Chiral α-branched mono phosphine auxiliaries, reversal of sense of asymmetric induction upon substitution

Article abstract of DOI:10.1016/j.tetasy.2005.09.008

A group of 10 (mono- or bis-) α-chiral mono phosphine ligands was synthesized from enantiopure phosphepine sulfide 3 by one or two subsequential highly diastereoselective α-deprotonation/alkylation steps, followed by desulfuration with Raney nickel. Their relative configuration was determined by X-ray crystal structure analysis. The new monophosphine ligands were tested in asymmetric hydrogenation, hydroboration, and Suzuki-Miyaura coupling showing asymmetric inductions up to 91% ee. In the case of hydrogenation, clear evidence was found that enantioselectivity is substantially controlled through α-C chirality rather than through biaryl chirality, which was demonstrated by a change of the sense of asymmetric induction upon change of substituents.

Full text of DOI:10.1016/j.tetasy.2005.09.008

Tetrahedron:
Asymmetry
Tetrahedron: Asymmetry 16 (2005) 3416–3426
Chiral a-branched mono phosphine auxiliaries, reversal of sense
of asymmetric induction upon substitution
a
b
a,
*
´
Peter Kasak, Kurt Mereiter and Michael Widhalm
aInstitute for Organic Chemistry, University of Vienna, Wa¨hringer Strasse 38, A-1090 Vienna, Austria
bInstitute of Chemical Technologies and Analytics, Vienna University of Technology, Getreidemarkt 9/164SC, A-1060 Vienna, Austria
Received 26 August 2005; accepted 8 September 2005
Available online 21 October 2005
Abstract—A groupof 10 (mono- or bis-) a-chiral mono phosphine ligands was synthesized from enantiopure phosphepine sulfide
3 by one or two subsequential highly diastereoselective a-deprotonation/alkylation steps, followed by desulfuration with Raney
nickel. Their relative configuration was determined by X-ray crystal structure analysis. The new monophosphine ligands were
tested in asymmetric hydrogenation, hydroboration, and Suzuki–Miyaura coupling showing asymmetric inductions up to
91% ee. In the case of hydrogenation, clear evidence was found that enantioselectivity is substantially controlled through a-C
chirality rather than through biaryl chirality, which was demonstrated by a change of the sense of asymmetric induction upon
change of substituents.
ꢀ 2005 Elsevier Ltd. All rights reserved.
1. Introduction
2,20-Bridged binaphthyl derivatives with a three atom
bridge constitute a promising chiral motif for auxiliaries
due to their rigidity and extended chiral bias. In parti-
cular, dinaphthoazepine 11 and phosphepine units 22
have been introduced as chiral modifiers in stoichio-
metric and catalytic asymmetric transformations. An
amplification of steric interactions can be expected upon
introduction of substituents into the ÔpseudoÕ benzylic 3-
and 5-positions. Substitution of 1 with Me or Et resulted
indeed in improved enantioselectivity in the allylic alkyl-
ation of selected substrates.3
R1
P
Ph
R
X
R2
R1 =
SiMe3
SiMe3
Me
Me
Et
R2
H
SiMe3
H
Me
H
Et
=
X =
2-Si/H
N
P
1
2
2-Si/Si
2-Me/H
2-Me/Me
2-Et/H
2-Et/Et
2-Pr/H
2-Pr/Pr
2-Bn/H
2-Bn/Bn
Azepine-type auxiliaries 1;
X = N, R = CH2C6H4(o-PPh2),
CH2C6H4(o-C(OH)Ph2),
CH2C6H4(o-CH2OH),
The successful use of monodentate P ligands in several
types of catalytic reactions over the last few years,4
has promoted the development of efficient methods for
their (enantioselective) synthesis. Keeping in mind the
successful application of numerous phospholane-type
ligands5 and recent reports on dinaphthophosphepines6
in asymmetric catalysis, it seemed a promising concept
to combine both structural features and investigate
3,5-disubstituted phosphepines 2 (Scheme 1).
Et
2-Pr
2-Pr
benzyl
benzyl
H
2-Pr
H
Phosphepine-type auxiliaries 2;
X = P, R = Aryl, Alkyl
benzyl
R
PPh2
m
N
n
R
R = H, Me, Et
n,m = 0,1
*
Corresponding author. Tel.: +43 1 4277 52111; fax: +43 1 4277
9521; e-mail: m.widhalm@univie.ac.at
Scheme 1.
0957-4166/$ - see front matter ꢀ 2005 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tetasy.2005.09.008

P. Kasa´k et al. / Tetrahedron: Asymmetry 16 (2005) 3416–3426
3417
2. Results and discussion
various conditions. In the case of R = 2-Pr the reaction
slowed down affording 68% and 15% of 4-Pr/H and 40-
Pr/H, respectively, together with some starting material.
The second substitution stepremained incomplete and
gave a mixture of mono- (28 + 8%) and disubstituted
(47%) products (entry 14). Attempts to introduce larger
substituents such as tert-butyl or 1-adamantyl failed
(entries 15 and 16). For the removal of sulfide, reducing
agents such as LiAlH4, Si2Cl6, P(n-Bu)3, and Raney nickel
have been employed frequently.8 Due to the simplicity of
the procedure, we gave preference to the latter method,
which proceeded smoothly at room temperature. Com-
pounds 2-Me/Me, 2-Et/Et, and 2-Bn/Bn were obtained
after chromatography on alumina under Ar or crystalli-
zation from hexane as moderately air sensitive powders
in 78–88% yield. Compounds 2-Pr/H and 2-Pr/Pr were
isolated as borane complexes. The same treatment of
4-Si/Si resulted in significant decomposition.
2.1. Synthesis
Sulfide 3 was obtained from 2,20-dimethyl-1,10-binaph-
thyl in an one-pot reaction. The a,a0-dilithio compound
prepared by reaction with n-BuLi/TMEDA was cyclized
with Cl2PPh6 followed by treatment with sulfur to give
72% of 3. With one exception, all a-disubstituted phos-
phepines were accessible from sulfide 3 via sequential
deprotonation steps with n- or t-BuLi and subsequent
reaction with TMS-Cl or appropriate alkyl iodides or
benzyl bromide (Scheme 2). An attempted one-pot proce-
dure with the formation of a dianion or using an in situ
protocol7 yielded a mixture of mono- and disubstituted
products (Table 1, entries 2 and 3). A separation of mono
substitution products 4-R/H and 40-R/H was conve-
niently performed by column chromatography on silica
gel with preferential elution of 4-R/H. If steric bulkiness
was moderate, both substitution steps proceeded with
good yield and in a highly diastereoselective fashion to af-
ford the a,a0-disubstituted phosphepines as single diaste-
reomers with a mutual trans arrangement of substituents
(Table 1 entries 4, 6, 9, and 12). We speculated that the ste-
reoselectivity of each stepis mainly controlled by steric
interactions between the attacking Li base and H-3 of
the naphthyl system resulting in exclusive introduction
of substituents at the pseudo-axial positions. A similar
selectivity was observed in the alkylation of analogous
azepine-type ligands.3 A less stringent stereocontrol ex-
erted by the P-phenyl group was also operating as shown
from a ꢀ3:1 to 5:1 preference for the mono-substitution
trans to the P-phenyl group. Table 1 summarizes yields
of mono- and disubstituted phosphepine sulfides under
2.2. Crystal structures of (rac)-5-Me/Me and (rac)-
4-Me/H
These two compounds were selected to determine by X-
ray structure analysis, the relative stereochemistry of the
disubstitution product and the predominating monosub-
stitution product with R = Me. Both structures showed
similar biaryl angles of 71.43(2)ꢁ (4-Me/H) and 71.36(2)ꢁ
(5-Me/Me), respectively. 4-Me/H showed the Me group
was located trans to the P-phenyl ring in a pseudo-axial
position, pointing to the center of the opposite naphthyl
˚
ring (C22–C11 = 3.149 A). Similarly, in 5-Me/Me, a
diaxial configuration of the Me groups was found
˚
˚
(C22–C11 = 3.240 A, C24–C1 = 3.092 A). The proxim-
ity of methyl groups and the aromatic moiety are also
reflected in 1H-shift values for Me groups (0.93 and
0.73/1.11 ppm) (Fig. 1).
