Highly efficient and versatile phosphine-phosphoramidite ligands for asymmetric hydrogenation

Article abstract of DOI:10.1002/adsc.200800653

A set of novel phosphine-phosphoramidite ligands possessing two elements of chirality have been prepared through a modular synthetic approach. The ligands (11bS)-N-[2-(diphenylphosphino)phenyl]-N-[(S)-1-phenylethyl]dinaphtho[2,1-d: 1′,2′-f][1,3,2]dioxaphosphepin-4-amine [(S_a,S _c)-1a] and (11bR)-N- [2-(diphenylphosphino)phenyl]-N-[(S)-1-(1- naphthyl)ethyl]dinaphtho[2,1-d:1′,2′-f]-[1,3,2]dioxaphosphepin-4- amine [(S_aS_c-1b] are unique in providing enantioselectivities ≥96% ee and ≥94% ee, respectively, in mechanistically distinct hydrogenations of C=C, C=N and C=O double bonds in combination with three different transition metals (rhodium, iridium, and ruthenium, respectively). Particularly remarkable are the enantiomeric excesses up to 97% achieved in the iridium-catalyzed hydrogenation of 2-substituted quinolines, where (11b5)-N-[2-(diphenylphosphino)phenyl]-N-[(S)-1-(naphthalen-1- yl)ethyl]-8,9,10,11, 12,13,14,15-octahydrodinaphtho[2,1-i/:1′,2′-f] [1,3,2]dioxaphosphepin-4-amine [(S_a,S_c)-2] proved to be the most selective ligand. Substantially lower ees were obtained with the mismatched diastereomer (R_a,S_c)-1b and with the N-phenyl-substituted ligand 1c, missing a second element of chirality.

Full text of DOI:10.1002/adsc.200800653

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DOI: 10.1002/adsc.200800653
Highly Efficient and Versatile Phosphine-Phosphoramidite
Ligands for Asymmetric Hydrogenation
Matthias Eggenstein,a Anika Thomas,a Jens Theuerkauf,a Giancarlo Franciꢀ,a,*
and Walter Leitnera,*
a
Institut fꢁr Technische und Makromolekulare Chemie, RWTH Aachen University, Worringerweg 1, 52074 Aachen,
Germany
Fax : (+49)-241-80-22177; e-mail: francio@itmc.rwth-aachen.de or leitner@itmc.rwth-aachen.de
Received: October 24, 2008; Revised: March 3, 2009; Published online: March 17, 2009
Abstract: A set of novel phosphine-phosphorami-
dite ligands possessing two elements of chirality
have been prepared through a modular synthetic
approach. The ligands (11bS)-N-[2-(diphenylphos-
phino)phenyl]-N-[(S)-1-phenylethyl]dinaphtho[2,1-
tion.[1] Thus, new chiral ligands should ideally be able
to generate highly active and enantioselective cata-
lysts with different metal centres having a broad sub-
strate acceptance (privileged ligands).[2] Moreover,
such ligands should be accessible through a concise
synthesis and easily modified in order to allow fine
tuning of the lead structure.
In 2000, we introduced a family of phosphine-phos-
phoramidite ligands, QUINAPHOS, fulfilling these
requisites.[3] Since then, several phosphine-phosphor-
d:1’,2’-f]
and (11bR)-N-[2-(diphenylphosphino)phenyl]-N-
[(S)-1-(1-naphthyl)ethyl]dinaphtho[2,1-d:1’,2’-f]-
ACHTUNGTRENNUNG[1,3,2]dioxaphosphepin-4-amine [(Sa,Sc)-1b] are
ACHTUNGTRENNUNG[1,3,2]dioxaphosphepin-4-amine [(Sa,Sc)-1a]
unique in providing enantioselectivities ꢀ96% ee
and ꢀ94% ee, respectively, in mechanistically dis-
tinct hydrogenations of C=C, C=N and C=O double
bonds in combination with three different transition
metals (rhodium, iridium, and ruthenium, respec-
tively). Particularly remarkable are the enantiomer-
ic excesses up to 97% achieved in the iridium-cata-
lyzed hydrogenation of 2-substituted quinolines,
where (11bS)-N-[2-(diphenylphosphino)phenyl]-N-
[(S)-1-(naphthalen-1-yl)ethyl]-8,9,10,11, 12,13,14,15-
AHCTUNGTREGaNNNU midites and other electronically dissymmetric P,P li-
gands having a phosphoramidite donor group have
been reported and successfully used in catalysis.[4] Re-
cently, Kostas et al. described the phosphine-phos-
phoramidite ligand Me-AnilaPhos 1d and applied it in
the Rh-catalysed hydrogenation of olefins with good
results.[5] We report here that with the related, readily
accessible ligands (Sa,Sc)-1a, 1b and 2 – bearing an ad-
ditional stereocentre in the amine part – higher enan-
tiomeric excesses are obtained as compared to (Ra)-1c
and 1d. Most notably, the new ligands give high to ex-
cellent asymmetric induction in mechanistically dis-
tinct hydrogenation reactions of C=C, C=N and C=O
double bonds using Rh, Ir, and Ru catalysts, respec-
tively.
octahydrodinaphtho[2,1-d:1’,2’-f]ACHTUNGTREN[NUGN 1,3,2]dioxaphos-
ACHTUNGTRENNUNGphepin-4-amine [(Sa,Sc)-2] proved to be the most se-
lective ligand. Substantially lower ees were obtained
with the mismatched diastereomer (Ra,Sc)-1b and
with the N-phenyl-substituted ligand 1c, missing a
second element of chirality.
The synthetic route to ligands 1a–c and 2 is depict-
ed in Scheme 1. The aminophosphine key intermedi-
ates 4a–c were prepared following the procedure of
Liang et al.[6] In the first step, the Pd-catalysed Buch-
wald–Hartwig amination was applied to obtain the 2-
fluoro-aniline derivatives 3a–c. In the second step,
phosphorylation of 3a–c with potassium diphenyl-
phosphide gave the desired products 4a–c in good
Keywords: asymmetric catalysis; enantioselective
hydrogenation; iridium; phosphine-phosphorami-
dite ligands; rhodium; ruthenium
Asymmetric hydrogenation catalysed by transition yields (52–60%) on a 10 g scale. Deprotonation of the
metal complexes is a powerful tool for the synthesis amino function of 4a–c with n-butyllithium/TMEDA
of a variety of enantiomerically pure or enriched com- and in situ reaction of the resulting lithium amide
pounds and several industrial applications reflect its with phosphorochloridites 5 and 6 derived from (Sa)-
practical utility.[1] Although a plethora of ligands form BINOL or (Ra)-BINOL[7] and (Sa)-H8-BINOL,[8] re-
efficient catalytic systems, most of them operate well spectively, produced the phosphine-phosphoramidites
only with specific metals or for certain functional 1a–c and 2. After filtration over basic alumina or a
groups, limiting the scope of their potential applica- PTFE membrane and recrystallisation from CH2Cl2/
Adv. Synth. Catal. 2009, 351, 725 – 732
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725

Matthias Eggenstein et al.
