Enantio-, Regio- and Chemoselective Copper-Catalyzed 1,2-Hydroborylation of Acylsilanes

Article abstract of DOI:10.1002/chem.201901785

Enantioselective synthesis of synthetically significant (α-hydroxyallyl)silanes, (α-hydroxyaryl)silanes, and (α-hydroxyalkyl)silanes is reported. The present copper-catalyzed 1,2-selective hydroborylation of acylsilanes affords the aforementioned products

Full text of DOI:10.1002/chem.201901785

A Journal of
Accepted Article
Title: Enantio-, regio- and chemoselective copper-catalysed 1,2-
hydroborylation of acylsilanes
Authors: Audric Naguy, Kiran Indukuri, laurent Collard, Tom Leyssens,
and Olivier Riant
This manuscript has been accepted after peer review and appears as an
Accepted Article online prior to editing, proofing, and formal publication
of the final Version of Record (VoR). This work is currently citable by
using the Digital Object Identifier (DOI) given below. The VoR will be
published online in Early View as soon as possible and may be different
to this Accepted Article as a result of editing. Readers should obtain
the VoR from the journal website shown below when it is published
to ensure accuracy of information. The authors are responsible for the
content of this Accepted Article.
To be cited as: Chem. Eur. J. 10.1002/chem.201901785
Link to VoR: http://dx.doi.org/10.1002/chem.201901785
Supported by

10.1002/chem.201901785
Chemistry - A European Journal
COMMUNICATION
Enantio-, regio- and chemoselective copper-catalysed 1,2-
hydroborylation of acylsilanes
Audric Nagy, Laurent Collard, Kiran Indukuri, Tom Leyssens* and Olivier Riant*
Dedication ((optional))
Abstract: The enantioselective synthesis of synthetically significant
(-hydroxyallyl)silanes, (-hydroxyaryl)silanes and (-
their soft nature.[11] Few examples of 1,2-selective copper hydride
additions were recently reported but proved highly ligand-[12] or
substrate-dependent,[13] particularly in terms of the conjugated
alkene’s  and  substitution pattern. Therefore, a catalytic
asymmetric 1,2-selective hydrocupration of -unsaturated
acylsilanes would provide an innovative entry to optically active
allylic -hydroxysilanes.
hydroxyalkyl)silanes is reported. The present copper-catalysed 1,2-
selective hydroborylation of acylsilanes affords the aforementioned
products in high yields and high enantiomeric excesses. This robust
and scalable additive-free catalytic system relies on the use of low
copper(II) acetate and diphosphine ligand loadings at room
temperature in the presence of a commercially available and bench
stable hydride source.
a) Copper-catalysed addition of silicon nucleophiles to aldehydes[9] (Cirriez et al., 2013)
Chiral copper catalyst
(5 mol%)
O
OH

The importance of -chiral organosilanes in organic chemistry
arises from the post-functionalisation opportunities offered by
silicon chemistry[1] and from the growing interest in silicon atoms
as non-toxic and metabolically stable bioisosters in
pharmaceutically important compounds.[2] Optically active (-
R
R
SiMe2Ph
PhMe2Si-BPin
R = Ar, Alk
ee up to 99 %
b) Copper-catalysed addition of Grignard reagents to acylsilanes[10] (Rong et al., 2015)
hydroxyallyl)silanes,[3]
(-hydroxyaryl)silanes[4]
and
their
Chiral copper catalyst
(5 mol%)
O
OH
derivatives have particular synthetic relevance in stereospecific
C-C bond forming reactions and rearrangements leading to a
variety of chiral organic molecules. The discovery of new
enantioselective synthetic methods leading to these silicon
containing molecules are therefore crucial.

