Enantioselective Arylation of Benzylic C?H Bonds by Copper-Catalyzed Radical Relay

Article abstract of DOI:10.1002/anie.201902191

A novel enantioselective copper-catalyzed arylation of benzylic C?H bonds, using alkylarenes as a limiting reagent, has been developed. A chiral bisoxazoline ligand bearing an acetate ester moiety plays a key role in both the reactivity and enantioselectivity of the reaction. The reaction provides efficient access to various chiral 1,1-diarylalkanes in good yields with good to excellent enantioselectivities, and displays excellent functional-group tolerance.

Full text of DOI:10.1002/anie.201902191

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Accepted Article
Title: Enantioselective Arylation of Benzylic C-H bonds via Copper-
Catalyzed Radical Relay
Authors: Guosheng Liu, Wen Zhang, Lianqian Wu, and Pinhong Chen
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10.1002/anie.201902191
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Enantioselective Arylation of Benzylic C-H bonds via Copper-
Catalyzed Radical Relay
Wen Zhang, Lianqian Wu, Pinhong Chen, and Guosheng Liu*
Abstract:
A novel enantioselective Cu-catalyzed arylation of
benzylic C-H bonds using alkylarenes as a limiting reagent has been
developed, where a chiral bisoxazoline ligand bearing an acetate
ester moiety plays a key role in both reactivity and enantioselectivity.
The reaction provides an efficient access to various chiral 1,1-
diarylalkanes in good yields with good to excellent
enantioselectivities, and displays excellent functional group
tolerance.
Asymmetric functionalization of sp3 C-H bonds, which
serves as a powerful tool for the straightforward synthesis of
highly valuable chiral building blocks and drug candidates,[1] has
received much attention in the last several decades.[2] Inspired
by enzyme catalysis,[3]
a
series of direct oxidative
functionalization of sp3 C-H bonds under non-enzymatic systems
has been developed, which was initiated by a hydrogen atom
transfer (HAT) process.[4] However, the related asymmetric
functionalization of sp3 C-H bonds is still extremely difficult, due
to the involvement of highly reactive carbon-centered radical
intermediates.[5] Recently, several groups independently
reported cooperative photoredox and nickel catalysis for the
direct arylation of sp3 C-H bonds using electrophilic aryl halides
as arylation reagents, however, only moderate enantioselective
control (54% ee at most) was achieved in sporadic examples.[6]
As our continuous efforts to develop asymmetric radical
Scheme 1. Asymmetric benzylic C-H arylation via radical relay.
transformations (ARTs),
a
copper-catalyzed radical relay
process for the asymmetric benzylic C-H cyanation using chiral
bisoxazoline (Box) ligands and alkylarenes as a limited reagent
has been demonstrated,7 where a benzylic radical as a key
intermediate generated through a HAT process could be
enantioselectively trapped by chiral (Box)Cu(II) cyanides.[7,8]
Meanwhile, we also disclosed the asymmetric copper-catalyzed
arylation of styrenes, in which benzylic radicals generated by the
addition of radicals to styrenes could also be efficiently trapped
by chiral (Box)CuIIAr species, leading to enantiopure 1,1-
diarylmethane derivatives.[9,10] By merging these studies, we
thus envisioned that the asymmetric arylation of benzylic C-H
bonds might be possible via a similar radical relay process
(Scheme 1A),[11] providing an attractive protocol for the synthesis
of enantiomerically enriched 1,1-diarylalkanes as important
pharmacophores.[12] Herein, we communicate our study on the
asymmetric benzylic C-H arylation (Scheme 1B), wherein
introducing a carbonyl ester group into Box ligand is essential for
the good chemo- and enantioselectivity.