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The catalytic potential of the new ligands was first
evaluated in the Rh-catalysed hydrogenation of C=C
double bonds using the corresponding [Rh
[L=1a–c or 2; X=BF4 or bis(trifluoromethylsulfon-
AHCTUNGTRENNyGUN l)amide, NTf2; COD=1,5-cyclooctadiene] com-
ACHTUNGTRENN(UNG COD)L]X
plexes. In all reactions full conversion was obtained
within one hour corresponding to TOFsꢀ1000 hÀ1
and high to excellent enantioselectivities were ach-
ieved (Table 1). The hydrogenation of the benchmark
substrate dimethyl itaconate (7) with two diastereo-
mers of 1b clearly shows that the absolute configura-
tion of the product is controlled by the axial chirality
of the binaphthyl backbone (entry 1 vs. entry 2).
Moreover, while (Ra,Sc)-1b resulted in a lower ee of
94% (mismatched diastereomer, entry 1), almost per-
fect enantioselectivity was achieved with (Sa,Sc)-1b
(matched diastereomer, entry 2). Lower enantioinduc-
tion of 96% ee (R) was also obtained with the ligand
(Ra)-1c, missing the additional stereocenter (entry 5).
On the other hand, >99% ee was observed for all li-
gands with the additional stereocenter in S-configura-
tion, irrespective of the substituent (1a/1b) or the
BINOL backbone (1a/2) (entries 2–4).
Next, the scope of the complex [Rh
ACHUTGTNERN(NUG COD)CAHTUNGTREN{NUGN (Sa,Sc)-
1a}]BF4 as hydrogenation catalyst was addressed
pentane or toluene/ethanol, the ligands 1a–c and using methyl a-acetamidoacrylate 8, methyl a-acet-
(Sa,Sc)-2 were obtained in sufficient purity for catalyt- amidocinnamate 9 and N-acetylphenylethylenamide
ic application and in reasonable yields (37–66%).[9] 10 as representative substrates for dehydroamino acid
The overall synthetic procedure is highly modular derivatives and enamides, respectively. All these sub-
since diverse primary amines and phosphines can be strates could be rapidly hydrogenated with excellent
introduced in the first and second step, as well as dif- enantioselectivity of ꢀ99% ee (entries 7–9).
ferent phosphorus moieties in the last step.
Scheme 1. Synthesis of ligands 1a–c and 2.
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Highly Efficient and Versatile Phosphine-Phosphoramidite Ligands
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Table 1. Rh-catalysed asymmetric hydrogenation of 7–10
with preformed complexes [RhACHTNUGRTNEUNG
(COD)L]X.[a]
Scheme 2. Ru-catalysed hydrogenation of b-keto ester 11.
Most recently, the asymmetric synthesis of tetrahydro-
quinolines with a chiral centre in two positions has
been achieved by Ir-catalysed hydrogenation of 2-sub-
stituted quinolines. Benchmark ligands for this trans-
formation are C2-symmetrical bisphosphines like
Entry
Ligand
Substrate
Conv. [%]
ee [%]
1[b]
2[b]
3[c]
4[b]
5[c]
6[c,d]
7[c]
8[c]
9[c]
A
N
R
E
7
7
7
7
7
7
8
9
>99
>99
>99
>99
>99
>99
>99
>99
>99
94 (R)
>99 (S)
>99 (S)
>99 (S)
96 (R)
>99 (S)
99 (R)
MeO-Biphep or H8-BINAPO.[11] Mrsic et al. applied
ˇ ´
the concept of mixing chiral monodentate phosphor-
R
N
R
C
ACHTUNGTRENaNGNU midites with achiral monodentate phosphines to this
reaction obtaining up to 89% ee.[12] Encouraged by
99 (R)
99 (R)
10
this report, we tested the new phosphine-phosphor-
[a]
AHCTUNGTREGUNaNN midite ligands in the same reaction (Table 2).
Reaction conditions: 2 mL CH2Cl2, 1.0 mmol substrate,
Using ligand (Ra)-1c under the conditions optimised
0.1 mol% [Rh
ture.
ACHTUNGTRENNUNG(COD)L]X, 10 bar H2, 1 h, room tempera-
by Wang et al.[11a] 2-methylquinoline 12a was quantita-
tively hydrogenated with a moderate enantioselectivi-
ty of 67% ee in favour of the S-enantiomer (entry 1).
However, a high ee of 96% (R) was obtained with
(Sa,Sc)-1a (entry 2). The difference in performance be-
tween (Sa,Sc)-1a and (Ra)-1c is even more pronounced
[b]
[c]
[d]
X=NTf2.
X=BF4.
5.0 mmol 7, 0.02 mol% catalyst, 15 bar H2, 32 min.
For a quantitative assessment of the catalytic activi- than in the Rh- and Ru-catalysed hydrogenation and
ty of [Rh(COD){(Sa,Sc)-1a}] BF4 the hydrogen con- underlines again the importance of the presence of a
A
ACHTUNGTRENNUNG
sumption was monitored for substrate 7 by following
the pressure drop at a catalyst loading of 0.02 mol%.
An initial TOF of 14,100 hÀ1 could be estimated from
the slope of the pressure curve and constant pressure
was reached within 32 min, corresponding to a TOFav
of 9,400 hÀ1. Offline analysis confirmed complete con-
version and showed that the enantioselectivity re-
mained at a high level even at this low catalyst load-
ing (entry 6).
Table 2. Ir-catalysed hydrogenation of 2-substituted quinoli-
nes.[a]
Next, the new ligands were applied in a typical Ru-
catalysed hydrogenation using the b-keto ester 11 as
benchmark substrate. The corresponding b-hydroxy
ester 12 was obtained quantitatively after 16 h at
608C and 60 bar of H2 in good to high enantiomeric
excesses (Scheme 2). In this reaction the Sa,Sc diaste-
reomers of 1a and 1b led again to the highest ees
(94% and 96%, respectively). Somewhat lower enan-
tioselectivity (86%) was obtained with (Sa,Sc)-2 com-
prising the H8-BINOL backbone. Lower enantioselec-
tivities in favour of the opposite enantiomer were
achieved with (Ra)-1c (83%) and (Ra,Sc)-1b (81%)
under the same conditions. Direct comparison of the
two diastereomers of 1b confirms again the pro-
nounced cooperativity of the two stereoelements.
Substituted 1,2,3,4-tetrahydroquinolines are an im-
portant class of biologically active compounds.[10]
Entry Ligand
Substrate t [h] Conv. [%] ee [%]
1
2
3
(Ra)-1c
(Sa,Sc)-1a
(Sa,Sc)-2
12a
12a
12a
16
16
16
48
48
16
48
48
16
48
16
>99
>99
96
>99
>99
>99
>99
84
67 (S)
96 (R)
96 (R)
97 (R)
81 (S)
94 (R)
92 (R)
97 (R)
90 (S)
89 (S)
95 (S)
ACHTUNGTRENNUNG
ACHTUNGTRENNUNG
4
A
5
ACHTUNGTRENNUNG
6
N
12b
7
ACHTUGNTRNEN(UGN Sa,Sc)-1b 12b
8
A
12b
12c
9
A
>99
>99
78
10
11
ACHTUGNTRNEN(UGN Sa,Sc)-1b 12c
(Sa,Sc)-2
12c
[a]
Reaction conditions: 2 mL toluene, 1.0 mmol substrate, 1
mol% catalyst, 40 bar H2, room temperature, catalyst
formed in situ from [Ir
mol%) and I2 (5 mol%).
