Palladium-Catalyzed Formal [4 + 1] Annulation via Metal Carbene Migratory Insertion and C(sp2)-H Bond Functionalization

Article abstract of DOI:10.1021/acscatal.6b03562

A highly efficient and operationally simple palladium-catalyzed formal [4 + 1] annulation reaction has been developed. The reaction is featured by the formation of two different C-C bonds on a carbenic center. It represents a concise method for the synthesis of a wide range of polycyclic aromatic hydrocarbons (PAHs) and 1H-indenes with easily available (trimethylsilyl)diazomethane as the carbene source. Metal carbene migratory insertion and C(sp²)-H bond activation are proposed as the key steps in this transformation. The reaction further demonstrates the versatility of the carbene-based coupling in combination with various transition-metal-catalyzed transformations.

Full text of DOI:10.1021/acscatal.6b03562

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Letter
Palladium-Catalyzed Formal [4+1] Annulation via Metal Carbene
Migratory Insertion and C(sp2)-H Bond Functionalization
Shuai Xu, Ri Chen, Zihao Fu, Qi Zhou, Yan Zhang, and Jianbo Wang
ACS Catal., Just Accepted Manuscript • DOI: 10.1021/acscatal.6b03562 • Publication Date (Web): 07 Feb 2017
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Palladium-Catalyzed Formal [4+1] Annulation via
Metal Carbene Migratory Insertion and C(sp2)-H
Bond Functionalization
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Shuai Xu,† Ri Chen,† Zihao Fu,† Qi Zhou,† Yan Zhang† and Jianbo Wang*,†,‡
Beijing National Laboratory of Molecular Sciences (BNLMS), Key Laboratory of Bioorganic
Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, Peking
University, Beijing 100871, China; and State Key Laboratory of Organometallic Chemistry,
Chinese Academy of Sciences, Shanghai 200032, China
ABSTRACT: A highly efficient and operationally simple palladium-catalyzed formal [4+1]
annulation reaction has been developed. The reaction is featured by the formation of two
different C-C bonds on a carbenic center. It represents a concise method for the synthesis of a
wide range of polycyclic aromatic hydrocarbons (PAHs) and 1H-indenes with easily available
(trimethylsilyl)diazomethane as the carbene source. Metal carbene migratory insertion and
C(sp2)-H bond activation are proposed as the key steps in this transformation. The reaction
further demonstrates the versatility of the carbene-based coupling in the combination with
various transition-metal-catalyzed transfroamtions.
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KEYWORDS: annulation, metal carbene, Pd catalysis, C-H activation, polycyclic aromatic
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hydrocarbons
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Transition-metal-catalyzed carbene coupling reactions have been extensively studied in the past
decades and they are now established as versatile and reliable methods for C-C bond
formations.1 The key steps in these transformations are proposed to involve metal carbene
formations and subsequent migratory insertions. Moreover, from the organometallic species that
are generated from the metal carbene migratory insertions, it is possible to further incorporate
various cascade processes, which significantly increases the diversity of this type of coupling
reactions.1e,2 One of such cascade transformations in palladium-catalyzed reaction is the
transmetallation with a second organometallic species in the reaction system, with the catalytic
cycle being terminated by reductive elimination. The overall transformation is the formation of
two separate C-C bonds in a carbenic carbon center, as shown in Scheme 1a.3
On the other hand, transition-metal-catalyzed C-H functionalization involving metal
carbene migratory insertion process has attracted significant attentions in recent years.4,5 In this
context, Yu’s group reported in 2012 the first Rh(III)-catalyzed C-H activation of aromatic ring
bearing a directing group.6 Subsequently, the groups of Rovis,7 Glorius,8 Li,9 Cui,10 Wang,11
Yi,12 Chang,13 Ackermann14 and our group15 reported C-H activation using diazo compounds as
the cross-coupling partners based on ortho-directing group-assisted C-H bond metalation
strategy. Ir(III) and Ru(II) complexes were also found effective for this type of
transformations.16,17 Moreover, Pd-catalyzed C(sp3)-H bond activation with metal carbene has
been recently reported by Martin and coworkers (Scheme 1b).18 These advances suggest that
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diazo substrates can be considered as a general type of cross-coupling partners for the transition-
metal-catalyzed C-H bond activation.
