Rare-earth metal amido complexes supported by bridged bis(β- diketiminato) ligand as efficient catalysts for hydrophosphonylation of aldehydes and ketones

Article abstract of DOI:10.1007/s11426-012-4789-1

A series of rare-earth metal amides supported by a cyclohexyl-linked bis(β-diketiminato) ligand were synthesized, and their catalytic activities for hydrophosphonylation of aldehydes and ketones were developed. Reaction of [(Me₃Si)₂N

Full text of DOI:10.1007/s11426-012-4789-1

SCIENCE CHINA
Chemistry
March 2013 Vol.56 No.3: 329–336
doi: 10.1007/s11426-012-4789-1
• ARTICLES •
· SPECIAL TOPIC · The Frontiers of Chemical Biology and Synthesis
Rare-earth metal amido complexes supported by bridged
bis(-diketiminato) ligand as efficient catalysts for
hydrophosphonylation of aldehydes and ketones
MIAO Hui1, ZHOU ShuangLiu1*, WANG ShaoWu1,2*, ZHANG LiJun1, WEI Yun1,
YANG Song1, WANG FenHua1, CHEN Zheng1, CHEN Yue1 & YUAN QingBing1
1Laboratory of Functionalized Molecular Solids, Ministry of Education; Anhui Laboratory of Molecule-Based Materials,
School of Chemistry and Materials Science, Anhui Normal University, Wuhu 241000, China
2State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences,
Shanghai 200032, China
Received September 12, 2012; accepted October 3, 2012; published online November 20, 2012
A series of rare-earth metal amides supported by a cyclohexyl-linked bis(β-diketiminato) ligand were synthesized, and their
catalytic activities for hydrophosphonylation of aldehydes and ketones were developed. Reaction of [(Me3Si)2N]3RE(-
Cl)Li(THF)3 with the cyclohexyl-linked bis(-diketimine) H2L (1) (L = Cy[NC(Me)CHC(Me)NAr]2, Cy = cyclohexyl, Ar = 2,
6-i-Pr2C6H3) gave the rare-earth metal amides LREN(SiMe3)2 (RE = Nd(2), Sm(3), Dy(4), Er(5), Y(6)). All complexes were
fully characterized by elemental, spectroscopic and single-crystal X-ray analyses. Investigation of the catalytic properties of
the complexes reveals that these complexes exhibited a high catalytic activity towards the hydrophosphonylation of aldehydes
and ketones in the presence of a very low loading of rare-earth metal amides (0.1–1 mol%) at room temperature in a short time.
Rare-earth metal, hydrophosphonylation, aldehyde, ketone
tones for the synthesis of quaternary -hydroxy phospho-
nates [22–24], but the yields of products were always not
good enough and a mixtures of products were sometimes
obtained due to the side reactions [25–27]. Recently, Feng
and co-workers reported that Lewis acids such as Ti(OiPr)4
[28] or Et2AlCl [29] could efficiently catalyze the hydro-
phosphonylation of acetophenones and trifluoromethyl ke-
tones. We have successfully developed the rare-earth metal
complexes containing pyrrolide ligands as the efficient cat-
alysts for hydrophosphonylation of aldehydes and unacti-
vated ketones [30–32]. New catalysts for the hydrophos-
phonylation of ketones are still required.
