A chiral bidentate sp2-N ligand, naph-diPIM: Application to CpRu-catalyzed asymmetric dehydrative C-, N-, and O-allylation

Article abstract of DOI:10.1002/anie.201100772

A handy new ligand: The CpRu complex (Cp=cyclopentadienyl) of a new type of chiral bisamidine ligand with a naphtho[1,2-b:7,8-b]dipyrroloimidazole (Naph-diPIM) skeleton with a Bronsted acid efficiently catalyzes dehydrative intermolecular C-allylation with high enantio- and regioselectivity. The catalytic system also gives nearly enantiomerically pure cycloalkanes and N- and O-heterocycles with a substrate/catalyst ratios of up to 10 000.

Full text of DOI:10.1002/anie.201100772

DOI: 10.1002/anie.201100772
Asymmetric Catalysis
A Chiral Bidentate sp2-N Ligand, Naph-diPIM: Application to CpRu-
Catalyzed Asymmetric Dehydrative C-, N-, and O-Allylation**
Kengo Miyata, Hironori Kutsuna, Sho Kawakami, and Masato Kitamura*
In asymmetric reactions catalyzed by chiral metal complexes,
the ligand plays a definitive role in cooperation with the
central metal. The introduction of new chiral ligands often
revolutionizes the catalytic performance in terms of reactivity,
selectivity, and productivity.[1] The chiral bidentate sp2-N-
ligands that possess a privileged bipyridine-, bisoxazoline-, or
diimine-skeleton have enabled the development of vast
numbers of asymmetric reactions.[2] We have designed a
novel ligand, naphtho[1,2-b:7,8-b’]dipyrroloimidazole (Naph-
diPIM), which has the following characteristics: 1) high
rigidity and planarity with fixation of
two sp2-hybridized N atoms on the same
side, 2) near 908 bite angle, making the
coordination plane and Naph-diPIM
plane coplanar to stabilize square-
planar and octahedral metal complexes,
3) an extended p-conjugated system
showing pyridine-level p-acceptability,
and 4) high s-donicity derived from the
two amidine units. Introduction of sub-
stituents on the pyrrolo moieties, such as
C2 chiral (S,S)- or (R,R)-Naph-diPIM-
dioxo-R (R = iPr, Me, H) (1a–c),[3]
should create a well-defined chiral envi-
ronment (see below).
The Naph-diPIM-dioxo-R ligands
1a–c were synthesized from 2,7-
dibromo-1,8-dinitronaphthalene
and
appropriate acetonides of enantiomerically pure 3,4-dihy-
droxypyrrolidine-2-one by a Buchwald coupling/NO2-reduc-
tion/dehydrative cyclization protocol.[4] We decided to access
the utility of the new chiral ligands in intermolecular
dehydrative C-allylation between (E)-3-phenylprop-2-en-1-
ol ((E)-2) and Meldrumꢀs acid (3). This particular reaction
was chosen because it remains intractable. There have,
however, been some recent breakthroughs in the develop-
ment of new asymmetric metal complex catalysts for other
important intramolecular dehydrative reactions, namely,
chiral bisphosphine/Au-catalyzed Friedel–Crafts C-allylation
of indoles,[5] chiral picolinic acid/CpRu-catalyzed cyclization
(Cp = cyclopentadienyl) of w-hydroxy allyl alcohols,[6] and
chiral bisphosphine/Hg-catalyzed cyclization of anilino sulfo-
namide allyl alcohols.[7] In contrast, there are numerous metal
complexes that catalyze C-, N-, and O-allylations using
activated allyl alcohols such as allyl esters or halides.[8,9]
From among these complexes, we focused on the high
potential ability of CpRuII complexes for direct activation of
allylic alcohols through p-allyl CpRuIV species based on both
our own experiments[6,10] and those of others.[11,12] The
standard conditions were set as [[RuCp(CH3CN)3]PF6
[*] K. Miyata, H. Kutsuna, S. Kawakami, Prof. Dr. M. Kitamura
Research Center for Materials Science and
Department of Chemistry, Nagoya University
Chikusa, Nagoya 464-8602 (Japan)
Fax: (+81)52-789-2958
E-mail: kitamura@os.rcms.nagoya-u.ac.jp
[**] This work was aided by a Grant-in-Aid for Scientific Research (No.