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Scheme 1. Formation of Two C-C Bonds in Palladium-Catalyzed Carbene Coupling
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As the continuation of our research interest in carbene-based coupling reactions, we have
conceived that the palladium carbene migratory insertion may be merged with an intramolecular
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C(sp2)-H activation process. As illustrated in Scheme 1c, the cascade transformation starts with
oxidative addition, followed by Pd(II) carbene formation and migratory insertion, intramolecular
C-H bond activation and finally reductive elimination to complete the catalytic cycle. Herein we
report our investigation based on this strategy, which involves Pd(II) carbene migratory insertion
and aromatic and vinylic C-H bond functionalizations. The reaction provides an efficient method
to synthesize polycyclic aromatic hydrocarbons (PAHs), including fluorenes, 1H-indenes19 and
pyrroloindoles, which are important structural motifs that have found applications in various
areas.20-23
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We initiated our study of palladium-catalyzed carbene coupling by using 2-bromo-1,1'-
biphenyl 1a and (trimethylsilyl)diazomethane 2 as the substrates (Table 1). The commercially
available diazo compound 2 is a safer alternative to diazomethane. With diazo compound 2 as
the one-carbon unit, we expected to develop [4+1] annulation method for the access to 9H-
fluorene derivatives. Gratifyingly, with Pd(PPh3)4 as the catalyst and K2CO3 as the base, the
o
reaction in dioxane at 100 C afforded the coupling products as a mixture of 3a and 3a' in 20%
yield (Table 1, entry 1). The reaction with iPr2NH as the base failed to give the coupling product
(Table 1, entry 2). We then screened a series of solvents that were commonly used in this type of
coupling reactions, but none of them gave better results than dioxane (Table 1, entries 3-6). We
also found that the phosphine ligands failed to promote the coupling (Table 1, entries 7 and 8).
To our delight, with NaOAc as the additive, the coupling product 3a was obtained in 65% yield
as a single product (Table 1, entry 9). We reasoned that NaOAc could not only promote the C-H
bond activation, but also accelerate the desilylation process. Further examination of additives
showed that KOAc could give the best result, affording 3a in 80% isolated yield. Notably, in
contrast to many metal-catalyzed carbene transfer reactions in which diazo substrates are
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generally used in large excess, the diazo substrate 2 in the present reaction is only employed in
1.2 equivalents. We also examined the reactions with other metal carbene precursors, such as N-
tosylhydrazones or aryldiazoacetates; however, in all of the cases only trace desired coupling
product could be observed.
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Table 1. Optimization of the Reaction Conditions
entry
solvent
cat. [Pd]
base
yield(%)a
1
2
dioxane
dioxane
toluene
DCE
Pd(PPh3)4
Pd(PPh3)4
Pd(PPh3)4
Pd(PPh3)4
Pd(PPh3)4
Pd(PPh3)4
Pd2(dba)3+L1
Pd2(dba)3+L2
Pd(PPh3)4
Pd(PPh3)4
K2CO3
iPr2NH
20
0
3
K2CO3
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4
K2CO3
trace
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5
MeCN
DMF
K2CO3
6
K2CO3
trace
<5
7
dioxane
dioxane
dioxane
dioxane
K2CO3
8
K2CO3
<5
9
K2CO3+NaOAc
K2CO3+KOAc
65b
10
85(80)b,c
aIf not otherwise noted, the yields were estimated by H NMR (400 MHz) of the crude product
1
b
c
containing both 3a and 3a'. The yield refers to 3a. 1.2 equiv of 2 was used. The yield in the
bracket refers to isolated yield. L1: tri(2-furanyl)phosphine; L2: tris(4-fluorophenyl)phosphine.
