Neutral yttrium tris(amide) and ate complexes coordinated by an (R)-N,N′-diisopropyl-1,1′-binaphthyl-2,2′-diamido ligand as enantioselective catalysts for intramolecular hydroamination

Article abstract of DOI:10.1002/ejic.200600872

A bis(amido)yttrium chloride coordinated by (R)-N,N′-diisopropyl-1, 1′-binaphthyl-2,2′-diamide [Y{(R)-C₂₀H ₁₂(NiPr)₂}-Cl(thf)₂] has been prepared and characterized by X-ray analysis along with the corresponding

Full text of DOI:10.1002/ejic.200600872

FULL PAPER
DOI: 10.1002/ejic.200600872
Neutral Yttrium Tris(amide) and Ate Complexes Coordinated by an (R)-N,NЈ-
Diisopropyl-1,1Ј-binaphthyl-2,2Ј-diamido Ligand as Enantioselective Catalysts
for Intramolecular Hydroamination
[
a]
[a]
[b]
[a]
David Riegert, Jacqueline Collin,* Jean-Claude Daran, Tauqir Fillebeen,
[a]
[c]
[c]
[c]
Emmanuelle Schulz, Dmitrii Lyubov, Georgy Fukin, and Alexander Trifonov*
Keywords: Asymmetric catalysis / N ligands / Yttrium / Hydroamination / Nitrogen heterocycles
A bis(amido)yttrium chloride coordinated by (R)-N,NЈ-di-
isopropyl-1,1Ј-binaphthyl-2,2Ј-diamide [Y{(R)-C20 12(NiPr) }-
Cl(thf) ] has been prepared and characterized by X-ray
analysis along with the corresponding yttrium ate complex
Li(thf) ][Y{(R)-C20 12(NiPr) ]. The reaction of [(R)-N,NЈ-di-
NMRspectroscopy.Thenewcomplexes[Y{(R)-C20
2
H12(NiPr) }-
H
2
{NiPr }] and [{Li(thf) }(Y{(R)-C20 12(NiPr) )], which contain
2
4
H
2 2
}
2
the same enantiopure binaphthyldiamido ligand, are com-
pared for the catalysis of several intramolecular hydroamin-
ation reactions. Both complexes provide pyrrolidines and
[
4
H
2 2
}
isopropyl-1,1Ј-binaphthyl-2,2Ј-diamido]yttrium chloride with piperidines with moderate to high enantioselectivities.
lithium diisopropylamine leads to the formation of a neutral
tris(amido)yttrium complex which was characterized by
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2007)
Introduction
thyl group synthesized by Marks et al. that possess two ste-
reogenic centers (backbone and lanthanide chirality, see A
[
6]
in Figure 1).
Diastereomeric mixtures and dia-
The intramolecular hydroamination of alkenes is an
atom-economic process that leads to the formation of nitro-
gen heterocycles that are found in numerous biologically
stereomerically pure precatalysts yielded the formation of
pyrrolidines with identical enantiomeric excesses of up to
74% ee. Similar rare-earth metal complexes with an octahy-
drofluorenido group instead of a tetramethylcyclopen-
tadienido group (structure B in Figure 1) have been isolated
and have been found to be more efficient for the prepara-
[
1]
active compounds. The pioneering work of Marks and co-
workers has shown the ability of lanthanocenes to perform
hydroamination/cyclization reactions.[2] More recently non-
[3]
cyclopentadienido rare-earth complexes as well as transi-
tion metal complexes and others[4] have been reported to
catalyze the intramolecular hydroamination of alkenes.
However, enantioselective hydroamination reactions have
[
7]
tion of piperidines (up to 67% ee). Both series of com-
plexes were prepared in a two-step synthesis that includes
the formation of a metal chloride followed by its transfor-
mation into the amido or alkyl complex. Chiral lanthanide
bis(aryloxide)s and bis(naphthoxide)s have been prepared
by a different route and studied for the catalysis of amino-
alkene cyclization. Scott et al. have thus synthesized chiral
rare-earth metal bis(aryloxide) complexes by the reaction of
the ligand [a bis(phenol) with a bis(arylamine) providing
the chirality, structure C] with the tris(amide) precursors
been less studied and only a few chiral asymmetric catalysts
have been reported to date.[5]
Chiral catalysts that are efficient for the asymmetric
cyclization of aminoalkenes are almost all prepared from
lanthanides with different types of ligands and are either
isolated or used in situ. The first enantioselective catalysts
reported for hydroamination/cyclization were the ansa-lan-
thanocene complexes substituted by a menthyl or neomen-
[
8]
[
Ln{N(SiHMe ) } (thf) ]. The lanthanum complex was
2 2 3 2
found to cyclize an aminopentene, albeit with low activity
reaction performed at 70 °C), with 61% ee. A similar chiral
a] Equipe de Catalyse Moléculaire, ICMMO, UMR 8182, Uni- cationic zirconium complex has also been characterized and
versité Paris-Sud,
(
[
tested for the hydroamination/cyclization of secondary
9
1405 Orsay, France
[
9]
amines; it affords 82% ee for a piperidine. Hultzsch et
Fax: +33-1-69154680
E-mail: jacollin@icmo.u-psud.fr
b] Laboratoire de Chimie de Coordination,
al. have synthesized various lanthanide bis(phenolate)s and
[
[
[10]
bis(naphtholate)s. They isolated dimeric alkyllanthanum
2
05 route de Narbonne, 31077 Toulouse, France
c] G. A. Razuvaev Institute of Organometallic Chemistry of Rus- bis(phenolate) complexes from the reaction of 3,3Ј-substi-
sian Academy of Sciences,
tuted bis(phenol) with [La{CH(SiMe ) } ] which exhibited
3
2 3
Tropinia 49, 603600 Nizhny Novgorod GSP-445, Russia
Fax: +7-8312-127497
only low enantioselectivity for hydroamination reac-
[
10a]
E-mail: trif@imoc.sinn.ru
tions.
The amidoyttrium biphenolate and binaphtholate
Eur. J. Inorg. Chem. 2007, 1159–1168
© 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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J. Collin, A. Trifonov et al.
FULL PAPER
Figure 1. Complexes for intramolecular hydroamination reactions.
complexes synthesized according to a similar procedure ation catalysts and that the stereoselectivity and the rate of
(
complex D in Figure 1) afforded moderate activities in the reaction can be tuned by varying the diamine li-
[
3b,3d]
these transformations, with enantiomeric excesses of up to gands,
5
the preparation of chiral lanthanide tris-
To the best of our knowledge, the highest enantio- (amide)s for the enantioselective catalysis of hydroamin-
[
10b]
7%.
selectivities obtained for intramolecular hydroamination are ation reactions has been a challenge. Interesting results have
provided by chiral lanthanide 3,3Ј-tris(arylsilyl)binaph- been reported by the group of Scott, who prepared precata-
tholates prepared by arene, alkane or amine elimination lysts by the reaction of bis(arylamine)s possessing axial chi-
and used in situ. The yttrium,[
10c]
lutetium, and scandium rality with lanthanide tris(amide)s. These complexes (struc-
binaphtholates prepared from [Ln{o-C H CH NMe } ] ture H in Figure 1) catalyze the cyclization of 2,2-dimeth-
6
4
2
2 3
and 3,3Ј-bis(triarylsilyl)binaphthol (structure E) allow the ylpent-4-enylamine at 60 °C, albeit with only moderate
[
14]
cyclization of aminopentenes to be performed at room tem- asymmetric inductions.
perature with high turnovers and with enantiomeric ex-
Other enantioselective catalysts nide catalysts coordinated by chiral amido ligands for intra-
have also been prepared by the same procedure and used in molecular hydroamination.