R
SiPh2Me
R
SiPh2Me
R1
CeCl3, BF3.OEt2
R1-MgBr
R = Ar, (-Me)alkenyl
R1= Alk
ee up to 96 %
The most direct entry to enantioenriched secondary
hydroxysilanes is the enantioselective reduction of prochiral
acylsilanes. However most reports of such chiral reduction
reactions depend on the use of stoichiometric amounts of chiral
reducing agents[3m, 3p, 3s, 5] or transition metal[6] and thus suffer from
poor atom economy and important costs. Recently, catalytic
methods to achieve this transformation were reported.[4b, 4c, 7] For
instance Arai et al. reported an extremely efficient ruthenium-
catalysed hydrogenation reaction of acylsilanes under high
hydrogen pressure.[7d] Besides asymmetric reduction reactions,
-hydroxysilanes are accessible with high enantiomeric excess
via copper-catalysis by addition of Suginome’s reagent[8] to
aldehydes[9] (Scheme 1a) and addition of Grignard reagents to
acylsilanes[10] (Scheme 1b) affording secondary and tertiary -
hydroxysilanes respectively.
Even though the above-mentioned reactions give access to
-hydroxysilanes, they mainly focus on aromatic and aliphatic -
hydroxysilanes, highlighting the need for new catalytic
methodologies towards optically active allylic -hydroxysilanes. A
desirable solution to this lack of method would be the copper-
catalysed 1,2-hydride addition to -unsaturated acylsilanes.
However, copper hydrides are notorious for undergoing highly
selective 1,4-addition to conjugated carbonyl compounds due to
This work
c)
: copper-catalysed regioselective 1,2-hydroborylation of acylsilanes
Chiral copper catalyst
OH
O

(0.1 - 5 mol%)
R
SiMe2tBu
R
SiMe2tBu
H-BPin
H
ee up to 96 %
R = Alkenyl, Ar, Alk
Scheme 1. Scheme Caption.
Herein we report an enantioselective copper-catalysed 1,2-
selective hydroborylation reaction of acylsilanes with emphasis on
-unsaturated acylsilanes. The resulting -hydroxysilanes are
obtained after a short reaction time at room temperature in the
presence of as low as 0.1 mol% catalyst with yields up to 98 %
and enantiomeric excesses up to 96 % (Scheme 1c).
We started our investigation by seeking the best chiral
ligand for the reduction of the -unsaturated acylsilane 1a
(Table 1). The initial experiments were carried out in toluene at
room temperature in the presence of
(PPh3)3CuF.2MeOH and five
(3)[14]
5
mol% of
equivalents of
(diethoxy)methylsilane as the hydride source. Several families of
chiral diphosphine ligands were tested and the best ligand of each
family is presented in Table 1.[15] Among the BINAP family, L1
gave (-hydroxyallyl)silane 2a with 46 % enantiomeric excess
(Entry 1). Segphos L2 increased the enantioselectivity to 65 %
(Entry 2). DTBM-Segphos L3 which gave the best results in a
previous study on -hydroxysilanes[9] disappointingly yielded 2a
with a 39 % ee only (Entry 3). The Josiphos family was ineffective
in promoting the copper-catalysed hydride transfer in an
asymmetric manner (Entry 4). Finally, MeO-biphep L5 exhibited
A. Nagy, L. Collard, K. Indukuri, Prof. T. Leyssens, Prof. O. Riant
Institute of Condensed Matter and Nanosciences, Molecular
Chemistry, Materials and Catalysis (IMCN/MOST)—Université
catholique de Louvain
Place Louis Pasteur 1, bte L4.01.02
1348 Louvain-la-Neuve (Belgium)
E-mail: olivier.riant@uclouvain.be
Supporting information for this article is given via a link at the end of
the document.
This article is protected by copyright. All rights reserved.

10.1002/chem.201901785
Chemistry - A European Journal
COMMUNICATION
similar enantio-induction as L2 with the added benefit of reaching
complete conversion within a few seconds (Entry 5).
Table 2. Reaction parameter screening.
Table 1. Chiral ligand screening.
Entry
1
Hydride source[a]
(EtO)2MeSi-H (5)
(EtO)2MeSi-H (5)
(EtO)2MeSi-H (5)
PinB-H (5)
R
Solvent
toluene
toluene
MeCN
MeCN
MeCN
MeCN
MeCN
Yield [%][b]
ee [%][c]
72
Me
tBu
tBu
tBu
tBu
tBu
tBu
n.d.
n.d.