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With the optimized reaction conditions in hand, we proceeded to explore the scope of the
substrates. First, we used 2-bromo-1,1'-biphenyl derivatives as the substrates which could be
easily prepared via Suzuki-Miyaura cross coupling reaction. As shown in Table 2, the 2-bromo-
1,1'-biphenyl substrates bearing either electron-donating or -withdrawing groups were all
tolerated, affording the corresponding 9H-fluorene derivatives in good to excellent yields.
Notably, vinyl substituent tolerated this transformation without the formation of the products due
to Heck-type reaction or [2+1] cyclopropanation (3e). Chloro substituent could also be tolerated,
which gave the chance for further functionalization through transition-metal-catalyzed reactions
(3g). As for ortho-substituted substrate 1l, the corresponding product 3l could only be obtained
in moderate yield, which might be due to the steric effect. In addition to the 9H-fluorene
derivatives, other structurally diversified PAHs could also be accessed by using this strategy
(3m-p).
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Table 2. The Reaction Scope of 2-Bromo-1,1‘-biphenyl Substratesa
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aReaction conditions: Pd(PPh3)4 (5 mol%), K2CO3 (1.0 equiv), KOAc (1.0 equiv) were mixed in
an oven-dried reaction tube. After degassed and backfilled with N2, 1a-p (0.1 mmol), 2 ( 1.2
equiv) and dioxane (1.0 mL) were added via syringe. The mixture was stirred at 100 oC for 24 h.
bAll the yields refer to the desilylated products 3a-p purified by silica gel chromatography.
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The site selectivity of this transformation was then evaluated by using meta-substituted 2-
bromo-1,1'-biphenyl derivatives as the substrates (eq 1). It was found that the ratio of the
products varied considerably depending on the substituents. When using methoxy substituted
substrate 1q, the yield was excellent. The regioselectivity was poor, but the two isomeric
products was easy to separate. When using methyl substituted 1r as the substrate, both the yield
and the regioselectivity were good (note: all the yields refer to the desilylated products).
(1)
In addition to 2-bromo-1,1'-biphenyl derivatives, 1-(2-bromophenyl)-1H-pyrrole derivatives
(4a-g) were also tested under the optimized reaction conditions. Gratifyingly, the coupling
reaction occurred smoothly and the corresponding 9H-pyrrolo[1,2-a]indole derivatives could be
obtained in good yields (Table 3). When 1-(2-bromophenyl)-1H-indole 4g was used as the
substrate, the corresponding 10H-indolo[1,2-a]indole 5g could be obtained in moderate yield.
Table 3. The Reaction with 1-(2-Bromophenyl)-1H-pyrrole Derivativesa
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aThe conditions are same as those described in Table 2. bAll the yields refer to the desilylated
products 5a-g purified by silica gel chromatography.
After surveying the aromatic C-H bond activation, we next explored the vinylic C-H
functionalization, with the expectation that 1H-indenes might be accessed with the same strategy.
To our delight, when 1-bromo-2-(1-phenylvinyl)benzene 6a was used as the substrate, the
desired 3-phenyl-1H-indene 7a could be obtained in good yield under slightly modified reaction
conditions (Table 4). The reactions with the bromo substrates bearing either electron-donating
(7b-c) or electron-withdrawing (7d-f) substituents all proceeded well, affording the
corresponding 1H-indenes in good yields. The reactions with substrates bearing ortho- and meta-
substituents also afforded the desired products in good yields (7h and 7i). Besides, the reactions
with substrates bearing naphthalene and thiophenyl groups exhibited good reactivity, furnishing
the desired products in excellent yields (7j and 7k).
