Rhodium-Catalyzed Synthesis of Chiral Monohydrosilanes by Intramolecular C?H Functionalization of Dihydrosilanes

Article abstract of DOI:10.1002/anie.202013041

The preparation of chiral monohydrosilanes remains a rarely achieved goal. To this end a Rh-catalyzed desymmetrization of dihydrosilanes by way of intramolecular C(sp²)?H functionalization under simple and mild conditions has now been developed

Full text of DOI:10.1002/anie.202013041

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Accepted Article
Title: Rh-Catalyzed Syntheses of Chiral Monohydrosilanes via
Intramolecular C−H Functionalization of Dihydrosilanes
Authors: Wenpeng Ma, Li-Chuan Liu, Kun An, Tao He, and Wei He
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10.1002/anie.202013041
Angewandte Chemie International Edition
RESEARCH ARTICLE
Rh-Catalyzed Syntheses of Chiral Monohydrosilanes via
Intramolecular C−H Functionalization of Dihydrosilanes
Wenpeng Ma, Li-Chuan Liu, Kun An, Tao He and Wei He*
[a]
Dr. W. Ma, L.-C. Liu, K. An, T. He and Prof. Dr. W. He
MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology and School of Pharmaceutical Sciences & Tsinghua-Peking Joint Center for
Life Sciences, Tsinghua University
Beijing, 100084 (P. R. China)
E-mail: whe@tsinghua.edu.cn
Supporting information for this article is given via a link at the end of the document.
Abstract: The preparation of chiral monohydrosilanes remains a
rarely achieved goal. To this end we developed a Rh catalyzed
desymmetrization of dihydrosilanes by way of intramolecular C(sp2)-
H functionalization under simple and mild conditions. This method
provides easy access to a broad range of chiral monohydrosilanes in
good yields with excellent enantioselectivities (up to >99% ee). The
monohydrosilanes constitute a good platform to access stereogenic
silicons, as well as useful tool compounds to probe silicon
stereochemistry.
The reaction involving unactivated C-H bonds are however
much more demanding, since it requires harsher reaction
conditions[9,2y,2z] due to the inert nature of the C-H bonds. This
means that the monohydrosilanes could suffer a second C-H
silylation, resulting in the undesired tetraorganosilanes as the
thermodynamically favored products. This difficulty is supported
by the only and few known examples reported to date. In 2016,
Takai and his coworkers reported that the monohydrosilanes
were only obtained when the reaction was stopped
prematurely.[9c] Nonetheless, the enantioselectivities of the two
reported examples were decent (Scheme 1a). In 2017, we
reported that the chiral monohydrosilanes were probably
produced in the Rh catalyzed dehydrogenative coupling between
Introduction
Stereogenic silicon compounds remain great synthetic
challenges.[1, 2] The chiral monohydrosilanes are among the least
accomplished goals in spite of their importance in material and
organic chemistry. The desymmetrization of dihydrosilanes
represents the most straightforward approach towards chiral
monohydrosilanes given the wide availability of dihydrosilanes.
However, the desymmetrization reactions are required to stop at
the monohydrosilanes stage so as to avoid over-reactions leading
to undesired tetrasubstituted silanes. To date, two types of
reagents have been successfully engaged in the
desymmetrization of dihydrosilanes: (1) π bonds such as
ketones,[3] alkenes[4] and alkynes,[5] as in the well-known
hydrosilylation reactions; (2) activated
σ bonds such as
carbenes,[6] alcohols[7] and aryliodides,[8] as in the formal
dehydrogenative coupling reactions. Since these two types of
reagents are of high reactivity, under carefully controlled
conditions, the over-reactions (e.g., the second C-O or C-C bond
formations) could be circumvented. As a result, desymmetrization
of dihydrosilanes with these two types of reagents has shown
good chemo- and enantio-selectivities.