Table 1. Synthesis of ligands
Entry Procedurea Electrophile
Yield
2.3. Asymmetric catalysis
4-R/H 40-R/H 5-R/R
Three types of catalytic reactions (Scheme 3) were
performed to investigate the slope and limitations of
new ligands. In all the experiments described below,
ligands with an (S)a-configuration were exclusively
used. Hydrogenations under standard conditions were
conducted with (E)-N-acetylcinnamic acid 6 [with the
addition of (i-Pr)2EtN] or with the corresponding
methyl ester 7 and 1 mol % of cationic Rh(I) complexes
prepared in situ from [Rh(COD)Cl]2/NaClO4 or
Rh(COD)2BF4 and the ligand in MeOH/CH2Cl2 (acid)
or toluene (ester).9 The results are summarized in Table
2. With equimolar mixtures of ligand/Rh, N-acetylphen-
ylalanine 8 was obtained in moderate yield and low
enantiomeric purity. With increasing bulkiness of sub-
stituents, the selectivity for the (R)-products changed to
(S) indicating a mismatching of biaryl and centro-chiral-
ity in the auxiliary. Changing the ligand/Rh ratio to 2:1
not only improved the reactivity but also overbalanced
the asymmetric induction of centro-chirality over axial-
chirality to result in a maximum of 91% ee of (S)-8 with
ligand 2-Me/Me. The effect of a counter ion and pressure
seems negligible (entries 11–13). It is interesting to note
that the presence of larger substituents had a detrimental
effect on both reactivity and enantioselectivity. Similar
1
2
3
4
5
6
7
8
Ab
TMSCl
TMSCl
TMSCl
TMSCl
MeI
MeI
MeI
EtI
EtI
BnBr
BnBr
BnBr
2-PrI
2-PrI
t-BuI
72%
42%
44%
22%
12%
4%
Ac
35%
40%
76%
Ad
B,C
A
B,C
A+B,C
A
B,C
A
B
C
Ag
A+B,C
Ah
Ai
70%
27%
96%e
94%f
62%
30%
20%
9
95%
10
11
12
13
14
16
17
76%
65%
71%
68%
28%
n.r.
15%
8%
n.r.
n.r.
59%
1-adamantyl-Br n.r.
a See Experimental; A: 3!4+40, B: 4!5, C: 40!5.
b With n-BuLi (1.1 equiv) and 5 equiv of electrophile.
c With n-BuLi (2.2 equiv) and 10 equiv of electrophile.
d In situ reaction with Li-TMP and TMSCl (6 equiv, À78 ꢁC!rt).
e With separated isomers, total yield.
f Step2 with mixture of isomers, yield after two steps.
g 15% of 3 recovered.
h 86% of 3 recovered.
i 80% of 3 recovered.

3418
P. Kasa´k et al. / Tetrahedron: Asymmetry 16 (2005) 3416–3426
S
CH3
i
P
CH3
Ph
3
ii
R1
S
S
P
P
Ph
Ph
R2
4-R/H
4'-R/H
ii
ii
iii
R1
S
P
Ph
R1
R2
P
Ph
5-R/R
iii
2-R/H
R1
P
Ph
R2
2-R/R
Scheme 2. Dinaphthoazepine and –phosphepine ligands. Reagents and conditions: (i) (1) n-BuLi, n-hexane 0 ꢁC!rt; (2) Cl2PPh; (3) S8, THF, 50 ꢁC.
(ii) (1) t-BuLi, THF, À78!À40 ꢁC; (2) RX, À78 ꢁC. (iii) Raney-Ni, THF, rt.
trends were found for methyl (E)-N-acetylcinnamate 7
(entries 16–25) with a maximum asymmetric induction
of 73% (entry 25). Competition experiments clearly indi-
cate a higher reactivity of the unsubstituted phosphepine
ligand with a factor ꢀ100, which may be attributed to the
preferred formation of species like Rh(2-H/H)n (n = 1
and 2) due to less steric hindrance and/or higher reactiv-
ity (entries 26 and 27).
affording predominantly the branched product 10
(Table 3). Asymmetric inductions were comparably
low with a maximum of 42% ee. The change of the
product configuration with varying substituents is less
pronounced than in the hydrogenation but may be also
explained by the mismatching of configurations in the
ligands.
Pd-mediated Ar–Ar0 coupling (Suzuki–Miyaura cou-
pling11) of ortho-substituted aromates leads to inher-
ently chiral biaryls providing sufficient steric restriction
Rhodium-catalyzed hydroboration10 of styrene with cat-
echol borane proceeded smoothly with all ligands 2

P. Kasa´k et al. / Tetrahedron: Asymmetry 16 (2005) 3416–3426
3419
Figure 1. Crystal structures of rac-5-Me/Me (left hand side) and rac-4-Me/H (right hand side). In both cases structures with (Sa) configuration are
depicted. H-atoms are omitted for clarity.
Asymmetric Hydrogenation
(S)-2-R1/R2 / Rh
COOR
COOR
H2
NHCOCH3
NHCOCH3
R =
H
R =
H
6
7
8
9
Me
Me
Asymmetric Hydroboration
OH
(S)-2-R1/R2/Rh
OH
H2O2
+
NaOH
O
BH
O
11
10
Asymmetric Suzuki Coupling
(S)-2-R1/R2 /Pd
B(OH)2
OMe
Me
Me
+
base
OMe
I
13
12
Scheme 3. Asymmetric transformations.
that take effect to prevent racemization.12 This is usually
the case when three or four ortho-substituents are pres-
ent. The first attempts to couple 1-iodo-2-methoxynaph-
thalene with 2-methoxynaphthalene-1-boronic acid
failed thus affording only traces of the desired biaryl.13
This lack of reactivity was attributed to steric hindrance
since the less sterically demanding ortho-tolyl boronic
acid exhibited significantly higher reactivities with 12
to give 13 in upto 76% yield (with 2-Me/Me and
5 mol % of CsF in DME at 70 ꢁC). With other catalysts,
isolated yields ranged between 21% and 46%. Generally,
the asymmetric inductions were moderate, not exceeding
18%, and no clear dependence from catalyst structure
could be observed (Table 4).
3. Conclusions
We were able to synthesize a groupof (mono- or bis-)
a-chiral monophosphine ligands by one or two sub-
sequent diastereoselective a-deprotonation steps of a
P-sulfide, followed by desulfuration with Raney nickel.
Their relative configuration was determined by crystal
structure analysis. This simple sequence constitutes a
highly flexible modular approach to monophosphine
ligands, since not only substituents R1, R2 but also
substituents at P other than Ph can be introduced inde-
pendently and with excellent control of stereoselectivity
induced by the binaphthyl backbone. The new ligands
were tested in three Rh- and Pd-catalyzed reactions

3420
P. Kasa´k et al. / Tetrahedron: Asymmetry 16 (2005) 3416–3426
Table 2. Asymmetric hydrogenation
Entry
Substrate
Conditions
2-R1/R2
L/Rh
Conv. (%, NMR)
ee conf.
Pressure (bar)
1
2
3
4
5
6
7
8
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
7
7
7
7
7
7
7
7
7
7
7
7
A
A
A
A
A
A
A
A
A
A
A
B
H/H
Me/H
Bn/H
Et/H
Et/Et
H/H
Me/H
Et/H
Pr/H
Bn/H
Me/Me
Me/Me
Me/Me
Et/Et
Bn/Bn
H/H
Me/H
Et/H
Bn/H
1/1
1/1
1/1
1/1
1/1
2/1
2/1
2/1
2/1
2/1
2/1
2/1
2/1
2/1
2/1
2/1
2/1
2/1
2/1
2/1
2/1
2/1
2/1
2/1
2/1
1/1/1
1/1/1
99
90
60
68
71
99
68
99
98
23
99
99
99
99
80
99
99
99
10
10
99
98
99
99
60
99
99
90 (R)
20 (R)
6 (R)
3
3
3
3
3
3
3
3
3
3
3
3
1.7
3
3
35 (S)
30 (S)
91 (R)
10 (S)
45 (S)
12 (S)
34 (S)
91 (S)
89 (S)
90 (S)
56 (S)
14 (S)
85 (R)
27 (S)
51 (S)
n.d.
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
B
A
A
C
C
C
C
C
C
C
C
C
C
C
C
3
1.7
1.7
3
3
1.7
3
1.7
3
3
3
3
Bn/H
n.d.
Me/Me
Me/Me
Et/Et
55 (S)
55 (S)
50 (S)
60 (S)
73 (S)
83 (R)
83 (R)
Et/Et
Bn/Bn
Me/Me, H/H
Et/Et, H/H
All reactions were conducted at rt on a 1 mmol scale with 1 mol % of Rh; A: [Rh(COD)Cl]2+NaClO4, MeOH/CH2Cl2, B: Rh(COD)2BF4, MeOH/
CH2Cl2, C: Rh(COD)2BF4, toluene; conversions were determined by 1H NMR integration, ees by chiral HPLC on a Chiralcel OJ column after
conversion to the methyl ester.
Table 3. Asymmetric hydroboration
Entry 2-R1/R2 L/Rh Conv.
Table 4. Asymmetric Suzuki couplinga
10
Entry
2-R1/R2
Isol. yield of 13
(sign of specific. rot.b) ee
(%, NMR)
Isol. yield ee, config.
1
2
3
4
5
6
7
8
H/H
Me/H
Et/H
Bn/H
Me/Me
Et/Et
Pr/Pr
Bn/Bn
46
47
32
28
76
21
42
56
(+) 8
(+) 10
(À) 2
1
2
3
4
5
6
7
8
H/H
2/1
1/1
2/1
2/1
2/1
98
74
56
62
80
57
73
52
80
10 (R)
7 (S)
10 (S)
31 (S)
6 (S)
42 (S)
13 (S)
7 (R)
Me/H
Me/H
Et/H
Bn/H
Me/Me 2/1
Et/Et
98
96
98
98
98
98
98
(+) 6
(+) 12
(+) 18
(+) 14
(+) 14
2/1
2/1
a Reactions were conducted on a 0.1 mmol scale with 2 equiv of o-tolyl
boronic acid, 5 mol % of Pd(OAc)2 and 5 mol % of CsF in DME
(70 ꢁC, 16 h). The product was isolated by preparative TLC; ee was
determined by chiral HPLC on a Chiralcel OD-H column; for details
see Section 4.