-Diketiminato ligands have been widely used in organo
rare-earth metal chemistry due to their strong binding to the
rare-earth metals and tunable electronic and steric factors
[33–37]. Various rare-earth metal complexes containing
-diketiminato ligands were synthesized and used as cata-
1 Introduction
The synthesis of -hydroxy phosphonates has attracted
much attentions due to their potential biological activities
[1–3]. The addition of dialkyl phosphites to carbonyl com-
pounds provides a direct and atomic efficient pathway for
the synthesis of -hydroxy phosphonates [4–6]. Various
metal complexes have been demonstrated to be the effective
catalysts for addition of dialkyl phosphites to aldehydes in
terms of hydrophosphonylation of aldehydes [7–21]. In
sharp contrast to hydrophosphonylation of aldehydes, the
hydrophosphonylation of ketones remains a challenge due
to their low reactivities. Indeed, there have been few reports
on the base-catalyzed addition of dialkyl phosphites to ke-
*Corresponding authors (email: slzhou@mail.ahnu.edu.cn; swwang@mail.ahnu.edu.cn)
© Science China Press and Springer-Verlag Berlin Heidelberg 2012
chem.scichina.com www.springerlink.com

330
Miao H, et al. Sci China Chem March (2013) Vol.56 No.3
lysts for polymerization [38, 39] and organic transformation
[40]. In order to further explore the application of rare-earth
metal complexes incorporating -diketiminato ligands, we
herein report synthesis and characterization of bridged
bis(-diketiminato) ligand supported rare-earth metal am-
ides and their catalytic activities for hydrophosphonylation
of aldehydes and ketones.
(1.080 g) yield by treatment of H2L (1) (0.815 g, 1.37 mmol)
with [(Me3Si)2N]3Sm(-Cl)Li(THF)3 (1.215 g, 1.37 mmol)
using the procedures similar to those described above for
the preparation of 2. m.p. 129–131 °C. IR (KBr pellet, cm1):
 = 3061 (w), 2959 (m), 2866 (w), 1622 (m), 1557 (s), 1435
(w), 1362 (w), 1252 (m), 1180 (m), 934 (s), 787 (m), 758
(m), 694 (w); Anal. Calc. for C46H76N5Si2Sm (905.6601): C,
61.00; H, 8.46; N, 7.73. Found: C, 61.22; H, 8.64; N,
7.62%.
2 Experimental
2.1 Materials and methods
2.4 Preparation of LDyN(SiMe3)2 (4)
All syntheses and manipulations of air- and moisture-
sensitive materials were performed under dry argon and
oxygen-free atmosphere using standard Schlenk techniques
or in a glovebox. All solvents were refluxed and distilled
over sodium benzophenone ketyl under argon prior to use
unless otherwise noted. Trans-cyclohexyl-1,2-diamine,
acetylacetone, 2,6-diisopropylaniline were purchased and
used without purification. 2-((2,6-Diisopropylphenyl)
imido)-2-penten-4-one [41] and [(Me3Si)2N]3RE(-Cl)Li
(THF)3 [42, 43], Cy[NHC(Me)CHC(Me)NAr]2 (1) (Cy =
cyclohexyl, Ar = 2, 6-iPr2C6H3) [39] were prepared accord-
ing to literature methods. Elemental analyses were obtained
This compound was prepared as yellow crystals in 84%
(0.910 g) yield from the reaction of H2L (1) (0.704 g, 1.18
mmol) with [(Me3Si)2N]3Dy(-Cl)Li(THF)3 (1.065 g, 1.18
mmol) using the procedures similar to those described
above for the preparation of 2. m.p. 105–107 C. IR (KBr
pellet, cm1):  = 3059 (w), 2959 (w), 2866 (w), 1624 (m),
1555 (s), 1437 (w), 1310 (w), 1257 (m), 1180 (s), 1024 (m),
934 (s), 843 (m), 758 (m). Anal. Calc. for C46H76DyN5Si2
(917.8001): C, 60.20; H, 8.35; N, 7.63. Found: C, 60.50; H,
8.57; N, 7.60%.
2.5 Preparation of LErN(SiMe3)2 (5)
1
on a Perkin-Elmer 2400 Series II elemental analyzer. H
NMR and 13C NMR spectra were recorded on a Bruker
This compound was prepared as yellow crystals in 81%
(0.934 g) yield from the reaction of H2L (1) (0.748 g, 1.25
mmol) with [(Me3Si)2N]3Er(-Cl)Li(THF)3 (1.137 g, 1.25
mmol) using the procedures similar to those described
above for the preparation of 2. IR (KBr pellet, cm1):  =
3059 (w), 2959 (w), 2864 (w), 2374 (w), 1850 (w), 1624 (s),
1504 (w), 1435 (w), 1379 (w), 1362 (w), 1309 (m), 1223 (m),
1181 (s), 1101 (s), 933 (s), 843 (m), 787 (m), 758 (m),
684 (w), 610 (w). Anal. Calc. for C46H76ErN5Si2 (922.5591):
C, 59.89; H, 8.30; N, 7.59. Found: C, 59.93; H, 8.64; N,
7.53%.