The desymmetrization of dihydrosilanes using unactivated C-
H bonds would be more attractive and ideal. The advantages
would include: (1) the reaction utilizes widely available C-H bonds
and is exempted from pre-functionalized reagents (e.g., π bonds,
alcohols, carbenes, etc.); (2) the substrate scope could be
significantly improved. We believe that the syntheses of chiral
monohydrosilanes is a more fundamental question than the
syntheses of tetrasubstituted silanes, since the further elaboration
of the monohydrosilanes could provide any tetrasubstituted
silanes products by virtue of the versatile reactivity of the Si-H
bond in a stereospecific manner (vide infra).
Scheme 1. Asymmetric syntheses of monohydrosilanes.
1
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Si-H and C-H bonds. However, these monohydrosilanes were
neither isolated in the premature reaction mixture, nor observed
by NMR studies.[10d] They very likely underwent an in-situ Si-C
bond formation in a stereospecific manner to afford the final
tetraorganosilanes products. Very recently, He group reported
two examples of intercepting the presumptive monohydrosilanes
with alkenes.[2y,2z] Again, only one monohydrosilane was reported
in a low yield in the mechanistic study. It is thus clear that the
preparation of chiral monohydrosilanes by way of C-H
functionalization is elusive.
The less hindered ligand (R)-BINAP, (R)-MeO-Biphep, (R)-
DTBM-Biphep, (R)-Segphos and (R)-DM-Segphos showed
moderate reactivities and enantioselectivities (Table 2, entries 2-
6). (R)-DTBM-Segphos, which possesses a wider dihedral angle
and more hindered 3,5-di-tBu-4-MeO-phenyl substituent, gave a
93% conversion with the highest 96% ee (Table 2, entry 7).
Table 2. Screening the optimal chiral ligands.
Given our long standing interest[10] in silicon chemistry, herein
we report the Rh catalyzed construction of a wide scope of chiral
monohydrosilanes, with unprecedented chemo- and enantio-
selectivity. We further illustrate that the chiral monohydrosilanes
are indeed a versatile platform to access structurally diverse
tetrasubstituted silanes (Scheme 1b), which are also of
importance implication in terms of silicon stereochemistry.
Entry
Ligand
-
Time(h)
12
Conv.[a]
-
ee[b]
-
1
2
3
4
5
6
(R)-BINAP
12
72%
75%
89%
75%
80%
63%
34%
87%
51%
36%
Results and Discussion
(R)-MeO-Biphep
(R)-DTBM-Biphep
(R)-Segphos
(R)-DM-Segphos
12
We commenced our investigation by using dihydrosilanes
substrates of type 1 as the substrate, (R)-BINAP as the chiral
ligand and toluene as the solvent (Table 1). In accordance with
Takai’s report, when R was phenyl, the substrate decomposed[9c]
(Table 1, entry 5). We thus shifted our attention to alkyl substituted
substrates (Table 1, entries 1-4). These results compiled in Table
1 collectively showed that: (1) the chemo-selectivity to achieve
monohydrosilanes was only possible with alkyl substituted
dihydrosilanes. The bulkier R groups gave higher yields, but they
required higher reaction temperatures (Table 1, entries 1-4); (2)
only a moderate enantioselectivity could be obtained (Table 1,
entry 3), suggesting that (R)-BINAP was not a competent ligand.
12
12
12
(R)-DTBM-
Segphos
7
12
93%
96%
Reaction conditions: substrate (0.2 mmol) in toluene (0.8 mL), [Rh(cod)Cl]2 (2
mol%), ligand (4 mol%), stirred at 35 oC for 12 h. [a] Determined by 1H NMR
spectroscopy of the crude reaction mixtures. [b] Determined by HPLC with a
chiral OD-H column.
We demonstrated that the optimized reaction condition was
applicable to isopropyl-Si substrates bearing different
substituents on either of the A or the B ring (Scheme 2). A variety
of substituents were well tolerated in general, giving good yields
and excellent enantioselectivities. It was found that the
enantioselectivity was insensitive to the steric hindrance of the
alkyl side chain at 4-position of A ring (2aa-2ad). In addition, the
electronic effect at 4-position of A ring (2ae-2ag) had no obvious
impact on enantioselectivity. For substrates that had two possible
reacting sites on A ring, the silylation took place exclusively on
the less steric hindered site with excellent enantioselectivities
(2ah-2ak). On the other hand, substituents of different electronic
demands and on the different positions on B ring were compatible
with the reaction. For example, electron neutral group (CH3 in
2an), electron withdrawing group (Cl in 2ao) and electron
donating group (OCH3 in 2ap) at the same position of B ring all
witnessed the same level of good yields and excellent
enantioselectivities. Notably, substrates 2am and 2aq, which
were very different in substitution pattern and electronic features,
both gave an impeccable enantioselectivity (>99% ee). The
absolute configuration of 2am was determined to be S based on
single-crystal X-ray analysis (Scheme S1 in SI).[11]
Table 1. Screening the proper dihydrosilanes substrates.