25
2
84
3
94
4
92
92
5[d]
6[e]
7[f]
PinB-H (1.5)
92
92
Entry
Ligand
L1
Time (minutes)
ee [%][a]
46
PinB-H (1.5)
32
16
1
2
3
4
5
30
30
30
30
< 1
PinB-H (1.5)
63
90
L2
65
[a] Number of equivalents used are given in brackets. [b] Isolated yields after
hydrolysis and flash column chromatography over SiO2 gel. [c] Determined
by chiral HPLC analysis. [d] The reaction was run with 0.1 mol% copper salt
and 0.125 mol% L5. [e] The reaction was run with 0.01 mol% copper salt
and 0.0125 mol% L5. [f] The reaction was run at – 20 °C.
L3
39
L4
10
L5
65
[a] Enantiomeric excesses were determined by chiral HPLC analysis on
crude samples after hydrolysis of the (-siloxyallyl)silanes.
configuration was determined to be (S) by XRD analysis (Figure
1).
In order to demonstrate the method’s applicability a range
of -unsaturated acylsilanes 1b-1p and aromatic acylsilanes
1q-1v were submitted to the optimal conditions though 1 mol%
catalyst was used for practical reasons[18] (Table 3). All -
unsaturated substrates reacted well 1,2-selectively affording very
high yields regardless of the substitution pattern on the aromatic
ring. The electronic properties of the substituents however seem
to affect the enantioselectivity. Electron-rich acylsilanes 1b and
1c gave the corresponding (-hydroxyallyl)silanes (S)-2b and 2c
with high ee’s, while a slight drop in enantioselectivity was
observed for electron-poor acylsilanes 1d and 1e. Various
halogenated acylsilanes 1f-1i as well as trifluoromethylated 1j
were well tolerated under the reported conditions yielding the
corresponding allylic -hydroxysilanes with very good ee’s. Ortho-
substituted acylsilane 1k suffered from slightly lower
enantioselectivity compared to its para-substituted analogue 1b.
Then the substitution pattern of the double bond was studied.
While the (E) isomer 1l gave 2l with good ee, the corresponding
(Z) isomer 1m underwent a dramatic drop in ee during the
reduction. Due to the steric strain of its -substituent, 2n was
obtained with moderate yield while -alkylated 1o disappointingly
gave poor yield upon reduction. However 2n and 2o were both
obtained with very high ee’s. Interestingly despite moderate ee
alkynyl acylsilane 1p was efficiently transformed to the
corresponding propargylic -hydroxysilane 2p without any
competing -addition to the triple bond.
Having established chiral MeO-biphep L5 as the best ligand,
other reaction parameters were studied (Table 2). Replacing
copper source
3
by copper(II) acetate increased the
enantioselectivity up to 72 %. This improvement is attributed to
suppression of the competing racemic hydride transfer by 3 (Entry
1). The effect of the silyl group size on the outcome of the reaction
was then investigated. Replacing the trimethylsilyl group (1a) by
the bulkier tert-butyldimethylsilyl group (1b) increased the
enantiomeric excess (Entry 2). Among the several solvents tested
acetonitrile was found to lead to optimal enantioselectivity of the
reaction as 94 % ee was observed. Despite high enantioselectivity
only 25 % of pure (-hydroxyallyl)silane (S)-2b[16] could be
isolated (Entry 3). This low yield is due to the low long-term
stability of the product under the hydrolysis conditions.[17] This
issue was tackled using pinacolborane instead of
(diethoxy)methylsilane as hydride donor. The resulting (-
boryloxyallyl)silane showed better hydrolysis behaviour thereby
shortening the time needed to reach full hydrolysis. As a result
(S)-2b was isolated with 92 % yield and 92 % ee (Entry 4).
Satisfyingly, the amount of pinacolborane could be reduced to 1.5
equivalents while the loading of copper salt and ligand were
lowered to 0.1 mol% and 0.125 mol% respectively without loss of
yield or enantiomeric excess (Entry 5). Further reducing the
catalytic loading resulted in a dramatic drop of both yield and ee
(Entry 6). Running the reaction at lower temperatures afforded
(S)-2b with moderate yield and similar ee (Entry 7). The absolute
This article is protected by copyright. All rights reserved.