We have previously reported the preparation of lantha-
cesses of up to 95%.[
10d]
[
15]
A new family of lanthanide
situ. The amidoyttrium compounds synthesized by Liv- ate complexes [Li(thf) ][Ln{(R)-C H (NR) } ] (Ln = Yb,
4
20 12
2 2
inghouse et al. from [Y{N(TMS) } ] and chiral bis(thiolate) Sm, Nd, Lu; 1 in Scheme 1) derived from chiral, disubsti-
2
3
ligands (complex F) catalyze the cyclization of aminoal- tuted (R)-binaphthylamido ligands was studied. These com-
kenes at 60 °C and with enantiomeric excesses above 80% pounds consist of a complex anion resulting from coordina-
for several substrates.[ Similarly, by the reaction of lan- tion of two (R)-binaphthylamine ligands to the lanthanide
11]
+
thanide amides with commercially available C -symmetric atom and a discrete [Li(thf) ] counterion. Both the influ-
2
4
bis(oxazoline)s, Marks et al. have prepared enantioselective ence of the lanthanide and of the alkyl substituent on the
catalysts (structure G in Figure 1) that are active at room nitrogen groups was examined in a hydroamination test re-
temperature (up to 67% ee).[ A chiral, bridged aminotro- action. The activity and enantioselectivity of these catalysts
poniminate complex of lutetium was very recently synthe- were evaluated for the cyclization of C-(1-allylcyclohexyl)-
12]
[
13]
sized by Roesky that shows moderate enantioselectivities methylamine. The ytterbium and lutetium complexes with
for intramolecular hydroamination. bulky substituents (isopropyl, cyclohexyl) on the nitrogen
Since the pioneering work of Livinghouse et al. that atom led to the highest enantioselectivities (up to 76% ee
showed that lanthanide tris(amide)s are active hydroamin- for the spiropyrrolidine).
1160
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Eur. J. Inorg. Chem. 2007, 1159–1168

Yttrium Complexes as Enantioselective Hydroamination Catalysts
FULL PAPER
[
18]
C H (NiPr) }
in thf at ambient temperature allowed
2
0
12
2
the isolation of the chiral diamidoyttrium chloride complex
in 81% yield (Scheme 2).
2
Scheme 2. Synthesis of the neutral yttrium complex [Y{(R)-
12(NiPr) }Cl(thf) ] (2).
C
20
H
2
2
Complex 2 was purified by extraction of the solid residue
with toluene after evaporation of thf and subsequent
1
13
recrystallization from thf/hexane mixtures. The H and
C
NMR spectra of complex 2 in C D at 20 °C show the ex-
6
6
pected sets of resonances due to the (R)-N,NЈ-diisopropyl-
,1Ј-binaphthyl-2,2Ј-diamido ligand and the coordinated
1
thf molecules.
This salt metathesis reaction turned out to be highly sen-
sitive to the substituent on the nitrogen atom of the starting
Scheme 1. Intramolecular hydroamination catalyzed by chiral lan-
thanide ate complexes.
(R)-1,1Ј-binaphthyl-2,2Ј-diamine. Thus, the reaction
of equimolar amounts of YCl and the dilithium derivative
3
of (R)-N,NЈ-diphenyl-1,1Ј-binaphthyl-2,2Ј-diamine under
analogous conditions afforded the ate complex [Li(thf)4]-
In order to gain insight into the nature of the active cata-
lytic species for the hydroamination reaction mediated by
the ionic compounds [Li(thf) ][Ln{(R)-C H (NR) } ], we
[
Y{(R)-C H (NPh) } ] (3) in 42% yield instead of the ex-
20 12 2 2
pected complex [Y{(R)-C H (NPh) }Cl(thf) ] (Scheme 3).
20
12
2
n
4
20 12
2 2
considered the synthesis of both neutral and ate complexes
of the same metal coordinated with the same chiral ligand
and compared their catalytic properties.
Results and Discussion
Preparation and Characterization of Complexes
Scheme 3. Synthesis of the yttrium ate complex [Li(thf)
12(NPh) ] (3).
4
][Y{(R)-
C
20
H
2 2
}
With the aim of preparing neutral tris(amido)lanthanide
complexes [Ln{(R)-C H (NR) }{NRЈ }] with binaph-
Complex 3 was purified by extraction of the solid residue
2
0
12
2
2
thylamino ligands, we focused on the synthesis of yttrium obtained after evaporation of thf with hot toluene. Slow
derivatives since yttrium tris(amide)s have been already cooling of hot solutions of 3 in toluene afforded crystalline
1
13
synthesized and characterized by X-ray analysis. Several samples. The H and C NMR spectra of complex 3 in
lanthanide tris(amide)s have been prepared by metathesis C D at 20 °C show the expected sets of signals correspond-
6
6
[
16]
reactions, and yttrium complexes coordinated by a chiral ing to the aromatic protons of the diamido ligand and the
bis(arylamido) ligand have been used as enantioselective coordinated thf molecules.
hydrosilylation catalysts.[17]
In order to synthesize the amidoyttrium complex con-
Initially, we attempted to use the amine elimination reac- taining a chiral ancillary ligand, we carried out the reaction
tion as a synthetic approach to the neutral complexes of complex 2 with LiNiPr2 in thf at room temperature
[
Ln{(R)-C H (NR) }{NRЈ }] (Ln = Y, La, Sm; R = (Scheme 4). After evaporation of thf, the crude complex
2
0
12
2
2
CH CMe , iPr; RЈ
=
SiMe3). Thus, reactions of [Y{(R)-C H (NiPr) }{NiPr }{LiCl(thf) }] (4) was charac-
2
3
20 12
1
2
2
2
13
[
Ln{N(SiMe ) } ] (Ln = Y, La, Sm) with chiral diamines terized by H and C NMR spectroscopy. According to the
3 2 3
1
(
R)-C H (NHR) (R = CH CMe , iPr) in a 1:1 molar ra-
H NMR spectrum, complex 4 contains two molecules of
2
0
12
2
2
3
tio were carried out in toluene at 70 °C. However, these re- thf. Unfortunately, the experimental data did not allow us
actions were found to occur with complete substitution of to conclude with certainty whether these thf molecules are
the N(SiMe ) groups in the parent tris(amido) complexes coordinated to Y or Li. Extraction of the complex with
3
2
1
since the H NMR spectra of the solid products indicated toluene and recrystallization from thf/hexane resulted in the
the absence of the corresponding signals. The salt metathe- products of ligand-redistribution reactions. All attempts to
sis reaction of anhydrous YCl with 1 equiv. of Li {(R)- isolate individual compounds to obtain samples suitable for
3
2
Eur. J. Inorg. Chem. 2007, 1159–1168
© 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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J. Collin, A. Trifonov et al.