Entry
R
Temp.(oC)
Conv.[a]
Yiled[b]
ee[c]
1
2
3
4
5
Me
nPr
iPr
20
20
35
70
20
55%
49%
72%
80%
>95%
50%
41%
61%
69%
-
3%
60%
63%
11%
-
tBu
Ph
Reaction conditions: substrate (0.2 mmol) in toluene (0.8 mL), [Rh(cod)Cl]2 (2
mol%), (R)-BINAP (4 mol%), stirred for 12 h. [a] Determined by 1H NMR
spectroscopy of the crude reaction mixtures. [b] Isolated yields through silica
chromatography. [c] Determined by HPLC with a chiral OD-H column.
Isopropyl-Si substrates bearing substituents on both the A
and the B rings were also compatible with optimized reaction
conditions (Scheme 3). In general, having substituents on both
rings decreased the yields and enantioselectivities. Such an
impact was very pronounced in the cases of 2ba, 2bh and 2bk.
We then set out to examine different diphosphine ligands by
using 1aa as the model substrate (Table 2), as our earlier work
had demonstrated that ligands play a central role[10c] in related
transformation. No reaction took place in the absence of a ligand
(Table 2, entry 1), suggesting there was no background reaction.
2
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Scheme 3. General conditions: substrate (0.2 mmol) in toluene (0.8 mL),
[Rh(cod)Cl]2 (2.0 mol%), (R)-DTBM-Segphos (4.0 mol%), stirred at 35 oC for 12
h. Yields of isolated product were given. The ee values were determined by
HPLC with chiral columns. [a] Stirred for 24 h.
Scheme 2. General conditions: substrate (0.2 mmol) in toluene (0.8 mL),
[Rh(cod)Cl]2 (2.0 mol%), (R)-DTBM-Segphos (4.0 mol%), stirred at 35 oC for 12
h. Yields of isolated product were given. The ee values were determined by
HPLC with chiral columns. [a] Stirred for 24 h. [b] On 4.5 mmol scale.
reaction conditions, giving the corresponding monohydrosilanes
in good yields and enantioselectivities. Overall, the results in
Scheme 4 suggested that all types of alkyl groups on the Si atoms
should be viable and the enantioselectivities were influenced by
the substitution patterns on both the Si atoms and the rings.
One would assume that the iso-propyl group on ring A had a
negative impact on the enantioselectivity, but it did not hold true
in the case of 2bj that also has an iso-propyl group at the same
position. The chlorine in 2bh was seemingly smaller than iso-
propyl group, yet it gave the lowest ee among all the cases. The
absolute configuration of 2bn was assigned as R by single-crystal
X-ray analysis of the corresponding derivative compound 8
(Scheme S2 in SI).[11]
We showed that other alkyl substitutions on the Si atoms
were also well tolerated (Scheme 4). Ethyl-Si substrates (i.e., 2ca,
2ce, 2ci, 2cm, 2cq and 2cu) gave good yields. The
enantioselectivities were comparable to those of isopropyl-Si
substrates, except that 2cu saw
a drastic decrease in
enantioselectivity. n-Propyl-Si substrates (i.e., 2cb, 2cf, 2cj, 2cn,
2cr and 2cv) were collectively superior than the ethyl-Si
substrates and were more similar to that of the isopropyl-Si
substrates. This trend again suggested that the steric hindrance
was an important factor. n-Hexyl-Si substrates (i.e., 2cc, 2cg, 2ck,
2co, 2cs and 2cw) reacted smoothly to afford the corresponding
chiral monohydrosilanes in consistently good yields (79-83%) and
enantioselectivities (85-97%). In the cyclohexyl-Si substrates (i.e.,
2cd, 2ch, 2cl, 2cp, 2ct and 2cx), the more congested Si center
did not compromise the yields and enantioselectivities. It was
interesting to see that a 98% ee was obtained in the case of 2cx.