Bn/Bn
showing different degrees and even alternating the sense
of asymmetric induction (compared to the parent com-
pound 2-H/H), which was attributed to mismatching
stereogenic units being present in the auxiliary.
b At 589 nm.
glet), d (doublet), t (triplet), q (quartet), m (multiplet), p
(pseudo), and b (broad). 13C{1H} NMR spectra are
recorded in a J-modulated mode; signals are assigned
as C, CH2, and CH3; undesignated signals refer to CH
resonances. In spectral areas with extensive signal, over-
lapping multiplets could not be identified; those signals
of unclear relationshipare underlined, ignoring probable
multiplet structures. MS: FINNIGAN MAT 8230 EI
(70 eV). HRMS: FINNIGAN MAT 8230. For HPLC
determination of chiral products a HP 1090 chromato-
graph equipped with a diode array detector was used.
Optical rotations were measured with a Perkin–Elmer
polarimeter 243 equipped with a 1 dm thermostated cell.
4. Experimental
4.1. General
Melting points were measured by Kofler melting point
apparatus and are uncorrected. NMR: Bruker AM 400
spectrometer at 400.13 MHz (1H), 100.61 MHz (13C),
and 161.98 MHz (31P), respectively, in CDCl3 if not
otherwise noted; chemical shifts d are reported in ppm
rel to CHCl3 (7.24 or 77.00 ppm, respectively) or rel to
H3PO4 (85%). Coupling patterns are designated as s (sin-

P. Kasa´k et al. / Tetrahedron: Asymmetry 16 (2005) 3416–3426
3421
Petroleum ether (PE) and ethyl acetate (EA) were dis-
tilled, absolute THF and DME from sodium benzophe-
none ketyl, Et2O and n-hexane from LiAlH4. n-BuLi
and t-BuLi were used as 1.6 molar (in n-hexane) and
1.7 molar (in pentane) solutions, respectively (Aldrich).
Catecholborane was applied as a 1 molar solution in
THF. TMSCl and benzylbromide were distilled. All
other chemicals were of analytical grade and used with-
out further purification.
dry THF (10 mL) was added over 15 min and the reac-
tion allowed to come to rt and stirred for an additional
hour. After quenching with a few drops of water the
mixture was concentrated and the residue was dissolved
in CH2Cl2 (50 mL). The organic phase was washed
sequentially with water and brine and dried over
Na2SO4. Removal of the solvent left the crude mixture
of monomethylated products, which were separated by
column chromatography (SiO2; eluent CH2Cl2/PE;
30:70).
4.2. Synthesis of ligands
4-Me/H: yield: 304 mg (70%). Mp: 268–272 ꢁC. 1H
NMR d: 8.07–7.92 (m, 4H); 7.76–7.64 (m, 3H); 7.54–
7.37 (m, 5H); 7.34–7.15 (m, 5H); 4.01 (dd, J = 13.1,
11.2 Hz, 1H); 3.14 (dd, J = 13.1, 13.0 Hz, 1H); 3.28
(dq, J = 13.2 Hz, 1H); 0.93 (dd J = 17.4, 7.5 Hz, 3H).
13C NMR d: 137.38 (d, J = 6.8 Hz, C); 134.05 (d,
J = 5.1 Hz, C); 133.87 (d, J = 2.3 Hz, C); 133.16 (d,
J = 1.3 Hz, C); 132.96 (C); 132.78 (d, J = 2.1 Hz, C);
132.55 (d, J = 58.0 Hz, C); 131.58 (d, J = 3.0 Hz);
130.93 (d, J = 9.1 Hz); 130.04 (d, J = 6.0 Hz); 129.03
(d, J = 3.7 Hz); 128.81 (d, J = 2.5 Hz); 128.49; 128.45
(d, J = 1.7 Hz); 128.36; 128.20 (d, J = 9.4 Hz, C);
128.18; 128.10; 128.44; 128.27; 128.94 (d, J = 0.9 Hz);
128.65 (d, J = 1.4 Hz); 126.10 (d, J = 1.0 Hz); 125.65
(d, J = 1.8 Hz); 45.84 (d, J = 43.8 Hz); 39.52 (d,
J = 45.4 Hz, CH2); 16.50 (d, J = 2.4 Hz, CH3). 31P
NMR d: 67.09 (s). MS (200 ꢁC) m/z (rel%): 434 (22,
4.2.1. (S)-4-Phenyl-4,5-dihydro-3H-dinaphtho[2,1-c;10,20-
e]phosphepine sulfide 3. Crude (S)-4-phenyl-4,5-dihy-
dro-3H-dinaphtho[2,1-c;10,20-e]phosphepine in hexane
as obtained from PhPCl2 and (S)-2,20-bis(lithio-
methyl)-1,10-binaphthyl–TMEDA complex [prepared
from (S)-2,20-dimethyl-1,10-binaphthyl (33.4 mmol), n-
BuLi (100 mmol), and TMEDA (100 mmol) according
to Ref. 14] was concentrated to half of its volume. To
this was added THF (60 mL) and sulfur powder
(1.98 g, 62 mmol) and the reaction mixture stirred over-
night at 50 ꢁC. After adding water (4 mL), the mixture
was concentrated and the residue dissolved in CH2Cl2
(200 mL). The organic layer was washed with H2O
(2 · 25 mL) and brine and dried over anhydrous
Na2SO4. Removal of the solvent left the crude product,
which was purified by chromatography (SiO2, PE/
CH2Cl2 = 50:50) to afford (S)-3 as a white powder; yield
10.09 g [72% from (S)-2,20-dimethyl-1,10-binaphthyl].
White solid. Mp: 147–150 ꢁC. 1H NMR d: 8.03 (d,
J = 8.3 Hz, 1H); 7.96 (d, J = 8.2 Hz, 1H); 7.95 (d, J =
8.2 Hz, 1H); 7.87 (d, J = 8.4 Hz, 1H); 7.71 (dd,
J = 1.5, 8.4 Hz, 1H); 7.62–7.27 (m, 9H); 7.21 (ddd, J =
1.5, 7.1, 8.4 Hz, 1H); 7.14 (d, J = 8.1 Hz, 1H); 7.10
(dd, J = 1.0, 8.2 Hz, 1H); 3.78 (dd, J = 13.5, 11.5 Hz,
1H); 3.31 (dd, J = 14.4, 18.6 Hz, 1H); 3.26 (dd,
J = 16.8, 10.8 Hz, 1H); 3.16 (dd, J = 13.1, 13.3 Hz,
1H). 13C NMR d: 134.30 (d, J = 3.5 Hz, C); 133.60
(d, J = 4.3 Hz, C); 133.21 (d, J = 3.0 Hz, C); 132.97
(d, J = 3.0 Hz); 132.37 (d, J = 1.7 Hz); 132.11 (d, J =
2.2 Hz); 131.90 (d, J = 3.0 Hz); 131.38 (d, J = 8.9 Hz);
130.98 (d, J = 67.5 Hz); 130.95 (d, J = 10.6 Hz);
129.17; 128.98; 128.96 (d, J = 2.1 Hz); 128.57 (d, J =
2.1 Hz); 128.49 (d, J = 1.3 Hz); 128.45; 128.32; 128.27
(d, J = 1.6 Hz); 128.08 (d, J = 4.3 Hz); 127.14 (d, J =
1.6 Hz); 126.67; 126.58; 126.30 (d, J = 1.3 Hz); 126.00
(d, J = 1.2 Hz); 125.72 (d, J = 1.3 Hz); 42.58 (d, J =
44.7 Hz, CH2); 38.45 (d, J = 49.1 Hz, CH2). 31P NMR
d: 63.43 (s). MS (200 ꢁC) m/z (rel%): 420 (5, M+).
M+). HRMS: calcd for C29H23PS: 434.1258, found:
20
434.1267. ½aŠ ¼ þ37:3 (c 0.49, CHCl3).
D
40-Me/H: yield: 117 mg (27%). Mp: 242–256 ꢁC. 1H
NMR d: 8.01–7.88 (m, 6H); 7.65 (dd, J = 1.0, 8.4 Hz,
1H); 7.56 (d, J = 8.4 Hz, 1H); 7.48–7.38 (m, 5H); 7.26–
7.15 (m, 3H); 7.04 (d, J = 8.5 Hz, 1H); 3.65–3.58 (m,
3H); 0.65 (dd, J = 7.8, 16.5 Hz, 3H). 13C NMR d:
135.68 (d, J = 4.1 Hz, C); 135.05 (d, J = 6.7 Hz, C);
133.35 (d, J = 2.3 Hz, C); 133.28 (d, J = 3.6 Hz, C);
133.17 (d, J = 2.2 Hz, C); 132.78 (d, J = 2.1 Hz, C);
132.71 (d, J = 2.1 Hz, C); 132.25 (d, J = 9.1 Hz);
131.75 (d, J = 3.0 Hz); 131.20 (d, J = 64.3 Hz, C);
130.78 (d, J = 4.8 Hz); 129.43 (d, J = 10.3 Hz, C);
128.85 (d, J = 1.0 Hz); 128.76; 128.29; 128.22 (d,
J = 13.5 Hz); 128.17; 127.85 (d, J = 4.6 Hz); 127.15;
126.80; 126.50; 126.12; 126.06; 125.81; 51.12 (d,
J = 45.8 Hz); 42.12 (d, J = 49.0 Hz, CH2); 17.14 (d,
J = 3.9 Hz, CH3). 31P NMR d: 64.69 (s). MS (200 ꢁC):
m/z (rel%) 434 (100, M+). HRMS: calcd for C29H23PS:
20
434.1258, found: 434.1265. ½aŠ ¼ þ48 (c 0.25, CHCl3).
