Сhiral tricyclic phosphines derived from 1-(+)-neomenthyl-1,2-diphosphole: Synthesis and applications in asymmetric homogeneous catalysis

Article abstract of DOI:10.1016/j.cattod.2016.06.015

A one-step diastereoselective synthesis of bulky P-chiral phosphines with a rigid bicyclic [2.2.1] structure was developed employing a cycloaddition reaction of 3,4,5-triphenyl-1-(+)-neomenthyl-1,2-diphosphole (1) and maleic acid derivatives. The catalyti

Full text of DOI:10.1016/j.cattod.2016.06.015

G Model
CATTOD-10258; No. of Pages5
ARTICLE IN PRESS
Catalysis Today xxx (2016) xxx–xxx
Contents lists available at ScienceDirect
Catalysis Today
journal homepage: www.elsevier.com/locate/cattod
Chiral tricyclic phosphines derived from
-(+)-neomenthyl-1,2-diphosphole: Synthesis and applications in
asymmetric homogeneous catalysis
1
a,∗
a
a
b
Almaz Zagidullin , Vasili Miluykov , Oleg Sinyashin , Evamarie Hey-Hawkins
a
A. E. Arbuzov Institute of Organic and Physical Chemistry, Kazan Scientific Center of the Russian Academy of Sciences, Arbuzov Str., 8, 420088 Kazan, Russia
Institut für Anorganische Chemie, Universität Leipzig, Johannisallee 29, 04103 Leipzig, Germany
b
a r t i c l e i n f o
a b s t r a c t
Article history:
A one-step diastereoselective synthesis of bulky P-chiral phosphines with a rigid bicyclic [2.2.1] structure
Received 2 January 2016
Received in revised form 31 May 2016
Accepted 6 June 2016
Available online xxx
was developed employing a cycloaddition reaction of 3,4,5-triphenyl-1-(+)-neomenthyl-1,2-diphosphole
(1) and maleic acid derivatives. The catalytic activity and asymmetric induction for the prepared enan-
tiopure tricyclic phosphines 2a and 3a were evaluated in Pd-catalyzed asymmetric allylic substitution
and [3 + 2] organocatalytic cyclization of allenes with activated alkenes (ee = 68%). This is the first example
of using a chiral phosphine with a P P bond as ligand in allylic alkylation and organocatalyst in a [3 + 2]
annulation.
Keywords:
Chiral phosphine
P-stereogenic
©
2016 Elsevier B.V. All rights reserved.
Asymmetric catalysis
Allylic alkylation
Organocatalytic [3 + 2] cyclization
1
. Introduction
other cyclic chiral phosphines and provides a new motif for chiral
phosphine design. However, the preparation of these phosphines is
rather complicated and mostly based on expensive starting mate-
rials or complex separation of enantiomers.
The increasing demand for enantiomerically pure pharmaceuti-
cals, agrochemicals, flavors and other fine chemicals has advanced
the field of asymmetric catalytic technologies. Today, mainly
transition metal complexes with chiral ligands are employed as
enantioselective catalysts because they allow carrying out asym-
metric synthesis under mild conditions with high selectivity, thus
reducing the cost of enantiomerically pure compounds. Phosphines
are powerful and versatile ligands in transition metal catalysis [1,2]
but also nucleophilic organocatalysts [3,4]. Phosphines based on
rigid bicyclic structures (Fig. 1) with the phosphorus atom embed-
ded in a five- or six-membered ring were shown to be highly
efficient chiral ligands (BIPNOR A [5], PennPhos B [6], 9-PBN C [7]
Briphos D [8], phosphabarrelene E [9], tricyclic phosphinite F [10],
In this paper we demonstrate that the enantiomerically
pure tricyclic P,C-stereogenic phosphines 10-neomenthyl-7,
2,6
8,9-triphenyl-1,10-diphosphatricyclo[5.2.1.0 ]-deca-8-ene-
3,5-diones 2a and 3a can be readily obtained by an efficient
diastereoselective [4 + 2] cycloaddition reaction of 1-(+)-(S ,S ,R5)-
1
2
neomenthyl-3,4,5-triphenyl-1,2-diphosphacyclopenta-2,4-diene
(1) (1-(+)-neomenthyl-1,2-diphosphole) and maleic acid deriva-
tives. The use of enantiopure phosphines 2a and 3a as ligands and
organocatalysts in asymmetric C C bond formation reactions is
also reported.