ACHTUNGRTEN(NUNG COD)Cl]2 (0.5 mol%), ligand (1.1
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Matthias Eggenstein et al.
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use with N-benzylbenzamide.[14] Phosphorochloridites 5[7]
and 6[8] were prepared according to literature procedures.
second element of chirality in (Sa,Sc)-1a to get high
asymmetric induction. Enantioselectivities in the
same range have been obtained also with (Sa,Sc)-2
and (Sa,Sc)-1b (entries 3 and 4), whereas the Ra,Sc dia-
stereomer of 1b led preferentially to the opposite en-
antiomer with a reduced enantioselectivity of 81%
(entry 5).
Synthesis of N-[(S)-1-Phenylethyl]-2-fluoraniline [(S)-
3a]
To a yellow solution of PdACTHNUTRGNE(UNG OAc)2 (67.3 mg, 0.30 mmol) and
rac-BINAP (268.0 mg, 0.45 mmol) in toluene (30 mL), 1-
bromo-2-fluorobenzene (60 mmol, 6.6 mL) and (S)-1-phe-
nylethylamine (6.92 mL, 60 mmol) were successively added
by syringe. As last component sodium tert-butoxide
(70 mmol, 6.74 g) was added, whereby the solution turned
immediately deep red. The mixture was refluxed for 4 d and
the reaction was monitored by TLC. After complete con-
sumption of 1-bromo-2-fluorobenzene, the reaction mixture
was cooled down to room temperature and extracted with
dichloromethane (3ꢃ15 mL). The combined organic phase
was dried over NaSO4 and the solvent was removed under
reduced pressure. The crude product was purified by
column chromatography (SiO2, pentane/ethyl acetate 10:1
Rf =0.64); yield: 84%, waxy solid. 1H NMR (CDCl3,
300 MHz): d=1.51 (d, J=6.6 Hz, 3H, CH3), 4.26 (br, 1H,
NH), 4.46 (m, 1H, CH), 6.40 (m, 1H, Ar), 6.52 (m, 1H, Ar),
6.78 (m, 1H, Ar), 6.92 (m, 1H, Ar), 7.20 (m, 1H, Ar), 7.31
(m, 4H, Ar); 13C{1H}-NMR (CDCl3, 75 MHz): d=25.1, 53.3,
113.2 (d, J=3.0 Hz), 114.2 (d, J=18.8 Hz), 116.5 (d, J=
7.0 Hz), 124.4 (d, J=3.4 Hz), 125.8, 127.0, 128.7, 135.7 (d,
J=11.4 Hz), 144.8, 151.4 (d, J=237.4 Hz); 19F{1H}-NMR
(CDCl3, 282 MHz): d=À136.5; MS (EI): m/z (%)=215
(M+, 54), 200 (55), 122 (13), 111 (67), 105 (100), 79 (14), 77
(21); HR-MS (ESI): m/z=215.111029, calcd. for C14H14NF:
215.111326; [a]2D0: +7.6 (c 0.55, CH2Cl2).
Ligands (Sa,Sc)-1a, (Sa,Sc)-1b and (Sa,Sc)-2 resulted
in high enantioselectivities also in the hydrogenation
of 2-butylquinoline 12b (94%, 92% and 97% ee, re-
spectively, entries 6-8) as well as of 2-phenylquinoline
12c (90%, 89% and 95% ee, respectively, entries 9–
11). These values represent some of the highest enan-
tioselectivities reported to date for the Ir-catalysed
hydrogenation of quinolines.[11,12,13]
In summary, we have disclosed new phosphine-
phosphoramidite ligands containing two elements of
chirality, which can be prepared via a modular ap-
proach. (Sa,Sc)-1a, (Sa,Sc)-1b and (Sa,Sc)-2 proved to
be very efficient ligands for asymmetric Rh-catalysed
hydrogenation of different classes of functionalised
olefins with ees ꢀ99% and TOFs up to 14,100 hÀ1.
High enantioselectivities have been achieved with
(Sa,Sc)-1a and (Sa,Sc)-1b also in the Ru-catalysed hy-
drogenation of b-keto esters and in the Ir-catalysed
asymmetric hydrogenation of 2-substituted quinolines.
The ligand (Sa,Sc)-2 resulted in enantioselectivities
ꢀ95% both in the hydrogenation of 2-alkyl- and 2-ar-
ylquinolines. Experiments with the opposite diaste-
reomers or ligands lacking the stereogenic centre sub-
stantiated the synergistic cooperativity of both ele-
ments of chirality in the (Sa,Sc) diastereomers. Hence,
these ligands represent privileged structural motifs for
asymmetric hydrogenation leading to high selectivities
and activities in mechanistically distinct hydrogena-
tions utilising different metal centres.
Synthesis of N-[(S)-1-(1-naphthyl)ethyl]-2-fluoraniline
[(S)-3b]
The title compound was obtained by the procedure de-
scribed above using (S)-1-(1-naphthyl)ethylamine (5.16 g,
30 mmol) as the amine and purified via column chromatog-
raphy (SiO2, pentane/ethyl acetate 20:1, Rf =0.54); yield:
1
93%, waxy solid. H NMR (CDCl3, 300 MHz): d=1.70 (d,
J=6.5 Hz, 3H, CH3), 4.42 (br, 1H, NH), 5.29 (m, 1H, CH),
6.29 (m, 1H, Ar), 6.54 (m, 1H, Ar), 6.74 (m, 1H, Ar), 6.98
(m, 1H, Ar), 7.41 (m, 1H, Ar), 7.57 (m, 3H, Ar), 7.76 (m,
1H, Ar), 7.91 (m, 1H, Ar), 8.16 (m, 1H, Ar); 13C{1H}-NMR
(75 MHz, CDCl3): d=23.8, 49.5, 113.2 (d, J=3.4 Hz, Ar),
114.2 (d, J=18.9 Hz, Ar, CH), 116.5 (d, J=6.8 Hz), 122.5 (d,
J=17.5 Hz), 124.5, 124.6, 125.6, 125.9, 126.2, 127.6, 129.2,
130.7, 134.2, 135.6 (d, J=11.5 Hz), 139.5, 151.5 (d, J=
237.5 Hz); 19F{1H}-NMR (CDCl3, 282 MHz): d=À136.6; MS
(EI): m/z (%)=265 (M+, 27), 250 (9), 155 (100), 128 (8),
122 (6), 115 (5), 95 (3), 75 (2); HR-MS (ESI): m/z=
265.126676, calcd. for C18H16NF (M+): 265.126401; [a]D20:
+166.6 (c 0.53, CH2Cl2).
Experimental Section
General Remarks
All reactions were carried out under an inert atmosphere of
dry and oxygen-free argon either with the use of standard
Schlenk techniques or in a glovebox. All solvents were dried
and distilled prior to use. NMR spectra were measured with
a Bruker AV-600 or a Bruker DPX-300 spectrometer.