1
AV-300 NMR spectrometer (300 MHz for H; 75.0 MHz
for 13C) in C6D6 for rare-earth metal complexes and in
CDCl3 for organic compounds. IR spectra were recorded on
a Shimadzu FTIR-8400s spectrometer (KBr pellet).
2.2 Preparation of LNdN(SiMe3)2 (2)
To a toluene (10.0 mL) solution of H2L (1) (0.882 g, 1.48
mmol) was added a toluene (20.0 mL) solution of
[(Me3Si)2N]3Nd(-Cl)Li(THF)3 (1.308 g, 1.48 mmol) at
room temperature. After the reaction mixture was stirred at
room temperature for 6 h, the mixture was then heated at 80
C for 12 h, the color of the solution was gradually changed
from blue to dark red. The solvent was evaporated under
reduced pressure. The residue was extracted with n-hexane
(15.0 mL). The extractions were combined and concentrated
to about 10.0 mL. The yellow green crystals were obtained
by cooling the concentrated solution at 0 C for several days
(1.131 g, 85 % yield). IR (KBr pellet, cm1):  = 3059 (w),
2934 (w), 2864 (w), 2376 (w), 1624 (s), 1557 (m), 1435 (w),
1379 (w), 1362 (w), 1250 (s), 1180 (s), 1144 (w), 1024 (s),
934 (s), 843 (m), 787 (m), 758 (m), 735 (m) , 694 (w), 609
(w). Anal. Calc. for C46H76N5NdSi2 (899.5421): C, 61.42; H,
8.52; N, 7.79. Found: C, 60.82; H, 8.50; N, 7.54%.
2.6 Preparation of LYN(SiMe3)2 (6)
This compound was prepared as yellow crystals in 86%
(0.773 g) yield from the reaction of H2L (1) (0.635 g, 1.06
mmol) with [(Me3Si)2N]3Y(μ-Cl)Li(THF)3 (0.883 g, 1.06
mmol) using the procedures similar to those described
1
above for the preparation of 2. H NMR (300 MHz, C6D6,
25 C, ppm):  = 7.20–7.03 (m, 6H), 5.19 (s, 1H), 4.36 (m,
1H), 4.16 (s, 1H), 3.31 (m, 1H), 3.18–3.04 (m, 4H), 2.38 (m,
2H,), 1.98 (s, 3H), 1.74 (s, 3H), 1.63 (s, 3H), 1.65–0.95 (m,
6H), 1.41 (s, 3H), 1.65–0.95 (m, 24H), 0.35 (s, 9H), 0.08 (s,
9H). IR (KBr pellet, cm1):  = 3061 (w), 2959 (w), 2934
(w), 2866 (w), 2376 (w), 1910 (w), 1850 (w), 1624 (s), 1557
(m), 1435 (w), 1379 (w), 1362 (w), 1310 (m), 1250 (s), 1180
(s), 1144 (w), 1024 (s), 934 (s), 758 (m), 735 (m) , 694 (w) ,
684 (w). Anal. calc. for C46H76N5Si2Y (844.2060): C, 65.45;
H, 9.07; N, 8.30. Found: C, 65. 49; H, 8.99; N, 8.34%.
2.3 Preparation of LSmN(SiMe3)2 (3)
This compound was prepared as yellow crystals in 87%

Miao H, et al. Sci China Chem March (2013) Vol.56 No.3
331
2.7 X-ray structure determination
produced the rare-erath metal amides with general formula
LREN(SiMe3)2 (L = Cy[NC(Me)CHC(Me)NAr]2, Ar = 2,
6-i-Pr2C6H3, RE = Nd(2), Sm(3), Dy(4), Er(5), Y(6))
(Scheme 1). The complexes are sensitive to air and moisture,
they have a good solubility in either polar solvents or non-
polar solvents. All complexes were fully characterized by
IR, elemental analyses and single-crystal X-ray analyses.
