New carbohydrate bisphosphites as chiral ligands

Article abstract of DOI:10.1016/S0957-4166(97)00622-8

The synthesis of the 2,3-bisphosphite derivatives of phenyl 4,6-O-benzylidene-β-D-glucopyranoside leads to new chelating ligands. Their rhodium(I) and platinum(II) complexes have been tested as catalysts for the asymmetric hydroformylation of vinyl acetate, allyl acetate and p-methoxystyrene. Good regioselectivity (>90% branched product), but an enantioselectivity of only ≤36% ee were found under mild reaction conditions (25-40°C, 40-70 bar syngas).

Full text of DOI:10.1016/S0957-4166(97)00622-8

Pergamon
Tetrahedron: Asymmetry 9 (1998) 329–340
New carbohydrate bisphosphites as chiral ligands
Renat Kadyrov, Detlef Heller and Rüdiger Selke ∗
Institut für Organische Katalyseforschung an der Universität Rostock, e.V. Buchbinderstr. 5–6, 18055 Rostock, Germany
Received 20 November 1997; accepted 4 December 1997
Abstract
The synthesis of the 2,3-bisphosphite derivatives of phenyl 4,6-O-benzylidene-β-D-glucopyranoside leads
to new chelating ligands. Their rhodium(I) and platinum(II) complexes have been tested as catalysts for the
asymmetric hydroformylation of vinyl acetate, allyl acetate and p-methoxystyrene. Good regioselectivity (>90%
branched product), but an enantioselectivity of only ≤36% ee were found under mild reaction conditions (25–40°C,
40–70 bar syngas). © 1998 Elsevier Science Ltd. All rights reserved.
Investigations of carbohydrate vicinal bisphoshinites as chiral chelating ligands in asymmetric
hydrogenations1 and hydroformylation2 of prochiral olefinic substrates with enantioselectivities reaching
99 or 72% ee, respectively, culminated in an industrial application for L-Dopa synthesis.3 The fact
that phosphites are suitable ligands for rhodium(I) catalyzed hydroformylation4 tempted us to try the
preparation of analogous hexopyranoside-2,3-O-bisphosphites. Previously high catalytic activities of
diphosphite rhodium(I) chelates in hydroformylation reactions have been published4a–c but asymmetric
induction was restricted to cases such as the hydroformylation of styrene with diphosphites based on
chiral pentane-2,4-diol (90% ee).4d The highest enantioselectivity in an asymmetric hydroformylation
was obtained with the phosphine–phosphite ligands introduced by Takaya and co-workers.5
Since aryl 4,6-O-benzylidene-β-D-glucopyranoside with only equatorial substituents led to the ligands
with the highest enantioselectivity in asymmetric hydrogenation,6 we started our synthetic work with that
compound. We are aware that application of such phosphites, in particular in other reactions, might show
distinct deviations to the case of the asymmetric hydrogenation with bisphosphinite chelates. However,
we thought that the range of electronic properties and particularly steric requirements of the residue R in
2 may be large enough to generate interesting differences.
∗
Corresponding author. E-mail: rselke@chemie1.uni-rostock.de
0957-4166/98/$19.00 © 1998 Elsevier Science Ltd. All rights reserved.
PII: S0957-4166(97)00622-8

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In order to examine the effect of the steric bulk of R on the selectivity of the hydroformylation
reaction we synthesized ortho bisphenyl substituted ligand 2e. The coupling of the 3,30-dibromo-2,20-
dimethoxybiphenyl with PhMgBr in the presence of Ni(dmpe)2Cl2, according to the procedure reported
for binaphthyl derivatives,7 gives the product 4 only in very poor yield. In contrast, the simple route
outlined in Scheme 1 allows the desired 3,30-diphenyl-2,20-biphenol 5 to be prepared in moderate yield.
Scheme 1. (a) n-BuLi, TMEDA, Et2O, 51%; (b) n-BuLi, CuCl2, Et2O, 40%; (c) BBr3, CH2Cl2, H2O, 99%
The chlorophosphites 1 are conveniently prepared from the proper diol and PCl3 in the presence of
base, except for 1a and 1d. These are synthesized by a modified procedure of Anschütz and co-workers.8
Most of the chlorophosphites 1a–d, f and j are known compounds.4a,9 The reaction of phenyl 4,6-O-
benzylidene-α-D-glucopyranoside with the corresponding chlorophosphites were carried out at 0°C,
with aliphatic phosphites at −20°C, and produced the desired carbohydrate bisphosphites 2 in good
yield. Phosphites 2a–e are stable for some time in air and moisture, and can be washed with alcohol to
spectroscopic purity. On the other hand, aliphatic derivatives 2f–l are very sensitive to moisture and all
procedures had to be performed under an inert atmosphere.
We are especially interested in these compounds as new chiral bidentate ligands which could be
used in asymmetric synthesis catalyzed by rhodium(I). The representative carbohydrate bisphosphites
2c and 2h react readily with [Rh(COD)2]BF4 (COD=(Z,Z)-cycloocta-1,5-diene) to give high yields of
the corresponding rhodium(I) complex salts.
[Rh(COD)2]BF4 + L -→ [RhL(COD)]BF4 + COD
6c, 6h
L = 2c, 2h
The 31P NMR spectra of the complexes show two signals split into clearly resolved double doub-
2
1
1
2
lets (6c: JP1P2=58.3, δ 109.9 JRhP1=256.5, δ 110.4 JRhP2=259.3 Hz; 6h: JP1P2=54.1, δ 140.8
1JRhP1=250.4, δ 144.53 1JRhP2=250.7 Hz). The assignment of the resonances in the 1H NMR spectrum
of complex 6c was made by use of COSY-experiments and is given in the experimental section.
In order to investigate the platinum catalyzed hydroformylation with the obtained ligands, we have
prepared two platinum(II) complexes. Treatment of the phosphites 2c and 2d with [Pt(COD)Cl2] yielded
the corresponding Pt(II)-complexes 7c and 7d.