Chemical shifts are given relative to TMS by using the sol-
1
vent signal as internal reference for H NMR as well as for
13C NMR and H3PO4 (85%) as external reference for
31P NMR spectroscopy. Mass spectra were recorded on a
Finnigan MAT 8200 (MS and HR-MS-EI), Bruker FTICR-
Apex III (HR-MS-ESI) or Finnigan MAT 95 (NBA, Cs+
gun operating at 70 eV). Optical rotations were measured
with a Jasco P-1020 polarimeter. Aniline was distilled under
argon prior to use, 1-bromo-2-fluorobenzene, (S)-1-phenyl-
ethylamine, sodium tert-butoxide, rac-BINAP, palladium
acetate and potassium diphenylphosphide (0.5M in THF)
were used as purchased. n-Butyllithium was titrated prior to
Synthesis of N-Phenyl-2-fluoraniline (3c)
The title compound was obtained by the procedure de-
scribed above using aniline (5.5 mL, 60 mmol) as the amine
and purified via column chromatography (SiO2, pentane/
ethyl acetate 20:1, Rf =0.64); yield: 83% colourless oil.
1H NMR (CDCl3, 300 MHz): d=5.79 (br, 1H, NH), 6.84 (m,
1H, Ar), 6.94–7.15 (m, 5H, Ar), 7.23–7.38 (m, 3H, Ar);
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Highly Efficient and Versatile Phosphine-Phosphoramidite Ligands
COMMUNICATIONS
13C{1H}-NMR (CDCl3, 75 MHz): d=115.6 (J=18.7 Hz),
117.4 (d, J=2.1 Hz), 118.8, 120.7 (d, J=6.9 Hz), 121.9, 124.4
(d, J=3.8 Hz), 129.6, 131.9 (d, J=11.1 Hz), 142.3, 153.2 (d,
J=242.0 Hz); 19F{1H}-NMR (CDCl3, 282 MHz): d=À132.1;
MS (EI): m/z (%)=187 (M+, 100), 167 (10), 159 (3), 77 (4),
51 (5); HR-MS (ESI): m/z=187.079730, calcd. for C12H10NF
(M+): 187.079554.
calcd. for C26H24NPNa (M+H)+: 432.187867; [a]D20: +143.1
(c 0.62, CH2Cl2).
Synthesis of N-Phenyl-2-diphenylphosphinoaniline
(4c)
The title compound was obtained by the procedure de-
scribed above using 3c (9.38 g, 50 mmol) instead of 3a. The
product was purified by recrystallisation from CH2Cl2/pen-
tane at À188C and obtained as a white crystalline solid;
Synthesis of N-[(S)-1-phenylethyl]-2-diphenylphos-
phinoaniline [(S)-4a]
1
yield: 60%. H NMR (CDCl3, 300 MHz): d=6.26 (br, 1H,
NH), 6.83–7.01 (m, 6H, Ar), 7.20–7.42 (m, 13H, Ar);
13C{1H}-NMR (75 MHz, CDCl3): d=116.7, 119.0, 121.1 (d,
J=2.2 Hz), 121.4, 124.5 (J=9.3 Hz), 128.7, 128.8 (d, J=
16.2 Hz), 129.2, 130.0, 133.7 (d, J=19.4 Hz), 134.6 (d, J=
3.9 Hz), 135.4 (d, J=8.7 Hz), 142.7, 146.7 (d, J=18.7 Hz);
31P{1H}-NMR (CDCl3, 125 MHz): d=À19.2; MS (EI): m/z
(%)=353 (41), 352 (M+, 100), 274 (2), 272 (1), 198 (10), 183
(3), 167 (3), 77 (2); HR-MS (ESI): m/z=376.122556, calcd.
for C24H20NPNa (M+Na)+: 376.122800.
Potassium diphenylphosphide (50 mmol, 100 mL, 0.5M in
THF) was transferred into a Schlenk flask by means of a
cannula. The solvent was removed under reduced pressure
and a solution of 3a (10.75 g, 50 mmol) in 1,4-dioxane
(50 mL) was added via syringe. The orange solution was re-
fluxed for 5 d and the reaction was monitored by 31P NMR
spectroscopy. After cooling to room temperature, the sol-
vent was removed under reduced pressure, degassed water
(40 mL) was added to the residue and the aqueous phase
was extracted with dichloromethane (3ꢃ50 mL). The com-
bined organic phase was dried over NaSO4 and the solvent
was removed under reduced pressure. The product was puri-
fied by column chromatography under an inert atmosphere
Synthesis of (11bS)-N-[2-(Diphenylphosphino)-
phenyl]-N-[(S)-1-phenylethyl]dinaphtho[2,1-d:1’,2’-
f]ACHTUGNTRENNNUG
(Al2O3 pH 9.5, pentane:CH2Cl2 =4:1, Rf =0.45); yield: 55%,
1
colourless oil. H NMR (CDCl3, 300 MHz): d=1.26 (d, J=
To a solution of aminophosphine 4a (762 mg, 2.0 mmol) in
THF (10 mL), TMEDA (2.0 mmol, 0.29 mL) was added and
the solution was cooled to À708C in dry ice bath. n-Butyl-
lithium (2.0 mmol, 1.25 mL, 1.6M in hexanes) was added
dropwise causing the solution to turn yellow immediately.
The mixture was stirred for 2 h and a solution of phosphoro-
chloridite (S)-5 (700 mg, 2.0 mmol) in THF (5 mL) was
added. The reaction mixture was allowed to warm to room
temperature and stirred overnight. The solvent was removed
under reduced pressure. The residue was taken up in tolu-
ene and filtered over basic alumina. Toluene was removed
under reduced pressure and the crude product was purified
by recrystallisation from CH2Cl2/pentane at À188C; yield:
49%; white, crystalline solid. 1H NMR (600 MHz, CDCl3):
d=1.77 (br, 3H, CH3), 4.67 (br, 1H, CH), 6.6 (br, 1H, Ar),
6.75–7.64 (m, 26H, Ar), 7.87 (d, J=8.2 Hz, 2H, Ar), 7.91 (d,
J=8.2 Hz, 2H, Ar); 13C{1H}-NMR (150 MHz, CDCl3): d=
22.8, 62.4, 122.3, 123.2, 124.1, 124.6 (d, J=52.7 Hz), 125.9,
126.0, 127.0, 127.3, 127.5, 128.1, 128.2, 128.3 (d, J=5.1 Hz),
128.45, 128.49, 129.0, 129.1, 129.5, 130.2, 131.1 (d, J=
121.1 Hz), 132.9, 133.5 (d, J=19.5 Hz), 133.6 (d, J=
19.5 Hz), 136.3, 138.1 (d, J=13.6 Hz), 139.3 (d, J=14.6 Hz),
142.5, 149.6, 150.1; 31P{1H}-NMR (250 MHz, CDCl3): d=
À17.1 (br), 140.1 (br); MS (EI): m/z (%)=695 (M+, 13), 590
(19), 381 (28), 380 (100), 302 (13); HR-MS (ESI): m/z=
696.221585, calcd. for C46H36NO2P2 (M+H)+: 696.221104;
[a]2D0: +127.0 (c 0.66, CH2Cl2).