A suitable crystal of complexes 2–6 was mounted in a
sealed capillary. Diffraction was performed on a Siemens
SMART CCD-area detector diffractometer using the graphite-
monochromated Mo-K radiation ( = 0.71073 Å), temper-
ature 293(2) K,  and  scan technique; SADABS effects
and empirical absorption were applied in the data correc-
tions. All structures were solved by direct methods
(SHELXL-97), completed by subsequent difference Fourier
syntheses, and refined by full-matrix least-square calcula-
tions based on F2 (SHELXL-97). Crystal date and details of
date collection are given in Table 4. CCDC-895685 (2),
CCDC-895686 (3), CCDC-895687 (4), CCDC-895688 (5)
and CCDC-895689 (6) contain the supplementary crystallo-
graphic data of this paper. These data can be obtained free
of charge from the Cambridge Crystallographic Data Centre
via www.ccdc.cam.ac.uk/data_request/cif.
1
The complex 6 was also characterized by H NMR spectra
analyses.
X-ray analyses reveals that complexes 2–6 are isostruc-
tural mononuclear structures, and a representative structure
diagram of complex 2 is shown in Figure 1 and Figure 2.
The rare-earth metal adopts a distorted square pyramidal, in
which the N(SiMe3)2 ligand occupies the apical position and
the four N atoms of the bridged β-diketiminato moieties
form the basis. The substituted aryl groups take the transoid
fashion in all complexes with one aryl substituent pointing
away from the amido group and the other aryl group point-
ing towards the amido group. The selected bond lengths and
angles are listed in Table 1.
From Table 1, we can see that the usual consequences of
the reduced of the ionic radius of the RE3+ ion when moving
from Nd3+ to Er3+ are clearly reflected by the average RE-N
distances of 2.433(2) Å found in 2, 2.402(2) Å found in 3,
2.350(2) Å found in 4, 2.324(2) Å found in 5, and 2.340(2)
Å in 6; but the lanthanide contraction is contrary reflected
by the average RE-C contacts of 3.048(2) Å in 2, 3.049(2)
Å in 3, 3.063(2) Å in 4, 3.064(2) Å in 5, and 3.063(2) Å in 6,
indicating steric effects on the Ln-C bonding. In comparison
with RE-C contacts (2.97–3.17 Å) in 2–6 with the La-C
contacts (2.97–3.19 Å) [37], both -diketiminato moieties in
complexes 2–6 are in the 5 bonding modes, are different to
the lanthanum amide supported by an ethylene-linked
bis(-diketiminato) ligand [37, 39]. In which RE-C contacts
(both -diketiminato fragment) deviate much more dramat-
ically, indicating that one -diketiminato fragment is bond-
ed in an 2 fashion with the lanthanum atom (La-C contacts,
3.446(3)–3.752(3) Å), the other -diketiminato moiety is
bonded in an 5 fashion with the lanthanum atom (La-C
contacts, 3.014(3)–3.180(3) Å) [37, 39].
2.8 General procedure for hydrophosphonylation of
aldehydes and ketones
A 30.0 mL Schlenk tube under dried argon was charged
with the complex 3 (9.0 mg, 0.01 mmol), diethyl phosphite
(1.657 g, 12 mmol) and solvent-free or toluene (3.0 mL),
and benzaldehyde (1.061 g, 10 mmol) was then added to the
mixture. The resulting mixture was stirred at room temper-
ature for 3 min. After the reaction was completed, the reac-
tion mixture was hydrolyzed with water, extracted with di-
ethyl ether, dried over anhydrous sodium sulfate and filtered.
After the solvent was removed under the reduced pressure,
the final products were further purified by recrystallization
from ethyl acetate. Compound 7a was isolated as white
crystals (2.395 g, 98%).
Compounds 7b–7v were synthesized by similar proce-
dures as those used for the preparation of 7a. Their NMR
data can be obtained in the Supporting Information.