Very recently, we[13a] and Stahl[13b] group simultaneously
reported copper-catalyzed arylation of benzylic C-H bonds via a
radical relay process. Owing to the slow transmetalation
(Scheme 1B), a less steric bulky ligand TMPhen (tetramethyl-
phenanthroline) is essential for our reaction to give the desired
arylation products 3 with excellent chemoselectivity.[13a] However,
when the bulky chiral ligand L1, a privileged ligand used in our
previous asymmetric arylation of styrenes,[10] was tested for the
asymmetric benzylic C-H arylation, the reaction of 1a exhibited a
moderate reactivity (53% conversion) and poor selectivity to give
the desired product 3a in 24% yield, along with the side
fluorination and amination products 4a and 5a in 21% overall
yield. The chiral ligand L2 with bulkier gem-dibenzylic groups
showed worse reactivity and selectivity (eq 1). We reasoned that
the larger steric hindrance of the chiral ligands L1 and L2 could
make the transmetalation between (L*)Cu(II) species and
PhB(OH)2 more difficult,[14] thus leading to the low-concentrated
(L*)CuIIAr species which is not enough to capture the active
benzylic radicals efficiently (Scheme 1B).[15] Therefore, other
side reactions of the benzylic radicals, such as radical
fluorination[16] and radical oxidation/amination,[17] occurred to
give the side products 4a and 5a. Although further optimization
[a]
W. Zhang, L. Wu, Dr. P. Chen, Prof. Dr. G. Liu
State Key Laboratory of Organometallic Chemistry, Center for
Excellence in Molecular Synthesis, Shanghai Institute of Organic
Chemistry, University of Chinese Academy of Sciences, Chinese
Academy of Sciences
345 Lingling Road, Shanghai, 200032 (China)
E-mail: gliu@mail.sioc.ac.cn
Homepage: http://guoshengliu.sioc.ac.cn/
Supporting information for this article is given via a link at the end of
the document.
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10.1002/anie.201902191
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of the reaction conditions slightly increased a yield of the
reaction, the chemo- and enantioselecivity could not be further
improved (see Table 1A and SI). Similar results were obtained
using other Box ligands (L3-L4).
In order to further survey the asymmetric benzylic C-H
arylation, we assumed that enhancing the interaction between
the (L*)Cu(II) species and ArB(OH)2 by introducing a functional
group (FG) into the chiral ligands (L*) might be a reasonable
strategy to accelerate the transmetalation step, thus leading a
higher concentration of (L*)CuIIAr and prohibiting side reactions.
mol%) and L6 (2.4 mol%) delivered the desired product 3a in 81%
yield with 94:6 er (Table 1B).
With the optimized reaction conditions in hand, the
substrate scope of this asymmetric benzylic C-H arylation was
then investigated. As shown in Table 2, 1-alkyl naphthalenes
bearing different alkyl groups and various functional groups on
the alkyl chain could be employed as substrate, affording the
corresponding products 3b-3l in moderate to good yields with
excellent enantioselectivities (up to 98.5:1.5 er). Meanwhile,
substrates bearing electron-donating or withdrawing groups on
the naphthyl ring were also suitable for the reaction to give the
Table1. Optimization of the reaction conditions.[a,b,c]
desired
products
3m-3x
with
good
to
excellent
enantioselectivities (up to 96:4 er). Notably, various functional
groups, such as halide, phthalimide, HCF2O, ether, cyano,
ketone, silyl, ketone, and ester, were compatible with the
reaction conditions. For 1,5-diethylnaphthylene 1t bearing two
benzylic positions, the reaction provided the major
monoarylation product 3t in 56% yield with 92.5:7.5 er, along
with α,α'-diarylation product 3t' in 22% yield (dr 9/1). In addition,
3-ethylbenzanthrone 1y yielded the desired product 3y in 43%
yield with good enantioselectivity. Furthermore, the reactions of
substrates bearing heteroarenes, such as benzothiophene (3z)
and indazole (6a), also worked nicely to deliver the arylation
products with good to excellent enantioselectivity, albeit in low
yields. Compared to alkyl naphthalenes, alkyl benzenes as
substrate generally exhibited worse reactivities to give the
desired arylation products 6b-6c with lower enantioselectivities
(~85:15 er). The absolute configuration of the products was
unambiguously determined by the X-ray crystal structure of 3o.
