, 156.7,
57.3. IR (film): 3206, 2932, 2240, 1621, 1508, 1475, 1241, 1093,
Acknowledgments
À1
+
063, 855, 733 cm . HRMS (ESI-TOF): m/z [M+H] calcd for [C27
-
+
H
32
N
3
O
2
S] 462.2215; found 462.2208.
Financial support from a statutory activity subsidy from the
Polish Ministry of Science and Higher Education for the Faculty
of Chemistry of Wrocław University of Science and Technology,
and from Wrocław Centre of Biotechnology (the Leading National
Research Centre programme (KNOW) for years 2014-2018) is
gratefully acknowledged.
4
.3.1.12. (9R)-N-Quinyl-p-tolylsulfonamide 13.
Yield 1.03 g
+
+
(
32 3 3
72%). HRMS (ESI-TOF): m/z [M+H] calcd for [C27H N O S]
4
78.2164; found 478.2152. Physicochemical characteristics in
23
agreement with the literature data.
4
.3.2. Synthesis of sulfinamide 15
Compound 15 was prepared according to the procedure
A. Supplementary data
3
reported by Brun et al. A round-bottomed flask equipped with a
magnetic stirring bar was charged with (R)-2-methyl-2-propane-
Supplementary data (CD and NOESY spectra of quinine-derived
1
13
sulfinamides, copies of H and C NMR spectra, X-ray data for 3a,
b, and 10b) associated with this article can be found, in the online
sulfinamide (0.31 g, 1.4 mmol) under argon atmosphere. Ti(OEt)
0.28 g, 1.2 mmol) in anhydrous THF (10 mL) was then added,
and the solution was stirred for 10 min at room temperature.
1S,3R,4R)-2-[(S)-1-Phenylethyl]-2-azabicyclo[2.2.1]heptan-3-al
4 (0.15 g, 1.2 mmol) was then added and the crude reaction mix-
4
4
(
version, at http://dx.doi.org/10.1016/j.tetasy.2017.03.00.
(
1
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[a
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2
5
3
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3
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3
): d 22.1, 22.5, 22.6, 28.9,
7854.
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.4. Typical procedure for the epoxide ring opening
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(
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Please cite this article in press as: Kami n´ ska, K.; et al. Tetrahedron: Asymmetry (2017), http://dx.doi.org/10.1016/j.tetasy.2017.03.004