FULL PAPER
2 2 2
Scheme 4. Synthesis of [Y{(R)-C20H12(NiPr) }{NiPr }{LiCl(thf) }] (4).
X-ray analysis failed. We also tried to prepare alkylyttrium
derivatives containing the (R)-N,NЈ-diisopropyl-1,1Ј-bi-
naphthyl-2,2Ј-diamido ligand. However, reactions of 2 with
the alkyllithium reagents LiCH SiMe (toluene 0 °C) and
2
3
MeLi (Et O, 0 °C, in the presence of a twofold molar excess
2
of TMEDA) did not afford any tractable organoyttrium
compounds.
The ate complex [Li(thf) ][Y{(R)-C H (NiPr) } ] (5)
4
20 12
2 2
was synthesized by the metathesis reaction of anhydrous
YCl with 2 equiv. of Li {(R)-C H (NiPr) } in thf at am-
3
2
20 12
2
bient temperature (Scheme 5).
Scheme 5. Synthesis of the ate complex [Li(thf)
12(NiPr) ] (5).
4
][Y{(R)-
Figure 2. ORTEP drawing of complex 2 with the atom labeling
scheme. Ellipsoids are drawn at the 30% probability level. The hy-
drogen atoms have been omitted for clarity. Selected bond lengths
C
20
H
2 2
}
[
2
Å] and angles [°]: Y1–N1 2.254(3), Y1–N2 2.257(4), Y1–Cl1
.5835(14), Y1–C11 2.700(4), Y1–C12 2.756(4), Y1–C21 2.717(4),
Y1–C22 2.746(4); N1–Y1–N2 123.36(15), N1–Y1–Cl1 115.78(12),
Complex 5 was purified by extraction of the solid residue
remaining after evaporation of thf with toluene and subse-
quent recrystallization from thf/hexane mixtures; it was iso- N2–Y1–Cl1 120.86(10).
lated in 71% yield. Complexes 2–5 were obtained as yellow,
highly air- and moisture-sensitive crystalline solids. Com-
plexes 2, 4, and 5 are soluble in thf and toluene and insolu- 2.745(4), Y(1)–C(212) 2.758(4) Å] comparable to those re-
ble in hexane. Complex 3 is soluble in thf and hot toluene. ported for the yttrium π-complexes [({PhP(CH SiMe NSi-
2
2
6
6
[19]
Clear single-crystalline samples of complex 2 suitable for Me CH ) PPh}Y) {η :η -(C H ) }] [2.699(1)–2.738(4) Å]
X-ray investigation were obtained by slow condensation of and [Y(o-2,6-Ph C H ) ] [2.84(1)–3.38(1) Å] probably re-
hexane into the concentrated thf solution at room tempera- flects an η -interaction of the yttrium atom with the aro-
ture. Complex 2 crystallizes in the monoclinic space group matic rings of the binaphthyl ligand, which leads to a satu-
2
2 2
2
6
5 2
[
20]
2
6
3 3
2
P2 with four molecules in the unit cell. The molecular ration of the coordination sphere of the yttrium atom. The
1
structure of 2 is depicted in Figure 2, and the crystal and Y–N bond lengths in 2 [2.254(3) and 2.257(4) Å] are very
structural refinement data are listed in the Experimental close to the length of the covalent bond reported for the
Section. The X-ray single-crystal structure analysis showed amidoyttrium complexes [{[6,6Ј-Me -(C H ) ](2,2Ј-NSi-
2
6
3 2
[
21]
that complex 2 adopts a monomeric structure, thus indicat- Me tBu) }YCl(thf) ] [2.247(7) and 2.252(7) Å]
and
The
2
2
2
[
22]
ing a considerable steric demand of the diamido ligand.
[Cp* Y{N(SiMe ) }] [2.274(1) and 2.253(1) Å].
2 3 2
The coordination sphere of the yttrium atom in 2 con- Y–Cl bond length in 2 [2.5835(14) Å] is comparable to
tains the two nitrogen atoms of the (R)-N,NЈ-diisopropyl- those in [{[6,6Ј-Me -(C H ) ](2,2Ј-NSiMe tBu) }YCl(thf) ]
2
6
3 2
2
2
2
[23]
[
21]
1
,1Ј-binaphthyl-2,2Ј-diamido ligand, one chlorido ligand, [2.574(2) Å] and [Cp* YCl(thf)] (2.579 and 2.577 Å).
2
and two oxygen atoms of two thf molecules. The formal
Clear single-crystal samples of complex 3 suitable for X-
coordination number of the metal atom is five, which is ray investigation were obtained by slow cooling of its hot
rather low for yttrium. The presence in complex 2 of short toluene solution from 70 °C to room temperature. Complex
contacts between the metal atom and the carbon atoms in 3 crystallizes in the orthorhombic space group P2 2 2 with
1
1 1
the ipso and ortho positions to the amido groups [Y(1)– four molecules in the unit cell. Complex 3 was isolated as a
C(211) 2.708(4), Y(1)–C(111) 2.719(5), Y(1)–C(112) solvate containing three molecules of toluene per molecule
1162
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Eur. J. Inorg. Chem. 2007, 1159–1168

Yttrium Complexes as Enantioselective Hydroamination Catalysts
FULL PAPER
+
Figure 3. ORTEP drawing of complex 3 with the atom labeling scheme. Ellipsoids are drawn at the 30% probability level. The Li(thf)
4
cation and the hydrogen atoms have been omitted for clarity. Selected bond lengths [Å] and angles [°]: Y1–N1 2.275(2), Y1–N2 2.267(2),
Y1–N3 2.270(2), Y1–N4 2.288(2), Y1–C26 2.747(2), Y1–C16 2.849(3), Y1–C7 2.727(3), Y1–C39 2.743(3), Y1–C58 2.746(3); N1–Y1–N2
118.47(8), N1–Y1–N3 103.74(8), N2–Y1–N3 104.69(9), N1–Y1–N4 108.65(8), N2–Y1–N4 103.84(8), N3–Y1–N4 118.15(8).
of complex, i.e., [{Li(thf) }(Y{(R)-C H (NPh) } )- distances in neutral complex 2 and are comparable to those
4
20 12
2 2
[
24]
(
C H ) ]. The molecular structure of 3 is depicted in Fig- in ionic [Li(thf) ][Y(NPh ) ] [2.244(2)–2.271(2) Å]. Short
7 8 3 4 2 4
ure 3 and the crystal and structural refinement data are contacts between the yttrium atom and the carbon atoms
listed in the Experimental Section. in the ipso and ortho positions [Y(1)–C(39) 2.743(3),
The X-ray single-crystal structure analysis revealed that Y(1)–C(58) 2.746(3), Y(1)–C(26) 2.747(2), Y(1)–C(16)
compound 3 is an ionic complex containing a discrete 2.849(3) Å] to the amido groups are also observed in com-
+
–
Li(thf)4 cation and a discrete [Y{(R)-C H (NPh) } ]
plex 3.