Furthermore, n-butyl-Si, neo-butyl-Si and cyclopentyl-Si (i.e., 2cy,
2cz and 2da) were competent substrates under the optimized
3
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Scheme 4. General conditions: substrate (0.2 mmol) in toluene (0.8 mL),
[Rh(cod)Cl]2 (2.0 mol%), (R)-DTBM-Segphos (4.0 mol%), stirred at 35 oC for 12
h. Yields of isolated product were given. The ee values were determined by
HPLC with chiral columns.
We demonstrated that our method also worked on non-
biphenyl systems (Scheme 5). When A ring were naphthaline
(2da and 2db), the reactions gave good yields (78-80%) while the
enantioselectivities saw a slight decrease (80-81%). Substituted
thiophene[12] (2dc and 2dd) afforded moderate yields (70-72%),
however the enantioselectivities were poor (15-20%). Substrates
bearing ferrocene skeleton on the A ring were shown to be
efficient and highly enantioselective. On the 10 representative
cases (e.g., 2ee-2en), the yields were in the range of 76-82%,
while the enantioselectivities were consistently high (93-99%). In
all these examples, only one single diastereomer was obtained,
featuring a planar chirality and a monohydrosilane functionality in
the final products. Comparison among a panel of substrates
bearing different alkyl groups on the Si atoms (cf., 2ee-2ek), it was
clear that for this type of substrates, the reaction yields and
enantioselectivities were not sensitive to the steric and electronic
demands of the alkyl groups (e.g., ethyl, n-propyl, isopropyl, n-
butyl, s-butyl, hexyl and cyclohexyl). We also examined the
ferrocene substrates with F-substitutions on the B ring (e.g., 2el,
2em and 2en), which showed that the substitution on B ring were
well tolerated with different alkyl-Si patterns. It was thus clear that
our method should work well on various type of ferrocene
substrates. The absolute configuration of the product 2eg was
determined to be RISSi, Rp according to single-crystal X-ray
analysis (Scheme S3 in SI).[11]
Taken together, the reaction scope studies have
demonstrated that our method can produce a wide variety of chiral
monohydrosilanes. The reaction worked well on bi-phenyl
skeletons, tolerating many types of substitution patterns on either
phenyl ring or on the bi-phenyls (Scheme 2 and 3). The
substitutions the Si could be selected from at least 7 different alkyl
groups (Scheme 4). The method could be extended to non-bi-
phenyl skeletons and was especially successful on the ferrocene
substrates (Scheme 5). With a few exceptions, our reactions were
usually efficient and highly enantioselective. This work represents
the first viable and general syntheses of the highly desired chiral
monohydrosilanes.
Scheme 5. General conditions: substrate (0.2 mmol) in toluene (0.8 mL),
[Rh(cod)Cl]2 (2.0 mol%), (R)-DTBM-Segphos (4.0 mol%), stirred at 35 oC for 12
h. Yields of isolated product were given. The ee values were determined by
HPLC with chiral columns. [a] Stirred for 24 h. [b] Stirred at 50 oC for 24 h.
We believed that the reaction mechanism should involve a
dehydrogenative pathway, as first proposed by Kuninobu and
Takai[9a] and then by Mitsudo and Suga.[12] We used 1aa as the
example (Figure 1) to illustrate such a pathway based on the main
ideas of the earlier reports.[9a,12] First, [Rh(cod)Cl] coordinated
with (R)-DTBM-Segphos, and the active catalytic species RhI-H
was generated. Oxidative addition of Rh-H with Si-H 1aa gave a
RhIII species I, followed by reductive elimination to afford RhI
species II. A second sequence of oxidative addition/reductive
elimination would produce the product 2aa and regenerated the
active catalytic species Rh-H. It was very likely the first oxidative
addition was the enantioselective step. The difference between
our reaction and that of Kuninobu and Takai was that one
hydrogen was preserved, probably due to choose of an alkyl
group instead of an aryl group and the relative mild reaction
condition. The difference between our reaction and that of
Mitsudo and Suga was that a hydrogen atom but not a R group
was a spectator. In the latter case, there was chemo- and enantio-
selectivity concerns.