Table 4. The Coupling Reaction involving Vinylic C-H Bond Functionalization
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aThe conditions are same as those described in Table 2. bAll the yields refer to the desilylated
products 7a-k purified by silica gel chromatography.
To gain insights into the mechanism of this transformation, several experiments were
carried out (Scheme 2). First, to measure the kinetic isotopic effect (KIE) of the reaction, parallel
experiments were carried out by using equimolar amounts of 1a and 1a-d5 under the standard
condtions in two separate flask (Scheme 2a). The reactions were terminated within 4 min to keep
the conversion below 10%. 1H NMR analysis of the products determined kH/kD = 2.3, suggesting
that the C-H bond cleavage is involved in the rate-determining step.24 Notably, the product 3a'
(or 3a'-d4) was formed at the beginning of the reaction, which was gradually converted into 3a
(or 3a-d4). The ratio of 3a (or 3a-d4) and 3a' (or 3a'-d4) was about 7:1 when the reaction was
terminated after 4 min. Notably, in all the cases only desilylation products were observed when
the reactions were continued for 24 h. Next, to evaluate the electronic effects of the reaction,
pairwise competition experiments were conducted using 1a, 1b, 1g and 1k (Scheme 2b). The
product ratio clearly suggests that the reaction is accelerated by electron-withdrawing
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substituents. These experiments indicate that aromatic C-H bond activation likely proceeds via a
concerted metalation deprotonation mechanism (CMD).25
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Scheme 2. Mechanistic Experiments on Aromatic C-H Bond Functionalization
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For vinylic C-H functionalization process, similar mechanistic experiments were carried out
(Scheme 3). We used 6a and 6a-d2 to investigate the kinetic isotopic effect. Both parallel
experiments (two reactions in two separate flasks) and intermolecular competition experiments
(two reactions in one flask) showed reaction rates of 6a and 6a-d2 were almost the same,
indicating that C-H bond cleavage is not the rate-determining step for the vinylic C-H
functionalization process (Scheme 3a).24 To investigate whether this vinylic C-H
functionalization follows a Heck-type reaction process, the reaction with 6l as the substrate was
carried out (Scheme 3b). We reasoned that both 7l and 8a would be obtained if the reaction
proceeds via a Heck-type mechanism. However, the reaction only gave 7l in 68% 1H NMR yield.
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8a could not be detected by H NMR or GC-MS. Besides, it was confirmed that only small
portion of 8a isomerized to 7l under the standard reaction conditions (Scheme 3c). Finally,
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control experiments showed that KOAc was necessary to this C-H functionalization reaction
(Scheme 3d). Therefore, we have reasoned that the vinylic C-H bond functionalization is not
likely to proceed via a Heck-type mechanism.
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Scheme 3. Mechanistic Experiments on Vinylic C-H Bond Functionalization
Based on the mechanistic experiments and previous reports on the related reactions,4,18,26 we
have proposed the reaction mechanisms as shown in Scheme 4. Taking 2-bromo-1,1'-biphenyl 1a
as the example, first oxidative addition generates PdII species A, from which two pathways are
possible. In path a, A reacts with diazo substrate 2 to form PdII carbene species B, which is
followed by migratory insertion to give intermediate C. From intermediate C, C-H bond
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activation occurs to generate palladacyclic intermediate D. Finally, the product 3a is formed
through reductive elimination and desilylation. In an alternative mechanism (path b), C-H bond
activation occurs first from intermediate A to generate palladacyclic intermediate E, which is
followed by carbene formation and migratory insertion (Scheme 4a).
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For the vinylic C(sp2)-H bond activation, we propose the formation of a five-membered
palladacycle H from G through a CMD mechanism.26 From H the PdII carbene I is formed,
followed by migratory insertion and reductive elimination to afford the product 7a (Scheme 4b).