1
-phosphanorbornadiene-oxazoline G [11]) and excellent chiral
2
. Experimental
organocatalysts (2-aza-5-phosphabicyclo[2.2.1]heptane H [12], 7-
phosphabicyclo-[2.2.1]heptane I [13]). The main structural feature
of these chiral phosphines is their rigid framework and a chiral, not
racemizable P-atom situated at the bridgehead of a bicyclic system
2.1. General methods
All reactions and manipulations were carried out under dry,
[
14], which excludes the conformational flexibility associated with
pure N2 in standard Schlenk apparatus. THF, toluene and n-hexane
were distilled from sodium/benzophenone and stored under nitro-
gen before use. The NMR experiments were performed at 303 K
with a Bruker AVANCE-600 spectrometer equipped with a 5 mm
diameter gradient inverse broad-band probe head (600.13 MHz in
∗ Corresponding author.
E-mail address: zagidullin@iopc.ru (A. Zagidullin).
http://dx.doi.org/10.1016/j.cattod.2016.06.015
920-5861/© 2016 Elsevier B.V. All rights reserved.
0
Please cite this article in press as: A. Zagidullin, et al., Chiral tricyclic phosphines derived from 1-(+)-neomenthyl-1,2-diphosphole:
Synthesis and applications in asymmetric homogeneous catalysis, Catal. Today (2016), http://dx.doi.org/10.1016/j.cattod.2016.06.015

G Model
CATTOD-10258; No. of Pages5
ARTICLE IN PRESS
2
A. Zagidullin et al. / Catalysis Today xxx (2016) xxx–xxx
Fig. 1. Selection of rigid bicyclic phosphines (* denotes chiral center).
1
13
31
3
3
4
H NMR, 150.90 MHz in C NMR, and 242.9 MHz in P NMR).
JHH = 7.5, m-Ph8), 6.93 (tt, 1H, JHH = 7.3, JHH = 1.4, p-Ph8), 7.07 (d,
1
H and C NMR chemical shifts were referenced to TMS, and 31
13
3
3
P
2H, JHH = 7.3, o-Ph9), 7.11 (m, 2H, m-Ph7), 7.12 (t, 2H, JHH = 6.8,
m-Ph9), 7.17 (t, 1H, JHH = 7.2, p-Ph7), 7.26 (t, 1H, JHH = 7.5, p-
Ph9), 8.08 (br, 2H, o-Ph7). P NMR (CDCl , ı, ppm, J, Hz): 84.7
3
3
NMR chemical shifts to 85% H PO . All experiments were carried
3
4
31
out using standard Bruker pulse programs. Infrared (IR) spectra
were recorded on a Bruker Vector-22 spectrometer. Elemental
analysis was accomplished with an automated EuroVector EA3000
CHNS-O elemental analyzer. Optical rotations were measured on a
Perkin–Elmer model 341 polarimeter. Chiral HPLC analyses were
performed with a chromatograph equipped with a Daicel HPLC
column Chiralcel OD-H.
3
1
1
13
(d, JPP = 207.5, P10), −14.4 (d, JPP = 207.5, P1). C NMR (CDCl3,
ı, ppm, J, Hz): 21.6 (s, C9’), 22.2 (s, C10’), 23.3 (br, C8’), 26.1 (d,
3
JCP = 9.8, C3’), 28.5 (s, C5’), 30.8 (s, C7’), 36.1 (s, C4’), 37.8 (s, C6’),
1
1
40.5 (d, JCP = 42.2, C1’), 49.4 (s, C6), 50.6 (d, JCP = 41.2, C2), 50.7
2
1
(d, JCP = 9.8, C2’), 78.0 (d, JCP = 36.3, C7), 126.9 (s, m-Ph7), 127.6
(s, p-Ph8), 127.9 (s, m-Ph8), 128.5 (br, o-Ph7, m-Ph9, p-Ph9), 129.4
(s, p-Ph7), 130.0 (d, 3JCP = 6.2, o-Ph9), 130.8 (s, o-Ph8), 143.0 (m, 9,
1
-(+)-(S ,S ,R5)-neomenthyl-3,4,5-triphenyl-1,2-
1 2
2
diphosphacyclopenta-2,4-diene
buta-2,3-dienoate (9) [16] were obtained according to lit-
erature procedures. Maleic anhydride, N-phenylmaleimide,
(1)
[15]
and
ethyl
ipso-Ph8, ipso-Ph9), 158.3 (d, JCP = 18.6, C8), 169.6 (s, C3), 171.8
−
1
(s, C5). IR (KBr, cm ): 405 (m), 419 (m), 457 (w), 697 (m), 755
(w), 806 (br.w), 1029 (m), 1084 (w), 1262 (m), 1385 (w), 1456 (w),
1491 (w), 1559 (w), 1634 (br), 1700 (m, CO), 1734 (m, CO), 2961
(w). [␣]25D = −303 (c 0.5, THF). Found: C 74.30, H 6.23, P 10.82%.
Calculated for C35H36O P : C 74.19, H 6.40, P 10.93%.