10.1002/chem.201901785
Chemistry - A European Journal
COMMUNICATION
reacted well independently of the electronic properties of their
substituents. A trend in terms of enantioselectivity could again be
observed as electron rich acylsilane 1q gave higher ee upon
reduction than the electron poor 1t and 1u. Selective
hydroborylation of the challenging ketone-bearing 1u highlighted
the extremely desirable chemoselectivity of the catalytic system
for acylsilanes as no ketone reduction was observed. Moderate
yield was however obtained due to some spontaneous Brook
rearrangement of the electron poor 2u under the reaction
conditions. In opposition to -unsaturated substrates, ortho
substitution of arylacylsilanes resulted in a dramatic drop in yield
as 2v was obtained in only 17 % yield with most of 1v recovered.
Satisfyingly, aliphatic acylsilane 1w gave very good yield and ee
after hydroborylation.
Table 3. Scope of the Cu-catalysed 1,2-hydroborylation of acylsilanes.[a]
OH
SiMe2 Bu
OH
SiMe2 Bu
OH
SiMe2 Bu
Me
MeO
NC
92 %
92 %
76 %
94 %
91 %
78 %
Finally, the method was scaled up to demonstrate its
robustness and potential applicability to large scale (Scheme 2).
-unsaturated acylsilane 1b was successfully hydroborylated
within 90 minutes in the presence of 0.1 mol% catalyst on a 5
mmol scale affording 1.2 grams of (S)-2b showing a 91 %
enantiomeric excess. 1q was also efficiently transformed on a 5
mmol scale with excellent 97 % isolated yield and 95 % ee
although 1 mol% catalyst was necessary to reach complete
conversion. Next, 2e was efficiently formed under air without
precautions in slightly lower yield and substantially similar ee
compared to small scale.
OH
SiMe2 Bu
OH
SiMe2 Bu
OH
SiMe2 Bu
Cl
98 %
84 %
95 %
87 %
85 %
84 %
CN
Cl
Cl
OH
SiMe2 Bu
OH
SiMe2 Bu
OH
SiMe2 Bu
Br
F
F3C
91 %
86 %
95 %
85 %
87 %
81 %
Me
OH
SiMe2 Bu
OH
OH
SiMe2 Bu
SiMe2 Bu
96 %
81 %
78 %
89 %
90 %
32 %
5 mmol scale
Standard (inert) conditions
1 mmol scale
Under air
OH
SiMe2 Bu
OH
SiMe2 Bu
OH
SiMe2 Bu
-Octyl
Me
OH
*
TBS
OH
*
TBS
OH
[b]
[b]
*
90 %
50 %
NC
26 %
94 %
52 %
90 %
TBS
MeO
OH
OH
SiMe2 Bu
OH
SiMe2 Bu
(S)-2b
91%
91%
2q
97%
96%
2e
88%
81%
SiMe2 Bu
ee
ee
ee
MeO
91 %
96 %
87 %
92 %
83 %
94 %
Figure 1. Large scale hydroborylation of acylsilanes.
Me OH
SiMe2 Bu
OH
SiMe2 Bu
OH
SiMe2 Bu
Cl
nBu
[b]
In conclusion we reported an enantio-, regio- and
chemoselective copper-catalysed hydroborylation reaction of
acylsilanes. In the presence of as low as 0.1 mol% catalyst our
conditions give rapid and easy access to a wide range of
otherwise difficult to prepare optically active secondary allylic,
aromatic and aliphatic -hydroxysilanes with high yields and
enantiomeric excesses. The hydroborylation operates on the
gram scale without significant loss of yield nor ee and tolerates
ambient atmosphere. The method relies on the use of
commercially available and bench stable copper source, ligand
and hydride donor without the need for any additive making it a
highly user-friendly process.