R. Kadyrov et al. / Tetrahedron: Asymmetry 9 (1998) 329–340
331
Table 1
Hydroformylation of vinyl acetate (X=OAc), allyl acetate (X=CH2OAc) and p-methoxystyrene
(X=C6H4OMe-p) using Rh- and Pt-catalystsa
[Pt(COD)Cl2] + L -→ [PtLCl2] + COD
7c, 7d
L = 2c, 2d
Preliminary results of asymmetric hydrogenation of methyl (Z)-2-N-acetamidocinnamate in THF
using rhodium(I) chelate 6c showed a rather low enantioselectivity of 13% ee for (S)-methyl N-
acetylphenylalanine. On account of lower phosphorus basicity their rhodium(I) chelates show the
expected lower activity compared with the corresponding phosphinite complex.
The new diphosphites have been evaluated in the hydroformylation of vinyl acetate, allyl acetate and
p-methoxystyrene. Table 1 lists some representative results obtained by use of complex 6c or catalyst
precursors prepared in situ by mixing [Rh(CO)2acac] and 1–10 equivalents of the ligands.
While complex 6c has a good activity in the hydroformylation of vinyl acetate, catalysts prepared in
situ show a low conversion. The highest enantiomeric excess (36% ee in the case of 2e) was achieved
by hydroformylating allyl acetate. A longer reaction time for 2e resulted in a slight racemization of
product from 36% after 2 h to 32% ee after 24 h. Unexpectedly, the higher L:Rh ratio of 10 improved

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catalytic activity but the enantioselectivity was rather low. Usually, the catalyst activity decreases slightly
on increasing the L:Rh ratio. For the hydroformylation of p-methoxystyrene, lower catalyst activity
was found than for the allyl acetate. In this case, a higher L:Rh ratio leads to a better regio- and
enantioselectivity. In comparison to the successful biphosphite–PtCl2(PhCN)2–SnCl2 system of Bakos10
(up to 91% ee) the phosphite chelate 7d gave a mixture of the hydrogenation product 4-ethylanisole and
the branched aldehyde with low enantiomeric excess (14% ee). However, with the catalysts prepared
in situ by simple mixing PtCl2(PhCN)2, SnCl2 and ligand the hydroformylation of p-methoxystyrene
proceeds more slowly. In the experiments with vinyl acetate and allyl acetate under the typical conditions
for platinum–tin catalyzed hydroformylation11 no aldehyde formation was detected.
1. Conclusion
Despite the acceptable activity and regioselectivity of the catalysts with the newly synthesized
hexopyranoside-2,3-O-bisphosphites, the generally low enantioselectivity gives the impression that the
butterfly-like arrangement of the bridged diaryls O-bounded on the phosphorus is no more favourable for
reaching optimum space filling than that of P-diarylphosphines or analogous C-bonded bridged diaryls as
in dibenzophosphole carrying diphosphines. Bis-ortho-aryl substitution of the cyclic diphenylphosphite
as in 2e leads only to a small improvement of the enantioselectivity up to 36% ee and also the rhodium(I)
chelates of the bisphophites derived from tartaric acid esters as 2h are disappointing. The results conform
with the postulate of van Leeuwen that bisphophites of vicinal diols are less useful than analogous ligands
derived from chiral 1,3-diols for asymmetric hydroformylation.4h,i,l
2. Experimental
Solvents were dried over appropriate drying agents and freshly distilled under argon before use. All
reactions were carried out under an argon atmosphere by using standard Schlenk techniques. NMR data
were recorded on a multi-nuclear FT-NMR spectrometer ARX300 and ARX400 (Bruker) with reference
to TMS and H3PO4 (85%), respectively. Mass spectra (EI, 70 eV) were measured on a single focusing
sector-field mass spectrometer AMD40 (Intectra).
The experimental procedures for the hydrogenation, the synthesis of the substrate, the derivatization
and the determination of the hydrogenated products are described in the literature.1a The experimental
procedure for the hydroformylation was first described in the preliminary communication.12 Gas chrom-
atographic analyses were carried out on a Hewlett–Packard 5890 Series II gas chromatograph with a
flame ionization detector, using a 25 m fused silica (HP101, Chiraldex G-TA or Lipodex E) capillary
column.
2.1. 3-Bromo-2-methoxybiphenyl 3
To a solution of 50 g (0.27 mol) 2-methoxybiphenyl and 81 ml (0.54 mol) TMEDA in 300 ml ether
was added dropwise a 2.5 M solution of BuLi in hexane (217.1 ml). After 2 h the mixture was cooled
to −78°C and a solution of 27.6 ml (0.54 mol) Br2 in 60 ml hexane was added dropwise. The reaction
mixture was allowed to warm, 100 ml 2 N HCl were added and the aqueous phase was extracted with
CH2Cl2. The combined organic phase was dried over Na2SO4 and the solvent evaporated. Distillation
of the oily residue under vacuum gave 48.8 g (69% yield) of 3 as a colorless oil; b.p. 105°C/0.45 mbar.

R. Kadyrov et al. / Tetrahedron: Asymmetry 9 (1998) 329–340
333
1H NMR (CDCl3) δ=3.81 (s, 3H), 6.95–7.56 (m, 8H). 13C NMR (CDCl3) δ=60.4, 118.1, 125.3, 127.4,
128.1, 129.0, 130.3, 132.4, 136.8, 137.6, 154.4; MS m/z 263 (M+). Anal. found C 60.49, H 4.30, Br
32.11; calcd for C13H11BrO (263.12) C 59.34, H 4.21, Br 30.37.
2.2. 20,200-Dimethoxy-1,10:30,100:300,1000-quaterphenyl 4
A solution of 2.5 M BuLi in hexane (88.2 ml) was cooled to −78°C and a solution of 48.5 g (0.184
mol) 3 in 200 ml ether was slowly added. After the addition was complete, the reaction mixture was
allowed to warm over 1 h, then again cooled to −78°C and with intensive stirring 49.5 g CuCl2 was
added portionwise. The resultant mixture was stirred at this temperature for 2 h and then allowed to
warm. The reaction mixture was quenched with 30 ml H2O and extracted with CH2Cl2. The combined
organic layers were dried over Na2SO4 and concentrated under vacuum to 100 ml. Crystals of 4 deposited
on cooling. The precipitate was washed with hexane and dried under vacuum. Yield 5.4 g (39%), m.p.
1
139–140°C. H NMR (CDCl3) δ=3.26 (s, 6H), 7.2–7.7 (m, 16H). 13C NMR (CDCl3) δ=60.5, 123.6,
127.0, 128.2, 129.0, 129.5, 130.9, 132.9, 135.1, 138.8, 155.3. Anal. found C 85.05, H 5.99; calcd for
C26H22O2 (366.46) C 85.21, H 6.05.