Then, we turn our attention to examining aryl boronic acids. As
shown in table 2, a wide variety of aryl boronic acids bearing
electron-donating or electron-withdrawing groups reacted
smoothly with 1a to give the corresponding products 6d-6i in
moderate to good yields (54-91%) with excellent enantio-
selectivities (up to 95.5 : 4.5 er). In addition, these aryl boronic
acids could also be coupled with various alkylnaphthylenes to
afford the enantiomerically enriched 1,1-diaryl alkanes 6j-6t in
good yields with good to excellent enantioselectivities (93:7-98:2
er). Again, excellent functional group tolerance was observed,
and pyridyl boronic acid was also suitable for the reaction to give
the desired product 6u in 64% yield with 87:13 er.
On the basis of the above-mentioned hypothesis, a series of
functional groups were introduced into Box ligands. The
screening results revealed that the ligands L5-L7 bearing a
carbonyl group exhibited much better chemoselectivity (Table
1B). The reaction using the ligand L5 provided the desired
product 3a in 46% yield (52% conversion) with an enantiomeric
ratio (er) of 90:10. The ligand L6 exhibited a better selectivity to
give 3a in 61% yield (65% conversion) with 93:7 er, along with
trace side products. Notably, the selectivity for the reaction with
L7 bearing an acetamidyl group was slightly lower, and the
ligand L8 bearing a hydroxyl group also exhibited excellent
chemoselectivity, but low conversion of 1a was observed. When
a strongly coordinating oxazoline moiety was introduced into the
ligand L9, low conversion of 1a was also observed, presumably
due to the increased steric hindrance in copper catalysts by a
1,1,1-Triarylmethanes can be frequently found in
pharmaceuticals and material science, but the synthesis of their
enantiomers is quite challenging.[19] It is noteworthy that 1,1,1-
triarylmethane 6v was easily prepared by our methodology in
acceptable yields with moderate enantioselectivity (80:20 er).
side-arm effect.[18] In addition, increasing
a
little steric
hinderance of alkyl groups in the Box ligand (L10) led to slightly
lower reactivity and selectivity. Finally, with further optimizing
reaction condition, the reaction of 1a in the presence of Cu(I) (1
Scheme 2. Gram-scale reaction and further transformations.
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Table 2. Substrate scope of alkylarenes and aryl boronic acids.a,b
To demonstrate the utility of our method, the asymmetric
arylations were performed on a gram scale to provide the
products 6a (2.05 g, 91% yield, 97.5:2.5 er) and 6b (1.12g, 73%
yield, 95.5:4.5 er), which could be easily converted to the
corresponding chiral 3,3-diarylpropionamide 7a, acid 7c, amine
7b and alcohol 7d in excellent yields without loss of
enantioselectivity (Scheme 2).
further converted into the ring-opening amination products 9 as
ROR-γ-modulator analogues (Scheme 3).[21]
Splitomicin and its analogues
8 were identified as
micromolar inhibitor of Sir2.[20] The late-stage asymmetric
arylation of Splitomicin could be successfully achieved by our
current method to provide various arylated products 8a-8c in
moderate yields with good enantioselectivities, which could be
Scheme 3. Late-stage functionalization of Splitomicin.
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In order to clarify the ligand effect on the arylation reaction,
the same reaction using different ligands (L6 vs L1) was
analyzed at various times. As shown in Figure 1, both two
reactions exhibited a remarkable induction period, and the
reaction with L6 had a shorter induction period than that using
L1. Meanwhile, the different reaction rates were observed as
follows: kL6 > kL1, indicating that the ester moiety in L6 had a
significant effect on the reaction. We reasoned that a possible
interaction between the ester group in L6 and ArB(OH)2
promoted the transmetalation step, thus leading to a relative
higher concentration of (L6)CuIIAr species, which could trap
benzylic radicals efficiently. Therefore, a shorter induction period
and faster rate were observed.[22]
Keywords: Asymmetric radical reaction • Copper-Catalyzed •
Benzylic C-H • Arylation • hydrogen atom abstraction
[1]
[2]
(a) F. Lovering, J. Bikker, C. Humblet, J. Med. Chem. 2009, 52, 6752-
6756. (b) T. Cernak, K. D. Dykstra, S. Tyagarajan, P. Vachal, S. W.