25E07B212) from the Ministry of Education, Science, Sports and
Culture (Japan). Naph-diPIM=naphtho[1,2-b:7,8-b’]dipyrroloimi-
dazole; Cp=cyclopentadienyl.
(4)][13] = [(S,S)-1a] = 0.5 mm,
[(E)-2] = 500 mm,
[3] =
2500 mm, CH2Cl2, reflux, 4 h, in which mono/di (M/D),
branch/linear (B/L), R and S (R/S or enantiomeric ratio
(e.r.)), and C- and O-allylation (C/O) selectivities are
involved to give (S)-MB, (R)-MB, ML, (R,R)-DBB, (S,S)-
DBB, (R,S)-DBB, (R)-DBL, (S)-DBL, DLL, and others.
Supporting information (synthesis of ligands and substrates,
general procedure for asymmetric allylation, X-ray crystallographic
analysis of CpRu complexes, and NMR spectral data of ligands,
substrates, and products) for this article is available on the WWW
under http://dx.doi.org/10.1002/anie.201100772.
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ꢀ 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
4649

Communications
Table 1: Inter- and intramolecular enantioselective dehydrative allylation
using the (S,S)-Naph-diPIM-dioxo-iPr/[RuCp(CH3CN)3]PF6/p-TsOH
combined catalyst.[a]
With (S,S)-Naph-diPIM-dioxo-iPr (1a), 28% of (E)-2 was
converted to give the (S)- and (R)-MB in a 99:1 e.r. with very
high MB/ML ratio (> 200:1).[4] Addition of p-TsOH (0.5 mm)
into this standard system (4/(S,S)-1a (0.5 mm)) completed the
reaction to give MB, ML, dl-DBB, dicinnamyl ether (5), 2-(1-
phenylallyl)malonic acid (6), and dicinnamyl malonate (7) in
the ratio 93.6:0.4:2.2:1.2:2.5:0.2 (MB/ML 228:1; MB/dl-DBB
43:1) and greater than 99:1 (S)-/(R)-MB. Neither meso-DBB,
DBL, nor DLL could be detected in the reaction mixture.
With concentrations [4/(S,S)-1a] = 5 mm and [p-TsOH] =
0.5 mm, a similar result was obtained. The best results were
achieved by increasing the concentrations of both 4/(S,S)-1a
and p-TsOH to 5 mm. The reaction was completed within 1 h
to give a mixture of MB/ML/dl-DBB only in a ratio of
98.9:0.35:0.7 and a high e.r. (> 99:1 (S)-/(R)-MB and > 99:1
(R,R)-/(S,S)-DBB).[14] Using this approach there was no
detectable formation of 5, 6, or 7. Decreasing the concen-
tration of 3 to 500 mm gave MB in 84% yield together with
DBB in 15% yield without change in the e.r. values. The
enantiomeric ligand (R,R)-1a afforded nearly enantiomeri-
cally pure (R)-MB. The acceleration effect was lowered in the
order of p-TsOH, p-TsOH/Py, CF3SO3H, and p-TsOH/
(C2H5)3N, and p-TsOH/2Py retarded the reaction. Less
acidic (C6H5)2PO2H or C6H5COOH showed no effect.
B(C6F5)3 as well as Zn(OTf)2 could be used, although the
formation of 5–7 became significant. In(OTf)3 and Sm(OTf)3
led to the formation of insoluble compounds of undetermined
structure, probably as a result of polymerization. CH2Cl2,
CHCl3, and toluene were the solvents of choice. In THF or
DMF, the major reaction route was alcoholysis of 3 by 2 to
afford 7. The reaction was sluggish in t-C4H9OH or CH3CN,
albeit with no detrimental effect on the e.r. of MB. Replace-
ment of the iPr group of (S,S)-1a with a Me group (1b)
decreased the e.r. from > 99:1 to 98:2 and MB/ML ratio from
228:1 to 60:1. The values were further decreased with (S,S)-1c
(R = H). Using conditions that gave the best result with 1a,
chiral bisoxazoline ligands La[15] and Lb[15] as well as
BINAP[15] or replacement of Cp with Cp* afforded mainly 7
with no MB.