3 Results and discussion
3.1 Synthesis and characterization of rare-earth metal
amides
3.2 Catalytic hydrophosphonylation of aldehydes and
ketones
Treatment of H2L(1) with 1 equiv. of lanthanide amides
[(Me3Si)2N]3RE(-Cl)Li(THF)3 in toluene at 60–80 C
The additions of diethyl phosphite to benzaldehyde were
Scheme 1 Synthesis of rare-earth metal amides.

332
Miao H, et al. Sci China Chem March (2013) Vol.56 No.3
Figure 1 Representative structure of rare-earth metal amides incorporat-
ing bridged bis(-diketiminato) ligand. Hydrogen atoms are omitted for
clarity.
Figure 2 Packing arrangement in the unit cell of representative rare-earth
metal amide incorporating bridged bis(-diketiminato) ligand.
Table 1 Selected bond length (Å) and bond angle (°) of complexes 2–6
2
3
4
5
6
RE(1)–N(1)
2.542(2)
2.435(2)
2.424(2)
2.368(2)
2.398(2)
2.433(2)
3.151(2)
3.110(2)
2.982(2)
2.968(2)
3.055(2)
3.021(2)
3.048(2)
75.05(8)
131.32(8)
135.39(8)
97.17(8)
97.02(8)
64.81(8)
136.26(8)
74.36(8)
117.97(8)
98.56(8)
2.494(2)
2.406(2)
2.347(2)
2.391(2)
2.373(2)
2.402(2)
3.133(2)
3.112(2)
2.972(2)
2.971(2)
3.081(2)
3.024(2)
3.049(2)
75.09(6)
135.85(6)
130.93(7)
97.48(7)
65.98(7)
95.62(7)
138.55(7)
74.61(7)
98.15(7)
117.66(7)
2.440(2)
2.360(2)
2.306(2)
2.329(2)
2.315(2)
2.350(2)
3.134(2)
3.166(2)
2.982(2)
2.989(2)
3.110(2)
2.998(2)
3.063(2)
76.76(6)
138.95(7)
128.33(6)
98.41(6)
67.23(7)
96.78(7)
140.81(7)
76.51(6)
97.33(7)
115.01(7)
2.408(2)
2.336(2)
2.284(2)
2.296(2)
2.296(2)
2.324(2)
3.121(2)
3.170(2)
2.978(2)
2.996(2)
3.126(2)
2.993(2)
3.064(2)
76.97(8)
139.10(8)
128.02(8)
98.51(8)
68.09(8)
95.64(8)
141.95(9)
77.34(8)
96.25(9)
115.18(8)
2.294(2)
2.318(2)
2.351(2)
2.422(2)
2.315(2)
2.340(2)
2.997(2)
3.125(2)
2.999(2)
2.976(2)
3.157(2)
3.125(2)
3.063(2)
76.72(8)
67.64(8)
138.74(8)
97.01(9)
95.52(8)
128.37(8)
115.37(8)
76.80(8)
141.87(8)
98.35(8)
RE(1)–N(2)
RE(1)–N(3)
RE(1)–N(4)
RE(1)–N(5)
RE–Nav
RE(1)–C(14)
RE(1)–C(15)
RE(1)–C(16)
RE(1)–C(25)
RE(1)–C(26)
RE(1)–C(27)
RE(1)–Cav
N(1)–RE(1)–N(2)
N(1)–RE(1)–N(3)
N(1)–RE(1)–N(4)
N(1)–RE(1)–N(5)
N(2)–RE(1)–N(3)
N(2)–RE(1)–N(4)
N(2)–RE(1)–N(5)
N(3)–RE(1)–N(4)
N(3)–RE(1)–N(5)
N(4)–RE(1)–N(5)
first optimized using the rare-earth metal amido complexes
2–6 as catalysts, and the results are summarized in Table 2.