We illustrated that our method could serve as a platform to
access various stereogenic silicon compounds (Scheme 6). To
showcase the general reactivity, we chose different chiral
monohydrosilanes as the starting points. First, alcoholysis[7] of
2aa with isopropanol afforded the corresponding siloxane 3a
under the ambient condition [Eq. (a)]. The hydrosilylation with π
4
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Figure 1. Proposed mechanism.
bond compounds such as ketone,[3] alkene[4] and alkyne[5] were
also successful [Eq. (b), (c) and (d)], affording different
stereogenic tetraorganosilanes containing Si-O, Si-C(sp2) and Si-
C(sp3) bonds. In all cases, the corresponding tetraorganosilanes
products were prepared in high yields without erosion of the
enantioselectivities. Notably, we showed that the Si-H bond
formation-hydrosilylation could be carried out in a tandem fashion
with high yields and enantioselectivity [Eq. (e) and (f)], of which of
the full accounts were reported separately. Intermolecular C−H
functionalization of 2cb with 2-methylthiophene[10d] provided the
tetraorganosilanes product 6 with high yield and enantioselectivity
[Eq. (g)]. Moreover, oxa-benzosilole 3c was converted to
tetraorganosilole 7 by nucleophilic substitution[13] of n-BuLi, of
which the enantiomerically-pure reaction has not been reported
before [Eq. (h)]. These examples, together with the versatile
reactivity of Si-H bonds, illustrated the ample potential of the chiral
monohydrosilanes. This method of chiral monohydrosilane
syntheses will serve as a platform technology to access other
stereogenic silicons, either in a step-wise manner or in a tandem
fashion.
Scheme 6. Derivatization of monohydrosilanes.
Our method also provided chiral monohydrosilanes as
probing compounds to investigate the stereochemistry
concerning Si centers. For example, we studied stereochemistry
concerning the hydrosilylation of the chiral monohydrosilane 2bn
with acetone (Scheme 7). A pair of reactions with either the (R)-
DTBM-Segphos [Eq. (1)] or the (S)-DTBM-Segphos [Eq. (2)]
afforded the identical siloxane product 8, according to NMR
spectra and HPLC chromatograms. The absolute configuration of
the siloxane 8 was determined to be S according to single-crystal
X-ray analysis (Scheme S2 in SI). DIBAL-H reduction of the
siloxane 8 produced the initial chiral monohydrosilane 2bn, which
was confirmed by comparing the NMR spectra and HPLC
chromatograms. This interesting sequences of reactions
indicated that: (1) the stereochemistry of hydrosilylation reactions
between the chiral Si-H and the acetone was substrate controlled
but not ligand controlled, which was in accordance with our earlier
report of the intermolecular C-H/Si-H dehydrogenative
coupling;[10d] (2) the DIBAL-H reduction of the siloxane was
stereospecific, which was consistent with the report of
Oestreich.[14] As Oestreich’s work proposed that during the
DIBAL-H reduction, the Si center had >99% retention, it was clear
that in the first hydrosilylation step [Eq. (1) and (2)], the Si center
also had >99% retention. This observation was very different than
the B(C6F5)3 catalyzed hydrosilylation reaction.[14] This example
showed that the chiral monohydrosilanes were useful tools to
probe stereochemistry questions that might seem intuitive but
remain vague [e.g., Scheme 6, Eq. (c) and (d)].
5
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g) R. Shintani, C. Takagi, T. Ito, M. Naito, K. Nozaki, Angew. Chem. Int.
Ed. 2015, 54, 1616; Angew. Chem. 2015, 127,1636; h) R. Shintani, H.
Kurata, K. Nozaki, Chem. Commun. 2015, 51, 11378; i) Y. Naganawa, T.
Namba, M. Kawagishi, H. Nishiyama, Chem. Eur. J. 2015, 21, 9319; j) R.