2.3. 20,200-Dihydroxy-1,10:30,100:300,1000-quaterphenyl 5
BBr3 (13 g, 52 mmol) was added at 0°C to a solution of 10 g (27.3 mmol) 3 in 100 ml CH2Cl2 and
stirred overnight at room temperature. The excess of BBr3 was decomposed by dropwise addition of 150
ml of H2O and the aqueous layer was extracted with CH2Cl2. The combined organic layers were dried
over Na2SO4 and concentrated under vacuum to 15 ml. Crystals of 5 deposited on cooling. The precipitate
1
was washed with hexane and dried under vacuum. Yield 7.72 g (84%), m.p. 129–130°C. H NMR
(CDCl3) δ=5.7 (s, OH), 7.02 (‘ABX’, 0.5|JAX+JBX|=7.59, H-5), 7.24 (‘ABX’, JAB=1.76, JAX=7.70, H-4
or H-6), 7.25 (‘ABX’, JBX=7.52, H-6 or H-4), 7.28 (tt, J=1.4, J=7.42, H-p), 7.36 (m, 2H-m), 7.5 (m,
2H-o). 13C NMR (CDCl3) δ=121.8, 125.4, 128.1, 129.3, 129.8, 130.0, 131.1, 131.5, 137.9, 150.2. MS
m/z 338 (M+). Anal. found C 84.52, H 5.43; calcd for C24H18O2 (338.38) C 85.18, H 5.36.
For the preparation of the chlorophosphite 1e the product was additionally azeotropically dried with
toluene.
2.4. 11-Chloro-2,9-diphenyl-(dibenzo[bd][1,3,2]dioxaphosphepin) 1e
To a mixture of 2.5 ml (31 mmol) pyridine and 0.9 ml (10.3 mmol) PCl3 was added dropwise a
solution of 3.5 g (10.3 mmol) 5 in dry toluene (30 ml) at −20°C. The mixture was stirred overnight at
room temperature and then filtered. Evaporation of the solvent gave a crude product which was used
without further purification. Yield 3.5 g (85%). 31P{1H} NMR (CDCl3) δ=178.3. 13C NMR (CDCl3)
δ=126.0, 127.5, 128.1, 129.5, 129.7, 131.0, 132.0 (d, J=3.7), 135.3 (d, J=2.4), 137.8, 146.1 (d, J=5.3).
MS m/z 402 (M+), 367 (M+−Cl). Anal. found C 71.71, H 4.00; calcd for C24H16ClPO2 (402.83) C 71.56,
H 4.00.
2.5. 2-Chloro-4,5-diphenyl-1,3,2-dioxaphospholane 1g
A solution of 25 g (0.117 mol) of meso-hydrobenzoin and 19 ml (0.12 mol) of pyridine in 100 ml THF
was added at −20°C to a stirred solution of 11 ml (0.12 mol) PCl3 in 50 ml THF. The resulting slurry
was filtered and the filtrate evaporated under vacuum. The solid residue was recrystallized from ether

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R. Kadyrov et al. / Tetrahedron: Asymmetry 9 (1998) 329–340
1
and afforded at −78°C 25 g (77%) of 1g, m.p. 61–63°C. 31P{1H} NMR (CDCl3) δ=170.3. H NMR
(CDCl3) δ=5.97 (d, J=2.1, H-4,5), 6.8–7.1 (m, 10H-aromatic). 13C NMR (CDCl3) δ=82.9 (d, J=6.8),
126.7, 127.9, 128.1, 134.3. Anal. found C 60.84, H 4.34; calcd for C14H12ClO2P (278.67) C 60.3, H 4.3.
2.6. General procedure for the preparation of aliphatic chlorophosphites 1h–k
A solution of 0.2 mol of the appropriate diol and 0.22 mol of the corresponding base (see below) in
100 ml ether was added at 0°C to a stirred solution of 19 ml (0.22 mol) PCl3 in 100 ml ether. The reaction
mixture was stirred for 4–6 h and the precipitate was filtered off. The resulting solution was concentrated
under reduced pressure and the residue was subjected to fractional distillation.
2.6.1. 2-Chloro-(4R,5R)-dicarbomethoxy-1,3,2-dioxaphospholane 1h
Colorless oil; b.p. 93–95°C/10−3 mbar; base: PhNEt2; yield 39.4 g (81%); 31P{1H} NMR (CDCl3)
δ=175.6. 1H NMR (CDCl3) δ=3.84 (s, 3H), 3.85 (s, 3H), 5.01 (dd, J=6.3, JPH=9.5, 1H), 5.45 (d, J=6.3,
1H); 13C NMR (C6D6) δ=53.5, 78.3 (br.), 168.4 (br.).
2.6.2. 2-Chloro-(4S,5S)-dicarbomethoxy-1,3,2-dioxaphospholane 1i
Colorless oil; b.p. 93–95°C/10−3 mbar; base: PhNEt2; yield 45.1 g (93%); 31P{1H} NMR (C6D6)
δ=175.7. 1H NMR (C6D6) δ=3.33 (s, 3H), 3.41 (br, 3H), 4.86 (dd, J=6.1, JPH=8.7, 1H), 5.61 (d, J=6.1,
1H).
2.6.3. 2-Chloro-(4R,5R)-dicarboethoxy-1,3,2-dioxaphospholane 1j
Colorless oil; b.p. 119–121°C/0.1 mbar (lit. b.p. 113°C/0.28 mm Hg)13; base: PhNEt2; yield 30.4 g
(56%). 31P{1H} NMR (CDCl3) δ=175.4 (lit. 175.4)13; 1H NMR (C6D6) δ=1.20 (t, J=7.1, 3H), 1.24 (t,
J=7.2, 3H), 4.19 (q, J=7.1, 2H), 4.24 (q, J=7.3, 2H), 5.20 (dd, J=6.2, JPH=9.5, 1H), 5.85 (d, J=6.2, 1H);
13C NMR (C6D6) δ=14.5, 63.2, 78.1 (d, J=9.4), 79.1 (d, J=8.8), 167.0 (d, J=3.6), 168.2.