From the table, we can see that the additions of diethyl
phosphite to benzaldehyde afforded the product 7a in high
yields (96%) by using 0.1 mol% of the complex 3 as a
catalyst in toluene or under solvent-free conditions (Table 2,
entries 2 & 7) in 3 min. It was found that the activity of the
catalytic reaction decreased as the temperature decreased
(Table 2, entries 4–6). It was also found that the RE(III)
ionic radii of the complexes had a little influence on the
hydrophosphonylation reaction of benzaldehyde (Table 2,
entries 8–11). Further exploration reveals that the additions
of diethyl phosphite to unactivated acetophenone (Table 2,
entries 12–18) provided a satisfactory yield requiring 1

Miao H, et al. Sci China Chem March (2013) Vol.56 No.3
Table 2 Optimizations of hydrophosphonylation of benzaldehyde and acetophenone a)
333
Entry
1
Catalyst (mol%)
3 (0.3)
3 (0.1)
3 (0.05)
3 (0.1)
3 (0.1)
3 (0.1)
3 (0.1)
2 (0.1)
4 (0.1)
5 (0.1)
6 (0.1)
3 (0.1)
3 (0.5)
3 (1.0)
3 (1.0)
3 (1.0)
3 (1.0)
3 (1.0)
R
H
Solvent
toluene
Temperature (°C)
Time (min)
Yield (%) b)
r.t.
r.t.
r.t.
15
78
r.t.
r.t.
r.t.
r.t.
r.t.
r.t.
r.t.
r.t.
r.t.
r.t.
78
r.t.
r.t.
3
99
99
70
96
86
98
98
96
98
97
98
48
63
81
92
75
86
89
2
H
toluene
60
3
H
toluene
180
360
360
60
4
H
toluene
5
H
toluene
6
H
THF
7
H
solvent free
solvent free
solvent free
solvent free
solvent free
toluene
3
8
H
3
9
H
3
10
11
12
13
14
15
16
17
18
H
3
H
3
CH3
CH3
CH3
CH3
CH3
CH3
CH3
180
180
180
360
360
360
360
toluene
toluene
toluene
toluene
n-hexane
THF
a) Reactions were performed with 10 mmol of PhCHO or PhCOCH3 and 12 mmol of H(O)P(OEt)2 in 3 mL of solvent or solvent-free; b) isolated yields.
Table 3 Hydrophosphonylation of aldehydes and ketones catalyzed by complex 3 a)
Entry
1
R1
Ph
R2
H
Loading (mol%)
Product
7a
7b
7c
Yield (%) b)
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
98 c)
2
4-O2NC6H4
2-O2NC6H4
3-FC6H4
4-FC6H4
2,4-ClC6H3
4-ClC6H4
4-MeC6H4
4-Me2NC6H4
4-CH3OC6H4
2-furyl
H
97
3
H
96
4
H
7d
7e
98 (93) d)
5
H
99 (95) d)
6
H
7f
96
98
99 (94) d)
7
H
7g
7h
7i
8
H
9
H
96
10
11
12
13
14
15
16
17
18
19
20
21
22
H
7j
99 (95) d)
98
H
7k
7l
Ph
Me
Me
Me
Me
Me
Me
Me
Ph
Me
Me
Et
92
3-O2NC6H4
3-ClC6H4
3-BrC6H4
4-BrC6H4
4-FC6H4
4-MeC6H4
Ph
7m
7n
7o
7p
7q
7r
96
91
99
98
99
95
7s
90
Me
7t
93
Pr
7u
7v
91
Et
94
a) Reaction conditions: aldehyde (10.0 mmol), diethyl phosphite (12.0 mmol), solvent: toluene (3 mL), room temperature; b) isolated yields; c) solvent-
free, time: 3min; d) solvent-free, time: 20 min.