6.4 Hz, 3H), 4.38 (m, 1H, CH), 4.91 (m, 1H, NH), 6.29 (dd,
J=5.1 Hz, 8.4 Hz, 1H, Ar), 6.48 (t, J=7.5 Hz, 1H, Ar), 6.75
(td, J=7.5 Hz, 1.8 Hz, 1H, Ar), 6.95–7.20 (m, 7H, Ar), 7.29
(m, 9H, Ar); 13C{1H}-NMR (75 MHz, CDCl3): d=25.3, 53.6,
111.4 (d, J=2.0 Hz), 117.1 (d, J=2.0 Hz), 118.6 (d, J=
2.0 Hz), 125.8, 126.7, 128.52, 128.58, 128.68, 128.82, 128.85,
130.5, 133.6 (d, J=4.2 Hz), 133.8 (d, J=4.2 Hz), 134.6 (J=
6.9 Hz), 135.4 (d, J=7.9 Hz), 135.5 (d, J=7.9 Hz), 145.2,
149.7 (d, J=16.1 Hz); 31P{1H}-NMR (CDCl3, 125 MHz): d=
À19.9; MS (EI): m/z (%)=381 (M+, 100), 367 (16), 366
(60), 304 (11), 303 (13), 288 (26), 277 (19), 276 (18), 261
(31), 198 (33), 194 (25), 183 (48), 181 (25), 167 (11), 105
(20), 77 (13); HR-MS (ESI): m/z=404.153860, calcd. for
C26H24NPNa (M+Na)+: 404.154180; [a]2D0: +122.7 (c 0.61,
CH2Cl2).
Synthesis of N-[(S)-1-(1-Naphthyl)ethyl]-2-diphenyl-
phosphinoaniline [(S)-4b]
Title compound was obtained by the procedure described
above using 3b (7.50 g, 30 mmol) instead of 3a. The product
was purified by recrystallisation from CH2Cl2/pentane at
À188C and obtained as colourless crystals; yield: 52%.
1H NMR (CDCl3, 300 MHz): d=1.44 (d, J=6.6 Hz, 3H),
5.09 (m, 1H, NH), 5.21 (m, 1H, CH), 6.19 (m, 1H, Ar), 6.51
(m, 1H, Ar), 6.82 (m, 1H, Ar), 6.93 (m, 1H, Ar), 7.23–7.61
(m, 14H, Ar), 7.65 (m, 1H, Ar), 7.84 (m, 1H, Ar), 8.07 (m,
1H, Ar); 13C{1H}-NMR (75 MHz, CDCl3) d=23.9, 49.7 ,
111.5, 117.2, 118.6 (d, J=7.6 Hz), 122.4 (d, J=8.5 Hz), 125.4,
126.0 (d, J=8.5 Hz), 127.4, 128.3, 128.7 (d, J=7.6 Hz), 128.9
(d, J=5.7 Hz), 129.2, 130.7 (d, J=5.7 Hz), 133.7, 133.9,
134.1, 134.7 (d, J=7.6 Hz), 135.4, 135.5, 135.6, 140.0, 149.5,
149.7; 31P{1H}-NMR (CDCl3, 125 MHz): d=À18.8; MS (EI):
m/z (%)=431 (M+, 100), 416 (44), 338 (10), 304 (12), 303
(45), 288 (32), 276 (17), 261 (12), 198 (30), 183 (18), 155
(27), 153 (11), 77 (4); HR-MS (ESI): m/z=432.187562,
Synthesis of (11bS)-N-[2-(Diphenylphosphino)-
phenyl]-N-[(S)-1-(1-naphthyl)ethyl]dinaphtho[2,1-
d:1’,2’-f]ACTHNUTRGNE[UNG 1,3,2]dioxaphosphepin-4-amine [(Sa,Sc)-1b]
The title compound was obtained by the procedure de-
scribed above using toluene as the solvent, (S)-4b (214.8 mg,
0.5 mmol) and (S)-5 (192.9 mg, 0.55 mmol). After 16 h, the
reaction mixture was filtered through a PTFE membrane
and the solvent removed under reduced pressure. The resi-
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Matthias Eggenstein et al.
COMMUNICATIONS
due was recrystallised from toluene/ethanol affording the
product with a purity of 88% based on 31P NMR; yield:
236 mg (66%). Analytically pure product was obtained after
a second recrystallisation; yield: 19 mg (5%). 1H NMR
(600 MHz, CD2Cl2): d=2.04 (br, 3H, CH3), 5.48 (br, 1H,
CH), 6.38 (br, 2H, Ar), 6.69 (br, 1H, Ar), 6.92 (br, 1H, Ar)
7.81–6.69 (m, 28H, Ar), 8.26 (br, 1H, Ar); 13C NMR
(150 MHz, CD2Cl2): d=23.5 (d, J=26.9 Hz, CH3), 60.2
(CH), 122.4 (Ar, CH), 123.2 (Ar, CH), 125.3 (Ar, CH),
125.9 (Ar, CH), 126.3 (Ar, CH), 126.5 (Ar, CH), 126.8 (Ar,
CH), 127.2 (Ar, CH), 127.4 (Ar, CH), 128.3 (Ar, CH), 128.4
(Ar, CH), 128.6 (Ar, CH), 128.8 (Ar, CH), 129.0 (Ar, CH),
129.2 (Ar, CH), 129.3 (Ar, CH), 129.9 (Ar, CH), 130.7 (Ar,
CH), 130.9 (Ar, Cq), 131.1 (Ar, CH), 131.9 (Ar, Cq), 133.1
(d, J=12.6 Hz, Ar, Cq), 133.6 (d, J=19.6 Hz, Ar, CH), 134.3
(Ar, Cq), 134.5 (d, J=19.6 Hz, Ar, CH), 136.7 (Ar, CH),
138.6 (Ar, Cq), 138.8 (d, J=12.6 Hz, Ar, Cq), 139.3 (Ar, Cq),
140.5 (Ar, Cq) 150.0 (Ar, Cq), 150.3 (Ar, Cq); 31P{1H}-NMR
(121 MHz, CDCl3): d=À17.2 (br), 138.4 (br); MS (EI): m/z
(%)=745 (M+, 1), 448 (11), 447 (34), 433 (26), 432 (100),
431 (50), 430 (12), 416 (23), 287 (19), 286 (100), 268 (13),
257 (13), 239 (16), 155 (12); HR-MS (ESI): m/z=745.23021,
calcd. for C50H37NO2P2: 745.22941; [a]2D0: +166.3 (c 0.51,
CH2Cl2).
HR-MS (ESI): m/z=745.22966, calcd. for C50H37NO2P2:
745.22941; [a]2D0: À83.3 (c 0.47, CH2Cl2).
Synthesis of (11bS)-N-[2-(Diphenylphosphino)phen-
yl]-N-[(S)-1-(naphthalen-1-yl)ethyl]-8,9,10,11,
12,13,14,15-octahydrodinaphtho[2,1-d:1’,2’-f]
AHCTUNGRTEN[GNUN 1,3,2]dioxaphosphepin-4-amine [(Sa,Sc)-2]
The title compound was obtained by the procedure de-
scribed above using toluene as the solvent, (S)-4a and a
slight excess (1.1 equiv.) of n-butyllithium, TMEDA and
(S)-6. The pure product was obtained after one recrystallisa-
tion from toluene/ethanol; yield: 37% Two sets of signals in
a ratio of 1.26:1 were observed in 31P NMR due to two ro-
tamers (referred to below as major and minor). For the
same reason broad signals were observed partly in the
1H NMR spectrum. 1H NMR (400 MHz, CDCl3): d=1.22–
1.76 (m, 11H, CH3/CH2), 2.03 (m, 2H, CH2), 2.43 (m, 2H,
CH2), 2.68 (m, 4H, CH2), 4.46 (br, 1H, CH), 6.09 (br, 1H,
Ar), 6.47 (br, 1H, Ar), 6.72 (br, 1H, Ar), 6.79–7.23 (m,
16H, Ar); 13C NMR (100 MHz, CD2Cl2): d=23.0, 27.8, 28.1,
29.4, 29.5, 60.2, 118.9, 119.6, 126.7, 127.5, 128.1, 128.4,
128.48, 128.51, 128.57, 128.6, 128.8, 128.9, 129.0, 129.2, 129.4,
129.5, 133.4, 133.9, 138.1, 138.6, 138.7, 139.5, 139.6, 149.0;
31P{1H}-NMR (125 MHz, CDCl3): d=À17.1, 136.2 (major);
À17.1, 135.9 (minor); MS (EI): m/z (%)=703.1 (M, 1), 382
(12), 381 (15), 380 (11), 337 (27), 183 (22), 92 (65), 91 (100);
HR-MS (ESI): m/z=703.27555, calcd. for C44H39O2NP2:
703.27636; [a]2D0: +30.3 (c 0.48, CH2Cl2).