[
1
{Pd(allyl)Cl} ], N,O-bis(trimethylsilyl)acetamide (BSA) and (E)-
2
◦
,3-diphenylallyl acetate were purchased from Aldrich and used
without additional purification. Dimethyl malonate (5), benzy-
lamine (6), ethyl acrylate (10) and tert-butyl acrylate (11) were
distilled before use.
3
2
2
.2. General method for preparation of phosphines 2a and 3a
2.4. 10-Neomenthyl-4,7,8,9-tetraphenyl-4-aza-1,10-
diphosphatricyclo[5.2.1.0 ]-deca-8-ene-3,5-dione
(3a)
2
,6
Maleic anhydride (0.18 g, 1.84 mmol) or N-phenylmaleimide
◦
(
of
0.32 g, 1.84 mmol) was added at −30 C to
a
solution
◦
1-(+)-(S ,S ,R5)-neomenthyl-3,4,5-triphenyl-1,2-
Yield: 0.55 g (50%). M.p. 151 C. Numbering scheme for NMR
1
2
1
diphosphacyclopenta-2,4-diene (1) (0.86 g, 1.83 mmol) in
2
for 24 h at 0 C. Then the solution was filtered and the sol-
vent was evaporated at reduced pressure to give 0.99 g (95%)
of a mixture of diastereomers (15:1, d.e. = 88%). The individual
major diastereoisomer 2a or 3a was isolated by slow pre-
assignments is given in Scheme 1. H NMR (CDCl , ı, ppm, J, Hz):
3
0.04 (d, 3H, 3
J
= 6.3, H10’), 0.72 (q, 1H, 2
J
= 12.3, H4a’), 0.85
= 6.5, H9’), 1.02
0 ml THF and stirred for 1 h at this temperature and then
HН
(m, 1H, H6a’), 0.93 (m, 1H, H5’), 0.96 (d, 3H,
(d, 3H, 3
HН
◦
3
J
HН
2
J
= 6.6, H8’), 1.15 (m, 1H, H2’), 1.41 (d, 1H,
J
= 13.5,
HН
HН
H6e’), 1.58–1.74 (m, 2H, H3’), 1.62 (m, 1H, H4e’), 1.74 (m, 1H, H7’),
3
= 8.7, 2JHP = 10.9, H2), 4.80
2.41 (br, 1H, H1’), 4.67 (dd, 1H,
J
HH
3
3
cipitation from a mixture of n-hexane and toluene (or THF)
(d, 1H, JHH = 8.7, H6), 6.70 (d, 2H, JHH = 7.8, o-Ph8), 6.87 (t, 2H,
JHH = 7.5, m-Ph8), 6.94 (tt, 1H, J = 7.3, J = 1.4, p-Ph8), 7.08 (d,
HH HH
◦
3
3
4
(
3 ml:3 ml) at −40 C. The precipitate was isolated and dried to
3
3
give about 0.50 g (47–50%) 10-neomenthyl-7,8,9-triphenyl-4-
2H, JHH = 7.3, o-Ph9), 7.12 (m, 2H, m-Ph7), 7.13 (t, 2H, JHH = 6.9,
2,6
m-Ph9), 7.15 (t, 1H, JHH = 7.2, p-Ph7), 7.26 (t, 1H, 3JHH = 7.5, p-
3
oxa-1,10-diphosphatricyclo[5.2.1.0 ]-deca-8-ene-3,5-dione
2a) or 10-neomenthyl-4,7,8,9-tetraphenyl-4-aza-1,10-
31
(
Ph9), 7.32 (m, 2H, NPh), 7.41 (m, 3H,) 8.08 (br, 2H, o-Ph7).
P
2,6
1
diphosphatricyclo[5.2.1.0 ]-deca-8-ene-3,5-dione (3a) as pale
yellow powders (Scheme 1).