D
HRMS (EI): m/z calcd for C28H21PS 420.1102, found:
4.2.3. (S,S,Sa)-3,5-Dimethyl-4-phenyl-4,5-dihydro-3H-di-
naphtho[2,1-c;10,20-e]phosphepine sulfide 5-Me/Me. Yield:
20
420.1097. ½aŠ ¼ þ99:6 (c 0.59, CHCl3).
D
1
430 mg (96%). Mp: 241–244 ꢁC. H NMR d: 8.12–7.92
4.2.2.
(S,Sa,Rp)-3-Methyl-4-phenyl-4,5-dihydro-3H-di-
(m, 6H); 7.69 (d, J = 8.7 Hz, 1H); 7.64 (d, J = 8.5 Hz,
1H); 7.54–7.42 (m, 5H); 7.29–7.18 (m, 3H); 7.08 (d,
J = 8.5 Hz, 1H); 3.70–3.55 (m, 2H); 1.11 (dd, J = 17.6,
7.7 Hz, 3H); 0.73 (dd, J = 16.5, 7.7 Hz, 3H). 13C
NMR d: 136.68 (d, J = 6.4 Hz, C); 135.45 (d, J =
3.5 Hz, C); 134.37 (d, J = 6.3 Hz, C); 134.26 (d, J =
1.3 Hz, C); 134.09 (d, J = 4.4 Hz, C); 133.88 (d,
J = 2.1 Hz, C); 133.55 (d, J = 61.0 Hz, C); 133.50
(d, J = 2.1 Hz, C); 133.21 (d, J = 1.1 Hz, C); 132.46
(d, J = 8.7 Hz); 131.91 (d, J = 2.8 Hz); 131.17 (d,
naphtho[2,1-c;10,20-e]phosphepine sulfide 4-Me/H and
(S,Sa,Sp)-3-Methyl-4-phenyl-4,5-dihydro-3H-dinaphtho-
[2,1-c;10,20-e]phosphepine sulfide 40-Me/H. Typical
procedure: To a degassed solution of (S)-3 (420 mg,
1 mmol) in dry THF (20 mL) was added dropwise
t-BuLi solution (0.95 mL, 1.6 mmol) with stirring at
À78 ꢁC. The dark red solution was allowed to warm
to À40 ꢁC over 2 h and then again cooled to À78 ꢁC.
The appropriate electrophile (10 mmol) dissolved in

3422
P. Kasa´k et al. / Tetrahedron: Asymmetry 16 (2005) 3416–3426
J = 5.2 Hz); 129.68 (d, J = 6.8 Hz); 129.39; 128.97 (d,
J = 1.1 Hz); 128.74 (d, J = 1.1 Hz); 128.65; 128.46
(d, J = 1.4 Hz); 127.37; 127.15; 126.80 (d, J = 0.7 Hz);
126.72 (d, J = 0.7 Hz); 126.57; 126.18 (d, J = 1.1 Hz);
51.84 (d, J = 44.1 Hz); 43.75 (d, J = 46.4 Hz); 17.67
(d, J = 1.8 Hz, CH3); 17.48 (d, J = 3.8 Hz, CH3). 31P
NMR d: 69.11 (s). MS (200 ꢁC) m/z (rel%): 448 (100,
(t, J = 7.1 Hz, 3H) 0.35 (t, J = 7.1 Hz, 3H). 13C NMR
d: 134.86 (d, J = 2.6 Hz, C); 134.28 (d, J = 6.6 Hz, C);
133.49 (d, J = 2.3 Hz, C); 133.44 (d, J = 2.3 Hz, C);
133.40 (d, J = 4.4 Hz, C); 133.16 (d, J = 2.1 Hz,
C); 133.13 (d, J = 2.1 Hz, C); 132.81 (d, J = 0.9 Hz,
C); 132.35 (d, J = 88.7 Hz, C); 132.26 (d, J = 8.7
Hz); 132.06; 132.01; 131.49 (d, J = 2.6 Hz); 130.78 (d,
J = 7.0 Hz); 128.54; 128.36; 128.31; 128.15; 128.09 (d,
J = 2.2 Hz); 126.88; 126.54; 126.26; 126.17; 125.77;
59.79 (d, J = 43.6 Hz); 51.25 (d, J = 45.8 Hz); 24.41 (d,
J = 34.3 Hz, CH2); 24.39 (d, J = 32.3 Hz, CH2); 13.40
(d, J = 12.1 Hz, CH3); 13.26 (d, J = 13.4 Hz, CH3). 31P
NMR d: 70.29 (s). MS (180 ꢁC) m/z (rel%): 476 (100,
M+). HRMS: calcd for C30H25PS 448.1415, found:
20
448.1426. ½aŠ ¼ þ122 (c 0.73, CHCl3).
D
4.2.4. (S,Sa,Rp)-3-Ethyl-4-phenyl-4,5-dihydro-3H-dinaph-
tho[2,1-c;10,20-e]phosphepine sulfide 4-Et/H. Yield:
1
278 mg (62%). Mp: 300–306 ꢁC. H NMR d: 8.00–7.87
(m, 4H); 7.68–7.60 (m, 3H); 7.51–7.34 (m, 5H); 7.30–
7.18 (m, 3H); 7.11(d, J = 8.2 Hz, 2H); 3.95 (dd, J =
11.3, 13.3 Hz, 1H); 3.07 (dd, J = 12.9, 13.0 Hz, 1H);
2.98 (m, 1H); 1.81 (m, 1H); 0.49 (m, 1H); 0.46 (t, J =
6.8 Hz, 3H). 13C NMR d: 135.28 (d, J = 6.8 Hz, C);
133.95 (d, J = 7.6 Hz, C); 133.92 (d, J = 2.3 Hz, C);
133.89; (d, J = 5.3 Hz, C); 133.06 (d, J = 2.0 Hz,
C); 132.95 (d, J = 4.4 Hz, C); 132.93 (d, J = 1.7 Hz,
C); 132.75 (d, J = 49.8 Hz, C); 132.51 (C); 131.60
(d, J = 2.8 Hz); 131.28 (d, J = 6.0 Hz); 130.93 (d, J =
9.1 Hz); 128.93 (d, J = 3.8 Hz); 128.73 (d, J = 2.3 Hz);
128.50 (d, J = 1.2 Hz); 128.33; 128.27 (d, J = 1.1
Hz); 128.10 (d, J = 0.9 Hz); 126.94; 126.45 (d, J =
1.0 Hz); 126.43; 126.28; 126.13; 125.64 (d, J = 1.2 Hz);
53.26 (d, J = 46.8 Hz); 39.56 (d, J = 49.2 Hz, CH2);
22.99 (d, J = 2.4 Hz, CH2); 13.58 (d, J = 13.4 Hz,
CH3). 31P NMR d: 67.78 (s). MS (170 ꢁC) m/z (rel%):
M+). HRMS: calcd for C32H29PS 476.1728, found:
20
476.1720. ½aŠ ¼+143 (c 0.69, CHCl3).
D
4.2.7. (S,Sa,Rp)-3-Isopropyl-4-phenyl-4,5-dihydro-3H-di-
naphtho[2,1-c;10,20-e]phosphepine
sulfide
4-iPr/H.
Yield: 314 mg (68%). Mp: 224–226 ꢁC. 1H NMR d:
8.01 (d, J = 8.3 Hz, 1H); 7.95 (d, J = 8.2 Hz, 1H); 7.86
(d, J = 8.3 Hz, 1H); 7.73 (d, J = 8.3 Hz, 1H); 7.66 (d,
J = 11.3 Hz, 1H); 7.64 (d, J = 8.4 Hz, 1H); 7.49–7.38
(m, 5H); 7.27–7.14 (m, 4H); 7.07 (d, J = 8.4 Hz, 1H);
3.91 (dd, J = 12.7, 12.7 Hz, 1H); 3.05 (dd, J = 12.5,
12.6 Hz, 1H); 2.92 (dd, J = 9.9, 12.1 Hz, 1H); 1.28
(m, 1H); 1.12 (d, J = 6.1 Hz, 3H); 0.27 (d, J = 6.6 Hz,
3H). 13C NMR d: 136.53 (d, J = 6.7 Hz, C); 134.63 (d,
J = 68.1 Hz, C); 134.53 (d, J = 2.3 Hz, C); 133.64
(d, J = 5.1 Hz, C); 133.11 (d, J = 2.6 Hz, C); 133.04
(d, J = 1.4 Hz, C); 132.61 (d, J = 1.3 Hz, C);
131.93 (d, J = 2.6 Hz); 131.86; 131.80 (d, J = 0.9 Hz);
131.42 (d, J = 0.7 Hz); 131.40; 130.64 (d, J = 9.1 Hz);
129.03 (d, J = 3.8 Hz); 128.70 (d, J = 1.3 Hz); 128.65
(d, J = 1.1 Hz); 128.38; 128.37 (d, J = 9.5 Hz, C);
128.25 (d, J = 3.8 Hz); 128.02; 127.10; 126.99; 126.39;
126.18; 125.95; 59.27 (d, J = 45.3 Hz); 40.61 (d,
J = 49.6 Hz, CH2); 29.17 (d, J = 1.0 Hz); 26.36 (CH3);
23.15 (d, J = 9.9 Hz, CH3). 31P NMR d: 65.41 (s). MS
448 (27, M+). HRMS: calcd for C30H25PS 448.1415,
20
found: 448.1422. ½aŠ ¼ þ314 (c 0.50, CHCl3).