2.6.4. 2-Chloro-(4S,5S)-dicarboethoxy-1,3,2-dioxaphospholane
Colorless oil; b.p. 103°C/10−3 mbar; base: Py; yield 31.7 g (58%). 31P{1H} NMR (C6D6) δ=175.8; 1H
NMR (C6D6) δ=1.28 (t, J=7.1, 6H), 4.27 (q, J=7.1, 4H), 4.95 (dd, J=5.9, JPH=9.3, 1H), 5.38 (d, J=5.9,
1H); 13C NMR (C6D6) δ=14.5, 63.2, 78.1 (d, J=9.1), 79.1 (d, J=8.6), 167.7 (d, J=4.1), 168.3.
2.6.5. 2-Chloro-(4R,5R)-dicarboisopropoxy-1,3,2-dioxaphospholane
Colorless oil; b.p. 104–105°C/10−3 mbar (lit.4a b.p. 108–110°C/10−3 mm Hg); base: PhNEt2; yield
1
46.5 g (78%). 31P{1H} NMR (C6D6) δ=175.9; H NMR (C6D6) δ=1.25 (d, J=5.8, 12H), 4.87 (dd,
J=6.6, JPH=9.2, 1H), 5.09 (sept, J=6.0, 1H), 5.11 (sept, J=6.1, 1H), 5.31 (d, J=6.6, 1H); 13C NMR
(C6D6) δ=21.4, 21.6, 70.87, 70.92, 77.0 (d, J=9.3), 78.1 (d, J=8.7), 166.6 (d, J=4.7), 167.0.
2.6.6. 2-Chloro-(4R,5R)-dicarbo-n-butoxy-1,3,2-dioxaphospholane 1k
Colorless oil; b.p. 102°C/10−3 mbar; base: Py; yield 35.3 g (54%). 31P{1H} NMR (C6D6) δ=175.7;
1H NMR (C6D6) δ=0.85 (m, 6H), 1.22 (m, 4H), 1.38 (m, 4H), 4.1 (m, 4H), 5.00 (dd, J=6.6, JPH=9.3,
1H) 5.70 (dd, J=6.6, JPH=4.5, 1H).

R. Kadyrov et al. / Tetrahedron: Asymmetry 9 (1998) 329–340
335
2.7. General procedure for carbohydrate bisphosphite synthesis
A solution of phenyl 4,6-O-benzylidene-β-D-glucopyranoside (10 mmol) and anhydrous pyridine (1.7
ml, 21 mmol) in 40 mL of THF was added dropwise over 30 min to a stirred solution of chlorophosphite 1
(20 mmol) in 20 mL THF under an argon atmosphere at 0°C or −20°C. The mixture was stirred overnight
at room temperature and then filtered. The solvent was evaporated under vacuum and necessarily ether or
pentane was added to induce crystallization. The product was purified by extraction and recrystallization
from a proper solvent (see below).
2.7.1. Phenyl 2,3-O-bis(benzo[1,3,2]dioxaphospholyl-2)-4,6-O-benzylidene-β-D-glucopyranoside 2a
Colorless solid; recrystallized from toluene; m.p. 169–172°C; [α]D24=−42.1 (c 1.0, THF); yield 3.6
1
g (57%). 31P NMR (CDCl3) δ=135.8 (JPH=7.3), 137.3 (JPH=8.1). H NMR (CDCl3) δ=3.28 (ddd,
0
0
J56 =5.0, J56=9.7, J54=9.6, H-5), 3.45 (dd, 0.5|J43+J45|=9.3, H-4), 3.68 (dd, 0.5|J65+J66 |=10.3, H-6),
0
0
0
3.99–4.03 (m, H-2 and H-3), 4.28 (dd, J56 =5.0, J66 =10.6, H-6 ), 4.99 (d, J12=7.0, H-1), 5.46 (s, H-b),
6.89–7.57 (m, 18H-aromatic). 13C NMR (CDCl3) δ=66.7, 68.7, 75.7 (dd, JPC=10.0, JPC=1.5), 76.3 (dd,
J
J
J
PC=10.4, JPC=2.3), 78.8, 101.0, 101.6, 111.7 (d, JPC=9.3), 112.9, 117.9, 123.1 (d, JPC=8.3), 123.3 (d,
PC=6.5), 126.6, 128.1, 128.3, 128.6, 128.7, 130.0, 145.5 (dd, JPC=15.6, JPC=7.3), 145.7 (dd, JPC=7.0,
PC=9.8), 157.5. MS m/z 620 (M+). Anal. found C 59.96, H 4.31, P 9.61; calcd for C31H26O10P2 (620.47)
C 60.00, H 4.22, P 9.98.
2.7.2. Phenyl 4,6-O-benzylidene-2,3-O-bis(naphtho[2,3-d][1,3,2]dioxaphospholyl-2)-β-D-glucopyra-
noside 2b
Colorless solid; recrystallized from THF; m.p. 149–152°C; [α]D24=−43.8 (c 1.0, CH2Cl2); yield 5.5 g
(77%). 31P NMR (THF-d8) δ=137.1 (JPH=9.0), 137.8 (JPH=9.1). 1H NMR (C6D6) δ=2.61 (ddd, J56 =4.9,
0
0
J56=9.9, J54=9.5, H-5), 2.97 (dd, 0.5|J43+J45|=9.3, H-4), 3.16 (dd, 0.5|J65+J66 |=10.2, H-6), 3.82 (dd,
0
0
0
J56 =5.0, J66 =10.4, H-6 ), 3.95 (ddd, J≈8.5–9.0, H-2 or H-3), 4.08 (ddd, J≈7.6–9.0, H-3 or H-2), 4.74
(d, J12=7.4, H-1), 5.38 (s, H-b), 7.18–8.10 (m, 22H-aromatic). MS m/z 720 (M+). Anal. found C 64.98,
H 4.26, P 8.63; calcd for C39H30O10P2 (720.58) C 65.00, H 4.20, P 8.60.