92 %
89 %
44 %
70 %
O
17 %
81 %
OH
SiMe2 Bu
[b]
79 %
81 %
[a] 0.2 mmol scale. Yields and ee’s are determined after hydrolysis of the (-
boryloxy)silanes and purification over SiO2 gel chromatography. [b] Modified
reaction conditions: 5 mol% Cu(OAc)2, 6.25 mol% L5, 40 °C, 16h.[c] The
absolute configuration was determined by comparison of the optical rotation
with the literature.[7d]
Experimental Section
The reaction conditions were then successfully applied to
aromatic acylsilanes 1q-1v. The same reactivity pattern as for
-unsaturated acylsilanes was observed. Acylsilanes 1q-1t
A flame-dried Schlenk tube was charged with L5 (1.25 mol%) under argon.
A solution of copper(II) acetate in freshly distilled acetonitrile (4 mM, 1
mol%) was added followed by pinacolborane (0.3 mmol). When the
reaction mixture had turned pale yellow, a saturated solution of acylsilane
This article is protected by copyright. All rights reserved.

10.1002/chem.201901785
Chemistry - A European Journal
COMMUNICATION
1b (0.2 mmol) in freshly distilled acetonitrile was added. The reaction
mixture was stirred at room temperature until complete consumption of 1b
as monitored by TLC. The reaction mixture was transferred to a separation
funnel, diluted with Et2O (15 mL) and submitted to hydrolysis by vigorous
shaking in the presence of diluted aqueous K2CO3 (0.5 M, 15 mL). The
organic phase was separated and the volatiles were removed under
reduced pressure. The residue was purified by flash column
chromatography on SiO2 gel (PE/EtOAc, 90:10) yielding pure (-
hydroxyallyl)silane 2b in 92% yield and 92% ee.
t) M. Higashino, N. Ikeda, T. Shinada, K. Sakaguchi, Y. Ohfune,
Tetrahedron Lett. 2011, 52, 422-425; u) A. Kamimura, Y. Kaneko, A.
Ohta, K. Matsuura, Y. Fujimoto, A. Kakehi, S. Kanemasa, Tetrahedron
2002, 58, 9613-9620; v) A. Romero, K. A. Woerpel, Org. Lett. 2006, 8,
2127-2130.
[4]
[5]
a) J. F. Collados, P. Ortiz, J. M. Pérez, Y. Xia, M. A. J. Koenis, W. J.
Buma, V. P. Nicu, S. R. Harutyunyan, Eur. J. Org. Chem. 2018; b) J.
Cossrow, S. D. Rychnovsky, Org. Lett. 2002, 4, 147-150; c) J. R. Huckins,
S. D. Rychnovsky, J. Org. Chem. 2003, 68, 10135-10145.
a) H. S. Mosher, M. S. Biernbaum, J. Org. Chem. 1971, 36, 3168-3177;
b) K. Takeda, Y. Ohnishi, T. Koizumi, Org. Lett. 1999, 1, 237-240; c) M.
Sasaki, Y. Kondo, M. Kawahata, K. Yamaguchi, K. Takeda, Angew.
Chem. Int. Ed. 2011, 50, 6375-6378; d) J. D. Buynak, J. B. Strickland, T.
Hurd, A. Phan, J. Chem. Soc., Chem. Commun. 1989, 89-90; e) K.
Sakaguchi, M. Fujita, H. Suzuki, M. Higashino, Y. Ohfune, Tetrahedron
Lett. 2000, 41, 6589-6592; f) J. A. Soderquist, C. L. Anderson, E. I.
Miranda, I. Rivera, G. W. Kabalka, Tetrahedron Lett. 1990, 31, 4677-
4680; g) J. D. Buynak, J. B. Strickland, G. W. Lamb, D. Khasnis, S. Modi,
D. Williams, H. Zhang, J. Org. Chem. 1991, 56, 7076-7083; h) C. Bolm,
S. Saladin, A. Claßen, A. Kasyan, E. Veri, G. Raabe, Synlett 2005, 2005,
461-464; i) J.-i. Matsuo, Y. Hattori, H. Ishibashi, Org. Lett. 2010, 12,
2294-2297; j) J.-i. Matsuo, Y. Hattori, M. Hashizume, H. Ishibashi,
Tetrahedron 2010, 66, 6062-6069.