No.
Reactant(s)
Product
Yield
[%][b] (e.r.)
96
1
2
3
4
5
X=H
OCH3
CH3
Cl
(>99:1)
95 (98:2)
96 (99:1)
94 (99:1)
NO2
[d]
–
(99:1)
6
7
73 (96:4)
89 (99:1)
[e]
8
9
–
–
–
93
(97:3)[f]
96
10
11
(96:4)[f]
no reac-
tion
12
13
87 (99:1)
89
(>99:1)[g]
88 (95:5,
95:5)[h]
14
15
[i]
–
–
98
(>99:1)[k]
98
16
17
18
8a: n=1, R=H
8b: n=1, R=CH3
8c: n=2, R=H
(>99:1)
97
(>99:1)[k]
The scope and limitations of the present method are
shown in Table 1. Electron-donative substituents as well as
the electron-withdrawing NO2 group at the para position of
the phenyl group of (E)-2 exerted little negative effect on
reactivity and selectivity (Table 1, entries 1–5), while satura-
tion of the phenyl group or introduction of a methyl
substituent at C(3) led to no detectable C-allylation
(Table 1, entries 8 and 11). Alkenyl or alkynyl group at C(3)
instead of a phenyl group was tolerable to give the corre-
sponding branched product with e.r. of 96:4–99:1 (Table 1,
entries 6, 7). (Z)-3-Phenylprop-2-en-1-ol ((Z)-2) gave (S)-
and (R)-MB in 97:3 e.r. (Table 1, entry 9). The predominant
formation of (S)-MB both from E and Z stereoisomers
implies that p–s–p interconversion should be faster than the
intermolecular nucleophilic attack on a p-allyl intermediate
(see below). This view can be supported by the high level of
asymmetric induction in dynamic kinetic resolution (DKR) of
racemic 1-phenylprop-2-en-1-ol (Table 1, entry 10). 5-Methyl
Meldrumꢀs acid, tetronic acid, and 3-methyl tetronic acid can
57
19
9
(88:12)[l]
99
(>99:1)[k]
99
20
21
22
23
10a: n=1
10b: n=2
(99:1)[k]
95
(99:1)[n]
83
(95:5)[o]
97
(82:18)
24
11
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Angew. Chem. Int. Ed. 2011, 50, 4649 –4653

Table 1: (Continued)
No.
Reactant(s)
Product
Yield
[%][b] (e.r.)
89
(99:1)[k]
98
25
26
27
28
12a: n=1, R=H
12b: n=2, R=H
(>99:1)[k]
93
12c: n=2, R=CH3
(94:6)[n]
94 (99:1)
[q]
–
29
13
(60:40)
[a] Conditions: 1.0 mmol scale; [allyl alcohol]=500 mm; [4]=[(S,S)-
1a]=[p-TsOH]=5 mm; CH2Cl2; reflux; 1 h. In the intermolecular case,
the concentrations of nucleophiles were set to 2500 mm. The absolute
configurations (AC) were not determined unless otherwise specified. For
the details of the results in Table 1, see the Supporting Information.
[b] Yield of isolated product. [c] The AC was determined with R=H.
[d] Quantitative by 1H NMR spectroscopic analysis but difficult in
separation from 3. Isolated as ethyl 3-(4-nitrophenyl)pent-4-enoate in
72% yield. [e] Major product: allylidenecyclohexane. [f] Five times more
dilute than the standard. [g] HPLC analysis after acetylation. [h] Diaste-
reomeric ratio: ca. 1:1. e.r. values of 96:4 and 94:6 are also possible.