Scheme 4. Proposed Reaction Mechanism
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In summary, we have developed a highly efficient Pd-catalyzed formal [4+1] annulation
reaction via C-H activation and metal carbene migratory insertion process. Two C-C bonds are
constructed in this transformation and a series of PAHs can be accessed staring from easily
available substrates. Moreover, vinylic C-H bond functionalization is also realized in
combination with palladium carbene migratory insertion. The reaction further demonstrates the
versatility of transition-metal-catalyzed carbene coupling reactions.
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ASSOCIATED CONTENT
AUTHOR INFORMATION
†Peking University
‡Chinese Academy of Sciences
Corresponding Author
wangjb@pku.edu.cn
Notes
The authors declare no competing financial interest.
Supporting Information. Experimental procedure, characterization data, copies of 1H and 13C
NMR spectra. This material is available free of charge via the Internet at http://pubs.acs.org.
The following files are available free of charge.
Procedures and analytical data (PDF)
ACKNOWLEDGMENT
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The project is supported by the National Basic Research Program of China (973 Program, No.
2015CB856600) and the Natural Science Foundation of China (Grant 21332002, 21472004).
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REFERENCES
(1) For reviews, see: (a) Zhang, Y.; Wang, J. Eur. J. Org. Chem. 2011, 6, 1015-1026. (b) Shao,
Z.; Zhang, H. Chem. Soc. Rev. 2012, 41, 560-572. (c) Barluenga, J.; Valdés, C. Angew. Chem.
Int. Ed. 2011, 50, 7486-7500. (d) Xiao, Q.; Zhang, Y.; Wang, J. Acc. Chem. Res. 2013, 46,
236-247. (e) Xia, Y.; Zhang, Y.; Wang, J. ACS Catal. 2013, 3, 2586-2598. (f) Liu, Z.; Wang,
J. J. Org. Chem. 2013, 78, 10024-10030.
(2) (a) Kudirka, R.; Van Vranken, D. L. J. Org. Chem. 2008, 73, 3585-3588. (b) Gutman, E. S.;
Arredondo, V.; Van Vranken, D. L. Org. Lett. 2014, 16, 5498-5501.
(3) Zhou, L.; Ye, F.; Zhang, Y.; Wang, J. J. Am. Chem. Soc. 2010, 132, 13590-13591.
(4) For a review, see: Hu, F.; Xia, Y.; Zhang, Y.; Wang, J. Chem. Commun. 2015, 51, 7986-7995.
(5) (a) Zhao, X.; Wu, G.; Zhang, Y.; Wang, J. J. Am. Chem. Soc. 2011, 133, 3296-3299. (b) Xiao,
Q.; Ling, L.; Ye, F.; Tan, R.; Tian, L.; Zhang, Y.; Li, Y.; Wang, J. J. Org. Chem. 2013, 78,
3879-3885. (c) Xu, S.; Wu, G.; Ye, F.; Wang, X.; Li, H.; Zhao, X.; Zhang, Y.; Wang, J.
Angew. Chem. Int. Ed. 2015, 54, 4669-4672.
(6) Chan, W.-W.; Lo, S.-F.; Zhou, Z.; Yu, W.-Y. J. Am. Chem. Soc. 2012, 134, 13565-13568.
(7) Hyster, T. K.; Ruhl, K. E.; Rovis, T. J. Am. Chem. Soc. 2013, 135, 5364-5367.
(8) (a) Shi, Z.; Koester, D. C.; Boultadakis-Arapinis, M.; Glorius, F. J. Am. Chem. Soc. 2013,
135, 12204-12207. (b) Kim, J. H.; Gensch, T.; Zhao, D.; Stegemann, L.; Strassert, C. A.;
Glorius, F. Angew. Chem. Int. Ed. 2015, 54, 10975-10979.
(9) Yu, X.; Yu, S.; Xiao, J.; Wan, B.; Li, X. J. Org. Chem. 2013, 78, 5444-5452.