Kumar, Y. Hoshimoto, H. Yabuki, M. Ohashi, S. Ogoshi, J. Am. Chem.
Soc. 2015, 137, 11838; k) M. Murai, H. Takeshima, H. Morita, Y.
Kuninobu, K. Takai, J. Org. Chem. 2015, 80, 5407; l) M. Murai, K.
Matsumoto, Y. Takeuchi, K. Takai, Org. Lett. 2015, 17, 3102; m) K. Igawa,
D. Yoshihiro, Y. Abe, K. Tomooka, Angew. Chem. Int. Ed. 2016, 55,
5814; Angew. Chem. 2016, 128, 5908; n) R. Shintani, R. Takano, K.
Nozaki, Chem. Sci. 2016, 7, 1205; o) J. Zhang, J.-Z. Xu, Z.-J. Zheng, Z.
Xu, Y.-M. Cui, J. Cao, L.-W. Xu, Chem. Asian J. 2016, 11, 2867; p) M.
Murai, Y. Takeuchi, K. Yamauchi, Y. Kuninobu, K. Takai, Chem. Eur. J.
2016, 22, 6048; q) M. Murai, R. Okada, A. Nishiyama, K. Takai, Org. Lett.
2016, 18, 4380; r) M. Murai, Y. Takeuchi, K. Yamauchi, Y. Kuninobu, K.
Takai, Chem. Eur. J. 2016, 22, 6048; s) Y. Sato, C. Takagi, R. Shintani,
K. Nozaki, Angew. Chem. Int. Ed. 2017, 56, 9211; Angew. Chem. 2017,
129, 9339; t) R. Shintani, N. Misawa, R. Takano, K. Nozaki, Chem. Eur.
J. 2017, 23, 2660; u) P.-W. Long, X.-F. Bai, F. Ye, L. Li, Z. Xu, K.-F. Yang,
Y.-M. Cui, Z.-J. Zheng, L.-W. Xu, Adv. Synth. Catal. 2018, 360, 2825; v)
H. Chen, Y. Chen, X. Tang, S. Liu, R. Wang, T. Hu, L. Gao, Z. Song,
Angew. Chem. Int. Ed. 2019, 58, 4695; Angew. Chem. 2019, 131, 4743;
w) Y. Lin, W.-Y. Ma, Z. Xu, Z.-J. Zheng, J. Cao, K.-F. Yang, Y.-M. Cui,
L.-W. Xu, Chem. Asian J. 2019, 14, 2082; x) G. Zhang, Y. Li, Y. Wang,
Q. Zhang, T. Xiong, Q. Zhang, Angew. Chem. Int. Ed. 2020, 59, 11927,
Angew. Chem. 2020, 132, 12025; while our manuscript is under review,
He group reported the syntheses of tetraorganosilicons: y) D. Mu, W.
Yuan, S. Chen, N. Wang, B. Yang, L. You, B. Zu, P. Yu, C. He, J. Am.
Chem. Soc. 2020, 142, 13459; z) B. Yang, W. Yang, Y. Guo, L. You, C.
He, Angew. Chem. Int. Ed. 2020, 10.1002/anie.202009912.
Scheme 7. Determination of the chirality.
Conclusion
In conclusion, we have developed the first viable and general
method for the construction of chiral monohydrosilanes, via Rh
catalyzed dehydrogenative coupling between dihydrosilane Si-H
bond and C(sp2)-H bonds. This method provided a wide scope of
chiral monohydrosilanes, with broad choices of substituents on
the Si centers, especially alkyl-substituted stereogenic silicons
that could not be made otherwise. The chiral monohydrosilanes
were a powerful platform to access chiral tetraorganosilanes by
virtue of the versatile reactivity of the remaining Si-H bonds, in
either a step-wise manner or a tandem fashion. It also can be
used as a valuable tool in probing the silicon stereochemistry.
Mechanistic studies as well as intermolecular variants of this
method are under investigation in our laboratory and will be
reported in due case.