[i] Major product: dicinnamyl ether (5). [j] The AC was determined with
n=1, R=H. [k] S/C=1000 ([(S,S)-1a]=[p-TsOH]=0.5 mm). [l] A 61:39
mixture of (Z)- and (E)-5-(hexa-3,5-dienyl)-2,2-dimethyl-1,3-dioxane-4,6-
dione was isolated in 13% yield. [m] The AC was determined with n=1.
[n] S/C=5000 ([sub]=1m; [4/(S,S)-1a]=0.2 mm; [p-TsOH]=0.4 mm;
6 h). [o] S/C=10000 ([sub]=1m; [4/(S,S)-1a]=0.1 mm; [p-TsOH]=
0.4 mm; 12 h). [p] The AC was determined with n=2, R=H. [q] Not
isolated. Quantitative by GC analysis.
be also used as C-nucleophiles, but no reaction occurred with
dimethyl malonate (Table 1, entries 12–15).
Figure 1. Molecular structures of a) [RuCp(CH3CN)((S,S)-1b)]PF6 (P21,
a=10.037(3), b=27.534(7), c=24.106(6) ꢀ, b=98.742(5)8,
V=6585(3) ꢀ3, Z=8, R=0.1177, RW =0.1280. Ru–N1 2.169 ꢀ, Ru–N2
2.107 ꢀ, N1-Ru-N2 86.38, Ca-N1-Ru-N2 0.28, Cb-N2-Ru-N1 3.68) and
b) [RuCp(C6H5CHCHCH2)((S,S)-1b)](PF6)2 (P1, a=10.189(5),
b=19.427(9), c=10.554(5) ꢀ, b=96.668(8)8, V=2074.9(17) ꢀ3, Z=2,
R=0.0627, RW =0.0755. Ru–N1 2.156 ꢀ, Ru–N2 2.137 ꢀ, Ru–C1
2.228 ꢀ, Ru–C2 2.193 ꢀ, Ru–C3 2.455 ꢀ, N1-Ru-N2 86.48, Ca-N1-Ru-N2
ꢁ22.848, Cb-N2-Ru-N1 16.748). PF6 is omitted for clarity.
Intramolecular C-allylation using 8a–c quantitatively
afforded the 2,3-dihydro-1H-indene and 1,2,3,4-tetrahydro-
naphthalene derivatives with > 99:1 e.r. in all cases (Table 1,
entries 16–18). Enantioselectivity deteriorated when the ali-
phatic substrate 9 was used, in which the benzene ring is
removed from 8a (Table 1, entry 19). Not only C-nucleophiles
but also N- and O-nucleophiles can be used in the intra-
molecular cyclization of 10 and 12 to give 1,2,3,4-tetrahy-
droisoquinoline, isoindoline, isochroman, and phthalan deriv-
atives quantitatively with high enantioselectivity (Table 1,
entries 20–23, 25–28). In most intramolecular cyclizations, the
reaction proceeds with an a substrate/catalyst (S/C) ratio of
1000–10000. The C(3) aliphatic compounds 11 and 13, having
no cinnamyl alcohol unit, were poor substrates (Table 1,
entries 24 and 29).
intermediate so as to avoid a C(3)Ph/Cp steric repulsion.
