Metal–Organic Layers Hierarchically Integrate Three Synergistic Active Sites for Tandem Catalysis

Article abstract of DOI:10.1002/anie.202011519

We report the design of a bifunctional metal–organic layer (MOL), Hf₁₂-Ru-Co, composed of [Ru(DBB)(bpy)₂]²⁺ [DBB-Ru, DBB=4,4′-di(4-benzoato)-2,2′-bipyridine; bpy=2,2′-bipyridine] connecting ligand as a photosensitizer and Co(dmgH)₂(PPA)Cl (PPA-Co, dmgH=dimethylglyoxime; PPA=4-pyridinepropionic acid) on the Hf₁₂ secondary building unit (SBU) as a hydrogen-transfer catalyst. Hf₁₂-Ru-Co efficiently catalyzed acceptorless dehydrogenation of indolines and tetrahydroquinolines to afford indoles and quinolones. We extended this strategy to prepare Hf₁₂-Ru-Co-OTf MOL with a [Ru(DBB)(bpy)₂]²⁺ photosensitizer and Hf₁₂ SBU capped with triflate as strong Lewis acids and PPA-Co as a hydrogen transfer catalyst. With three synergistic active sites, Hf₁₂-Ru-Co-OTf competently catalyzed dehydrogenative tandem transformations of indolines with alkenes or aldehydes to afford 3-alkylindoles and bisindolylmethanes with turnover numbers of up to 500 and 460, respectively, illustrating the potential use of MOLs in constructing novel multifunctional heterogeneous catalysts.