Krska, Chem. Soc. Rev. 2016, 45, 546-576.
For selected reviews, see: (a) T. G. Saint-Denis, R.-Y. Zhu, G. Chen,
Q.-F. Wu, J.-Q. Yu, Science 2018, 359, 759. (b) H. M. L. Davis, D.
Morton, Chem. Soc. Rev. 2011, 40, 1857-1869. (c) R. Giri, B.-F. Shi, K.
M. Engle, N. Maugel, J.-Q. Yu, Chem. Soc. Rev. 2009, 38, 3242-3271.
(d) S.-L. You, Asymmetric Functionalization of C-H Bonds, RSC
Catalysis Series, the Royal Society of Chemistry, Cambridge, UK, 2015.
(a) B. Meunier, S. P. de Visser, S. Shaik, Chem. Rev. 2004, 104, 3947-
3980. (b) P. R. Ortiz de Montellano, Chem. Rev. 2010, 110, 932-948.
For some reviews, see: (a) C.-M. Che, V. K.-Y. Lo, C.-Y. Zhou, J.-S.
Huang, Chem. Soc. Rev. 2011, 40, 1950-1975. (b) H. Lu, X. P. Zhang,
Chem. Soc. Rev. 2011, 40, 1899-1909. (c) X. Huang, J. T. Groves,
Chem. Rev. 2018, 118, 2491-2553. (d) W. Liu, J. T. Groves, Acc. Chem.
Res. 2015, 48, 1727-1735.
[3]
[4]
100
L6
TMPhen
L1
80
[5]
For some reviews, see: (a) M. P. Sibi, S. Manyem, J. Zimmerman,
Chem. Rev. 2003, 103, 3263–3296. (b) F. Wang, P. Chen, G. Liu, Acc.
Chem. Res. 2018, 51, 2036–2046. (c) Q. Lu, F. Glorius, Angew. Chem.
Int. Ed. 2017, 56, 49-51. (d) K. Wang, W. Kong, Chin. J. Chem. 2018,
36, 247-256. For selected examples, see: (e) M. Milan, M. Bietti, M.
Costas, ACS Cent. Sci. 2017, 3, 196-204. (f) J. T. Groves, P. Viski, J.
Am. Chem. Soc. 1989, 111, 8537-8538. (g) R. Zhang, W. Y. Yu, T. S.
Lai, C. M. Che, Chem. Commun. 1999, 1791–1792. (h) M. B. Andrus, Z.
Zhou, J. Am. Chem. Soc. 2002, 124, 8806-8807.
60
40
20
0
0
50
100
150
200
[6]
(a) M. T. Pirnot, D. A. Rankic, D. B. C. Martin, D. W.C. MacMillan,
Science 2013, 339, 1593-1596. (b) D. K. Ahneman, A. G. Doyle, Chem.
Sci. 2016, 7, 7002-7006. (c) Y. Shen, Y. Gu, R. Martin, J. Am. Chem.
Soc. 2018, 140, 12200-12209.
Reaction Time (hour)
Figure 1. Ligand effect on the reaction of 1a.
[7]
[8]
W. Zhang, F. Wang, S. D. McCann, D. Wang, P. Chen, S. S. Stahl, G.
Liu, Science 2016, 353, 1014-1018.
In conclusion, we have developed a copper-catalyzed
enantioselective arylation of benzylic C-H bonds via radical relay
using alkylarenes as limiting reagent, which provides an efficient
and straightforward approach to various chiral 1,1-diarylalkanes
with good to excellent enantioselectivities. The enhancement of
chemo- and enantioselectivity for the arylation of benzylic C-H
bonds depends on the introduction of a benzyl ester moiety into
bisoxazoline (BOX) ligands. Owing to the limited substrate
scope on alkyl naphthylene substrates of this arylation,[23] further
improving catalytic systems and the mechanism study are still in
progress in our laboratory.