[3]
[4]
a) R. J. P. Corriu, J. J. E. Moreau, J. Organomet. Chem. 1974, 64, C51;
b) T. Hayashi, K. Yamamoto, M. Kumada, Tetrahedron Lett. 1974, 15,
331; c) T. Ohta, M. Ito, A. Tsuneto, H. Takaya, J. Chem. Soc. Chem.
Commun. 1994, 2525.
a) K. Tamao, K. Nakamura, H. Ishii, S. Yamaguchi, M. Shiro, J. Am.
Chem. Soc. 1996, 118, 12469; b) Y. Naganawa, T. Namba, M. Kawagishi,
H. Nishiyama, Chem. Eur. J. 2015, 21, 9319; c) G. Zhan, H.-L. Teng, Y.
Luo, S.-J. Lou, M. Nishiura, Z. Hou, Angew. Chem. Int. Ed. 2018, 57,
12342; Angew. Chem. 2018, 130, 12522; d) X Chang, P.-L Ma, H.-C.
Chen, C.-Y. Li, P. Wang, Angew. Chem. Int. Ed. 2020, 59, 8937; Angew.
Chem. 2020, 132, 9022; e) Z.-Y. Zhao, Y.-X. Nie, R.-H. Tang, G.-W. Yin,
J. Cao, Z. Xu, Y.-M. Cui, Z.-J. Zheng, L.-W. Xu, ACS Catal. 2019, 9, 9110.
a) K. Igawa, D. Yoshihiro, N. Ichikawa, N. Kokan, K. Tomooka, Angew.
Chem. Int. Ed. 2012, 51, 12745; Angew. Chem. 2012, 124, 12917; b) H.
Wen, X. Wan, Z. Huang, Angew. Chem. Int. Ed. 2018, 57, 6319; Angew.
Chem. 2018, 130, 6427.
Acknowledgements
[5]
We thank the National Natural Science Foundation of China (Nos.
21625104 and 21971133), National Key Research
&
[6]
[7]
Y. Yasutomi, H. Suematsu, T. Katsuki, J. Am. Chem. Soc. 2010, 132,
4510.
Development Program of China (Nos. 2017YFA0505203), and
the General Financial Grant from the China Postdoctoral Science
Foundation (2017M610074).
a) R. J. P. Corriu, J. J. E. Moreau, Tetrahedron Lett. 1973, 14, 4469; b)
R. J. P. Corriu, J. J. E. Moreau, J. Organometallic Chem. 1976, 120, 337;
c) D. R. Schmidt, S. J. O’Malley, J. L. Leighton, J. Am. Chem. Soc. 2003,
125, 1190.
Keywords: monohydrosilane • dihydrosilanes •
desymmetrization • enantioselectivity
[8]
a) Y. Kurihara, M. Nishikawa, Y. Yamanoi, H. Nishihara, Chem. Commun.
2012, 48, 11564; b) L. Chen, J.-B. Huang, Z. Xu, Z.-J. Zheng, K.-F. Yang,
Y.-M. Cui, J. Cao, L.-W. Xu, RSC Adv. 2016, 6, 67113; c) S. Koga, S.
Ueki, M. Shimada, R. Ishii, Y. Kurihara, Y. Yamanoi, J. Yuasa, T. Kawai,
T. Uchida, M. Iwamura, K. Nozaki, H. Nishihara, J. Org. Chem. 2017, 82,
6108.
[1]
For reviews, see: a) L.-W. Xu, L.Li, G.-Q. Lai, J.-X. Jiang, Chem. Soc.
Rev., 2011, 40, 1777; b) R. Shintani, Asian J. Org. Chem. 2015, 4, 510;
c) C. Cheng, J. F. Hartwig, Chem. Rev. 2015, 115, 8946; d) L. Li, Y.
Zhang, L. Gao, Z. Song, Tetrahedron Lett. 2015, 56, 1466; e) J. O. Bauer,
C. Strohmann, Eur. J. Inorg. Chem. 2016, 2868; f) Y.-M. Cui, Y. Lin, L.-
W. Xu, Coord. Chem. Rev. 2017, 330, 37; g) R. Shintani, J. Synth. Org.
Chem. Jpn. 2018, 76, 1163; h) R. Shintani, Synlett 2018, 29, 388.