Crystals of 5 suitable for X-ray diffraction studies were
20
12
2 2
complex anion resulting from the coordination of two di-
amido ligands to the trivalent yttrium atom. The Y–N obtained by slow condensation of hexane into concentrated
bonds within the complex anion of 3 [2.267(2), 2.270(2), thf solutions at room temperature. Complex 5 crystallizes
2.275(2), and 2.288(2) Å] are slightly longer than the same as a thf solvate containing one molecule of thf per molecule
+
Figure 4. ORTEP drawing of complex 5 with the atom labeling scheme. Ellipsoids are drawn at the 30% probability level. The Li(thf)
4
cation and the hydrogen atoms have been omitted for clarity. Selected bond lengths [Å] and angles [°]: Y1–N1 2.297(5), Y1–N2 2.284(5),
Y1–N3 2.290(5), Y1–N4 2.265(6), Y1–C11 2.712(6), Y1–C21 2.767(6), Y1–C31 2.733(7), Y1–C41 2.753(7); N1–Y1–N2 118.50(2), N1–
Y1–N3 102.07(18), N2–Y1–N3 109.1(2), N1–Y1–N4 108.7(2), N2–Y1–N4 100.8(2), N3–Y1–N4 118.5(2).
Eur. J. Inorg. Chem. 2007, 1159–1168
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J. Collin, A. Trifonov et al.
FULL PAPER
of complex, i.e., [Li(thf) ][Y{(R)-C H (NiPr) } ](C H O). dimethylpent-4-enylamine (10) and 2,2-diphenylpent-4-en-
4
20 12
2 2
4
8
The molecular structure of 5 is shown in Figure 4, and the ylamine (12), for example, complex 4 proved to be both
structure refinement data are listed in the Experimental more active and enantioselective than 5 – catalysts 4 and 5
Section. Complex 5 crystallizes in the orthorhombic space afforded the pyrrolidine 11 with 68% ee and 40% ee, respec-
group P2 2 2 with four molecules in the unit cell. The X- tively (Entries 5 and 6), and the pyrrolidine 13 with 65% ee
1
1 1
ray diffraction study shows that complex 5, similarly to 3, and 50% ee (Entries 7 and 8).
+
is an ionic complex consisting of a discrete Li(thf) cation
The cyclization of aminohexene derivatives into piperi-
4
–
and a complex {Y[(R)-C H (NiPr) ] } anion. The yt- dines is a more difficult process, and substrate 14 could only
2
0
12
2 2
trium is coordinated by the four nitrogen atoms of the two be partially transformed into the corresponding spiropiper-
(R)-1,1Ј-binaphthyl-2,2Ј-diamido ligands. The Y–N bond idine 15 within 12 d in the presence of catalyst 4 (Entry 9).
lengths in 5 are 2.297(5), 2.284(5), 2.290(5), and 2.265(6) Å. This transformation was greatly accelerated at 60 °C, how-
The average value of the Y–N bond lengths in 5 ever, and the piperidine was obtained after only 8 h with
[
2.284(5) Å] is very similar to that found for complex 3 18% ee (Entry 10). Under the same reaction conditions, the
[
2.275(2) Å].
aminohexene was cyclized in 17 h in the presence of com-
plex 5. Surprisingly, and only for this substrate, catalyst 5
gave a better enantioselectivity and product 15 was isolated
with 29% ee (Entry 11).
Catalytic Tests
The yttrium complex 4 is more stable than the ate lantha-
nide complexes that we prepared earlier as we performed
catalytic hydroamination reactions with samples of 4 pre-
pared two months previously with no loss of enantio-
selectivity. We thus investigated the possibility of reusing
catalyst 4 in successive reactions. The results are given in
Table 2.
We have previously reported the efficiency of an ytter-
bium ate complex [Li(thf) ][Yb{(R)-C H (NiPr) } ] for
4
20 12
2 2
the cyclization of various aminopentene derivatives to the
corresponding pyrrolidines with high enantioselectivities
up to 70% ee).[
15b]
(
This complex requires several days of
reaction at room temperature, however, to reach complete
conversion. The new amidoyttrium complexes 3, 4, and 5
have been tested for their ability to perform enantioselective
intramolecular hydroamination reactions. Complex 3 is not
active for the cyclization of C-(1-allylcyclohexyl)methyl-
amine (6), whereas 4 and 5 are efficient catalysts for several
intramolecular hydroaminations (see Table 1).
The hydroamination/cyclization of 6 was initially investi-
gated with both complexes at room temperature; the ex-
pected spiropyrrolidine (7) was obtained with a similar
enantioselectivity (68% ee). It should be noted that catalyst
Table 2. Reuse of catalyst 4 for the cyclization of aminopentene 6.
Reuse
Cat. ratio
t
(h)
Conv.
(%)
ee
(%)
(
mol-%)
0
1
2
3
4
8
4
3
2
1.5
4
100
100
100
79
69
67
65
65
62
17
14
14
23
59[
a]
[
a] New substrate was added in the fourth reuse before complete
4
is much more active since it cyclized substrate 6 in 4 h,
whereas a reaction time of 20 h was necessary for catalyst
to achieve the same transformation (Entries 1 and 2,
consumption of the substrate in the preceding run.
5
The experiments were performed in an NMR tube. After
Table 1). Similarly, in the cyclization of C-(1-allylcyclopen- the first reaction, an aliquot of the reaction mixture was
tyl)methylamine (8) both catalysts afforded the spiropyrrol- separated to determine the enantiomeric excess and ad-
idine 9 with the same enantiomeric excess (Entries 3 and 4). ditional substrate in solution in C D was added to the
6
6
With other substrates, however, the enantioselectivity de- NMR tube. This procedure was repeated three times with-
pended on the catalyst employed. For the cyclization of 2,2- out loss of enantioselectivity. For the fourth reuse, a slight
Table 1. Intramolecular hydroamination reactions with 4 and 5.
1164
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© 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Inorg. Chem. 2007, 1159–1168

Yttrium Complexes as Enantioselective Hydroamination Catalysts
FULL PAPER
decrease of enantioselectivity was observed together with a by ansa-lanthanocenes[2] or lanthanide binaphtholates,[10d]
lower rate of reaction due to the decrease in the catalytic several species with different coordination numbers that are
ratio or inhibition by the reaction product.[
10d,25]
Neverthe- in equilibrium have been proposed to be formed after the
less, these results indicate that this neutral, chiral yttrium reaction of the amino olefin with the precatalyst.
complex is highly stable and active for performing enantio- Reaction of neutral complex 4 with an amino olefin may
selective hydroamination reactions. While this work was go- indeed form the tris(amide) species 4a with selective re-
ing on, Marks et al. reported a new procedure for the reuse placement of the diisopropylamido group by the unsatu-
[
26]
of nonchiral organolanthanide hydroamination catalysts.
rated substrate as the amido ligand. One or two amino li-
Their homogeneous lanthanocene precatalyst was recycled gands arising from the substrate or the cyclized product
three times in the presence of amino-derived polystyrene may then coordinate to the lanthanide center to give species
resins.