D
4.2.5. (S,Sa,Sp)-3-Ethyl-4-phenyl-4,5-dihydro-3H-dinaph-
tho[2,1-c;10,20-e]phosphepine sulfide 40-Et/H. Yield:
1
135 mg (30%). White foam. H NMR d: 8.01–7.87 (m,
6H); 7.63 (dd, J = 0.8, 8.4 Hz, 1H); 7.54 (d,
J = 8.4 Hz, 1H); 7.50–7.39 (m, 5H); 7.28–7.15 (m, 3H);
7.02 (d, J = 8.5 Hz, 1H); 3.63–3.56 (m, 2H); 3.42 (m,
1H); 0.94 (m, 1H); 0.78 (m, 1H); 0.38 (dt, J = 1.0,
7.1 Hz, 3H). 13C NMR d: 135.46 (d, J = 4.2 Hz, C);
133.36 (d, J = 2.2 Hz, C); 133.14 (d, J = 5.0 Hz, C);
132.85 (d, J = 3.0 Hz, C); 132.80 (d, J = 0.7 Hz,
C); 132.74 (d, J = 2.2 Hz, C); 132.71 (d, J = 2.0 Hz,
C); 132.55 (d, J = 9.1 Hz); 132.08 (d, J = 4.7 Hz);
131.75 (d, J = 2.9 Hz); 131.02 (d, J = 64.0 Hz, C);
129.52 (d, J = 10.5 Hz, C); 128.78 (d, J = 1.0 Hz);
128.58; 128.28 (d, J = 0.7 Hz); 128.23 (d, J = 1.4 Hz);
128.10; 127.87 (d, J = 2.9 Hz); 127.05; 126.66; 126.43;
126.11; 126.05 (d, J = 1.0 Hz); 125.83 (d, J = 0.7 Hz);
59.12 (d, J = 44.6 Hz); 42.33 (d, J = 41.6 Hz, CH2);
23.55 (d, J = 7.7 Hz, CH2); 13.79 (d, J = 12.0 Hz,
CH3). 31P NMR d: 65.36 (s). MS (180 ꢁC) m/z (rel%):
(150 ꢁC) m/z (rel%): 462 (70, M+). HRMS: calcd
20
for C31H27PS 462.1571, obsd 462.1566. ½aŠ ¼ þ540 (c
D
0.285, CHCl3).
4.2.8. (S,S,Sa)-3,5-Diisopropyl-4-phenyl-4,5-dihydro-3H-
dinaphtho[2,1-c;10,20-e]phosphepine sulfide 5-iPr/iPr.
Yield: 297 mg (59%). Mp: 256–265 ꢁC. 1H NMR d:
8.11 (d, J = 8.4 Hz, 1H); 8.08 (d, J = 7.5 Hz, 1H); 8.01
(d, J = 8.4 Hz, 1H); 7.94–7.90 (m, 3H); 7.60 (dd,
J = 1.0, 8.4 Hz, 1H); 7.51–7.40 (m, 6H); 7.30–7.14 (m,
4H); 3.22–3.14 (m, 2H); 1.41 (m, 1H); 1.11 (m, 1H);
1.04 (d, J = 6.1 Hz, 3H); 0.30 (d, J = 6.4 Hz, 3H); 0.29
(d, J = 6.7 Hz, 3H); À0.03 (d, J = 6.1 Hz, 3H). 13C
NMR d: 135.98 (d, J = 61.0 Hz, C); 135.73 (d, J =
6.6 Hz, C); 135.18 (d, J = 2.5 Hz, C); 133.59 (d, J =
6.4 Hz, C); 133.41 (d, J = 4.6 Hz, C); 133.16 (d,
J = 2.2 Hz, C); 132.96 (d, J = 5.5 Hz); 132.89 (d,
J = 0.7 Hz, C); 132.46 (d, J = 1.3 Hz, C); 132.31
(d, J = 2.5 Hz, C); 132.07 (d, J = 8.7 Hz); 131.57 (d,
J = 2.9 Hz); 131.39 (d, J = 8.0 Hz); 128.70; 128.46;
128.33; 128.16; 128.12; 127.72; 127.06; 126.17; 126.08;
125.68; 125.62; 69.95 (d, J = 41.2 Hz); 58.34 (d,
J = 45.1 Hz); 29.83; 28.51 (d, J = 4.0 Hz); 26.60 (CH3);
23.76 (CH3); 23.70 (d, J = 9.6 Hz, CH3); 22.77 (d,
J = 9.5 Hz, CH3). 31P NMR d: 65.57 (s). MS (180 ꢁC)
448 (100, M+). HRMS: calcd for C30H25PS 448.1415,
20
found: 448.1406. ½aŠ ¼ þ533 (c 0.26, CHCl3).
D
4.2.6. (S,S,Sa)-3,5-Diethyl-4-phenyl-4,5-dihydro-3H-di-
naphtho[2,1-c;10,20-e]phosphepine sulfide 5-Et/Et. Yield:
1
451 mg (95%). White solid. Mp: 229–233 ꢁC. H NMR
d: 8.02–7.90 (m, 6H); 7.58 (d, J = 8.3 Hz, 1H); 7.51 (d,
J = 8.3 Hz, 1H); 7.48–7.38 (m, 5H); 7.27–7.14 (m, 3H);
6.98 (d, J = 8.5 Hz, 1H); 3.40–3.20 (m, 2H); 2.01 (m,
1H); 0.93 (m, 1H); 0.82 (m, 1H); 0.70 (m, 1H); 0.53

P. Kasa´k et al. / Tetrahedron: Asymmetry 16 (2005) 3416–3426
3423
m/z (rel%): 504 (100, M+). HRMS: calcd for C34H33PS
132.18 (d, J = 8.9 Hz); 131.78 (d, J = 2.6 Hz); 131.05
(d, J = 6.9 Hz); 128.98; 128.64; 128.48; 128.46; 128.34;
128.27 (d, J = 0.4 Hz); 128.17; 127.91; 127.90; 127.69;
126.96 (d, J = 0.4 Hz); 126.42; 126.15 (d, J = 0.4 Hz);
126.03 (d, J = 1.1 Hz); 125.87; 59.54 (d, J = 41.5 Hz);
51.68 (d, J = 43.6 Hz); 37.37 (d, J = 11.1 Hz, CH2);
37.28 (d, J = 9.6 Hz, CH2). 31P NMR d: 72.91 (s). MS
(electro spray) m/z (rel%): 623.2 (100, M+Na+). HRMS
20
504.2041, found: 504.2048. ½aŠ ¼ þ1524 (c 0.1, CHCl3).
D
4.2.9.
(S,Sa,Rp)-3-Benzyl-4-phenyl-4,5-dihydro-3H-di-
naphtho[2,1-c;10,20-e]phosphepine sulfide 4-Bn/H. Yield:
1
388 mg (76%). Mp: 236–239 ꢁC. H NMR d: 8.11 (d,
J = 8.3 Hz, 1H); 8.03 (d, J = 8.1 Hz, 1H); 7.95 (d,
J = 8.1 Hz, 1H); 7.82–6.63 (m, 4H); 7.58–7.49 (m, 3H);
7.44–7.20 (m, 6H); 7.01–6.97 (m, 3H); 6.85 (d,
J = 8.4 Hz, 1H); 6.65–6.62 (m, 2H); 4.05 (dd, J = 13.2,
11.2 Hz, 1H); 3.52–3.31 (m, 2H); 3.19 (dd, J = 12.9,
13.0 Hz, 1H); 1.83 (m, 1H). 13C NMR d: 140.25 (d,
J = 14.0 Hz, C); 135.11 (d, J = 6.7 Hz, C); 133.97
(C); 137.42 (d, J = 51.7 Hz, C); 133.16 (d, J = 2.0 Hz,
C); 133.07; (J = 2.0 Hz, C); 132.91 (d, J = 1.8 Hz, C);
133.74 (d, J = 51.7 Hz, C); 133.16 (d, J = 1.7 Hz,
C); 133.07 (d, J = 2.0 Hz, C); 132.91 (d, J = 1.4 Hz,
C); 132.80 (C); 132.37 (d, J = 2.8 Hz, C); 131.73 (d,
J = 2.7 Hz); 131.45 (d, J = 5.7 Hz); 130.95 (d, J =
9.3 Hz); 129.18 (d, J = 3.9 Hz); 129.01 (d, J = 2.3 Hz);
128.71; 128.59 (d, J = 1.1 Hz); 128.35 (C); 128.28;
128.18; 128.09; 127.88; 127.07; 126.40; 126.18; 125.90
(d, J = 1.1 Hz); 125.77; 53.86 (d, J = 45.0 Hz); 39.66
(d, J = 49.0 Hz, CH2); 35.72 (CH2). 31P NMR d: 69.05
(electro spray) [M+Na]+: m/z calcd for C42H33NaPS
20
623.1938, obsd 623.1932. ½aŠ ¼ þ947 (c 0.325, CHCl3).