2.7.3. Phenyl 4,6-O-benzylidene-2,3-O-bis(naphtho[1,8-de][1,3,2]dioxaphosphorinyl-2)-β-D-glucopy-
ranoside 2c
Colorless solid; recrystallized from benzene; m.p. 226–227°C; [α]D24=−115.5 (c 1.0, CH2Cl2); yield 5
g (69%). 31P NMR (C6D6) δ=113.7 (JPH=7.9), 114.4 (JPH=8.1). 1H NMR (C6D6) δ=2.68 (ddd, J56 =4.8,
0
0
J56=9.7, J54=9.5, H-5), 02.75 (dd, 0.5|J43+J45|=9.1, H-4), 3.16 (dd, 0.5|J65+J66 |=10.0, H-6), 3.84 (dd,
0
0
J56 =4.8, J66 =10.4, H-6 ), 3.93 (ddd, J≈8.5–9.0, H-3), 4.07 (ddd, J≈7.6–9.0, H-2), 4.33 (d, J12=7.5, H-
1), 5.01 (s, H-b), 6.5–7.8 (m, 22H-aromatic). 13C NMR (C6D6) δ=66.0, 68.2, 76.4 (d, JPC=22.3), 77.4 (d,
J
PC=19.0), 78.3, 100.1, 101.1, 112.1, 112.8 (d, JPC=8.6), 117.6, 122.2, 122.3, 123.3, 126.6–129.5, 138.0,
144.8 (dd, JPC=7.9, JPC=3.7), 144.9 (dd, JPC=5.8, JPC=3.7), 157.6. MS m/z 720 (M+). Anal. found C
64.55, H 4.17, P 8.63; calcd for C39H30O10P2 (720.58) C 65.00, H 4.20, P 8.60.
2.7.4. Phenyl 2,3-O-bis(dibenzo[df][1,3,2]dioxaphosphepinyl-2)-4,6-O-benzylidene-β-D-glucopyra-
noside 2d
Colorless solid; extracted with ether and recrystallized from acetone; m.p. 215–216°C; [α]D24=−29.3
1
(c 1.0, CH2Cl2); yield 5.5 g (71%). 31P NMR (CDCl3) δ=153.1 (JPH=7.3), 153.5 (JPH=8.0). H NMR
0
(CDCl3) δ=3.54 (ddd, J56 =5.0, J56=9.9, J54=9.5, H-5), 3.74 (dd, 0.5|J43+J45|=9.2, H-4), 3.78 (dd,
0
0
0
0
0.5|J65+J66 |=10.3, H-6), 4.36 (dd, J56 =5.0, J66 =10.5, H-6 ), 4.50 (ddd, J=7.6, J=8.2, J=8.4, H-3 or

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R. Kadyrov et al. / Tetrahedron: Asymmetry 9 (1998) 329–340
H-2), 4.58 (ddd, J=7.5, J=8.8, J=9.0, H-2 or H-3), 5.11 (d, J12=7.4, H-1), 5.56 (s, H-b), 6.74–7.66 (m,
26H-aromatic). 13C NMR (CDCl3) δ=66.2 (CH), 68.4 (CH2), 76.1 (dd, JPC=23.3, JPC=2.9, CH), 77.2
(dd, JPC=21.5, JPC=3.3, CH), 78.9, 100.3, 101.4, 117.1, 122.0, 122.1, 122.4, 123.4, 125.2, 126.2, 128.3,
129.0–129.7 (CH), 130.9, 131.3 (d, JPC=3.0), 131.4 (d, JPC=3.3), 136.8, 149.0 (dd, 0.5|JPC+JPC|=5.0),
149.4 (dd, JPC=5.8, JPC=7.8), 156.6 (C). MS m/z 772 (M+). Anal. found C 66.89, H 4.37, P 8.63; calcd
for C43H34O10P2 (772.65) C 66.84, H 4.44, P 8.02.
2.7.5. Phenyl 4,6-O-benzylidene-2,3-O-bis[2,9-diphenyl-(dibenzo[df][1,3,2]dioxaphosphepinyl-11)]-
β-D-glucopyranoside 2e
Colorless solid; purified by column chromatography (silica gel, 1% NEt3 in toluene); m.p. 127–129°C;
[α]D24=6.7 (c 1.0, acetone); yield 4.7 g (44%). 31P NMR (CDCl3) δ=148.2 (JPH=6.7), 149.6 (JPH=3.0).
1H NMR (CDCl3) δ=2.35 (dd, 0.5|J43+J45|=9.2, H-4), 2.88 (ddd, J56 =4.9, J56=9.9, J54=9.8, H-5), 3.36
0
0
0
(dd, 0.5|J65+J66 |=10.3, H-6), 3.38–3.45 (m, H-2 and H-3), 3.71 (d, J12=6.3, H-1), 4.13 (dd, J56 =4.9,
J66 =10.3, H-6 ), 4.90 (s, H-b), 6.7–7.5 (m, 42H-aromatic). 13C NMR (CDCl3) δ=65.8 (CH), 68.4 (CH2),
76.3 (dd, JPC=22.6, JPC=2.6, CH), 76.4 (dd, JPC=22.9, JPC=3.6, CH), 78.4, 100.4, 101.7, 118.1, 123.6,
124.7, 124.8, 125.68, 125.74, 126.2, 127.2, 127.4, 127.6, 127.7, 128.2, 128.49, 138.60, 128.68, 129.1,
129.4, 129.7, 130.0, 130.24, 130.37, 130.54, 130.62, 131.1, 131.4 (CH), 133.58 (d, JPC=3.8), 133.67 (d,
0
0
J
PC=3.8), 135.3, 135.7, 137.28, 137.38, 137.48, 138.95, 140.0, 145.8 (d, JPC=8.1), 147.5 (d, JPC=8.1),
157.0 (C). MS m/z 1077 (M+). Anal. found C 74.68, H 5.19; calcd for C67H50O10P2 (1077.02) C 74.71,
H 4.68.