Outside attack of nucleophile 3 onto C(3), which is more
electrophilic than C(1) (Ru-C(3): 2.455 ꢁ vs. Ru-C(1):
2.228 ꢁ),[12a,17a] affords (S)-MB. Indeed, reaction of
[RuCp(C6H5CHCHCH2)((S,S)-1b)](PF6)2 with 3 in a 1:5
ratio in CD3CN[18] at 608C afforded a 96:4 mixture of (S)-
and (R)-MB in 49% yield. Moreover, the mechanism outlined
above explains the increased enantioselectivity and MB/ML
ratio with a bulkier R group as well as the enantioface
selection observed in the reactions with 8a, 10a, and 12b. The
Based on the molecular structures of CpRuII/(S,S)-1b and
CpRuIV(C6H5CHCHCH2)/(S,S)-1b complexes shown in
Figure 1,[4,16] we assume that the reaction of (E)-2 with 3
proceeds via syn-endo-SiC(3)-14, which has a C(2)H/C(3)Ph
syn stereochemistry in the more stable endo-p-allyl
ligand[12,17] with Si face selection at C(3). Steric repulsion
between the 2,2-dialkyl-1,3-dioxolane moiety of Naph-diPIM
p-allyl intermediates syn-endo-SiC(3)-14 and anti-endo-ReC(3)
-
14 are thought to be generated from the structurally similar
catalyst/(E)-2 complex 15 and catalyst/(Z)-2 complex 16,
respectively. Here, the electrophilicity of C(3) is enhanced by
protonation of p-TsOH on the hydroxy oxygen atom. More-
over, nucleophilicity of the RuII central metal is enhanced by
the coordination of electron-donative Cp ligand and the
amidine-based bidentate Naph-diPIM ligand. The synergistic
ligand and C(3)Ph group would destabilize syn-endo-ReC(3)
-
14. The stereoisomeric anti-endo-ReC(3)-14, which is generated
from (Z)-2 or (ꢀ )-1-phenylprop-2-en-1-ol (Table 1, entries 9
and 10), is then isomerized to syn-endo-SiC(3)-14 via an s-allyl
Angew. Chem. Int. Ed. 2011, 50, 4649 –4653
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Communications
106, 3561 – 3651; c) N. C. Fletcher, J. Chem. Soc. Perkin Trans. 1
2002, 1831 – 1842; d) G. Chelucci, R. P. Thummel, Chem. Rev.
2002, 102, 3129 – 3170; e) A. Togni, L. M. Venanzi, Angew.
Chem. 1994, 106, 517 – 547; Angew. Chem. Int. Ed. Engl. 1994,
33, 497 – 526.
effect of the “redox-mediated donor–acceptor bifunctional
catalyst”[1c,19] facilitates p-allyl formation even without acti-
vation of the allyl alcohol as an ester or halide. The lack of
catalytic activity of the electronically richer Cp*Ru complex
would be ascribed to the steric crowding around the central
metal, inhibiting the coordination of substrate.
[3] For example, (S,S)-Naph-diPIM-dioxo-iPr represents (3aR,11a-
R,14aS,16bS)-2,2,13,13-tetraisopropyl-3a,11a,14a,16b-tetrahy-
drobis(1,3-dioxolano[4’,5’:3,4]pyrrolo)[1,2-a:1’,2’-a]naphtho[1,2-
d:8,7-d’]diimidazole.
[4] For details, see the Supporting Information.
[5] M. Bandini, A. Eichholzer, Angew. Chem. 2009, 121, 9697 – 9701;
Angew. Chem. Int. Ed. 2009, 48, 9533 – 9537.
[6] S. Tanaka, T. Seki, M. Kitamura, Angew. Chem. 2009, 121, 9110 –
9113; Angew. Chem. Int. Ed. 2009, 48, 8948 – 8951.
[7] H. Yamamoto, E. Ho, K. Namba, H. Imagawa, M. Nishizawa,
Chem. Eur. J. 2010, 16, 11271 – 11274.
[8] Reviews for asymmetric Tsuji–Trost-type reactions: a) B. M.
Trost, M. L. Crawley, Chem. Rev. 2003, 103, 2921 – 2943; b) J. T.
Mohr, B. M. Stoltz, Chem. Asian J. 2007, 2, 1476 – 1491; c) G.
Helmchen, A. Dahnz, P. Dꢃbon, M. Schelwies, R. Weihofen,
Chem. Commun. 2007, 675 – 691; d) Z. Lu, S. Ma, Angew. Chem.
2008, 120, 264 – 303; Angew. Chem. Int. Ed. 2008, 47, 258 – 297;
See also, J. F. Teichert, B. L. Feringa, Angew. Chem. 2010, 122,
2538 – 2582; Angew. Chem. Int. Ed. 2010, 49, 2486 – 2528.
[9] For in situ activation of allylic alcohols, see: 9-BBN-C6H13:
a) B. M. Trost, J. Quancard, J. Am. Chem. Soc. 2006, 128, 6314 –
6315; Nb(OC2H5)3 or B(C6H5)3/MS 4 A: b) Y. Yamashita, A.