D
4.2.12. (S,Sa,Sp)-3-Methyl-4-phenyl-4,5-dihydro-3H-di-
naphtho[2,1-c;10,20-e]phosphepine
2-Me/H. Typical
procedure: An excess of a slurry of freshly prepared
Raney nickel in water (ꢀ1.5 g) was placed in a Schlenk
tube and washed repeatedly with degassed THF. A THF
solution of (S,Sa,Rp)-4-Me/H (434 mg, 1 mmol, 2 mL)
was added under Ar and the mixture stirred overnight.
Filtration through Celite and a short pad of alumina
under Ar removed residues of Raney nickel. The fil-
trate was concentrated and the crude product purified
by chromatography on alumina under Ar yielding
340 mg (85%) of (S,Sa,Sp)-2-Me/H. Mp: 102–105 ꢁC.
1H NMR d: 7.90–7.84 (m, 3H); 7.73 (d, J = 8.3 Hz,
1H); 7.62 (dd, J = 8.3, 0.9 Hz, 1H); 7.39–7.36 (m, 2H);
7.26–7.17 (m, 9H); 6.95 (d, J = 8.4 Hz, 1H); 2.97–2.91
(m, 3H); 0.75 (dd, J = 18.8, 7.9 Hz, 3H). 13C NMR d:
139.76 (d, J = 3.7 Hz, C); 139.06 (d, J = 20.8 Hz, C);
134.45 (d, J = 5.2 Hz, C); 133.10 (d, J = 1.3 Hz, C);
133.05 (d, J = 2.6 Hz, C); 132.66; 132.65 (d, J =
2.2 Hz, C); 132.60 (d, J = 1.0 Hz, C); 131.60 (d, J =
18.8 Hz, C); 129.38; 128.87; 128.52 (d, J = 1.2 Hz);
128.26; 128.25; 128.19; 127.99; 127.76; 127.42 (d,
J = 2.3 Hz); 126.67; 126.57; 126.06; 125.75; 125.03;
125.01; 41.48 (d, J = 18.8 Hz); 31.96 (d, J = 16.7 Hz,
CH2); 20.92 (d, J = 30.6 Hz, CH3). 31P NMR d: 18.57
(s). MS (200 ꢁC) m/z (rel%): 510 (75, M+). HRMS: calcd
20
for C35H27PS 510.1571, obsd 510.1579. ½aŠ ¼ þ324 (c
D
0.30, CHCl3).
4.2.10. (S,Sa,Sp)-3-Benzyl-4-phenyl-4,5-dihydro-3H-di-
naphtho[2,1-c;10,20-e]phosphepine sulfide 40-Bn/H. Yield:
1
101 mg (20%). Mp: 257–261 ꢁC. H NMR d: 8.07 (d,
J = 8.4 Hz, 1H); 8.03–7.98 (m, 3H); 7.89 (d, J =
8.1 Hz, 1H); 7.84 (d, J = 8.4 Hz, 1H); 7.64 (d, J =
8.4 Hz, 1H); 7.53–7.39 (m, 5H); 7.36 (dd, J = 0.9,
8.4 Hz, 1H); 7.28 (ddd, J = 1.6, 7.2, 8.4 Hz, 1H); 7.20–
7.14 (m, 2H); 7.07 (d, J = 8.5 Hz, 1H); 6.93–6.89 (m,
3H); 6.41–6.39 (m, 2H); 3.96–3.82 (m, 1H); 3.76 (d,
J = 17.7 Hz, 1H); 3.69 (d, J = 12.8 Hz, 1H); 2.30 (m,
1H); 2.10 (m, 1H). 13C NMR d: 138.82 (d, J =
13.1 Hz, C); 135.56 (d, J = 3.9 Hz, C); 133.32 (CH2);
133.30 (CH2); 132.92 (d, J = 2.3 Hz, C); 132.68 (C);
132.45 (d, J = 9.1 Hz); 132.08 (d, J = 4.8 Hz); 131.96
(d, J = 2.9 Hz); 131.08 (d, J = 64.4 Hz, C); 129.63 (d,
J = 10.6 Hz); 129.10; 129.09; 128.49; 128.37; 128.33;
128.22; 128.02; 127.92; 128.79; 126.66; 126.48; 126.28;
126.05; 125.85; 58.91 (d, J = 42.7 Hz); 42.16 (d,
J = 49.0 Hz, CH2); 37.19 (d, J = 2.1 Hz, CH2). 31P
NMR d: 67.05 (s). MS (230 ꢁC) m/z (rel%): 510 (100,
(s). MS (160 ꢁC): m/z (rel%) 402 (100, M+). HRMS:
20
D
calcd for C29H23P: 402.1537, found: 402.1542. ½aŠ
¼
À90 (c 0.545, CHCl3).
4.2.13. (S,S,Sa)-3,5-Dimethyl-4-phenyl-4,5-dihydro-3H-
dinaphtho[2,1-c;10,20-e]phosphepine
2-Me/Me. Yield:
1
366 mg (88%). Mp: 212–215 ꢁC. H NMR d: 7.92–7.86
(m, 4H); 7.63–7.52 (m, 4H); 7.40–7.30 (m, 5H); 7.16–
7.13 (m, 4H); 3.47 (m, 1H); 3.38 (m, 1H); 0.92 (dd,
J = 7.8, 20.2 Hz, 3H); 0.38 (dd, J = 5.3, 7.4 Hz, 3H).
13C NMR d: 141.23 (d, J = 2.5 Hz, C); 138.54 (d, J =
25.5 Hz, C); 138.53 (d, J = 1.0 Hz, C); 134.65
(d, J = 6.0 Hz, C); 134.26 (C); 133.90 (C); 133.86 (d,
J = 2.7 Hz, C); 132.74 (d, J = 19.4 Hz); 132.65 (C);
132.22 (C); 132.85 (d, J = 3.0 Hz); 128.74; 132.55;
128.42; 128.27 (d, J = 5.2 Hz); 128.17; 128.07; 127.85;
126.56; 126.47; 126.01; 125.95; 125.18; 125.13; 39.30
(d, J = 20.4 Hz); 36.58 (d, J = 19.8 Hz); 22.31 (d, J =
35.8 Hz, CH3); 14.00 (d, J = 3.4 Hz, CH3). 31P NMR
d: 33.09 (s). MS (180 ꢁC) m/z (rel%): 416 (100, M+).
M+). HRMS: calcd for C35H27PS 510.1571, obsd
20
510.1565. ½aŠ ¼ þ397 (c 0.49, CHCl3).
D
4.2.11. (S,S,Sa)-3,5-Dibenzyl-4-phenyl-4,5-dihydro-3H-
dinaphtho[2,1-c;10,20-e]phosphepine sulfide
5-Bn/Bn.
Yield: 426 mg (71%). Mp: 277–278 ꢁC. 1H NMR d:
8.06–7.86 (m, 6H); 7.50–7.38 (m, 6H); 7.27–7.15 (m,
5H); 7.01–6.91 (m, 6H); 6.68–6.66 (m, 2H); 6.44–6.41
(m, 2H); 3.86 (m, 1H); 3.73 (m, 1H); 3.60 (m, 1H);
2.30 (m, 1H); 2.12 (m, 1H); 1.97 (m, 1H). 13C NMR d:
139.95 (d, J = 14.4 Hz, C); 138.35 (d, J = 13.0 Hz, C);
134.53 (d, J = 2.5 Hz); 134.01 (d, J = 6.1 Hz); 133.43
(d, J = 4.4 Hz); 133.32 (d, J = 2.1 Hz); 133.25 (C);
132.98 (d, J = 61.0 Hz, C); 132.95 (d, J = 2.1 Hz,
C); 132.81 (d, J = 1.0 Hz, C); 132.33 (C); 132.28 (C);
HRMS: calcd for C30H25P 416.1694, found: 416.1689.
20
½aŠ ¼ þ95 (c 0.55, CHCl3).
D
4.2.14.