NMR (CDCl , ı, ppm, J, Hz): 81.2 (d, JPP = 200.3, P10), −21.1 (d,
3
1
13
JPP = 200.3, P1). C NMR (CDCl , ␦, ppm, J, Hz): 20.6 (s, C9’), 21.2
3
3
(
s, C10’), 23.4 (br, C8’), 26.3 (d, JCP = 9.7, C3’), 28.3 (s, C5’), 30.3 (s,
1
2.3. 10-neomenthyl-7,8,9-triphenyl-4-oxa-1,10-
C7’), 36.3 (s, C4’), 37.8 (s, C6’), 41.5 (d, JCP = 41.2, C1’), 48.4 (s, C6),
51.6 (d, 1JCP = 43.2, C2), 51.7 (d, 2JCP = 9.8, C2’), 76.7 (d, 1JCP = 38.3,
C7), 124.2 (s, CРh), 124.6 (s, CРh), 124.9 (s, CРh), 125.2 (s, CРh), 126.8
2,6
diphosphatricyclo[5.2.1.0 ]-deca-8-ene-3,5-dione
2a)
(
(
s, m-Ph7), 127.7 (s, p-Ph8), 128.0 (s, m-Ph8), 128.2 (br, o-Ph7, m-
Ph9, p-Ph9), 128.4 (s, p-Ph7), 131.0 (d, JCP = 6.2, o-Ph9), 131.8 (s,
◦
3
Yield: 0.50 g (47%). M.p. 143 C. Numbering scheme for NMR
1
2
assignments is given in Scheme 1. H NMR (CDCl , ı, ppm, J, Hz):
0
o-Ph8), 142.0 (m, 9, ipso-Ph8, ipso-Ph9), 156.3 (d, JCP = 18.6, C8),
3
3
= 6.3, H10’), 0.71 (q, 1H, 2
−1
.03 (d, 3H,
J
J
= 12.6, H4a’), 0.85
= 6.5, H9’), 1.00
168.6 (s, C3), 170.8 (s, C5). IR (KBr, cm ): 406 (m), 420 (m), 457
HН
HН
HН
3
(
(
m, 1H, H6a’), 0.94 (m, 1H, H5’), 0.95 (d, 3H,
J
(w), 697 (m), 755 (w), 812 (br.w), 1029 (m), 1083 (w), 1261 (m),
1383 (w), 1440 (w), 1492 (w), 1560 (w), 1634 (br), 1710 (m, CO),
1721 (m, CO), 2961 (w). [␣]25D = −284 (c 0.5, THF). Found: C 76.80,
H 6.39, N 2.34, P 9.79%. Calculated for C41H41NO2P2: C 76.74, H 6.44,
N 2.18, P 9.65%.
d, 3H, 3
J
= 6.5, H8’), 1.14 (m, 1H, H2’), 1.40 (d, 1H,
2
J
= 13.5,
HН
HН
◦
H6e’), 1.59–1.75 (m, 2H, H3’), 1.62 (m, 1H, H4e’), 1.70 (m, 1H, H7’),
.41 (br, 1H, H1’), 4.66 (dd, 1H, JHH = 8.7, 2JHP = 10.9, H2), 4.79
3
2
(
d, 1H, JHH = 8.7, H6), 6.69 (d, 2H, 3JHH = 7.8, o-Ph8), 6.88 (t, 2H,
3
Please cite this article in press as: A. Zagidullin, et al., Chiral tricyclic phosphines derived from 1-(+)-neomenthyl-1,2-diphosphole:
Synthesis and applications in asymmetric homogeneous catalysis, Catal. Today (2016), http://dx.doi.org/10.1016/j.cattod.2016.06.015

G Model
CATTOD-10258; No. of Pages5
ARTICLE IN PRESS
A. Zagidullin et al. / Catalysis Today xxx (2016) xxx–xxx
3
Scheme 1. Preparation of chiral tricyclic phosphines 2a and 3a.
2
.5. General procedure for the Pd-catalyzed asymmetric allylic
give N-((E)-1,3-diphenyl-2-propenyl)benzylamine (S)-8 [17]. The
enantiomeric excess was determined by HPLC analysis using a
Daicel Chiralcel OD-H column (eluent 2-propanol:n-hexane, 1:99;
flow rate 0.5 mL/min; detection UV 254 nm; retention times:
alkylation of rac-1,3-diphenyl-2-propenyl acetate (4) with
dimethyl malonate (5) to give 7
A
solution of the ligand 2a or 3a (0.025 mmol) and
t(R) = 45.8 min, t(S) = 47.1 min for 8 (Table 1).
1
[
{Pd(allyl)Cl} ] (0.004 g, 0.01 mmol) in THF (1 mL) was stirred
8: H NMR (CDCl , ı, ppm, J, Hz): 1.75 (br.s, 1H, NH), 3.57 (d,
2
3
at room temperature for 30 min. Then the solution was suc-
cessively treated with a solution of rac-1,3-diphenyl-2-propenyl
acetate (4) (0.13 g, 0.50 mmol), dimethyl malonate (5) (0.17 mL,
1H, J = 13.4), 3.89 (d, 1H, J = 13.4), 4.38 (d, 1H, J = 7.3), 6.29 (dd, 1H,
J = 15.8 and 7.4), 6.57 (d, 1H, J = 15.8), 7.14–7.45 (m, 10H, Ph).