Gopalarathnam, J. F. Hartwig, J. Am. Chem. Soc. 2007, 129,
7508 – 7509; SO3NH3/DMF: c) C. Defieber, M. A. Ariger, P.
Moriel, E. M. Carreira, Angew. Chem. 2007, 119, 3200 – 3204;
Angew. Chem. Int. Ed. 2007, 46, 3139 – 3143.
In summary, we have developed a new chiral bidentate
sp2-N-ligand and demonstrated the high utility of this CpRu
complex in enantioselective dehydrative C-, N-, and O-
allylation. The reaction proceeds with high reactivity and
selectivity without stoichiometric activation of allylic alcohols
as esters or halides and without the use of extra additives.
Water is the only co-product, thereby making the reaction
clean and simplifying product isolation. Various allylic
alcohols having an sp2- or sp-hybridized carbon at C(3) can
be used both in inter- and intramolecular systems. Of
particular importance is the highly enantioselective construc-
tion of five- and six-membered cycloalkanes and N- and O-
heterocycles, all of which are versatile key intermediates for a
wide range of biologically active natural products.[8] We are
currently exploring the applications of this novel catalytic
system for asymmetric synthesis and elucidation of detailed
reaction mechanisms as well as expansion of the utility of
Naph-diPIM-related ligands to other asymmetric catalysis
reactions.
Experimental Section
[10] a) H. Saburi, S. Tanaka, M. Kitamura, Angew. Chem. 2005, 117,
1758 – 1760; Angew. Chem. Int. Ed. 2005, 44, 1730 – 1732; b) S.
Tanaka, P. K. Pradhan, Y. Maegawa, M. Kitamura, Chem.
Commun. 2010, 46, 3996 – 3998.
A 150 mL Young-type Schlenk tube was charged with [RuCp-
(CH3CN)3]PF6 (14.9 mg, 34.4 mmol), (S,S)-1a (18.8 mg, 34.4 mmol),
and acetone (2.0 mL). The mixture was stirred at room temperature
for 30 min, and then the resulting pale yellow solution was concen-
trated in vacuo. To this solution was added CH2Cl2 (35.0 mL), p-
TsOH·H2O (6.5 mg, 34.4 mmol), and 8a (10.0 g, 34.4 mmol). After
stirring at reflux temperature for 3 h followed by cooling to room
temperature, the mixture was concentrated, and the residue was
passed through a pad of silica gel (15 g, 3.5 cm fꢂ 3.7 cm). The filtrate
was concentrated to give the 5-endo-trig-cyclized product (9.18 g,
98% yield) with a 99.7:0.3 S/R e.r. The white solid was recrystallized
from EtOAc (20 mL) and hexane (60 mL) to give enantiomerically
[11] a) T. Kondo, Y. Morisaki, S. Uenoyama, K. Wada, T. Mitsudo, J.
Am. Chem. Soc. 1999, 121, 8657 – 8658; b) S. Gruber, P. S.
Pregosin, Adv. Synth. Catal. 2009, 351, 3235 – 3242; c) I. F.
Nieves, D. Schott, S. Gruber, P. S. Pregosin, Helv. Chim. Acta
2007, 90, 271 – 275; d) J. A. van Rijn, M. A. Siegler, A. L. Spek,
E. Bouwman, E. Drent, Organometallics 2009, 28, 7006 – 7014.
[12] Review for the utility of Cp*Ru catalysts (Cp* = 1,2,3,4,5-
pentamethylcyclopentadienyl) in allylation using allyl esters and
halides: a) C. Bruneau, J.-L. Renaud, B. Demerseman, Chem.
Eur. J. 2006, 12, 5178 – 5187; The related-asymmetric versions:
b) Y. Matsushima, K. Onitsuka, T. Kondo, T. Mitsudo, S.