(S,Sa,Sp)-3-Ethyl-4-phenyl-4,5-dihydro-3H-di-
naphtho[2,1-c;10,20-e]phosphepine 2-Et/H. Yield: 345
mg (83%). Mp: 125–127 ꢁC. 1H NMR d: 7.91–7.87
(m, 3H); 7.76 (d, J = 8.3 Hz, 1H); 7.62 (dd, J = 1.0,

3424
P. Kasa´k et al. / Tetrahedron: Asymmetry 16 (2005) 3416–3426
8.4 Hz, 1H); 6.96 (d, J = 8.4 Hz, 1H); 3.03–2.98 (m, 2H);
2.73 (m, 1H); 1.17 (m, 1H); 0.70 (m, 1H); 0.57
(t, J = 7.6 Hz, 3H). 13C NMR d: 139.24 (C); 138.09
(d, J = 3.1 Hz, C); 136.36 (d, J = 14.0 Hz, C); 134.40
(d, J = 4.9 Hz, C); 134.02 (C); 133.52 (C); 132.98
(d, J = 25.3 Hz, C); 132.58 (C); 133.57 (d, J = 2.2 Hz,
C); 132.48; 131.65 (d, J = 18.8 Hz); 130.42; 128.80;
128.47 (d, J = 1.5 Hz); 125.96; 125.75; 125.04; 124.99;
50.48 (d, J = 19.3 Hz); 31.78 (d, J = 16.8 Hz, CH2);
28.01 (d, J = 29.5 Hz, CH2); 14.19 (d, J = 15.1 Hz,
CH3). 31P NMR d: 15.09 (s). MS (180 ꢁC) m/z (rel%):
6H); 7.57 (d, J = 8.3 Hz, 1H); 7.49–7.35 (m, 6H); 7.26–
7.20 (m, 2H); 7.16 (ddd, J = 1.4, 6.8, 8.0 Hz, 1H); 7.09
(d, J = 8.5 Hz, 1H); 4H; 3.11 (dd, J = 6.5, 10.8 Hz,
1H); 2.88 (dd, J = 9.3, 10.4 Hz, 1H); 1.20–1.17
(m, 2H); 0.94 (d, J = 6.2 Hz, 3H); 0.85 (bm, 3H); 0.33
(d, J = 6.6 Hz, 3H); 0.30 (d, J = 6.6 Hz, 3H); À0.02
(d, J = 6.2 Hz, 3H). 13C NMR d: 136.63 (d, J = 8.2
Hz, C); 134.86 (C); 134.82 (d, J = 4.5 Hz, C); 133.90
(d, J = 4.5 Hz, C); 133.40 (d, J = 7.8 Hz); 133.18 (C);
133.02 (d, J = 30.7 Hz, C); 132.78 (d, J = 11.2 Hz, C);
132.37 (C); 132.34 (d, J = 5.9 Hz); 132.21 (C); 131.37
(d, J = 2.3 Hz); 131.16 (d, J = 4.5 Hz); 128.57; 128.48;
128.40; 128.31; 128.20 (d, J = 4.3 Hz); 127.41; 126.85;
126.13; 125.95; 125.72; 125.65; 56.88 (d, J = 28.7 Hz);
53.82 (d, J = 26.7 Hz); 29.71 (d, J = 3.7 Hz); 27.75
(d, J = 6.1 Hz); 24.63 (CH3); 23.66 (CH3); 23.50 (d,
J = 0.4 Hz, CH3); 23.50 (d, J = 4.4 Hz, CH3). 31P
NMR d: 41.11 (bs). MS (150 ꢁC) m/z (rel%): 472 (100,
416 (100, M+). HRMS: calcd for C30H25P 416.1694,
20
found: 416.1699. ½aŠ ¼ þ82 (c 0.21, CHCl3).
D
4.2.15.
(S,S,Sa)-3,5-Diethyl-4-phenyl-4,5-dihydro-3H-
dinaphtho[2,1-c;10,20-e]phosphepine 2-Et/Et. Yield: 346
1
mg (78%). Mp: 174–177 ꢁC. H NMR d: 7.94–7.88 (m,
4H); 7.59–7.56 (m, 4H); 7.38–7.28 (m, 5H); 7.17–7.11
(m, 4H); 3.20 (m, 1H); 3.04 (m, 1H); 1.30–1.26
(m, 2H); 0.91 (m, 1H); 0.82 (m, 1H); 0.62 (m, 1H);
0.60 (t, J = 7.6 Hz, 3H); 0.22 (t, J = 7.6 Hz, 3H). 13C
NMR d: 139.95 (d, J = 2.3 Hz, C); 138.31 (d, J =
25.4 Hz, C); 136.25 (d, J = 0.7 Hz, C); 134.58 (d, J =
6.5 Hz, C); 133.86 (C); 133.63 (C); 133.62 (C); 133.38
(d, J = 20.4 Hz); 132.66 (d, J = 1.6 Hz, C); 132.30 (C);
130.18 (d, J = 3.2 Hz); 129.93; 128.60; 128.41; 128.19
(d, J = 6.8 Hz); 128.09; 127.99; 127.92; 126.70; 126.34;
125.86; 125.78; 125.19; 125.13; 47.55 (d, J = 19.8 Hz);
45.28 (d, J = 19.3 Hz); 29.51 (d, J = 35.2 Hz, CH2);
21.22 (d, J = 3.1 Hz, CH2); 14.12 (d, J = 17.3 Hz,
CH3); 13.68 (d, J = 0.8 Hz, CH3). 31P NMR d: 31.51
M+ÀBH3). HRMS: calcd for C34H33P 472.2320, found:
20
472.2320. ½aŠ ¼ þ184 (c 0.12, CHCl3).
D
4.2.18. (S,Sa,Sp)-3-Benzyl-4-phenyl-4,5-dihydro-3H-di-
naphtho[2,1-c;10,20-e]phosphepine 2-Bn/H. Yield: 377
1
mg (79%). Mp: 100–102 ꢁC. H NMR d: 7.97 (d, J =
8.4 Hz, 1H); 7.93 (d, J = 8.2 Hz, 1H); 7.85 (d, J =
8.2 Hz, 1H); 7.70 (dd, J = 1.0, 8.4 Hz, 1H); 7.65 (d,
J = 8.23 Hz, 1H); 7.44–6.98 (m, 14H); 6.78 (d, J =
8.4 Hz, 1H); 6.68–6.65 (m, 2H); 3.16 (m, 1H); 3.08–
2.95 (m, 2H); 2.48 (m, 1H); 2.05 (m, 1H). 13C NMR
d: 141.02 (d, J = 13.5 Hz, C); 138.91 (d, J = 21.4 Hz,
C); 137.72 (d, J = 3.6 Hz, C); 134.37 (d, J = 5.0 Hz,
C); 133.33 (C); 132.88 (C); 132.77 (C); 132.75 (d,
J = 2.2 Hz, C); 132.59 (C); 132.50 (C); 131.65 (d, J =
18.8 Hz); 130.43; 128.94; 128.8; 128.72 (d, J = 1.1 Hz);
128.40; 128.30; 128.24; 127.97; 127.83; 127.63;
127.50 (d, J = 2.5 Hz); 127.06; 126.63; 126.07; 125.72
(d, J = 5.1 Hz); 125.22; 125.13; 50.46 (d, J = 20.5 Hz);
41.35 (d, J = 31.4 Hz, CH2); 31.99 (d, J = 16.7
Hz, CH2). 31P NMR d: 17.34 (s). MS (160 ꢁC) m/z
(s). MS (160 ꢁC) m/z (rel%): 444 (100, M+). HRMS:
20
D
calcd for C32H29P 444.2007, found: 444.2014. ½aŠ
¼
þ145 (c 0.62, CHCl3).
4.2.16. (S,Sa,Sp)-3-Isopropyl-4-phenyl-4,5-dihydro-3H-
dinaphtho[2,1-c;10,20-e]phosphepine borane complex 2-
iPr/H-BH3. Yield: 309 mg (70%). Mp: 202–205 ꢁC.
1H NMR d: 7.97 (d, J = 8.4 Hz, 1H); 7.93 (d, J =
7.7 Hz, 2H); 7.81 (d, J = 8.4 Hz, 1H); 7.69 (dd,
J = 1.3, 8.4 Hz, 1H); 7.48–7.18 (m, 11H); 6.96 (d, J =
8.2 Hz, 1H); 3.37 (dd, J = 12.6, 16.4 Hz, 1H); 2.98 (dd,
J = 2.3, 12.6 Hz, 1H); 2.69–2.64 (m, 2H); 0.93 (d,
J = 1.6 Hz, 3H); 1.3–0.6 (bm, 3H); 0.33 (d, J = 1.6 Hz,
3H). 13C NMR d: 136.19 (d, J = 8.3 Hz, C); 134.10 (d,
J = 1.7 Hz, C); 133.86 (d, J = 4.4 Hz, C); 133.14
(d, J = 2.3 Hz, C); 132.76 (d, J = 52.4 Hz, C); 131.92
(d, J = 2.2 Hz, C); 131.51 (d, J = 8.1 Hz); 131.25;
131.23; 131.20; 131.16 (C); 129.12 (C); 128.90
(d, J = 3.6 Hz); 128.73 (d, J = 1.4 Hz); 128.61; 128.61;
128.51; 128.07 (d, J = 5.1 Hz); 126.88; 126.83 (d, J =
1.2 Hz); 126.34; 126.01; 125.52 (d, J = 1.4 Hz); 55.26
(d, J = 24.2 Hz); 31.86 (d, J = 35.8 Hz, CH2); 29.20
(d, J = 2.9 Hz); 24.25 (CH3); 23.54 (d, J = 10.6 Hz,
CH3). 31P NMR d: 42.20 (s). MS (130 ꢁC) m/z (rel%):
(rel%): 478 (21, M+). HRMS: calcd for C35H27P
20
478.1850, found: 478.1795. ½aŠ ¼ þ163 (c 0.38, CHCl3).