334
Miao H, et al. Sci China Chem March (2013) Vol.56 No.3
Table 4 Crystallographic data for complexes 2–6
Crustal date
2
3
4
5
6
Formula
C46H76N5NdSi2
901.55
C46H76N5Si2Sm
905.65
C46H76DyN5Si2
917.80
C46H76ErN5Si2
922.56
C46H76N5Si2Y
844.21
Formula weight
Crystal system
triclinic
triclinic
triclinic
triclinic
triclinic
Space group
P1
11.7342(6)
12.2984(7)
18.4593(10)
89.1920(10)
78.7950(10)
69.4310(10)
2442.3(2)
293(2)
P1
11.7098(8)
12.3577(8)
18.5422(12)
88.8040(10)
75.1870(10)
70.3320(10)
2436.4(3)
293(2)
P1
11.7822(8)
12.1763(8)
18.4610(12)
89.4620(10)
78.1540(10)
68.8690(10)
2411.7(3)
293(2)
P1
11.7259(6)
12.2729(7)
18.4586(10)
88.4790(10)
75.5660(10)
69.8730(10)
2410.3(2)
293(2)
P1
11.7363(13)
12.2862(14)
18.491(2)
88.5010(10)
75.4680(10)
69.9540(10)
2419.4(5)
293(2)
a (Å)
b (Å)
c (Å)
 (°)
 (°)
 (°)
V (Å3)
T (K)
Z
2
2
2
2
2
Dcalcd (g cm3)
 (mm1)
1.226
1.235
1.264
1.271
1.159
1.146
1.288
1.633
1.825
1.289
1.77–27.68
954
1.75–27.61
954
1.80–27.64
962
1.77–27.69
966
1.77–27.64
908
 range (°)
F (000)
Reflns collected
Unique reflns (Rint)
Parameters
21288
21195
21053
21082
20810
11076 (0.0213)
505
10980 (0.0185)
505
10931 (0.0174)
505
10930 (0.0215)
505
10850 (0.0321)
505
Goodness-of-fit
R1 [I  2(I)]
wR2 [I > 2(I)]
Largest diff. in peak and hole (e Å3)
1.027
1.038
1.069
1.078
0.992
0.0327
0.0261
0.0232
0.0283
0.0470
0.0810
0.0786
0.0605
0.0703
0.1038
0.597, 0.660
0.602, 0.529
0.594, 0.722
0.661, 0.639
0.540, 0.381
mol% of the rare-earth metal amido complex in 6 h (Table 2,
entry 15).
lylamine elimination reaction of [(Me3Si)2N]3RE(-Cl)Li
(THF)3 (RE = Nd, Sm, Dy, Er and Y) with Cy[NHC(Me)-
CHC(Me)NAr]2 in toluene in good yields. All complexes
exhibited an excellent catalytic activity for hydrophospho-
nylation of aldehydes and ketones. The catalysts have the
advantages of a high efficiency, a low catalyst loading, a
wide of solvents and substrates compatibility, and mild
conditions. The results represent the first application of the
bridged bis(-diketiminato) rare-earth metal amido com-
plexes for hydrophosphonylation on both aldehydes and
ketones. Further investigations of asymmetric hydrophos-
phonylation of aldehydes and ketones catalyzed by chiral
organolanthanide complexes are in progress.
Next, we examined hydrophosphonylations of a wide va-
riety of aldehydes in the presence of the samarium amide 3
as a catalyst (0.1 mol%) in toluene or under solvent-free
conditions at room temperature, the hydrophosphonylation
of ketones were carried out in the presence of 1 mol% of 3
in toluene at room temperature (Table 3). The results
showed that the additions of diethyl phosphite to aromatic
aldehydes afforded the corresponding α-hydroxy phospho-
nates in excellent yields (95%), regardless of the electronic
natures or the steric effects of the substituents on the aryl
groups (Table 3, entries 1–11). It is worth noting that the
addition of diethyl phosphate to aromatic or aliphatic ke-
tones could also provide corresponding -hydroxy phos-
phonates in high yields (Table 3, entries 12–22).
This work was co-supported by the National Natural Science Foundation
of China (20832001, 21072004, 21172004, 21172003) and the National
Basic Research Program of China (2012CB821604). We are also grateful
for the assistance of Fuyang Teachers College and Prof. Jiping Hu in
running IR and NMR spectra.
4 Conclusion
A series of rare-earth metal amides supported by a cyclohexyl-
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