Takahashi, J. Am. Chem. Soc. 2001, 123, 10405 – 10406;
c) M. D. Mbaye, J.-L. Renaud, B. Demerseman, C. Bruneau,
Chem. Commun. 2004, 1870 – 1871; d) K. Onitsuka, H. Okuda,
H. Sasai, Angew. Chem. 2008, 120, 1476 – 1479; Angew. Chem.
Int. Ed. 2008, 47, 1454 – 1457; e) M. Austeri, D. Linder, J. Lacour,
Chem. Eur. J. 2008, 14, 5737 – 5741.
[13] Review for the utility in organic synthesis: B. M. Trost, M. U.
Frederiksen, M. T. Rudd, Angew. Chem. 2005, 117, 6788 – 6825;
Angew. Chem. Int. Ed. 2005, 44, 6630 – 6666.
[14] The R/S indication is reversed between MB and DBB because of
the priority rule.
[15] La: (S,S)-(ꢁ)-2,2’-isopropylidenebis(4-tert-butyl-2-oxazoline);
Lb: (+)-2,2’-methylenebis[(3aR,8aS)-3a,8a-dihydro-8H-indeno-
[1,2-d]oxazole]; BINAP: (2,2’-bis(diphenylphosphino)-1,1’-
binaphthyl).
pure
2,2-dimethyl-1’-vinyl-1’,3’-dihydrospiro[{1,3}dioxane-5,2’-
indene]-4,6-dione (8.00 g, 85% yield) as prismatic crystals: m.p.
20
848C, ½aꢂD ¼ꢁ108.5 degcm3 gꢁ1 dmꢁ1 (c = 0.01 gcmꢁ3, CHCl3).
Received: January 30, 2011
Revised: February 21, 2011
Published online: April 15, 2011
Keywords: allylation · asymmetric catalysis · chirality ·
.
cyclopentadienyl ligands · heterocycles
[1] a) R. Noyori, Science 1990, 248, 1194 – 1199; b) R. Noyori, M.
Kitamura, T. Ohkuma, Proc. Natl. Acad. Sci. USA 2004, 101,
5356 – 5362; c) M. Kitamura, H. Nakatsuka, Chem. Commun.
2011, 47, 842 – 846; see also: K. Mikami, M. Lautens in New
Frontiers in Asymmetric Catalysis, Wiley-VCH, New York, 2007,
pp. 1 – 418.
[2] Reviews for N-based ligands: a) M. Lemaire, P. Mangeney in
Chiral Diaza-Ligands for Asymmetric Synthesis in Topics in
Organometallic Chemistry, Vol. 15, Springer, Berlin, 2005, pp. 1 –
301; b) G. Desimoni, G. Faita, K. A. Jørgensen, Chem. Rev. 2006,
[16] The dicationic CpRuIV-p-allyl complex was prepared from the
CpRuII complex, cinnamyl chloride, and AgPF6 by reference to:
M. D. Mbaye, B. Demerseman, J.-L. Renaud, L. Toupet, C.
Bruneau, Angew. Chem. 2003, 115, 5220 – 5222; Angew. Chem.
Int. Ed. 2003, 42, 5066 – 5068.
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[17] a) S. Bi, A. Ariafard, G. Jia, Z. Lin, Organometallics 2005, 24,
680 – 686; b) R. Hermatschweiler, I. Fernꢄndez, P. S. Pregosin,
E. J. Watson, A. Albinati, S. Rizzato, L. F. Veiros, M. J. Calhorda,
Organometallics 2005, 24, 1809 – 1812.
[19] For the original reaction of the donor–acceptor bifunctional
catalyst concept: a) M. Kitamura, S. Suga, K. Kawai, R. Noyori,
J. Am. Chem. Soc. 1986, 108, 6071 – 6072; b) R. Noyori, M.
Kitamura, Angew. Chem. 1991, 103, 34 – 55; Angew. Chem. Int.
Ed. Engl. 1991, 30, 49 – 69.
1
[18] CD2Cl2 could not be used for the H NMR experiment because
of the low solubility of the CpRu complex. CD3CN also affords
high enantioselectivity, albeit with low reactivity.[4]
Angew. Chem. Int. Ed. 2011, 50, 4649 –4653
ꢀ 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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