1
.5 mmol), N,O-bis(trimethylsilyl)acetamide (0.37 mL, 1.5 mmol)
and sodium acetate (0.01 mmol) in THF (2 mL). The reaction
mixture was stirred for 24 h at 25 C or 50 C. Then the reac-
2
.7. General procedure for the [3 + 2] annulation of ethyl
◦
◦
buta-2,3-dienoate (9) with alkyl acrylates 10 or 11
tion mixture was quenched with saturated aqueous NH Cl, and
4
extracted with diethyl ether. The organic layer was dried over
anhydrous Na SO , filtered and evaporated to dryness. The residue
was chromatographed on silica gel (ethyl acetate:n-hexane, 1:4)
to give dimethyl-(1,3-diphenyl-2-propenyl)malonate (S)-7 [17].
The enantiomeric excess was determined by HPLC analysis using
a Daicel Chiralcel OD-H column (eluent 2-propanol:n-hexane,
Ethyl buta-2,3-dienoate (9) (0.30 mmol, 35 ␮L) was added
2
4
under argon atmosphere to
a mixture of freshly distilled
ethyl acrylate (10) (3.0 mmol, 330 ␮L) and phosphine 2a or 3a
(
5 mol%, 0.015 mmol) in toluene (1.0 mL). The solution was
◦
stirred for 12 h at 100 C. The crude mixture was concentrated
in vacuo and purified by flash chromatography on silica gel
1
:99; flow rate 0.3 mL/min; detection UV 254 nm; t(R) = 18.6 min,
(
10% EtOAc/n-hexane). The ratio of the two regioisomers was
t(S) = 20.2 min for and t(R) = 27.8 min, t(S) = 29.3 min for
4
7
1
assigned by H NMR spectroscopy. The enantiomeric excess was
determined by HPLC analysis using a Daicel Chiralcel OD-H col-
umn (eluent 2-propanol:n-hexane, 1:99; flow rate 1 mL/min;
detection UV 215 nm; retention times: diethyl cyclopent-1-
ene-1,3-dicarboxylate (12a) [18] 12.1 min (minor) and 13.4 min
(
Table 1).
1
7:
H NMR (CDCl , ı, ppm, J, Hz): 3.52 (s, 3H), 3.70 (s, 3H), 3.95
3
(
d, 1H, J = 10.9), 4.26 (dd, 1H, J = 10.9, J = 8.4), 6.32 (dd, 1H, J = 15.8,
J = 8.4), 6.47 (d, 1H, J = 15.8), 7.17–7.34 (m, 10H, Ph).
(major)]; diethyl cyclopent-1-ene-1,2-dicarboxylate (12b) [18]
1
7.5 min (major) and 18.9 min (minor) (Table 2).
2
.6. General procedure for the Pd-catalyzed asymmetric allylic
1
1
2a: H NMR (CDCl , ı, ppm, J, Hz): 1.25–1.31(m, 6H, CН ),
amination of rac-1,3-diphenyl-2-propenyl acetate (4) with
benzylamine (6) to give 8
3
3
2
.80–2.91 (m, 4H, CН ), 3.23 (dt, 1H, J = 7.3, J = 9.2, CH), 4.13–4.23
2
(m, 4H, OCН ), 6.69 (t, 1H, J = 2.5).
2
1
1
2b: H NMR (CDCl , ı, ppm, J, Hz): 1.23–1.30 (m, 6H, CН ), 2.12
A
solution of the ligand 2a or 3a (0.025 mmol) and
3
3
(m, 1H, CН ), 2.30–2.42 (m, 1H, CН ), 2.47–2.70 (m, 2H, CН ), 3.76
[
{Pd(allyl)Cl} ] (0.004 g, 0.01 mmol) in THF (1 mL) was stirred at
2 2 2
2
(m, 1H, CН), 4.21 (m, 4H, OCН ), 6.95 (t, 1H, J = 2.2).
room temperature for 30 min. The solution was then successively
2
1
1
3a: H NMR (CDCl , ı, ppm, J, Hz): 1.25 (t, 3H, J = 7.2, CН ), 1.43
treated with a solution of rac-1,3-diphenyl-2-propenyl acetate (4)
3
3
(s, 9H, tert-CH ), 2.72–2.85 (m, 4H, CН ), 3.09–3.15 (m, 1H, CН),
(
(
0.13 g, 0.50 mmol) and benzylamine (6) (0.13 g, 1.2 mmol) in THF
1 mL). The reaction mixture was stirring for 24 h at 50 C. Then
3
2
◦
4.17 (q, 2H, J = 7.2, OCH ), 6.64 (m, 1H).