(a) F. Wang, D. Wang, X. Wan, L. Wu, P. Chen, G. Liu, J. Am. Chem.
Soc. 2016, 138, 15547-15550. (b) D. Wang, F. Wang, P. Chen, Z. Lin,
G. Liu, Angew. Chem., Int. Ed. 2017, 56, 2054-2058. (c) D. Wang, N.
Zhu, P. Chen, Z. Lin, G. Liu, J. Am. Chem. Soc. 2017, 139, 15632-
15635.
[9]
(a) L. Wu, F. Wang, X. Wan, D. Wang, P. Chen, G. Liu, J. Am. Chem.
Soc. 2017, 139, 2904-2907. (b) D. Wang, L. Wu, F. Wang, X. Wan, P.
Chen, Z. Lin, G. Liu, J. Am. Chem. Soc. 2017, 139, 6811-6814.
[10] For more examples on the copper catalyzed asymmetric radical
transformations, see: (a) R. Zhu, S. L.Buchwald, J. Am. Chem. Soc.
2015, 137, 8069-8077. (b) R. Zhu, S. L.Buchwald, Angew. Chem., Int.
Ed. 2013, 52, 12655-12658. (c) J.-S. Lin, X.-Y. Dong, T.-T. Li, N.-C.
Jiang, B. Tan, X.-Y. Liu, J. Am. Chem. Soc. 2016, 138, 9357–9360. (d)
J.-S. Lin, F.-L. Wang, X.-Y. Dong, W.-W. He, Y. Yuan, S. Chen, X.-Y.
Liu, Nat. Commun. 2017, 8, 14841. (e) X.-T. Li, Q. -S. Gu, X.-Y. Dong,
X. Meng, X.-Y. Liu, Angew. Chem., Int. Ed. 2018, 57, 7668-7672. (f) J.-
S. Lin, T.-T. Li, J.-R. Li, G.-Y. Jiao, Q.-S. Gu, J.-T. Cheng, Y.-L. Guo, X.
Hong, X.-Y. Liu, J. Am. Chem. Soc. 2019, 141, 1074-1083.
[11] For recent advances in the asymmetric sp3 C-H arylation by metal-
catalyzed C-H activation, see: (a) F.-L. Zhang, K. Hong, T.-J. Li, H.
Park, J.-Q. Yu, Science 2016, 351, 252-256. (b) H. Wang, H.-R. Tong,
G. He, G. Chen, Angew. Chem., Int. Ed. 2016, 55, 15387-15391. (c) S.-
B. Yan, S. Zhang, W.-L. Duan, Org. Lett. 2015, 17, 2458-2461. (d) J. H.
Kim, S. Greßies, M. Boultadakis-Arapinis, C. Daniliuc, F. Glorius, ACS
Catal. 2016, 6, 7652-7656. (e) G. Chen, T. Shigenari, P. Jain, Z. Zhang,
Z. Jin, J. He, S. Li, C. Mapelli, M. M. Miller, M. A. Poss, P. M. Scola, K.-
S. Yeung, J.-Q. Yu, J. Am. Chem. Soc. 2015, 137, 3338-3351. (f) J. He,
S. Li, Y. Deng, H. Fu, B. N. Laforteza, J. E. Spangler, A. Homs, J.-Q.
Yu, Science 2014, 343, 1216-1220. (g) G. Chen, W. Gong, Z. Zhuang,
M. S. Andrä, Y.-Q. Chen, X. Hong, Y.-F. Yang, T. Liu, K. N. Houk, J.-Q.
Yu, Science, 2016, 353, 1023-1027.
Acknowledgements
We are grateful for financial support from the National Basic
Research Program of China (973-2015CB856600), the National
Nature Science Foundation of China (NFSC, Nos. 21532009,
21790330, 21821002 and 21761142010), the Science and
Technology Commission of Shanghai Municipality (Nos.
17XD1404500, 17QA1405200 and 17JC1401200), and the
strategic Priority Research Program (No. XDB20000000) and
the
Key
Research
Program
of
Frontier
Science
(QYZDJSSWSLH055) of the Chinese Academy of Sciences.