Synthesis of (11bR)-N-[2-(Diphenylphosphino)-
phenyl]-N-[(S)-1-(1-naphthyl)ethyl]dinaphtho[2,1-
d:1’,2’-f]ACHTUNGTRENNUNG[1,3,2]dioxaphosphepin-4-amine [(Ra,Sc)-1b]
The title compound was obtained by the procedure de-
scribed above using (R)-5 instead of (S)-5; yield: 44%,
purity: 94% based on 31P NMR. An analytical pure sample
was obtained after a second recrystallisation; yield: 7%.
Two sets of signals in a ratio of 1.3:1 were observed in the
1H, 13C NMR and 31P NMR spectra due to two rotamers (re-
ferred to below as major and minor). Major: 1H NMR
(600 MHz, CD2Cl2): d=1.77 (br, 3H, CH3), 5.62 (br, 1H,
CH), 6.92 (br, 2H, Ar, major), 7.05–8.08 (m, 31H, Ar);
31P{1H}-NMR (250 MHz, CDCl3): d=À19.4 (d, J=32.1 Hz),
Synthesis of (11bR)-N-[2-(Diphenylphosphino)phen-
yl]-N-phenyldinaphtho[2,1-d:1’,2’-f][1,3,2]dioxaphos-
phepin-4-amine [(Ra)-1c]
The title compound was obtained by the procedure de-
scribed above using THF as the solvent, N-phenyl-2-diphe-
nylphosphinoaniline 4c (706 mg, 2.0 mmol) and (R)-5
(700 mg, 2.0 mmol). The crude product was purified by re-
crystallisation from toluene/ethanol; yield: 59%; white crys-
1
1
talline solid. H NMR (600 MHz, CDCl3): d=6.85 (m, 1H,
140.3 (d, J=32.1 Hz). Minor: H NMR (600 MHz, CD2Cl2):
Ar), 6.88–7.01 (m, 6H, Ar), 7.08 (m, 1H, Ar), 7.13–7.44 (m,
19H, Ar), 7.67 (d, J=8.7 Hz, 1H, Ar), 7.84 (d, J=8.7 Hz,
1H, Ar), 7.85 (d, J=8.2 Hz, 1H, Ar), 7.89 (d, J=8.7 Hz,
1H, Ar); 13C{1H}-NMR (150 MHz, CDCl3): d=121.8, 122.0,
122.2, 122.6, 124.3 (d, J=4.5 Hz), 124.8 (d, J=56.9 Hz),
125.9 (d, J=33.7 Hz), 127.1 (d, J=34.3 Hz), 127.3, 128.3 (d,
J=14.2 Hz), 128.4, 128.55 (d, J=16.8 Hz), 128.58, 128.7,
129.6, 130.23, 130.25, 131.2 (d, J=116.6 Hz), 132.8 (d, J=
34.4 Hz), 133.8 (d, J=18.8 Hz), 134.1 (d, J=19.9 Hz), 135.9,
138.0 (dd, J=159.1 Hz, 11.1 Hz), 138.2 (d, J=12.5 Hz),
145.6 (d, J=11.0 Hz), 147.4 (dd, J=27.0 Hz, 6.2 Hz), 148.8,
149.9; 31P{1H}-NMR (250 MHz, CDCl3): d=À15.5 (d, J=
34.7 Hz), 141.4 (d, J=34.7 Hz); MS (EI): m/z (%)=667
(M+, 93), 590 (100), 527 (17), 352 (26), 315 (12), 299 (12),
275 (11), 274 (14), 268 (25), 252 (12), 198 (12), 183 (10);
HR-MS (ESI): m/z=668.190283 (C44H32NO2P2), calcd. for
(M+H)+: 668.189413; [a]D20: À78.1(c 0.56, CH2Cl2).
d=1.70 (br, 3H, CH3), 5.96 (br, 1H, CH), 6.24 (br, 1H, Ar),
6.74 (br, 1H, Ar), 6.98 (br, 2H, Ar), 7.05–7.94 (m, 28H,
Ar), 8.21 (br, 1H, Ar); 31P{1H}-NMR (250 MHz, CDCl3):
d=À17.1 (d, J=16.4 Hz), 141.8 (d, J=16.4 Hz); 13C NMR
(150 MHz, CD2Cl2): d=22.9 (CH3, minor), 23.9 (CH3,
major) 53.3 (CH, minor), 56.7 (CH, major), 121.6 (Ar, Cq),
122.3 (Ar, CH), 122.5 (Ar, CH), 122.8 (Ar, CH), 123.1 (Ar,
CH), 123.7 (Ar, CH), 124.2 (Ar, Cq), 124.8 (Ar, CH), 125.0
(Ar, CH), 125.2 (Ar, CH), 125.3 (Ar, CH), 125.4 (Ar, CH),
125.6 (Ar, CH), 126.0 (Ar, CH), 126.3 (Ar, CH), 126.4 (Ar,
CH), 126.7 (Ar, CH), 127.2 (Ar, CH), 127.4 (Ar, CH), 127.7
(Ar, CH), 127.9 (Ar, CH), 128.5 (Ar, CH), 128.7 (Ar, CH),
128.9 (Ar, CH) 129.1 (Ar, CH), 129.8 (Ar, CH), 129.9 (Ar,
CH), 130.4 (Ar, CH), 130.8 (Ar, Cq), 131.0 (Ar, CH), 131.2
(Ar, Cq), 131.5 (Ar, Cq), 131.8 (Ar, Cq), 132.1 (Ar, Cq), 133.1
(Ar, Cq), 133.4 (Ar, CH), 133.9 (d, J=20 Hz, Ar, CH), 134.2
(d, J=20 Hz, Ar, CH), 134.6 (d, J=20 Hz, Ar, CH), 135.2
(Ar, CH), 137.1 (Ar, CH), 138.3 (Ar, Cq), 139.1 (Ar, Cq),
139.6 (Ar, Cq), 140.1 (Ar, Cq), 149.6 (Ar, Cq), 150.3 (Ar, Cq),
151.2 (Ar, Cq); MS (EI): m/z (%)=745 (M+, 3), 448 (33),
447 (100), 433 (12), 431 (81), 430 (27), 417 (11), 416 (33),
287 (18), 286 (100), 268 (21), 257 (12), 239 (12), 155 (10);
Synthesis of [RhACHTUNRTGENNG(U COD)AHCUTNGTRNE{NUNG (Sa,Sc)-1a}] BF4
To a solution of [Rh
ACHUTNGTRENNUG(COD)ACHTUNGTRNE(NUGN acac)] (0.1 mmol, 31.2 mg) in
THF (2 mL), HBF4·Et2O (0.1 mmol, 13.6 mL) was added at
730
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Highly Efficient and Versatile Phosphine-Phosphoramidite Ligands
COMMUNICATIONS
room temperature. After 15 min, a solution of (Sa,Sc)-1a
(69.5 mg, 0.1 mmol) in THF (3 mL) was added dropwise.