Acknowledgements
The authors wish to thank the Fonds de la Recherche Scientifique
(F.R.S.-FNRS), the Fonds pour la Formation à la Recherche dans
l’Industrie et dans l’Agriculture (FRIA), PDR-T.1027.14, as well as
the Université catholique de Louvain for funding. We are grateful
to Dr. Koen Robeyns for the XRD measurement and Prof.
Raphael Robiette for discussions on the mechanism.
Keywords: Copper • Acylsilane • -hydroxysilane •
Hydroborylation • Asymmetric
[6]
[7]
G. Gao, X.-F. Bai, F. Li, L.-S. Zheng, Z.-J. Zheng, G.-Q. Lai, K. Jiang, F.
Li, L.-W. Xu, Tetrahedron Lett. 2012, 53, 2164-2166.
a) C. Syldatk, A. Stoffregen, F. Wuttke, R. Tacke, Biotechnol. Lett 1988,
10, 731-734; b) R. Tacke, H. Hengelsberg, H. Zilch, B. Stumpf, J.
Organomet. Chem. 1989, 379, 211-216; c) P. Zani, J. Mol. Catal. B:
Enzym. 2001, 11, 279-285; d) N. Arai, K. Suzuki, S. Sugizaki, H.
Sorimachi, T. Ohkuma, Angew. Chem. Int. Ed. Engl. 2008, 47, 1770-
1773.
[1]
[2]
[3]
a) M. Oestreich, Synlett 2017, 28, 2394-2395; b) R. Sharma, R. Kumar,
I. Kumar, B. Singh, U. Sharma, Synthesis 2015, 47, 2347-2366; c) G.
Eppe, D. Didier, I. Marek, Chem. Rev. 2015, 115, 9175-9206; d) I. I. I. A.
B. Smith, W. M. Wuest, Chem. Commun. 2008, 5883-5895; e) M. A.
Brook, Silicon in Organic, Organometallic, and Polymer Chemistry, Wiley,
1999; f) I. Fleming, A. Barbero, D. Walter, Chem. Rev. 1997, 97, 2063-
2192; g) J. S. Mills, G. A. Showell, Expert Opinion on Investigational
Drugs 2004, 13, 1149-1157.
[8]
[9]
M. Suginome, T. Matsuda, Y. Ito, Organometallics 2000, 19, 4647-4649.
V. Cirriez, C. Rasson, T. Hermant, J. Petrignet, J. Díaz Álvarez, K.
Robeyns, O. Riant, Angewandte Chemie International Edition 2013, 52,
1785-1788.
a) R. Shintani, Synlett 2017, 29, 388-396; b) N. F. Lazareva, I. M. Lazarev,
Russ. Chem. Bull. 2016, 64, 1221-1232; c) S. Yao, P. Petluru, A. Parker,
D. Ding, X. Chen, Q. Huang, H. Kochat, F. Hausheer, Cancer
Chemotherapy and Pharmacology 2015, 75, 719-728; d) F. Bartoccini,
S. Bartolucci, S. Lucarini, G. Piersanti, Eur. J. Org. Chem. 2015, 2015,
3352-3360; e) G. K. Min, D. Hernández, T. Skrydstrup, Acc. Chem. Res.
2013, 46, 457-470; f) A. K. Franz, S. O. Wilson, J. Med. Chem. 2013, 56,
388-405.
[10] J. Rong, R. Oost, A. Desmarchelier, A. J. Minnaard, S. R. Harutyunyan,
Angew. Chem. Int. Ed. Engl. 2015, 54, 3038-3042.
[11] a) B. H. Lipshutz, in Modern Organocopper Chemistry, Wiley-VCH
Verlag GmbH, 2002, pp. 167-187; b) C. Deutsch, N. Krause, B. H.
Lipshutz, Chem. Rev. 2008, 108, 2916-2927.