D
4.2.19. (S,S,Sa)-3,5-Dibenzyl-4-phenyl-4,5-dihydro-3H-
dinaphtho[2,1-c;10,20-e]phosphepine
2-Bn/Bn. Yield:
1
488 mg (86%). Mp: 106–109 ꢁC. H NMR d: 7.89–7.83
(m, 4H); 7.63 (ddd, J = 1.5, 6.7, 8.2 Hz, 2H); 7.48
(dd, J = 1.2, 8.4 Hz, 1H); 7.47–7.31 (m, 6H); 7.23
(d, J = 3.3 Hz, 2H); 7.13 (ddd, J = 1.4, 6.7, 8.1 Hz,
1H); 7.06–7.01 (m, 4H); 6.84–6.81 (m, 3H); 6.74–6.72
(m, 2H); 6.24–6.21 (m, 2H); 3.69 (m, 1H); 3.62 (m,
1H); 2.71 (m, 1H); 2.27 (m, 1H); 1.95 (m, 1H); 1.93
(m, 1H). 13C NMR d: 141.27 (d, J = 2.3 Hz, C);
140.74 (d, J = 13.0 Hz, C); 139.80 (d, J = 2.2 Hz, C);
138.18 (d, J = 26.6 Hz, C); 136.51 (C); 134.64 (d, J =
6.2 Hz, C); 134.19 (C); 133.40 (d, J = 2.3 Hz, C);
133.31 (C); 132.96 (d, J = 20.0 Hz); 132.45 (C); 130.27
(d, J = 3.0 Hz); 130.09; 128.85; 128.83; 128.72; 128.58
(d, J = 6.8 Hz); 128.25; 128.24; 128.20; 127.96; 127.86;
127.61; 127.43; 126.99; 125.94; 125.79; 125.78; 125.49;
125.45; 125.26; 47.11 (d, J = 22.8 Hz); 44.85 (d, J =
21.0 Hz); 42.87 (d, J = 28.5 Hz, CH2); 33.54 (d,
J = 3.0 Hz, CH2). 31P NMR d: 36.21 (s). MS (230 ꢁC)
430 (100, M+ÀBH3). HRMS: calcd for C31H27P
20
430.1850, found: 430.1846. ½aŠ ¼ þ222 (c 0.34, CHCl3).
D
4.2.17.
(S,S,Sa)-3,5-Diisopropyl-4-phenyl-4,5-dihydro-
3H-dinaphtho[2,1-c;10,20-e]phosphepine borane complex
2-iPr/iPr-BH3. Yield: 306 mg (65%) isolated as borane
1
complex. Mp: 186–190 ꢁC. H NMR d: 8.00–7.83 (m,

P. Kasa´k et al. / Tetrahedron: Asymmetry 16 (2005) 3416–3426
3425
m/z (rel%): 568 (100, M+). HRMS: calcd for C42H33P
4.6. Crystal structure analysis
20
568.2320, found: 568.2333. ½aŠ ¼ þ417 (c 0.51, CHCl3).
D
Colorless crystals of racemic samples of 4-Me/H and 5-
Me/Me were obtained by diffusion of EtOAc into
CH2Cl2 solutions. X-ray data were collected at
T = 173(2) K on a Bruker Smart APEX CCD area
detector diffractometer with graphite monochromated
4.3. Asymmetric hydrogenation (general procedure)
Rh(COD)2BF4 (2 mg, 0.5 · 10À5 mol, 1 mol % Rh) and
ligand 2 (1 · 10À5 mol) were stirred in degassed toluene
(1 mL) for 15 min and transferred via teflon canula to a
100 mL high-pressure glass tube under Ar. To this was
added a degassed solution of substrate 7 (0.5 mmol) in
toluene (7 mL) and the tube purged with H2 and finally
desired pressure was adjusted. After stirring for 20 h, the
mixture was evaporated. Conversion was determinated
˚
MoKa radiation, k = 0.71073 A, using 0.3ꢁ x-scan
frames covering either a hemisphere (4-Me/H) or a com-
plete sphere (5-Me/Me) of the reciprocal space. After
data integration with program SAINT, corrections for
absorption and k/2-effects were applied with program
SADABS.16 The structures were solved with direct
methods and then refined on F2 with the program pack-
age SHELX97.17 The non-hydrogen atoms were refined
with anisotropic thermal parameters and hydrogens
were included in idealized positions. Complete structure
data have been deposited.18 Salient crystal data are as
follows:
1
by H NMR and ee by chiral HPLC of the methylester
on a Chiralcel OJ column (250 · 4.6 mm) with i-PrOH/
n-hexane, 6:94 as the eluent at 40 ꢁC with v =
1.0 mL minÀ1; tR = 13.01 min, tS = 19.03 min, starting
material: t3 = 27.02 min.
4.4. Asymmetric hydroboration (general procedure)
4-Me/H: C29H23PS, Mr = 434.50, monoclinic, space
˚
group P21/c (no. 14), T = 173(2) K, a = 13.5899(9) A,
A flame dried Schlenk tube was loaded with ligand 2 (3.8
or 7.6 lmol) and Rh(COD)2BF4 (1.5 mg, 3.8 lmol) and
dry degassed THF (1.5 mL) was added under Ar at rt.
The solution was stirred for 5 min and then cooled to
0 ꢁC followed by the addition of styrene (43 lL,
0.38 mmol). Catecholborane (0.46 mL, 0.46 mmol) was
added and the color of the solution changed from yellow
to orange. Stirring was continued for 12 h at 5 ꢁC. The
reaction mixture was quenched upon addition of EtOH
(2 mL) at 0 ꢁC followed by NaOH solution (2.5 mL,
3 mol) and H2O2 (0.5 mL, 35%) and stirred vigorously
for 0.5 h at rt. The mixture was extracted with diethyl
ether (3 · 10 mL) and the combined organic phases
washed with water and brine and dried over MgSO4.
The crude mixture of products was separated by chro-
matography (SiO2, PE/diethyl ether, 50:50); Ee was
determinated by HPLC with a Chiralcel OD-H col-
umn (250 · 4.6 mm) in i-PrOH/n-hexane (5:95); tR =
23.1 min, tS = 29.5 min.
˚
˚
˚
b = 10.5222(7) A, c = 15.7802(10) A, b = 90.734(1)ꢁ,
3
V = 2256.3(3) A , Z = 4,
q
calc = 1.279 g/cm3, l =
0.229 mmÀ1. Of 16988 reflections collected upto hmax
=
30ꢁ, 6523 were independent, Rint = 0.036, and 5207 were
observed (I > 2r(I)); final R indices: R1 = 0.059 (all
data), wR2 = 0.135 (all data). Selected bond lengths:
P–C24 = 1.8143(15), P–C23 = 1.8286(15), P–C21 =
1.8624(15), P–S = 1.9478(5).
5-Me/Me: C30H25PS, Mr = 448.53, monoclinic, space
˚
group C2/c (no. 15), T = 173(2) K, a = 17.6646(8) A,
˚
˚
˚
b = 10.7614(5) A, c = 25.2144(11) A, b = 102.539(1)ꢁ,
3
V = 4678.8(4) A , Z = 8,
q
calc = 1.273 g/cm3, l =
0.223 mmÀ1. Of 29144 reflections collected upto hmax
=
30ꢁ, 6800 were independent, Rint = 0.019, and 6128
were observed (I > 2r(I)); final R indices: R1 = 0.043
(all data), wR2 = 0.111 (all data). Selected bond lengths
P–C25 = 1.8136(12), P–C23 = 1.8463(10), P–C21 =
1.8631(12), P–S = 1.9618(4).
4.5. Asymmetric Suzuki–Miyaura cross coupling (general
procedure)
Acknowledgements
A flame dried Schlenk tube was charged with Pd(OAc)2
(2.25 mg, 0.1 mmol, 5 mol %) and ligand 2 (0.02 mmol,
10 mol %) and filled with Ar. DME was added
(0.5 mL) and the mixture was stirred for 15 min at rt
and 5 min at 70 ꢁC. To this was added iodide 12
(56.8 mg, 0.2 mmol) and ortho-tolyl boronic acid
(54.4 mg, 2 equiv 0.4 mmol) dissolved in DME (1 mL)
followed by CsF (76 mg, 0.5 mmol, 5 mol %) in water
(0.05 mL). The reaction mixture was stirred at 70 ꢁC
for 16 h, cooled to rt and HCl (0.2 mL) and CH2Cl2
(5 mL) were added. The organic phase was washed
with 1 M NaOH and water and dried with MgSO4.
After concentration, the residue was subjected to pre-
parative TLC (PE/CH2Cl2, 80:20) to give 13.15 Ee
was determinated by chiral HPLC using a Chiralcel
OD-H column (250 · 4.6 mm) in n-hexane/i-PrOH
(99.75:0.25); v = 0.5 mL minÀ1, at 28 ꢁC; t1 = 24.5 min,
t2 = 27.6 min.
P.K. is grateful for a grant provided by the Fonds zur
¨
Fo¨rderung der wissenschaftlichen Forschung in Osterreich
(Lise Meitner Grant Nr M852-N11).
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