2
1
1
3b: H NMR (CDCl , ı, ppm, J, Hz): 1.24 (t, 3H, J = 7.1, CН ),
the reaction mixture was quenched with saturated aqueous NH Cl,
and extracted with diethyl ether. The organic layer was dried over
anhydrous Na SO , filtered and evaporated to dryness. The residue
3
3
4
1
2
.45 (s, 9H, tert-CH ), 2.10 (m, 1H, CН ), 2.27–2.37 (m, 1H, CН ),
3 2 2
.43–2.55 (m, 2H, CН ), 3.68 (m, 1H, CН), 4.17 (m, 4H, OCН ), 6.94
2
2
2
4
(t, 1H, J = 2.3).
was chromatographed on silica gel (ethyl acetate:n-hexane, 1:4) to
Please cite this article in press as: A. Zagidullin, et al., Chiral tricyclic phosphines derived from 1-(+)-neomenthyl-1,2-diphosphole:
Synthesis and applications in asymmetric homogeneous catalysis, Catal. Today (2016), http://dx.doi.org/10.1016/j.cattod.2016.06.015

G Model
CATTOD-10258; No. of Pages5
ARTICLE IN PRESS
4
A. Zagidullin et al. / Catalysis Today xxx (2016) xxx–xxx
Table 1
Palladium-catalyzed allylic substitution.
◦
Entry
L
T,
C
Product
Conversion, %
ee, % (S)
1
2
3
4
5
6
2a
2a
3a
3a
2a
3a
25
50
25
50
50
50
7
7
7
7
8
8
65
99
67
96
94
95
14
12
15
14
22
25
Table 2
Phosphine-catalyzed asymmetric [3 + 2] annulation (left) and a proposed transition state (right).
Entry
Phosphine
R
Conversion, %
a:b
ee for a,%
ee for b,%
1
2
3
4
2a
2a
3a
3a
Et
Bu
89
93
91
96
62:38
78:22
61:39
79:21
48
59
52
68
21
22
20
23
t
Et
t
Bu
3
. Results and discussion
-(+)-neomenthyl-1,2-diphosphole (1) with chiral substitutent
typical pyramidal environment. The sum of bond angles at the two
◦
phosphorus atoms of 2a and 3a is different: for caged P1 ∼270 ,
◦
1
and for bridging P10 ∼300 [20–22]. There are eight chiral centers
reacts with achiral derivatives of maleic acid (maleic anhydride
and N-phenylmaleimide) at 25 C to give the corresponding [4 + 2]
cycloadducts 2a and 3a with high diastereoselectivity (d.r. >8:1,
d.e. > 80) (Scheme 1). The stereoselectivity of the cycloaddition
in 2a and 3a (Scheme 1); P1 has R and P10 has S configuration [15].
The enantiopure P,C-stereogenic phosphines 2a and 3a were
tested as chiral ligands and organocatalysts in asymmetric reac-
tions known to be efficiently catalyzed by monophosphines or their
organometallic complexes.
◦
◦
reaction increased at −30 C giving an even better d.e. up to 88%
and higher yields for the main diastereomers 2a or 3a.
Metal-catalyzed asymmetric allylation has become a power-
ful method for the efficient formation of carbon–element bonds
in a highly enantioselective manner, and has been applied suc-
cessfully in the total synthesis of many natural products [23,24].
Therefore, catalytic allylic substitution reactions were studied
with palladium complexes formed in situ from 2a and 3a and 2
The main diastereoisomers 2a and 3a were isolated by slow pre-
◦
cipitation from a mixture of n-hexane and toluene at −40 C with
3
1
1
4
7–50% yields. In the P{ H} NMR spectra of the enantiopure P-
chiral tricyclic phosphines 2a and 3a two doublets are observed at
1
= 208 Hz. The 1H and C{ H}
13
1
∼
+80 ppm and ∼−20 ppm with
J
PР
NMR spectra of 2a and 3a are unremarkable and are consistent of
one set of signals indicating scalemic tricyclic phosphines. Addi-
tionally, the structure of chiral phosphines was clearly proved by a
mol% [{Pd(allyl)Cl} ] (Table 1). Treatment of (E)-1,3-diphenylallyl
2
acetate (4) with dimethyl malonate (5) in the presence of 2a or 3a
and [{Pd(allyl)Cl} ] as catalyst precursor gave the allylated mal-
2
1
D/2D NMR correlation methods, the absolute configuration of 2a
onate 7 (14% ee with 2a and 15% ee with 3a). The same procedure
with benzylamine (6) as nucleophile gave the allylamine derivative
8 in ca. 95% yield (22 or 25% ee).
and 3a can be assigned as 10P: S, 1P: R, 2C: R, 6C: R, 7C: R [15].
Thus, the asymmetric diastereoselective Diels-Alder reaction of
chiral 3,4,5-triphenyl-1-(+)-neomenthyl-1,2-diphosphole (1) with
maleic acid derivatives was used for the selective synthesis of enan-
tiopure tricyclic phosphines 2a and 3a.