4b. As for the yttrium ate complex 5, at least two different
The reactions catalyzed by the neutral yttrium complex structures can be considered for the active species formed
4
and the yttrium ate complex 5 coordinated with the same by reaction with the amino olefin: after the proton transfer,
binaphthylamine ligand do not afford the same rates and/ a binaphthylamine ligand is transformed into the corre-
or enantiomeric excesses for the various hydroamination re- sponding monolithium salt, which can coordinate (5a), or
[
28]
actions studied. Shibasaki has demonstrated that for enan- not (4a), to the yttrium atom. In the case of the complete
tioselective carbon–carbon bond formation promoted by decoordination of one binaphthlyamine ligand, the struc-
heterodimetallic catalysts both lanthanide and alkali metals tures of the active species for the catalysis by neutral com-
are involved in the reaction mechanism.[ Hence, these re- plex 4 or ate complex 5 should be identical (4a and 4b,
sults suggest that the catalytically active species are not the Scheme 6). Furthermore, additional amino ligands from the
same in the reactions involving precatalysts 4 and 5. A substrate or the product may coordinate to the yttrium
27]
mechanism for hydroamination reactions catalyzed by lan- atom to form species 5b.
thanocenes has been proposed by Marks.[ In the first step,
2]
For reactions involving substrates 6 or 8 the same cata-
the lanthanide–carbon or lanthanide–nitrogen bond of the lytic species could be involved during catalysis by complexes
precatalyst is cleaved by the amino olefin to form an ami- 4 or 5. This is probably not the case for hydroamination
dolanthanide intermediate. This proton transfer is then fol- reactions involving the other substrates, although further
lowed by the insertion of the double bond in the lantha- studies are required to gain insight into the mechanism of
nide–nitrogen bond, which is the rate-determining step. Re- hydroamination catalyzed by lanthanide ate complexes for
lease of the cyclized product is favored by reaction of an- more precise explanations concerning the role of the second
other amino olefin. For hydroamination reactions catalyzed chiral ligand.
Scheme 6. Proposed structures for the intermediate catalytic species.
Eur. J. Inorg. Chem. 2007, 1159–1168
© 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
1165

J. Collin, A. Trifonov et al.
FULL PAPER
thf was evaporated in vacuo and the resulting solid extracted with
hot toluene (15 mL). Slow cooling of the toluene extract from 70
Conclusion
We have prepared new asymmetric yttrium ate complexes to 20 °C resulted in yellow crystals of 3 (0.480 g, 42%). C101H100Li-
and an asymmetric yttrium tris(amide) coordinated by N-
Y (1529.7): calcd. C 79.30, H 6.53, Y 5.81; found C 78.86, H
2
substituted binaphthylamine ligands. An ate and a neutral 6.17, Y 6.00. H NMR (C , thf),
4 4
N O
1
6
D
6
): δ = 1.08 (br. s, 16 H, β-CH
), 3.10 (br. s, 16 H, α-CH , thf), 6.58–7.99
): δ = 21.1 (CH ), 24.8 (β-
, thf), 117.0, 117.5, 118.3, 120.0, 122.1,
2
.09 (s, 9 H, CH
3
C
6
H
5
3
2
complex coordinated with the same ligand are active cata-
lysts for intramolecular hydroamination reactions. Com-
parison of the hydroamination reactions with different sub-
strates catalyzed by both complexes has shown differences
in activity and/or enantioselectivity, thus indicating that dif-
ferent active species are involved. Higher reaction rates and/
or higher asymmetric inductions are generally observed for
the formation of several pyrrolidines with the neutral yt-
trium tris(amide).
1
(
m, 59 H, Ar) ppm. C NMR (C
6
D
6
3
CH
2
, thf), 67.9 (α-CH
2
1
1
1
1
8
23.1, 123.7, 124.7, 125.2, 125.4, 125.6, 126.6, 127.6, 128.0, 129.0,
29.2, 129.5, 129.7, 129.9, 130.2, 130.5, 134.4, 136.1, 137.6, 140.8,
42.7, 154.7 (Ar) ppm. IR (Nujol, KBr): ν˜ = 3050 (w), 1587 (m),
348 (s), 1297 (s), 1173 (m), 1148 (m), 1079 (m), 1015 (m), 965 (m),
–1
59 (m), 726 (s), 696 (s) cm .
Synthesis of [Y{(R)-C20
12(NiPr) }Cl(thf)
a solution of LiNiPr
2 2 2
H12(NiPr) }{NiPr }{LiCl(thf) }] (4): [Y{(R)-
C
20
H
2
2
] (0.039 g, 0.061 mmol) was slowly added to
(0.007 g, 0.061 mmol) in thf (1.5 mL) at 20 °C
with vigorous stirring. The reaction mixture was then stirred for
0 h and the thf evaporated in vacuo. The complex was used with-
2
Experimental Section
2
1
out further purification as a crude yellow powder. H NMR
): δ = 1.06–1.14 (m, 12 H, CHCH ), 1.20–1.27 (m, 6 H,
CHCH ), 1.28 (br. s, 8 H, β-CH , thf), 1.48–1.62 (m, 6 H, CHCH ),
.02–3.15 (m, 2 H, CHCH ), 3.35 (br. s, 8 H, α-CH , thf), 3.88–
.13 (m, 2 H, CHCH ), 6.62–7.84 (m, 12 H, Ar) ppm. C NMR
): δ = 25.1, 25.3, 25.4, 25.52, 25.60, 25.64, 25.7, 26.0 (CH ),
5.2 (β-CH , thf), 47.1, 48.3, 48.5, 67.9 (α-CH , thf), 116.0, 116.4,
General: All procedures were performed under argon using stan-
dard Schlenk and glove-box techniques. Tetrahydrofuran (thf) was
distilled from sodium benzophenone ketyl prior to use. Hexane and
toluene were purified by distillation from sodium/triglyme benzo-
(
C
6
D
6
3
3
2
3
3
4
(
3
2
1
3
3
phenone ketyl or CaH
2
. Deuterated benzene was dried with sodium
C
6
D
6
3
benzophenone ketyl and vacuum-transferred. Anhydrous LnCl
3
2
2
2
was purchased from Aldrich. The N,NЈ-diisopropylbinaphthyldi-
amine ligand and its lithium salt were prepared according to ref.[15b]
117.2, 118.0, 118.8, 120.8, 121.0, 121.1, 122.7, 124.7, 126.6, 126.7,
28.9, 131.5, 131.9, 132.5, 133.2, 135.4, 150.5, 154.9 (Ar) ppm. IR
1
The N,NЈ-diphenylbinaphthyldiamine ligand was prepared accord-
[
29]
(Nujol, KBr): ν˜ = 3047 (m), 1610 (s), 1593 (s), 1540 (m), 1496 (s),
ing to ref. The substrates for the hydroamination/cyclization re-
[15c]
1421 (s), 1377 (s), 1310 (s), 1246 (s), 1171 (s), 1038 (s), 916 (m),
actions were prepared as reported in ref.