After 1 h the solution was concentrated under reduced pres-
sure to 2 mL and the complex was precipitated by addition
of diethyl ether (10 mL). The product was collected by fil-
tration and washed with diethyl ether (3ꢃ5 mL); Yellow
powder; yield: 90%. 1H NMR (300 MHz, CDCl3): d=0.89
(d, J=7.2 Hz, 3H, CH3), 1.84–2.68 (m, 8H, COD), 4.40 (m,
1H, COD), 4.64 (m, 1H, COD), 4.95 (m, 1H, CH), 5.26 (m,
1H, COD), 5.69 (m, 1H, COD), 6.39–8.17 (m, 31H, Ar);
31P{1H}-NMR (125 MHz, CDCl3): d=16.8 (dd, J=61.0 Hz,
142.3 Hz), 140.5 (dd, J=61.0 Hz, 243.9 Hz); HR-MS (ESI
pos): m/z=906.213158, calcd. for C54H47NO2P2Rh ([Rh-
Synthesis of [RhACHTNUGTRNEUNG(COD){(Ra)-1c}] BF4
Title compound was obtained by the procedure described
for [Rh(COD){(Sa,Sc)-1a}] BF4 using (Ra)-1c as the ligand;
A
ACHTUNGTRENNUNG
yellow powder; yield: 88%. 1H NMR (300 MHz, CDCl3):
d=1.67 (m, 1H, COD), 2.02 (m, 3H, COD), 2.60 (m, 3H,
COD), 2.89 (m, 1H, COD), 4.13 (m, 1H, COD), 4.23 (m,
1H, COD), 5.77 (m, 1H, COD), 5.92 (m, 1H, COD), 6.32–
8.46 (m, 31H, Ar); 31P{1H}-NMR (125 MHz, CDCl3): d=
23.3 (dd, J=58.1 Hz, 142.7 Hz), 128.5 (dd, J=58.1 Hz,
255.8 Hz); HR-MS (ESI pos): m/z=878.182042, calcd. for
C52H43NO2P2Rh ([RhACTHNUTRGNEUNG
(COD){(Ra)-1c)}]+): 878.181858.
ACHTUNGTRENNUNG(COD){ACHTUNGTRENNUNG
(Sa,Sc)-1a}]+): 906.214637.
Typical Procedure for the Hydrogenation of Olefins
The substrate (1.0 mmol) was placed under argon in a stain-
less steel autoclave (10 mL) equipped with a glass inlet. A
Synthesis of [RhACHTUNGTRENNUNG(COD)CAHUTNGTRNE{NGUN (Sa,Sc)-1b}] NTf2
stock solution of [RhACHTUNGTRENUNG(COD)(1a)]BF4 in CH2Cl2 (2 mL,
A mixture of [RhACHTUNGTRENNUNG(COD)ACHUTNGTREN(NGUN acac)] ( 31.2 mg, 0.1 mmol) and
0.5 mM) was transferred into the autoclave via syringe.
After stirring for 20 min, the autoclave was pressurised with
hydrogen (10 bar). After 1 h, the hydrogen pressure was
carefully released. The reaction mixture was filtered over a
pad of silica and analysed by chiral GC and NMR.
bis(trifluoromethyl)sulfonamide (28.6 mg, 0.1 mmol) in etha-
nol (5 mL) was stirred until a clear yellow solution was ob-
tained (ca. 10 min). A solution of (Sa,Sc)-1b (74.6 mg,
0.1 mmol) in THF (2 mL) was then added. The resulting
orange reaction mixture was stirred for 30 min and then the
solvent removed under reduced pressure. The residue was
recrystallised from CH2Cl2 (1 mL) and pentane (10 mL).
The product was collected by filtration and washed with
pentane; orange powder; yield: 88%. 1H NMR (300 MHz,
CD2Cl2): d=1.07 (br, 3H, CH3), 1.70–2.40 (m, 8H, COD),
3.83 (m, 1H, COD), 4.34 (m, 1H, COD), 4.57 (m, 1H, CH),
5.49 (m, 1H, COD), 5.57 (m, 1H, COD), 6.99–8.02 (m,
35H, Ar); 31P{1H}-NMR (125 MHz, CDCl3): d=13.4 (dd,
J=67.5 Hz, 135.1 Hz), 149.6 (dd, J=67.5 Hz, 237.7 Hz); MS:
Typical Procedure for the Hydrogenation of
Quinolines
To a solution of [Ir
ACHTUNGTRENNUNG
ene (1.5 mL) was added
a
(0.011 mmol) in the same solvent (1.5 mL). After 30 min,
the mixture was transferred under argon into a Schlenk tube
containing the substrate (1.0 mmol) and iodine (12.6 mg,
0.05 mmol). The resulting solution was stirred for 30 min
and transferred into a stainless steel autoclave (10 mL)
equipped with a glass inlet. The autoclave was pressurised
with hydrogen and stirred for 16 h. After releasing the hy-
drogen pressure, the reaction mixture was diluted with
CH2Cl2 (5 mL) and extracted with saturated NaHCO3 solu-
tion (10 mL). The aqueous phase was washed with CH2Cl2
(3ꢃ5 mL) and the organic phase dried over Na2SO4. After
removal of the solvent under reduced pressure, the residue
was analysed by NMR and chiral GC or chiral HPLC.
m/z=956.6, calcd. for C58H49NO2P2Rh ([Rh
ACHUTGTNERN(NUG COD){ACHTUGNTRENN(GUN Sa,Sc)-
1b}]+): 956.9.
Synthesis of [RhACHTUNGTRENNUNG(COD)CAHUTNGTRNE{NGUN (Ra,Sc)-1b}] NTf2
The title compound was obtained by the procedure de-
scribed above using (Ra,Sc)-1b as the ligand; orange powder;
yield: 82%. 1H NMR (300 MHz, CD2Cl2): d=1.17 (d, J=
7.0 Hz, 3H, CH3), 1.99–2.47 (m, 8H, COD), 4.64 (m, 1H,
COD), 4.95 (m, 1H, COD), 5.73 (m, 1H, CH), 5.89 (m, 1H,
COD), 6.17 (m, 1H, COD), 6.68–8.18 (m, 35H, Ar);
31P{1H}-NMR (125 MHz, CDCl3): d=14.3 (dd, J=58.7 Hz,
141.1 Hz), 141.1 (dd, J=58.7 Hz, 242.9 Hz); MS: m/z=
Typical Procedure for the Hydrogenation of 11
ACHUTNGREN[NUG RuCl2ACHTUNGTREN(NUNG p-cymene)]2 (0.005 mmol, 2.9 mg) was placed in
956.6, calcd. for C58H49NO2P2Rh ([Rh
956.9.