According to X-ray data of related 1,10-diphosphanorbornene
derivatives which are accessible through [4 + 2] cycloaddition reac-
tion of 1-alkyl-1,2-diphospholes [19], each phosphorus atom has a
To the best of our knowledge, this is the first example of using
chiral phosphines with a P P bond as ligands in contrast to the
well-known P C, P O, or P N ligands widely used in asymmetric
catalysis. Diphosphines 2a and 3a have two chiral phosphorus cen-
ters with different configuration (R and S), which could be a reason
for the low enantioselectivity in allylic substitution (Table 1).
Please cite this article in press as: A. Zagidullin, et al., Chiral tricyclic phosphines derived from 1-(+)-neomenthyl-1,2-diphosphole:
Synthesis and applications in asymmetric homogeneous catalysis, Catal. Today (2016), http://dx.doi.org/10.1016/j.cattod.2016.06.015

G Model
CATTOD-10258; No. of Pages5
ARTICLE IN PRESS
A. Zagidullin et al. / Catalysis Today xxx (2016) xxx–xxx
5
Phosphines 2a and 3a were also employed in organocatalytic
3 + 2] cyclization between ethyl buta-2,3-dienoate (9) and selected
olefins (ethyl acrylate (10) and tert-butyl acrylate (11)) to afford
functionalized cyclopentenes [25,26], which are important syn-
thons in the total syntheses of natural products and medicinally
important agents [4]. The asymmetric reaction was performed with
from scholarship programs of the German Academic Exchange Ser-
vice (DAAD, personal ref. no. A/09/83492, A/13/71336) and of the
government of the Republic of Tatarstan “Algarish” is gratefully
acknowledged.
[
References
5
mol% of 2a or 3a by mixing ethyl buta-2,3-dienoate (9) and alkyl
◦
[1] P. Loxq, E. Manoury, R. Poli, E. Deydier, A. Labande, Coord. Chem. Rev. 308
acrylate 10 or 11 in toluene and heating up to 100 C (there is no
reaction or low conversion at lower temperatures). With these two
substrates, good regioselectivity (a:b = 79:21) and enantioselectiv-
ity (up to 68% ee for 3a) were observed (Table 2). Changing the size
of the ester group in the electron-deficient olefin alters the regio-
and enantioselectivity. With phosphine 3a, the enantioselectivity
increases with the size of the ester increases (entry 3, Et, 52% ee;
(
2016) 131–190.
[
2] Y.-M. Li, F.-Y. Kwong, W.-Y. Yu, A.S.C. Chan, Coord. Chem. Rev. 251 (2007)
2119–2144.
[
[
[
3] Y. Xiao, Z. Sun, H. Guo, O. Kwon, Beilstein J. Org. Chem. 10 (2014) 2089–2121.
4] Z. Wang, X. Xu, O. Kwon, Chem. Soc. Rev. 43 (2014) 2927–2940.
5] F. Robin, F. Mercier, L. Ricard, F. Mathey, M. Spagnol, Chem. Eur. J. 3 (1997)
1365–1369.
[6] Q. Jiang, D. Xiao, Z. Zhang, P. Cao, X. Zhang, Angew. Chem. Int. Ed. 38 (1999)
516–518.
t
entry 4, Bu, 68% ee). A similar trend was observed with phosphine
2
[
7] Y. Hamada, N. Seto, H. Ohmori, K. Hatano, Tetrahedron Lett. 37 (1996)
565–7568.
[8] A. Lee, H. Kim, J. Am. Chem. Soc. 137 (2015) 11250–11253.
9] B. Breit, E. Fuchs, Synthesis 13 (2006) 2121–2128.
10] M. Clochard, E. Mattmann, F. Mercier, L. Ricard, F. Mathey, Org. Lett. 5 (2003)
093–3094.
[11] S.R. Gilbertson, D.G. Genov, A.L. Rheingold, Org. Lett. 2 (2000) 2885–2888.
a (entries 1 and 2).
In particular, the enantioselectivity is considerably higher with
a (68% ee, entry 4) than with known phosphines such as BINAP
7
[
3
[
and BPE (12% and 6% ee [18]), which illustrates the effects of using
a rigid bicyclic [2.2.1] structure rather than the conformationally
more flexible 5-membered rings. Thus, there was also excellent
regioselectivity and enantioselectivity of this reaction for related
rigid monocyclic [27–29] or bicyclic [12,18] monodentate chiral
phosphines.