2.7.6. Phenyl 4,6-O-benzylidene-2,3-O-bis(4,4,5,5-tetramethyl-1,3,2-dioxaphospholyl-2)-β-D-glucopy-
ranoside 2f
Colorless solid; recrystallized from petroleum ether; m.p. 40–44°C; [α]D24=−45.7 (c 1.0, THF); yield
1
2 g (31%). 31P NMR (C6D6) δ=148.2 (JPH=8.3), 149.2 (JPH=8.8). H NMR (C6D6) δ=1.16 (s, 3H),
1.21 (s, 3H), 1.24 (s, 3H), 1.26 (s, 3H), 1.28 (s, 3H), 1.43 (s, 3H), 1.52 (s, 3H), 1.60 (s, 3H), 3.23 (ddd,
0
0
J56 =4.9, J56=10.0, J54=9.3, H-5),03.52 (dd, 0.5|J43+J45|=9.4, H-4), 3.53 (dd, 0.5|J65+J66 |=10.2, H-6),
0
0
4.17 (dd, J56 =4.9, J66 =10.3, H-6 ), 4.46 (ddd, J≈8.7–9.6, H-3 or H-2), 4.55 (ddd, J≈7.2–9.0, H-2 or
H-3), 4.96 (d, J12=7.3, H-1), 5.36 (s, H-b), 7.0–7.9 (m, 10H-aromatic). MS m/z 636 (M+). Anal. found
C 54.42, H 6.68, P 9.48; calcd for C31H42O10P2 (636.6) C 58.49, H 6.65, P 9.73.
2.7.7. Phenyl
noside 2g
4,6-O-benzylidene-2,3-O-bis(4,5-diphenyl-1,3,2-dioxaphospholyl-2)-β-D-glucopyra-
Colorless solid; recrystallized from benzene; m.p. 71–74°C; [α]D24=−2.9 (c 1.0, THF); yield 5.3 g
(64%). 31P NMR (C6D6) δ=140.0 (JPH=9.0), 141.6 (JPH=9.6). 1H NMR (C6D6) δ=3.36 (ddd, J56 =4.8,
0
0
J56=9.7, J54=10.3, H-5), 3.62 (dd, 0.5|J65+J66 |=10.0, H-6), 3.73 (dd, 0.5|J43+J45|=9.0, H-4), 4.23 (dd,
0
0
0
J56 =4.8, J66 =10.2, H-6 ), 4.73 (ddd, J≈8.5–9.0, H-3 or H-2), 4.83 (ddd, J≈8.3–9.0, H-2 or H-3), 5.16
(d, J12=7.2, H-1), 5.45 (s, H-b), 5.89 (d, JPH=7.3, 1H), 6.04 (br., 3H), 6.9–7.9 (m, 30H-aromatic). 13C
NMR (C6D6) δ=67.5, 69.2, 75.7 (d, JPC=12.8), 76.7 (d, JPC=13.8), 80.5, 82.5, 82.6, 82.7, 83.6, 102.1,
102.5, 118.6, 124.2–130.5, 137.3 (d, JPC=3.3), 137.4 (d, JPC=4.0), 137.5 (d, JPC=1.8), 138.6, 158.8. MS
m/z 828 (M+). Anal. found C 69.68, H 5.33, P 7.13; calcd for C47H42O10P2 (828.76) C 68.11, H 5.12, P
7.49.

R. Kadyrov et al. / Tetrahedron: Asymmetry 9 (1998) 329–340
337
2.7.8. Phenyl 4,6-O-benzylidene-2,3-O-bis((4R,5R)-dicarbomethoxy-1,3,2-dioxaphospholyl-2)-β-D-
glucopyranoside 2h
Colorless solid; recrystallized from ether; m.p. 96–99°C; [α]D24=−104.6 (c 1.0, THF); yield 3 g
1
(56%). 31P NMR (C6D6) δ=147.5 (dd, JPH=8.8, JPH≈8.6), 146.6 (dd, JPH=9.3, JPH=7.4). H NMR
0
(C6D6) δ=3.01 (ddd, J56 ≈5, J56≈10, J54=9.8, H-5), 3.20, 3.23, 3.41, 3.48 (s, 4×3H), 3.27–3.40 (m,
0
0
0
H-4, H-6), 4.00 (dd, J56 =5.0, J66 =10.3, H-6 ), 4.30 (ddd, J12=7.2, J23=9.0, J2P=8.7, H-2), 4.39 (ddd,
J34=7.8, J23=9.0, J3P=8.1, H-3), 4.78 (d, J12=7.2, H-1), 4.82 (dd, JHH=5.9, JPH=9.7, 1H), 4.89 (dd,
J
HH=6.0, JPH=9.8, 1H), 5.23 (s, H-b), 5.47 (d, JHH=5.8, 1H), 5.64 (d, JHH=5.9, 1H), 6.9–7.9 (m, 10H-
aromatic). MS m/z 756 (M+), 725, 663. Anal. found C 49.33, H 4.47, P 7.49; calcd for C31H34O18P2
(756.53) C 49.21, H 4.53, P 8.19.
2.7.9. Phenyl
glucopyranoside 2i
4,6-O-benzylidene-2,3-O-bis((4S,5S)-dicarbomethoxy-1,3,2-dioxaphospholyl-2)-β-D-
Colorless solid; recrystallized from ether; m.p. 107–110°C; [α]D24=19.4 (c 1.0, THF); yield 6.26 g
(83%). 31P NMR (C6D6) δ=143.4 (dd, JPH≈7.8, JPH≈6.6), 146.4 (dd, JPH≈8.1, JPH≈8.2). H NMR
1
0
(C6D6) δ=3.22 (ddd, J56 =4.9, J56=10.1, J54=9.3, H-5), 3.33, 3.38, 3.39, 3.46 (s, 4×3H), 3.56 (dd,
0
0
0
0
J56=10.1, J66 =10.3, H-6), 3.70 (dd, J54=9.3, J34=9.3, H-4), 4.16 (dd, J56 =4.9, J66 =10.3, H-6 ),
4.36–4.49 (m, H-2, H-3), 4.87 (dd, JHH=6.0, JPH=9.2, 1H), 4.89 (dd, JHH=6.4, JPH=8.6, 1H), 5.04 (d,
J12=7.2, H-1), 5.51 (s, H-b), 5.69 (d, JHH=6.4, 1H), 5.70 (d, JHH=6.0, 1H), 6.9–7.9 (m, 10H-aromatic).
MS m/z 756 (M+), 725, 663. Anal. found C 48.42, H 4.24, P 8.16; calcd for C31H34O18P2 (756.53) C
49.21, H 4.53, P 8.19.