ACS Paragon Plus Environment

Page 15 of 16
ACS Catalysis
1
2
3
4
5
6
(10) (a) Cui, S.; Zhang, Y.; Wang, D.; Wu, Q. Chem. Sci. 2013, 4, 3912-3916. (b) Zhang, Y.;
Zheng, J.; Cui, S. J. Org. Chem. 2014, 79, 6490-6500.
7
8
9
(11) Liang, Y.; Yu, K.; Li, B.; Xu, S.; Song, H.; Wang, B. Chem. Commun. 2014, 50, 6130-6133.
(12) Shi, J.; Yan, Y.; Li, Q.; Xu, H. E.; Yi, W. Chem. Commun. 2014, 50, 6483-6486.
(13) (a) Jeong, J.; Patel, P.; Hwang, H.; Chang, S. Org. Lett. 2014, 16, 4598-4601. (b) Dateer, R.
B.; Chang, S. Org. Lett. 2016, 18, 68-71.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
(14) Li, J.; Tang, M.; Zang, L.; Zhang, X.; Zhang, Z.; Ackermann, L. Org. Lett. 2016, 18, 2742-
2745.
(15) Hu, F.; Xia, Y.; Ye, F.; Liu, Z.; Ma, C.; Zhang, Y.; Wang. J. Angew. Chem. Int. Ed. 2014,
53, 1364-1367.
(16) Xia, Y.; Liu, Z.; Feng, S.; Zhang, Y.; Wang, J. J. Org. Chem. 2015, 80, 223-236.
(17) Li, Y.; Qi, Z.; Wang, H.; Yang, X.; Li, X. Angew. Chem. Int. Ed. 2016, 55, 11877-11881.
(18) Gutiérrez-Bonet, Á.; Juliá-Hernández, F.; Luis, B.; Martin, R. J. Am. Chem. Soc. 2016, 138.
6384-6387.
(19) (a) Das, B. G.; Chirila, A.; Tromp, M.; Reek, J. N. H.; de Bruin, B. J. Am. Chem. Soc. 2016,
138, 8968-8975. (b) Wang, Y.; McGonigal, P. R.; Herlé, B.; Besora, M.; Echavarren, A. M.
J. Am. Chem. Soc. 2014, 136, 801-809.
(20) (a) Bernius, M. T.; Inbasekaran, M.; O’Brien, J.; Wu, W. Adv. Mater. 2000, 12, 1737-1750.
(b) Scherf, U.; List, E. J. W. Adv. Mater. 2002, 14, 477-487.
(21) Anthony, J. E. Chem. Rev. 2006, 106, 5028-5048.
ACS Paragon Plus Environment

ACS Catalysis
Page 16 of 16
1
2
3
4
5
6
(22) (a) Lnganäs, O.; Zhang, F.; Andersson, M. R. Acc. Chem. Res. 2009, 42, 1731-1739. (b)
Anthony, J. E. Chem. Rev. 2006, 106, 5028-5048.
7
8
9
(23) (a) Tierney, M. T.; Grinstaff, M. W. J. Org. Chem. 2000, 65, 5355-5359. (b) Saikawa, Y.;
Hashimoto, K.; Nakata, M.; Yoshihara, M.; Nagai, K.; Ida, M.; Komiya, T. Nature 2004,
429, 363-363. (c) Galm, U.; Hager, M. H.; Van Lansen, S. G.; Ju, J.; Thorson, J. S.; Shen, B.
Chem. Rev. 2005, 105, 739-758.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
(24) Simmons, E. M.; Hartwig, J. F. Angew. Chem. Int. Ed. 2012, 51, 3066-3072.
(25) Gorelsky, S. I.; Lapointe, D.; Fagnou, K. J. Am. Chem. Soc. 2008, 130, 10848-10849.
(26) Hu, T.-J.; Zhang, G.; Chen, Y.-H.; Feng, C.-G.; Lin, G.-Q. J. Am. Chem. Soc. 2016, 138,
2897-2900.
ACS Paragon Plus Environment