This research was also partially supported by CAS
Interdisciplinary Innovation Team.
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[12] (a) D. Ameen, T. Snape, J. Med. Chem. Commun. 2013, 4, 893-907. (b)
T. Jia, P. Cao, J. Liao, Chem. Sci. 2018, 9, 546-559.
[18] For the side-arm effect, see: S. Liao, X.-L. Sun, Y. Tang, Acc. Chem.
Res. 2014, 47, 2260-2272.
[13] (a) W. Zhang, P. Chen, G. Liu, J. Am. Chem. Soc. 2017, 139, 7709-
7712. (b) A. Vasilopoulos, S. L. Zultanski, S. S. Stahl, J. Am. Chem.
Soc. 2017, 139, 7705-7708. (c) Z. Li, Q. Wang, J.-P. Zhu, Angew.
Chem., Int. Ed. 2018, 57, 13288-13292. (d) Z. Zhang, L. M. Stateman,
D. A. Nagib, Chem. Sci. 2019, 10, 1207-1211. and there are only two
examples of the asymmetric C-H arylation ( 65% ee at most).
[14] For the mechanistic studies on the copper-catalyzed arylation via
radical relay, see: F. Wang, D. Wang, X. Mu, P. Chen, G. Liu, J. Am.
Chem. Soc. 2014, 136, 10202-10205.
[19] For the synthesis of optically pure triaryl methanes by asymmetric
cross-coupling reactions or asymmetric arylation of alkenes, see: (a) C.
M. Crudden, J. Am. Chem. Soc. 2014, 136, 5828-5831. (b) Y. Huang, T.
Hayashi, J. Am. Chem. Soc. 2015, 137, 7556-7559.
[20] R. C. Neugebauer, U. Uchiechowska, R. Meier, H. Hruby, V. Valkov, E.
Verdin, W. Sippl, M. Jung, J. Med. Chem. 2008, 51, 1203-1213.
[21] P. M. Khan, B. E.-D. M. El-Gendy, N. Kumar, R. Garcia-Ordonez, L. Lin,
C. H. Ruiz, M. D. Cameron, P. R. Griffin, T. M. Kamenecka, Bioorg.
Med. Chem. Lett. 2013, 23, 532-536.
[15] Similar results were observed in our previously reported asymmetric
aminoarylation of styrenes. For details, see ref. 9b.
[22] Although details are unclear at the moment, we assumed a weak
hydrogen bonding effect between the ester moiety in L6 and aryl
boronic acids might be possibly beneficial for the transmetalation step.
[23] When p-ethyl tert-butylbenzene was treated under standard condition,
the reaction exhibited poor reactivity to give trace amount product,
along with recovered substrate (>95%). It is possible that the hydrogen
atom abstraction of benzylic C-H did not occur with unclear reason.
[16] M. Rueda-Becerril, C. C. Sazepin, J. C. T. Leung, T. Okbinoglu, P.
Kennepohl, J.-F. Paquin, G. M. Sammis, J. Am. Chem. Soc. 2012, 134,
4026-4029.
[17] Z. Ni, Q. Zhang, T. Xiong, Y. Zheng, Y. Li, H. Zhang, J. Zhang, Q. Liu,
Angew. Chem., Int. Ed. 2012, 51, 1244-1247.
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Entry for the Table of Contents (Please choose one layout)
Layout 1:
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Asymmetric Cu-catalyzed arylation of
benzylic C-H bonds using alkylarenes
as a limiting reagent has been
W. Zhang, L. Wu, P. Chen, G. Liu *
Page No. – Page No.
developed, providing an efficient
access to various chiral 1,1-
Enantioselective Arylation of Benzylic
C-H bonds via Copper-Catalyzed
Radical Relay
diarylalkanes in good yields with good
to excellent enantioselectivities, and
displays excellent functional group
tolerance. A chiral bisoxazoline ligand
bearing an acetate ester moiety plays
a key role in both reactivity and
enantioselectivity.
Layout 2:
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Author(s), Corresponding Author(s)*
((Insert TOC Graphic here))
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Title
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