For examples for chiral tetraorganosilanes, see: a) R. Shintani, K. Moriya,
T. Hayashi, J. Am. Chem. Soc. 2011, 133, 16440; b) R. Shintani, H.
Otomo, K. Ota, T. Hayashi, J. Am. Chem. Soc. 2012, 134, 7305; c) R.
Shintani, E. E. Maciver, F. Tamakuni, T. Hayashi, J. Am. Chem. Soc.
2012, 134, 16955; d) M. Onoe, K. Baba, Y. Kim, Y. Kita, M. Tobisu, N.
Chatani, J. Am. Chem. Soc. 2012, 134, 19477; e) R. Shintani, K. Moriya,
T. Hayashi, Org. Lett. 2012, 14, 2902; f) Y. g) X. Lu, L. Li, W. Yang, K.
Jiang, K.-F. Yang, Z.-J. Zheng, L.-W. Xu, Eur. J. Org. Chem. 2013, 5814;
[9]
a) Y. Kuninobu, K. Yamauchi, N. Tamura, T. Seiki, K. Takai, Angew.
Chem. Int. Ed. 2013, 52, 1520; Angew. Chem. 2013, 125, 1560; b) M.
Murai, H. Takeshima, H. Morita, Y. Kuninobu, K. Takai, J. Org. Chem.
2015, 80, 5407; c) M. Murai, Y. Takeuchi, K. Yamauchi, Y. Kuninobu, K.
Takai, Chem. Eur. J. 2016, 22, 6048.
[2]
[10]
a) Q-W Zhang, K. An, W He, Angew. Chem. Int. Ed. 2014, 53, 5667;
Angew. Chem. 2014, 126, 5773; b) Q. W. Zhang, K. An, L. C. Liu, Y. Yue,
W. He, Angew. Chem. Int. Ed. 2015, 54, 6918; Angew. Chem. 2015, 127,
7022; c) Q.-W. Zhang, K. An, L.-C. Liu, S. Guo, C. Jiang, H. Guo, W. He,
Angew. Chem. Int. Ed. 2016, 55, 6319; Angew.Chem. 2016, 128, 6427;
d) Q.-W. Zhang, K. An, L.-C. Liu, Q. Zhang, H. Guo, W. He, Angew.
6
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10.1002/anie.202013041
Angewandte Chemie International Edition
RESEARCH ARTICLE
Chem. Int. Ed. 2017, 56, 1125; Angew. Chem. 2017, 129,1145; e) T He,
L.-C. Liu, L. Guo, B. Li, Q.-W. Zhang, W. He, Angew. Chem. Int. Ed. 2018,
57, 10868; Angew. Chem. 2018, 130, 11034. f) T. He, L.-C. Liu, W.-P.
Ma, B. Li, Q.-W. Zhang, W. He, Chem. Eur. J. 2020,
10.1002/chem.202003506.
[11] CCDC 1975576 (2am), 2032647 (8) and 2032648 (2eg) contains the
supplementary crystallographic data for 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.
[12] K. Mitsudo, S. Tanaka, R. Isobuchi, T. Inada, H. Mandai, T. Korenaga,
A. Wakamiya, Y. Murata, S. Suga, Org. Lett. 2017, 19, 2564.
[13] T. Fallon, M. Oestreich, Angew.Chem. Int. Ed. 2015, 54, 12488; Angew.
Chem. 2015, 127, 12666.
[14] D. T. Hog, M. Oestreich, Eur. J. Org. Chem. 2009, 5047.
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10.1002/anie.202013041
Angewandte Chemie International Edition
RESEARCH ARTICLE
Rh-Catalyzed Syntheses of Chiral Monohydrosilanes via Intramolecular C−H Functionalization
of Dihydrosilanes
Chiral Silanes! A Rh-chiral diphosphine complex catalyzed desymmetrization of dihydrosilanes were achieved via formal
intramolecular Si-H/C-H dehydrogenative coupling reactions. This simple, mild and practical method enjoys a unprecedently high
enantioselectivity and a unprecedently wide substrate scope. These chiral monohydrosilanes could be further elaborated into various
stereogenic silicons in a stereospecific manner.
8
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