(Ra,Sc)-1b}]+):
ACHUTGTNRNEUG(N COD){ACHTUTGNRENNUGN
Schlenk tube and a solution of 1a (0.01 mmol, 6.9 mg) in tol-
uene (1 mL) was added. The mixture was heated to 808C
for 1 h and then the solvent removed under reduced pres-
sure. The residue was dissolved in methanol (2.0 mL) and
the substrate (1.0 mmol, 130.1 mg) was added. The mixture
was transferred into a stainless steel high pressure autoclave
(10 mL) equipped with a glass inlet. The autoclave was pres-
surised with hydrogen (60 bar) and stirred for 16 h at 608C.
After releasing the hydrogen pressure, the solvent was re-
moved under reduced pressure. The residue was extracted
with CH2Cl2, filtered over a pad of silica and analysed by
chiral GC and NMR.
Synthesis of [RhACHTUNGTRENNUNG(COD)CAHUTNGTRNE{NGUN (Sa,Sc)-2}] NTf2
Title compound was obtained by the procedure described
above using (Sa,Sc)-2 as the ligand; orange powder; yield:
96%. 1H NMR (400 MHz, CDCl3): d=1.17 (d, 3J=7.2 Hz,
3H, CH3), 1.39–2.85 (m, 8H COD, 16H CH2), 4.56 (m, 1H,
COD), 4.98 (m, 1H, CH), 5.04 (m, 1H, COD), 5.67 (m, 1H,
COD), 5.96 (m, 1H, COD), 6.57–7.54 (m, 23H, Ar);
31P{1H}-NMR (125 MHz, CDCl3):=15.0 (dd, J=61.1 Hz, J=
142.0 Hz), 135.4 (dd, J=61.1 Hz, J=236.6 Hz); 19F NMR
(280 MHz, CDCl3): d=À79.4.
Adv. Synth. Catal. 2009, 351, 725 – 732
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asc.wiley-vch.de
731

Matthias Eggenstein et al.
COMMUNICATIONS
Acknowledgements
[8] A. Korostylev, D. Selent, A. Monsees, C. Borgmann, A.
Bçrner, Tetrahedron: Asymmetry 2003, 14, 1905–1909.
[9] For most ligands one recrystallisation yields the pure li-
gands. Ligands (Sa,Sc)-1b and (Ra,Sc)-1b were obtained
after one recrystallisation with a lower purity of 86%
and 94%, respectively (based on 31P NMR). Control ex-
periments showed that the major impurity 4b did not
interfere with the in situ catalyst. Analytically pure
(Sa,Sc)-1b and (Ra,Sc)-1b could be obtained after a
second recrystallisation on the expense of the yield
(see Experimental Section).
We thank the European Union (STRP 505167–1 LIGBANK)
for financial support, Thomas Brosi, Patrick Brosinski and
Jennifer Julis for experimental support, Prof. Klaus Ditrich
(BASF) for a generous gift of chiral amines and Dr. Antonio
Zanotti-Gerosa (Johnson Matthey) for fruitful discussion.
References
[1] a) The Handbook of Homogenous Hydrogenation,
(Eds.: J. G. de Vries, C. J. Elsevier), Wiley-VCH, Wein-
heim, 2006; b) special issue on hydrogenation: Acc.
Chem. Res. 2008, 40, 1237–1419; c) W. Tang, X. Zhang,
Chem. Rev. 2003, 103, 3029–3070.
[10] A. R. Katritzky, S. Rachwal, B. Rachwal, Tetrahedron
1996, 52, 15031–15070.
[11] a) Y. G. Zhou, Acc. Chem. Res. 2007, 40, 1357–1366,
and references cited therein; b) S. H. Chan, F. L. Lam,
X. Li, L. Xu, W. Tang, F. L. Lam, W.-h. Lo, S.-B. Yu,
Q.-H. Fan, A. S. C. Chan, Tetrahedron: Asymmetry
2007, 18, 2625–2631; c) C. Deport, M. Buchotte, K.
Abecassis, H. Tadaoka, T. Ayad, T. Ohshima, J.-P.
Genet, K. Mashima, V. Ratovelomanana-Vidal Synlett
2007, 2743–2747; d) S.-M. Lu, C. Bolm Adv. Synth.
Catal. 2008, 350, 1101–1105; e) X.-B. Wang, Y.-G.
Zhou J. Org. Chem. 2008, 73, 5640–5642; .
[2] T. P. Yoon, E. N. Jacobsen, Science 2003, 299, 1691–
1693.
[3] a) G. Franciꢀ, F. Faraone, W. Leitner, Angew. Chem.
2000, 112, 1486–1488; Angew. Chem. Int. Ed. 2000, 39,
1428–1430; b) S. Burk, G. Franciꢀ, W. Leitner, Chem.
Commun. 2005, 3460–3462; c) G. Franciꢀ, F. Faraone,
W. Leitner, in: Asymmetric Synthesis with Chemical
and Biological Methods, (Eds.: D. Enders, K.-E.
Jaeger), Wiley-VCH, Weinheim, 2007, pp 250–277.
[4] a) N. W. Boaz, J. A. Ponasik, in: Phosphorus Ligands in
Asymmetric Catalysis, (Ed. A. Bçrner), Wiley-VCH,
Weinheim, 2008, pp 453–476; b) F. Boeda, T. Beney-
ton, C. Crꢄvisy, Mini-Reviews in Organic Chemistry,
2008, 5, 96–127; c) S. H. L Kok, T. T. L. Au-Yeung,
H. Y. Cheung, W. S. Lam, S. S. Chan, A. S. C. Chan, in:
The Handbook of Homogenous Hydrogenation, (Eds.:
J. G. de Vries, C. J. Elsevier), Wiley-VCH, Weinheim,
2006, pp 883–994.
ˇ ´
[12] N. Mrsic, L. Lefort, J. A. F. Boogers, A. J. Minnaard,
B. L. Feringa, J. G. de Vries Adv. Synth. Catal. 2008,
350, 1081–1089.
[13] Very recently, Chan, Fan and co-workers reported the
application of an extremely efficient ruthenium-dia-
mine complex for the asymmetric hydrogenation of 2-
alkylquinolines. However, modest enantioselectivity
(79%) was obtained for 12c: a) H. Zhou, Z. Li, Z.
Wang, T. Wang, L. Xu, Y. He, Q.-H. Fan, J. Pan, L. Gu,
A. S. C. Chan, Angew. Chem. 2008, 120, 8592–8595;
Angew. Chem. Int. Ed. 2008, 47, 8464–8467; b) Z.-W.
Li, T.-L. Wang, Y.-M. He, Z.-J. Wang, Q.-H. Fan, J.
Pan, L.-J. Xu, Org. Lett. 2008, 10, 5265–5268.
[5] K. A. Vallianatou, I. D. Kostas; J. Holz, A. Bçrner, Tet-
rahedron Lett. 2006, 47, 7947–7950.
[6] L.-C. Liang, W.-Y. Lee, C.-H. Hung, Inorg. Chem. 2003,
42, 5471–5473.
[7] G. Franciꢀ, C. G. Arena, F. Faraone, C. Graiff, M. Lan-
franchi, A. Tiripicchio, Eur. J. Inorg. Chem. 1999,
1219–1227.
[14] A. F. Burchat, J. M. Chong, N. Nielsen, J. Organomet.
Chem. 1997, 542, 281–283.
732
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