All other commercially
–
1
8
10 (s), 746 (s) cm .
available chemicals were used after the appropriate purification.
Bruker AM 250, and Bruker DRX 400 NMR spectrometers (op-
erating at 250 and 400 MHz, respectively) were used to record the
Synthesis of [Li(thf)
4
][Y{(R)-C20
H
12(NiPr)
2
}
2
] (5): YCl
solution of Li
20 2
H12(NiPr) } (0.238 g, 0.626 mmol) in thf (15 mL) at 20 °C with
3
(0.061 g,
0.313 mmol) was slowly added to
a
2
{(R)-
1
13
NMR spectra. Chemical shifts for H and C NMR spectra were
referenced internally with respect to the residual solvent reso-
nances. IR spectra were recorded with a Perkin–Elmer FT-IR spec-
trometer as Nujol mulls. Elemental analyses were performed by
the Microanalytical laboratory of the Institute of Organometallic
Chemistry of RAS.
C
vigorous stirring. The reaction mixture was stirred for 3 h, then the
thf was evaporated in vacuo and the resulting solid extracted with
toluene (20 mL). The extracts were filtered, the toluene was evapo-
rated off, and the solid residue was dissolved in thf (2 mL). Slow
condensation of hexane into the thf solution at 20 °C resulted in
yellow crystals of 5 (0.276 g, 71%). C72
calcd. C 72.75, H 7.73, Y 7.47; found C 72.28, H 7.30, Y 7.81. H
4 5
H92LiN O Y (1189.35):
Synthesis of [Y{(R)-C20
12(NiPr) } (0.303 g, 0.799 mmol) was slowly added to a sus-
pension of YCl (0.156 g, 0.799 mmol) in thf (25 mL) at 20 °C with
vigorous stirring. The reaction mixture was stirred for 3 h, then the
thf was evaporated in vacuo and the resulting solid extracted with
toluene (15 mL). The extracts were filtered, the toluene was evapo-
rated off, and the solid residue was dissolved in thf (5 mL). Slow
condensation of hexane into the thf solution at 20 °C resulted in
H
12(NiPr)
2
}Cl(thf)
2
]
2
(2): Li {(R)-
1
C
20
H
2
3
NMR (C
6.1 Hz, 12 H, CHCH
.30–3.50 (m, 20 H, α-CH
6
D
6
): δ = 1.29–1.35 (m, 20 H, β-CH
2
, thf), 1.37 (d, JH,H
), 1.41 (d, JH,H = 6.1 Hz, 12 H, CHCH ),
), 6.90–
), 25.1
3
3
=
3
7
3
3
2
1
, thf), 3.90–4.10 (m, 4 H, CHCH
3
3
.85 (m, 24 H, Ar) ppm. C NMR (C
, thf), 26.9 (CH
17.9, 124.9, 125.2, 125.8, 127.1, 129.1, 138.5, 155.0 (Ar) ppm. IR
6
D
6
): δ = 24.7 (CH
3
(
1
β-CH
2
3 2
), 45.9, 67.7 (α-CH , thf), 113.5, 115.3,
(
1
Nujol, KBr): ν˜ = 3036 (w), 2802 (w), 2578 (w), 1609 (s), 1590 (s),
540 (m), 1496 (m), 1420 (s), 1364 (s), 1304 (m), 1286 (s), 1247 (m),
1208 (w), 1168 (m), 1145 (m), 1115 (w), 1043 (s), 1015 (w), 916 (m),
yellow crystals of 1 (0.410 g, 81%). C34
2 2
H42ClN O Y (634.77):
calcd. C 64.33, H 6.61, Y 14.00; found C 63.81, H 6.20, Y 14.11.
1
3
H NMR (C
5.8 Hz, 6 H, CHCH
.28, 3.40 (2 br. s, 8 H, α-CH
.07–7.34 (m, 8 H, Ar), 7.64–7.74 (m, 4 H, Ar) ppm. 13C NMR
): δ = 24.7 (β-CH , thf), 25.4, 25.2 (CHCH ), 46.6 (CHCH ),
0.7 (α-CH , thf), 112.7, 116.4, 121.2, 124.7, 126.7, 127.6, 128.1,
31.6, 136.4, 150.2 (Ar) ppm. IR (Nujol, KBr): ν˜ = 3048 (w), 1610
6
D
6
): δ = 1.07 (br. s, 8 H, β-CH
2
, thf), 1.35 (d, JH,H
), 1.62 (d, JH,H = 5.8 Hz, 6 H, CHCH ),
3
, thf), 4.04 (br. m, 4 H, CHCH )
–
1
3
886 (m), 851 (w), 835 (w), 808 (s), 745 (s) cm .
=
3
7
3
3
2
General Procedure for NMR-Scale Hydroamination/Cyclization of
Aminoalkenes: In an argon-filled glove box, the appropriate amino-
alkene (0.176 mmol) was dissolved in C D (0.1 mL) and dried with
6 6
molecular sieves (4 Å) for 2 h. Complex 4 or 5 (see Tables 1 and 2
for the corresponding catalytic ratio) was introduced into an NMR
6 6
tube equipped with a Teflon screw cap, dissolved in C D (0.5 mL),
(C
6
D
6
2
3
3
7
1
2
(s), 1591 (s), 1541 (s), 1364 (s), 1301 (s), 1286 (s), 1249 (s), 1209 (s),
1
8
146 (m), 1118 (w), 1036 (m), 1016 (m), 976 (w), 940 (w), 918 (m),
and the aminoalkene solution was then introduced. The hydroa-
–1
70 (m), 836 (w), 808 (w), 745 (s) cm .
][Y{(R)-C20 12(NPh)
} (0.338 g, 0.756 mmol) was slowly added to a sus-
pension of YCl (0.147 g, 0.756 mmol) in thf (25 mL) at 20 °C with
vigorous stirring. The reaction mixture was stirred for 5 h, then the
1
mination reaction was monitored by H NMR spectroscopy by ob-
Synthesis of [Li(thf)
12(NPh)
4
H
2
}
2
]
(3): Li
2
{(R)-
serving the decrease of the signals of the olefinic protons. After the
reaction time mentioned in the tables, the reaction was quenched
C
20
H
2
3
with CH
2 2
Cl . Determination of the enantiomeric excesses of the
[15c]
products was performed as described in ref.
1166
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© 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Inorg. Chem. 2007, 1159–1168

Yttrium Complexes as Enantioselective Hydroamination Catalysts
FULL PAPER
Table 3. Crystal data and structure refinement for complexes 2, 3 and 5.