[12] a) J.-X. Chen, J. F. Daeuble, D. M. Brestensky, J. M. Stryker,
Tetrahedron 2000, 56, 2153-2166; b) H. Shimizu, T. Nagano, N. Sayo,
T. Saito, T. Ohshima, K. Mashima, Synlett 2009, 2009, 3143-3146; c) K.
R. Voigtritter, N. A. Isley, R. Moser, D. H. Aue, B. H. Lipshutz,
Tetrahedron 2012, 68, 3410-3416.
a) M. Sasaki, Y. Shirakawa, M. Kawahata, K. Yamaguchi, K. Takeda,
Chem. Eur. J. 2009, 15, 3363-3366; b) M. Sasaki, M. Fujiwara, Y.
Kotomori, M. Kawahata, K. Yamaguchi, K. Takeda, Tetrahedron 2013,
69, 5823-5828; c) M. Leibeling, K. A. Shurrush, V. Werner, L. Perrin, I.
Marek, Angew. Chem. Int. Ed. 2016, 55, 6057-6061; d) J. F. Collados, P.
Ortiz, S. R. Harutyunyan, Eur. J. Org. Chem. 2016, 2016, 3065-3069; e)
R. E. Ireland, M. D. Varney, J. Am. Chem. Soc. 1984, 106, 3668-3670; f)
M. A. Avery, C. Jennings-White, W. K. M. Chong, Tetrahedron Lett. 1987,
28, 4629-4632; g) M. A. Avery, C. Jennings-White, W. K. M. Chong, J.
Org. Chem. 1989, 54, 1789-1792; h) P. A. Jacobi, C. Tassa, Org. Lett.
2003, 5, 4879-4882; i) H. M. Nelson, J. R. Gordon, S. C. Virgil, B. M.
Stoltz, Angew. Chem. Int. Ed. 2013, 52, 6699-6703; j) K. Sakaguchi, H.
Suzuki, Y. Ohfune, Chirality 2001, 13, 357-365; k) Y. Morimoto, M.
Takaishi, T. Kinoshita, K. Sakaguchi, K. Shibata, Chem. Commun. 2002,
42-43; l) K. Sakaguchi, M. Yamamoto, T. Kawamoto, T. Yamada, T.
Shinada, K. Shimamoto, Y. Ohfune, Tetrahedron Lett. 2004, 45, 5869-
5872; m) I. Izzo, E. Avallone, L. D. Corte, N. Maulucci, F. De Riccardis,
Tetrahedron: Asymmetry 2004, 15, 1181-1186; n) J. S. Panek, P. F.
Cirillo, J. Am. Chem. Soc. 1990, 112, 4873-4878; o) P. F. Cirillo, J. S.
Panek, J. Org. Chem. 1994, 59, 3055-3063; p) K. Sakaguchi, H. Mano,
Y. Ohfune, Tetrahedron Lett. 1998, 39, 4311-4312; q) K. Sakaguchi, T.
Yamada, Y. Ohfune, Tetrahedron Lett. 2005, 46, 5009-5012; r) K.
Sakaguchi, T. Okada, T. Yamada, Y. Ohfune, Tetrahedron Lett. 2007,
48, 3925-3928; s) S. Perrone, P. Knochel, Org. Lett. 2007, 9, 1041-1044;
[13] a) R. Moser, Ž. V. Bošković, C. S. Crowe, B. H. Lipshutz, J. Am. Chem.
Soc. 2010, 132, 7852-7853; b) K. Junge, B. Wendt, D. Addis, S. Zhou,
S. Das, M. Beller, Chem. Eur. J. 2010, 16, 68-73; c) L.-J. Cheng, S. M.
Islam, N. P. Mankad, J. Am. Chem. Soc. 2018, 140, 1159-1164.
[14] D. J. Gulliver, W. Levason, M. Webster, Inorg. Chim. Acta 1981, 52, 153-
159.
[15] Complete screening of the chiral ligands is presented in the supporting
information.
[16] The absolute configuration was determined to be (S) by XRD analysis.
Full crystallographic data is available in supporting information.
[17] Additional details about the hydrolysis are given in the supporting
information.
[18] 1 mol% catalyst was used in order to ensure accurate weighing of the
ligand.
This article is protected by copyright. All rights reserved.

10.1002/chem.201901785
Chemistry - A European Journal
COMMUNICATION
This article is protected by copyright. All rights reserved.