2.7.10. Phenyl
glucopyranoside 2j
4,6-O-benzylidene-2,3-O-bis((4R,5R)-dicarboethoxy-1,3,2-dioxaphospholyl-2)-β-D-
Colorless solid; recrystallized from ether/hexane; m.p. 71–74°C; [α]D24=−114.9 (c 1.0, THF); yield
5.7 g (70%). 31P NMR (C6D6) δ=146.7 (dd, JPH=8.0, JPH 7.6), 147.5 (dd, JPH=8.1, JPH=8.2). 1H NMR
(C6D6) δ=0.90 (t, J=7.0, 3H), 0.92 (t, J=7.3, 3H), 1.06 (t, J=7.0, 3H), 1.12 (t, J=7.0, 3H), 3.12 (ddd,
0
0
J56 =5.0, J56=10.1, J54=9.3, H-5), 3.43 (dd, J56=10.1, J66 =10.3, H-6), 3.44 (dd, J54=9.3, J34=9.0, H-4),
3.91 (q, J=7.1, 1H), 3.92 (q, J=7.2, 1H), 3.94 (q, J=6.9, 2H), 4.09 (q, J=7.3, 1H), 4.09 (q, J=6.8, 1H),
0
0
0
4.10 (dd, J56 ≈5, J66 ≈10, H-6 ), 4.16 (q, J=6.9, 1H), 4.17 (q, J=7.3, 1H), 4.40–4.57 (m, H-2, H-3), 4.89
(d, J12=7.2, H-1), 4.97 (dd, JHH=6.2, JPH=9.1, 1H), 5.01 (dd, JHH=6.3, JPH=9.4, 1H), 5.31 (s, H-b), 5.56
(d, JHH=6.2, 1H), 5.73 (d, JHH=6.3, 1H), 7.2–8.2 (m, 10H-aromatic). MS m/z 812 (M+), 767, 719. Anal.
found C 51.85, H 5.21, P 7.77; calcd for C35H42O18P2 (812.64) C 51.73, H 5.21, P 7.62.
2.7.11. Phenyl 4,6-O-benzylidene-2,3-O-bis((4R,5R)-dicarbo-n-butoxy-1,3,2-dioxaphospholyl-2)-β-D-
glucopyranoside 2k
Colorless oil; [α]D24=−87.4 (c 1.0, THF); yield 16.7 g (90%). 31P {1H} NMR (C6D6) δ=146.6, 147.5.
1H NMR (C6D6) δ=1.02 (t, J=7.3, 3H), 1.03 (t, J=7.2, 3H), 1.07 (t, J=7.1, 3H), 1.13 (t, J=7.3, 3H),
0
0
1.25–1.86 (m, 16H), 3.39 (ddd, J56 =5.0, J56=10.1, J54=9.3, H-5), 3.69 (dd, J56=10.1, J66 =10.4, H-6),
3.70 (dd, J54=9.3, J34=9.0, H-4), 3.91 (q, J=7.1, 1H), 3.92 (q, J=7.2, 1H), 3.94 (q, J=6.9, 2H), 4.09 (q,
J=7.3, 1H), 4.09 (q, J=6.8, 1H), 4.19–4.49 (m, 9H), 4.68–4.84 (m, H-2, H-3), 5.15 (d, J12=7.1, H-1),
5.24 (dd, JHH=6.7, JPH=8.5, 1H), 5.27 (dd, JHH=6.7, JPH=8.6, 1H), 5.56 (s, H-b), 5.80 (d, JHH=6.7, 1H),
5.98 (d, JHH=6.7, 1H), 7.2–8.2 (m, 10H-aromatic). MS m/z 924 (M+), 831. Anal. found C 55.85, H 6.36,
P 6.86; calcd for C43H58O18P2 (924.84) C 55.84, H 6.32, P 6.70.

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R. Kadyrov et al. / Tetrahedron: Asymmetry 9 (1998) 329–340
2.7.12. [Rh(2c)(COD)]BF4 6c
The phosphite 2c (360 mg, 0.5 mmol) and [Rh(COD)2]BF4 (203 mg, 0.5 mmol) were dissolved in
40 ml of THF and heated to reflux. The cooled solution was clarified by filtration through Celite and
evaporated to 8 ml under reduced pressure. Ether was added and a yellow precipitate was filtered, washed
with ether and dried under vacuum. Yield 436 mg (86%). 31P NMR ((CD3)2CO) δ=109.6 (1JRhP=255.9,
2
1
2JPP=60.2, JPH=9.7), 111.0 (1JRhP=259.1, JPP=60.0, JPH=9.3). H NMR (CDCl3) δ=2.4–2.9 (br. m,
0
0
4×CH2), 3.43 (dd, J54=9.2, J34=9.4, H-4), 3.49 (dd, J56=10.3, J66 =10.4, H-6), 3.75 (ddd, J56 =4.9,
0
0
0
J56=10.3, J54=9.2, H-5), 4.17 (dd, J56 =4.9, J66 =10.4, H-6 ), 4.39 (dd, J12=7.4, J23=8.3, JPH=9.3, H-2),
4.96 (s, H-b), 5.24 (d, J12=7.4, H-1), 5.46 (ddd, J23=8.7, J34=9.4, JPH=9.6, H-3), 6.0–6.4 (br. s, 4×CH),
6.6–7.7 (m, 10H-aromatic). 13C NMR ((CD3)2CO) δ=30.2, 30.4 (2×CH2), 65.6 (CH), 67.9 (CH2), 77.9
(d, JPC=12.8, CH), 79.6 (d, JPC=2.8, CH), 99.2 (d, JPC=5.7, CH), 111.8 (br. m, CH), 112.9 (br. m,
CH), 113.4 (CH), 115.6 (t, JPC=14.3, C), 117.2, 123.4, 124.1, 124.4, 126.5 (CH), 128.1 (d, JPC=3.8,
CH), 128.19, 128.24, 128.3, 128.1, 129.4 129.5 (CH), 135.4, 135.5, 137.4 (C), 144.02 (dd, JPC=24.8,
J
PC=9.5), 144.37 (dd, JPC=10.5, JPC=3.8), 156.8 (C). Anal. found C 54.80, H 4.23, P 6.90; calcd for
C47H42BF4O10P2Rh (1018.5) C 55.43, H 4.16, P 6.08.