2
3
5
Empirical formula
Formula mass
Temperature [K]
Wavelength [Å]
Crystal system
Space group
a [Å]
b [Å]
c [Å]
α [°]
C
635.06
180(2)
0.71073
monoclinic
P2
9.8722(7)
10.3133(8)
15.9820(11)
90
34
H
42ClN
2
O
2
Y
C
101
H
100LiN
4
O
4
Y
C
72 4 5
H92LiN O Y
1529.70
180(2)
0.71073
orthorhombic
P2
17.8673(5)
19.9247(6)
23.1695(7)
90
1189.35
180(2)
0.71073
orthorhombic
P2
10.5453(10)
17.7356(16)
35.465(3)
90
1
1
2
1
2
1
1 1 1
2 2
β [°]
99.829(6)°
90
1603.3(2)
2
1.315
1.933
664
90
90
8248.4(4)
4
1.232
0.763
3232
90
90
γ [°] 3
V [Å ]
6632.9(11)
4
1.191
0.930
2536
Z
D
–3
calcd. [Mgm ]
–1
µ [mm ]
F(000)
Crystal size [mm]
θ range [°]
0.43ϫ0.37ϫ0.15
3.26 to 26.37
11197
0.30ϫ0.27ϫ0.25
1.76 to 24.50
63151
0.44ϫ0.17ϫ0.06
3.00 to 24.97
45105
Reflections collected
Independent reflections [Rint
Absorption correction
Refinement method
Data/restraints/parameters
GOF on F2
]
5691 [0.0489]
multi-scan
13688 [0.0888]
sadabs
11698 [0.1777]
multi-scan
2
2
2
F
F
F
5691/1/365
0.985
13688/27/1006
1.000
11698/144/801
1.000
R1, wR2 [I Ͼ 2σ(I)]
R1, wR2 (all data)
Flack parameter
Largest diff. peak/hole
0.0474, 0.1029
0.0585, 0.1089
–0.002(6)
0.0486, 0.0961
0.0743, 0.1035
0.022(4)
0.0915, 0.1210
0.1475, 0.1421
0.000(8)
0.593/–0.533
0.450/–0.320
0.615/–0.499
X-ray Structure Determination: A single crystal of each compound
was mounted under inert perfluoropolyether at the tip of a glass
fiber and cooled in the cryostream of an Oxford Diffraction XCA-
LIBUR CCD diffractometer for 2, 3, and 5. Data were collected
3985; c) J. J. Brunet, D. Neibecker, in Catalytic Heterofunction-
alization: From Hydroamination to Hydrozirconation (Eds.: A.
Togni, H. Grützmacher), Wiley-VCH, Weinheim, 2001, pp. 91–
141; d) F. Pohlki, S. Doye, Chem. Soc. Rev. 2003, 32, 104–114;
e) M. Beller, A. Tillack, J. Seayad, in Transition Metals for
Organic Synthesis, 2nd ed. (Eds.: M. Beller, C. Bolm), Wiley-
VCH, Weinheim, 2004, vol. 2, pp. 403–414; f) S. Hong, T. J.
Marks, Acc. Chem. Res. 2004, 37, 673–686.
α
using monochromatic Mo-K radiation (λ = 0.71073). Further de-
tails are provided in Table 3. The structures were solved by direct
[
30]
2
methods (SIR97) and refined by least-squares procedures on F
[
31]
using SHELXL-97.
All hydrogen atoms attached to carbon
[
2] M. R. Gagné, C. L. Stern, T. J. Marks, J. Am. Chem. Soc. 1992,
atoms were introduced in the calculation in idealized positions and
treated as riding models. In compound 5, there is one thf solvate
molecule disordered over two positions. The disordered moieties
were refined applying the restraints available within SHELXL-
114, 275–294 and references cited therein.
[3]
a) Y. K. Kim, T. Livinghouse, J. E. Bercaw, Tetrahedron Lett.
2001, 42, 2933–2935; b) Y. K. Kim, T. Livinghouse, Angew.
Chem. Int. Ed. 2002, 41, 3645–3647; c) Y. K. Kim, T. Liv-
inghouse, Y. Horino, J. Am. Chem. Soc. 2003, 125, 9560–9561;
d) J. Y. Kim, T. Livinghouse, Org. Lett. 2005, 7, 4391–4393; e)
K. C. Hultzsch, F. Hampel, T. Wagner, Organometallics 2004,
[
32]
9
7.
Flack parameter
drawings of the molecules were produced with ORTEP32.
The absolute configuration was determined by refining the
[
32]
using a large number of Friedel pairs. The
[33]
2
3, 2601–2612; f) A. Zulys, T. K. Panda, M. T. Gamer, P. W.
CCDC-615714, -615715 and -625520 (2, 3, and 5, respectively) con-
tain the supplementary crystallographic data for this paper. These
data can be obtained free of charge from The Cambridge Crystallo-
graphic Data Centre via www.ccdc.cam.ac.uk/data_request/cif.
Roesky, Chem. Commun. 2004, 2584–2585; g) T. K. Panda, A.
Zulys, M. T. Gamer, P. W. Roesky, J. Organomet. Chem. 2005,
6
90, 5078–5089; h) M. Rastätter, A. Zulys, P. W. Roesky, Chem.
Commun. 2006, 874–876; i) S. Bambirra, H. Tsurugi, D.
van Leusen, B. Hessen, Dalton Trans. 2006, 1157–1161; j) F.
Lauterwasser, P. G. Hayes, S. Bräse, W. E. Piers, L. L. Schafer,
Organometallics 2004, 23, 2234–2237.
Acknowledgments
[
4] a) A. Ates, C. Quinet, Eur. J. Org. Chem. 2003, 1623–1626; b) P.
Horillo Martinez, K. C. Hultzsch, F. Hampel, Chem. Commun.
2006, 2221–2223; c) M. R. Crimmin, I. J. Casely, M. S. Hill, J.
Am. Chem. Soc. 2005, 127, 2042–2043; d) A. Zulys, M. Dochn-
ahl, D. Hollmann, K. Löhnwitz, J.-S. Herrmann, P. W. Roesky,
S. Blechert, Angew. Chem. Int. Ed. 2005, 44, 7794–7798; e) N.
Meyer, K. Löhnwitz, A. Zulys, P. W. Roesky, M. Dochnahl, S.
Blechert, Organometallics 2006, 25, 3730–3734; f) J. A. Bexrud,
J. D. Beard, D. C. Leitch, L. L. Schafer, Org. Lett. 2005, 7,
1959–1962; g) C. Müller, C. Loos, N. Schulenberg, S. Doye,
Eur. J. Org. Chem. 2006, 2499–2503; h) R. K. Thomson, J. A.
Bexrud, L. L. Schafer, Organometallics 2006, 25, 4069–4071; i)
The CNRS is acknowledged for giving financial support and a
postdoctoral grant to D. R. A. T. thanks the Russian Foundation
for Basic Research (grant no. 05-03-32390), the Russian Founda-
tion for Science Support, the Federal Agency for Science and Inno-
vation (contract 02.445.11.7365), and a Grant of the President of
the RF for leading scientific schools (grant no. 8017.2006.3).
[
1] For general reviews on hydroamination reactions, see: a) T. E.