It was previously shown that the bridging phosphorus atom
P10 of 10-alkyl-7,8,9-triphenyl-1,10-diphosphatricyclo[5.2.1.02,6]-
deca-8-ene-3,5-diones is involved in oxidation and sulfurization
reactions [30]. Since the catalytic [3 + 2] cyclization is initiated by
a nucleophilic attack of the phosphine at ethyl buta-2,3-dienoate
3
[
[
[
[
12] C.E. Henry, Q. Xu, Y.C. Fan, T.J. Martin, L. Belding, T. Dudding, O. Kwon, J. Am.
Chem. Soc. 136 (2014) 11890–11893.
13] Z. Chen, Q. Jiang, G. Zhu, D. Xiao, P. Cao, C. Guo, X. Zhang, J. Org. Chem. 62
(1997) 4521–4523.
14] A. Germoni, B. Deschamps, L. Ricard, F. Mercier, F. Mathey, J. Organomet.
Chem. 690 (2005) 1133–1139.
15] A. Zagidullin, V. Miluykov, F. Poyancev, Sh. Latypov, O. Sinyashin, P. Lönnecke,
E. Hey-Hawkins, Eur. J. Org. Chem. 2015 (2015) 5326–5329.
16] L. Rout, A.M. Harned, Chem. Eur. J. 15 (2009) 12926–12928.
17] S. Breeden, M. Wills, J. Org. Chem. 64 (1999) 9735–9738.
18] G. Zhu, Z. Chen, Q. Jiang, D. Xiao, P. Cao, X. Zhang, J. Am. Chem. Soc. 119 (1997)
3836–3837.
[
[
[
(
9) leading to a resonance-stabilized phosphonium dienolate, only
the bridging phosphorus atom P10 should be involved here as well
Table 2, right).
[19] A. Zagidullin, Y. Ganushevich, V. Miluykov, O. Sinyashin, E. Hey-Hawkins,
Phosphorus Sulfur Silicon 188 (2013) 238–242.
[
20] V. Miluykov, I. Bezkishko, A. Zagidullin, O. Sinyashin, P. Lönnecke, E.
Hey-Hawkins, Eur. J. Org. Chem. 2009 (2009) 1269–1274.
(
[
21] A. Zagidullin, V. Miluykov, D. Krivolapov, S. Kharlamov, Sh. Latypov, O.
Sinyashin, P. Lönnecke, E. Hey-Hawkins, Eur. J. Org. Chem. 2011 (2011)
4
. Conclusions
4910–4918.
[
22] A. Zagidullin, V. Miluykov, E. Oschepkova, A. Tufatullin, O. Kataeva, O.
Sinyashin, Beilstein J. Org. Chem. 11 (2015) 169–173.
The new class of chiral phosphines with P-P bond reported
[
[
[
23] B.M. Trost, M.L. Crawley, Chem. Rev. 103 (2003) 2921–2943.
24] Z. Lu, S. Ma, Angew. Chem. Int. Ed. 47 (2008) 258–297.
25] N. Fleury-Bregeot, L. Jean, P. Retailleau, A. Marinetti, Tetrahedron 63 (2007)
11920–11927.
here with a rigid [2.2.1] phosphabicyclic structure, namely 1,10-
diphosphanorbornenes, can be employed as ligands in Pd-catalyzed
asymmetric allylation (25% ee) and organocatalysts in phosphine-
catalyzed [3 + 2] cyclization between allenes and activated alkenes
[
[
26] M. Schuler, A. Voituriez, A. Marinetti, Tetrahedron Asymmetry 21 (2010)
1569–1573.
(
68% ee). While these preliminary results reveal good yields but
27] R.P. Wurz, G.C. Fu, J. Am. Chem. Soc. 127 (2005) 12234–12235.
only moderate enantioselectivity, the facile synthesis of these new
enantiopure chiral ligands should allow versatile modulation of
electronic and steric effects to achieve higher enantioselectivity in
asymmetric catalysis.
[28] A. Voituriez, A. Panossian, N. Fleury-Brégeot, P. Retailleau, A. Marinetti, J. Am.
Chem. Soc. 130 (2008) 14030–14031.
[
29] D. Duvvuru, N. Pinto, C. Gomez, J.F. Betzer, P. Retailleau, A. Voituriez, A.
Marinetti, Adv. Synth. Catal. 354 (2012) 408–414.
[30] A. Zagidullin, V. Miluykov, O. Sinyashin, P. Lönnecke, E. Hey-Hawkins,
Heteroatom Chem. 25 (2014) 28–34.
Acknowledgments
This work was supported by the Council on Grants of the
Russian Federation President (MK-7748.2015.3). Financial support
Please cite this article in press as: A. Zagidullin, et al., Chiral tricyclic phosphines derived from 1-(+)-neomenthyl-1,2-diphosphole:
Synthesis and applications in asymmetric homogeneous catalysis, Catal. Today (2016), http://dx.doi.org/10.1016/j.cattod.2016.06.015