2.7.13. Reaction of 2h with [Rh(COD)2]BF4
Similarly, from phosphite 2h (378 mg, 0.5 mmol) and [Rh(COD)2]BF4 (203 mg, 0.5 mmol) 442
mg of a yellow solid were obtained. According to the 31P NMR spectrum this was a mixture of
[Rh(2h)(COD)]BF4 (6h) and probably [Rh(2h)2]BF4. 31P{1H} NMR (CDCl3) δ=140.8 (1JRhP=250.4,
2JPP=54.1), 144.5 (1JRhP=250.7, 2JPP=54.1) and broad multiplet at 150–155 ppm. The 1H NMR (CDCl3)
spectrum of the mixtures showed two sets of signals for ligand 2h.
2.7.14. [Pt(2c)Cl2] 7c
A solution of phosphite 2c (288 mg, 0.4 mmol) in 3 mL of THF was added to a solution of
[Pt(COD)Cl2] (152 mg, 0.4 mmol) in 5 mL CH2Cl2 and the mixture was stirred overnight. The
precipitate was filtered, washed with ether and dried under vacuum. Yield 205 mg (51%). 31P NMR
2
2
1
(CDCl3) δ=62.6 (1JPtP=5926.5, JPP=29.5, JPH=9.7), 63.8 (1JPtP=5958.6, JPP=29.5, JPH=11.8). H
0
0
NMR (CDCl3) δ=3.41 (ddd, J56 =5.0, 0.5|J56+J54|=9.7, H-5),03.63 (dd, 0.5|J65+J66 |=10.3, H-6), 3.67
0
0
(dd, 0.5|J45+J43|=9.5, H-4), 4.24 (dd, J56 =5.0, J66 =10.5, H-6 ), 4.79 (dd, J12=7.5, J23=9.0, JPH=11.3,
H-2), 4.98 (ddd, J23=9.0, J34=10.5, JPH=9.3, H-3), 4.99 (d, J12=7.4, H-1), 5.02 (s, H-b), 6.08 (d, 2H-
aromatic), 6.75 (d, 2H-aromatic), 7.00–7.46 (m, 24H-aromatic). 13C NMR (CDCl3) δ=66.6 (CH), 68.4
(CH2), 78.2 (CH), 79.7 (d, JPC=4.8, CH), 80.0 (d, JPC=5.7, CH), 99.1, 102.1, 117.4, 122.7 (d, JPC=8.2),
123.1, 124.1, 126.7, 127.3, 127.5, 128.65 (CH), 128.98, 129.08 (C), 129.13, 129.79, 129.87, 130.37 (d,
J
J
PC=6.7), 130.51 (d, JPC=11.4), 130.77 (d, JPC=13.3), 131.01 (d, JPC=12.4) (CH), 136.6, 148.50 (d,
PC=10.5), 148.62 (d, JPC=9.5), 148.69 (d, JPC=10.5), 148.81 (d, JPC=12.4), 156.3 (C). Anal. found C
48.12, H 3.52, P 5.83; calcd for C39H30Cl2O10P2Pt (986.59) C 47.48, H 3.06, P 6.28.
2.7.15. [Pt(2d)Cl2] 7d
A solution of phosphite 2d (387 mg, 0.5 mmol) in 5 mL of THF was added to a solution of
[Pt(COD)Cl2] (187 mg, 0.5 mmol) in 5 mL CH2Cl2 and the mixture was stirred overnight. The solvent
was evaporated in vacuum and the residue crystallized from acetone at −78°C. Yield 245 mg (47%). 31
P
NMR (CDCl3) δ=80.78 (1JPtP=5785.2, 2JPP=30.5, JPH=9.7), 81.08 (1JPtP=5773.4, 2JPP=30.5, JPH=9.7).
1H NMR (CDCl3) δ=3.58 (ddd, J56 =5.0, 0.5|J56+J54|=9.7, H-5)0, 3.82 (dd, 0.5|J65+J66 |=10.2, H-6), 3.90
0
0
0
0
(dd, 0.5|J45+J43|=9.5, H-4), 4.40 (dd, J56 =5.2, J66 =10.6, H-6 ), 4.97 (dd, J12=7.6, J23=9.5, JPH=9.7,
H-2), 5.12 (d, J12=7.6, H-1), 5.25 (ddd, J23=9.5, J34=9.5, JPH=9.7, H-3), 5.42 (s, H-b), 6.61 (d, 2H-

R. Kadyrov et al. / Tetrahedron: Asymmetry 9 (1998) 329–340
339
aromatic), 7.23–7.56 (m, 18H-aromatic). 13C NMR (DMSO-d6) δ=65.8 (CH), 67.8 (CH2), 77.4 (d,
PC=2.7, CH), 79.6 (d, JPC=7.9, CH), 80.3 (d, JPC=8.0, CH), 98.0, 100.7 (CH), 113.9–114.0 (CH), 114.1
J
(d, JPC=5.7, CH), 114.2 (d, JPC=13.9, C), 114.4 (d, JPC=14.3, C), 116.7, 123.7, 125.2, 125.3, 125.4,
126.2, 128.49, 128.62, 128.69, 128.9, 129.4, 129.9 (CH), 135.4, 135.6, 137.0 (C), 143.64 (dd, JPC=9.5,
J
PC=26.7), 143.92 (dd, JPC=10.0, JPC=17.6), 156.2 (C). Anal. found C 50.46, H 3.64, P 6.86; calcd for
C43H34Cl2O10P2Pt (1038.67) C 49.72, H 3.30, P 5.96.
2.8. Catalytic experiments
2.8.1. Hydrogenation
For hydrogenation at 25°C and 0.1 MPa total pressure, 1 mmol substrate was added to a catalyst
solution prepared in situ from 0.01 mmol [Rh(COD)2]BF4 and 0.01 mmol phosphite in 15 ml THF under
anaerobic conditions.
2.8.2. Hydroformylation
A mixture of 1 mmol substrate, 0.01 mmol of Rh(CO)2(acac) and 0.01–0.05 mmol ligand in 10 ml
solvent was placed into a 40 ml autoclave (Ernst HAAGE, Mühlheim, Germany), pressurized to the
appropriate initial pressure with syngas (CO:H2=1:1) and heated to the reaction temperature. Conversion,
selectivity and enantiomeric excess were determined by GC.
Acknowledgements
The authors thank Mrs. Burneleit, Mrs. Buths, Mrs. Kortus and Mrs. Pribbenow for skillful technical
assistance. We thank the VW-Stiftung, the Max-Planck-Gesellschaft and the Fonds der Chemischen
Industrie for financial support.
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