Müller, M. Beller, Chem. Rev. 1998, 98, 675–704; b) M. Nobis,
B. Driessen-Hölscher, Angew. Chem. Int. Ed. 2001, 40, 3983–
Eur. J. Inorg. Chem. 2007, 1159–1168
© 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
1167

J. Collin, A. Trifonov et al.
FULL PAPER
C. F. Bender, R. A. Widenhoefer, J. Am. Chem. Soc. 2005, 127,
[17] T. I. Gountchev, T. D. Tilley, Organometallics 1999, 18, 5661–
1070–1071; j) A. Takemiya, J. F. Hartwig, J. Am. Chem. Soc.
5667.
2006, 128, 6042–6043.
[18]
C. Drost, P. B. Hitchcock, M. F. Lappert, J. Chem. Soc., Dalton
Trans. 1996, 3595–3601.
[
5] For reviews on enantioselective hydroamination reactions, see:
a) P. W. Roesky, T. E. Müller, Angew. Chem. Int. Ed. 2003, 42,
[
19] a) M. D. Fryzuk, J. B. Love, S. J. Rettig, J. Am. Chem. Soc.
997, 119, 9071–9072; b) M. D. Fryzuk, L. Jafarpour, F. M.
Kerton, J. B. Love, B. O. Patrick, S. J. Rettig, Organometallics
001, 20, 1387–1396.
2708–2710; b) K. C. Hultzsch, Adv. Synth. Catal. 2005, 347,
367–391; c) K. C. Hultzsch, Org. Biomol. Chem. 2005, 3, 1819–
1824.
1
2
[
6] a) M. R. Gagné, L. Brard, V. P. Conticello, M. A. Giardello,
C. L. Stern, T. J. Marks, Organometallics 1992, 11, 2003–2005;
b) M. A. Giardello, V. P. Conticello, L. Brard, M. Sabat, A. L.
Rheingold, A. L. Stern, T. J. Marks, J. Am. Chem. Soc. 1994,
[
20] G. B. Deacon, T. Feng, C. M. Forsyth, A. Gitlits, D. Hockless,
Q. Slien, B. W. Skelton, A. H. White, J. Chem. Soc., Dalton
Trans. 2000, 961–966.
[
[
21] T. I. Gountchev, T. D. Tilley, Organometallics 1999, 18, 2896–
1
16, 10212–10240; c) M. A. Giardello, V. P. Conticello, L.
Brard, M. R. Gagné, T. J. Marks, J. Am. Chem. Soc. 1994, 116,
0241–10254.
2905.
22] K. H. Den Haan, J. L. De Boer, J. H. Teuben, A. L. Speak, B.
1
Kojic-Prodic, G. R. Hays, R. Huis, Organometallics 1986, 5,
[
[
[
[
7] M. R. Douglass, M. Ogasawara, S. Hong, M. V. Metz, T. J.
1726–1733.
Marks, Organometallics 2002, 21, 283–292.
8] P. N. O’Shaughnessy, P. D. Knight, C. Morton, K. M. Gilles-
pie, P. Scott, Chem. Commun. 2003, 1770–1771.
9] P. D. Knight, I. Munslow, P. N. O’Shaughnessy, P. Scott, Chem.
Commun. 2004, 894–895.
10] a) D. V. Gribkov, F. Hampel, K. C. Hultzsch, Eur. J. Inorg.
[
[
23] W. J. Evans, J. W. Grate, K. R. Levan, I. Bloom, T. T. Petersen,
R. J. Doedens, H. Zhang, J. L. Atwood, Inorg. Chem. 1986, 25,
3614–3619.
24] Y. Yao, X. Lu, Q. Shen, K. Yu, J. Chem. Crystallogr. 2004, 34,
275–279.
Chem. 2004, 4091–4101; b) D. V. Gribkov, K. C. Hultzsch, F. [25] S. Hong, A. M. Kawaoka, T. J. Marks, J. Am. Chem. Soc. 2003,
Hampel, Chem. Eur. J. 2003, 9, 4796–4810; c) D. V. Gribkov,
K. C. Hultzsch, Chem. Commun. 2004, 730–731; d) D. V. Grib-
kov, K. C. Hultzsch, F. Hampel, J. Am. Chem. Soc. 2006, 128,
125, 15878–15892.
[26] J. Zhao, T. J. Marks, Organometallics 2006, 25, 4763–4772.
[27] M. Shibasaki, N. Yoshikawa, Chem. Rev. 2002, 102, 2187–2209.
[28] We have checked that the mono- and dilithium salts of the (R)-
N,NЈ-diisopropyl-1,1Ј-binaphthyl-2,2Ј-diamido ligand are not
active catalysts for the hydroamination reactions even at higher
temperatures (see ref.[ ).
3748–3759.
[
[
11] J. Y. Kim, T. Livinghouse, Org. Lett. 2005, 7, 1737–1739.
12] S. Hong, S. Tian, M. V. Metz, T. J. Marks, J. Am. Chem. Soc.
4b]
2
003, 125, 14768–14783.
13] N. Meyer, A. Zulys, P. W. Roesky, Organometallics 2006, 25,
179–4182.
14] a) P. N. O’Shaughnessy, P. Scott, Tetrahedron: Asymmetry
003, 14, 1979–1983; b) P. N. O’Shaughnessy, K. M. Gillespie,
P. D. Knight, I. Munslow, P. Scott, Dalton Trans. 2004, 2251–
256.
[
[
[29] S. Vyskocil, S. Jaracz, M. Smrcina, M. Sticha, V. Hanus, M.
Polasek, P. Kocovsky, J. Org. Chem. 1998, 63, 7727–7737.
[30] SIR97, a program for automatic solution of crystal structures by
direct methods: A. Altomare, M. C. Burla, M. Camalli, G. L.
Cascarano, C. Giacovazzo, A. Guagliardi, A. G. G. Moliterni,
G. Polidori, R. Spagn, J. Appl. Crystallogr. 1999, 32, 115.
[31] G. M. Sheldrick, SHELXL97, a program for crystal structure
refinement, University of Göttingen, Germany, 1997.
[32] a) H. D. Flack, Acta Crystallogr., Sect. A 1983, 39, 876–881;
b) G. Bernardinelli, H. D. Flack, Acta Crystallogr., Sect. A
1985, 41, 500–511.
4
2
2
[
15] a) J. Collin, J. C. Daran, E. Schulz, A. Trifonov, Chem. Com-
mun. 2003, 3048–3049; b) J. Collin, J.-C. Daran, O. Jacquet, E.
Schulz, A. Trifonov, Chem. Eur. J. 2005, 11, 3455–3462; c) D.
Riegert, J. Collin, A. Meddour, E. Schulz, A. Trifonov, J. Org.
Chem. 2006, 71, 2514–2517.
[
16] a) F. G. N. Cloke, B. R. Elvidge, P. B. Hitchcock, V. M. E. La-
marche, J. Chem. Soc., Dalton Trans. 2002, 2413–2414; b) A. G.
Avent, F. G. N. Cloke, B. R. Elvidge, P. B. Hitchcock, Dalton
Trans. 2004, 1083–1096.
[33] ORTEP3 for Windows: L. J. Farrugia, J. Appl. Crystallogr.
1997, 30, 565.
Received: September 19, 2006
Published Online: February 9, 2007
1168
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Eur. J. Inorg. Chem. 2007, 1159–1168