Full text of DOI:10.1002/anie.202011519

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Tandem Catalysis
Hot Paper
Metal–Organic Layers Hierarchically Integrate Three Synergistic
Active Sites for Tandem Catalysis
Yangjian Quan+, Guangxu Lan+, Wenjie Shi+, Ziwan Xu, Yingjie Fan, Eric You, Xiaomin Jiang,
Cheng Wang, and Wenbin Lin*
Abstract: We report the design of a bifunctional metal–organic
layer (MOL), Hf12-Ru-Co, composed of [Ru(DBB)(bpy)2]2+
[DBB-Ru, DBB = 4,4’-di(4-benzoato)-2,2’-bipyridine; bpy =
2,2’-bipyridine] connecting ligand as a photosensitizer and
Co(dmgH)2(PPA)Cl (PPA-Co, dmgH = dimethylglyoxime;
PPA = 4-pyridinepropionic acid) on the Hf12 secondary build-
ing unit (SBU) as a hydrogen-transfer catalyst. Hf12-Ru-Co
efficiently catalyzed acceptorless dehydrogenation of indolines
and tetrahydroquinolines to afford indoles and quinolones. We
extended this strategy to prepare Hf12-Ru-Co-OTf MOL with
a [Ru(DBB)(bpy)2]2+ photosensitizer and Hf12 SBU capped
with triflate as strong Lewis acids and PPA-Co as a hydrogen
transfer catalyst. With three synergistic active sites, Hf12-Ru-Co-
OTf competently catalyzed dehydrogenative tandem trans-
formations of indolines with alkenes or aldehydes to afford 3-
alkylindoles and bisindolylmethanes with turnover numbers of
up to 500 and 460, respectively, illustrating the potential use of
MOLs in constructing novel multifunctional heterogeneous
catalysts.
Introduction
Figure 1. a),b) Schematic representation of MOLs with one (a) or
two (b) catalytic centers. c) Rational design of a new trifunctional MOL
with three different catalytic centers.
Metal-organic layers (MOLs), a 2D monolayered version
of 3D MOFs,[1–21] have recently provided a tunable material
platform for the design of heterogeneous catalysts featuring
isolated, uniform, and well-defined active sites (Fig-
ure 1a).[22–31] Hierarchical integration of multiple catalytic
centers into MOLs can facilitate synergistic or tandem
catalysis to potentially afford atom-economic and step-
efficient synthetic methodologies.[32,33] Although several
MOLs with two different active centers have been construct-
ed (Figure 1b)[34–38] and some of them have shown enhanced
catalytic performance over their homogenous counter-
parts,[37,38] the design of MOLs containing three or more
different catalytic centers remains a challenge.[23,39]
Nature synergistically integrates a number of enzymes to
perform complicated biosynthetic transformations. For exam-
ple, “ubiquitin-mediated protein degradation” relies on
ternary enzyme systems to degrade unneeded or damaged
proteins.[40] Inspired by nature, chemists have devoted sig-
nificant efforts to develop multicatalytic systems as mimics for
natural multienzymatic complexes to perform complex trans-
formations. Despite the considerable progress in binary
catalysis,[41–44] ternary catalysis is less developed. The key
challenge in ternary catalysis is the mutual quenching of
catalytic centres. We posit that MOLs can integrate multiple
isolated active centres in a site-isolate fashion to enhance
catalytic performance. Herein we report the rational design of
the first trifunctional MOL containing a photosensitizer,
a Lewis acid, and a hydrogen transfer catalyst for dehydro-
genative tandem transformations of indolines to 3-alkylin-
doles and bisindolylmethanes.
[*] Dr. Y. Quan,[+] Dr. G. Lan,[+] W. Shi,[+] Z. Xu, Y. Fan, E. You, X. Jiang,
Prof. Dr. W. Lin
Department of Chemistry, The University of Chicago
Chicago, IL 60637 (USA)
E-mail: wenbinlin@uchicago.edu
W. Shi,[+] Prof. Dr. C. Wang
College of Chemistry and Chemical Engineering, iCHEM, State Key
Laboratory of Physical Chemistry of Solid Surface, Xiamen University
Xiamen 361005 (P. R. China)
[+] These authors contributed equally to this work.
Catalytic acceptorless dehydrogenation (CAD) is an
environmentally benign synthetic strategy that does not
require chemical oxidants and generates dihydrogen as the
only by-product.[45,46] CAD of N-heterocycles provides facile
Supporting information and the ORCID identification number(s) for
the author(s) of this article can be found under:
https://doi.org/10.1002/anie.202011519.
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access to important motifs for pharmaceuticals and bioactive
molecules.[47,48] Recently, photo-induced catalytic acceptor-
less dehydrogenation reactions have received increased
interest due to their ability to facilitate important trans-
formations under mild conditions.[49–54] In this work, we
designed trifunctional Hf12-Ru-Co-OTf MOL consisting of
[Ru(DBB)(bpy)2]2+ [DBB = 4,4’-di(4-benzoato)-2,2’-bipyri-
dine; bpy = 2,2’-bipyridine] ligand as photosensitizer and
Hf12 SBU capped with triflate (OTf) as strong Lewis acid
and Co(dmgH)2(PPA)Cl (PPA-Co, dmgH = dimethylglyox-
ime; PPA = 4-pyridinepropionic acid) as hydrogen transfer
catalyst. Hf12-Ru-Co-OTf catalyzed synergistic tandem trans-
formations of indolines to 3-alkylindoles and bisindolylme-
thanes via acceptorless dehydrogenation and electrophilic
substitution of N-heterocycles (Figure 1c). This multi-cata-
lytic system allows the combination of multiple transforma-
tions in a one-pot manner, bypassing the traditional stop-and-
go approach.[55]
Results and Discussion
We first prepared bifunctional Hf12-Ru-Co MOL contain-
ing [Ru(DBB)(bpy)2]2+ photosensitizer and PPA-Co hydro-
gen transfer catalyst for acceptorless dehydrogenation of N-
heterocycles (Figure 2). Free-standing Hf12-Ru MOL of the
formula Hf12(m3-O)8(m3-OH)8(m2-OH)6(DBB-Ru)6(TFA)6 was
prepared through a solvothermal reaction between HfCl4 and
RuCl2(DBB)(bpy)2 in N,N-dimethylformamide (DMF) at
808C using trifluoroacetic acid (TFA) and water as modu-
lators.[56] Hf12 SBUs in Hf12-Ru are laterally connected by
[Ru(DBB)(bpy)2]2+ ligands to form an infinite 2D network
and vertically terminated by six trifluoroacetate (TFA)
groups. Transmission electron microscopy (TEM, Figure S4a)
and atomic force microscopy (AFM, Figure S4b) analyses
supported the monolayer morphology of Hf12-Ru with
a diameter of ꢀ 100 nm and a thickness of ꢀ 1.6 nm (Fig-
ure S4c). Hf12-Ru subsequently reacted with Co(dmgH)2-
(PPA)Cl (Figure 2d) in DMF at room temperature to
generate Hf12-Ru-Co of the formula Hf12(m3-O)8(m3-OH)8(m2-
OH)6(DBB-Ru)6(PPA-Co)6 (Figure 2a).
The monolayer structure of Hf12-Ru-Co was confirmed by
TEM (Figure 2e) and AFM (Figures 2g,h) imaging. The
measured thickness of 3.6 nm is consistent with the modeled
height of 3.5 nm for PPA-Co-capped Hf12-SBU (Figure S15).
High-resolution TEM (HRTEM) showed a 6-fold symmetry
(Figure 2 f), consistent with the projection of Hf12-Ru-Co
structure along the vertical direction. Hf12-Ru-Co retained the
crystallinity of Hf12-Ru as shown by their similar PXRD
patterns, which matched well with that simulated from the
proposed Hf12 MOL structure (Figure 2c). In addition, the
1H NMR spectrum of digested Hf12-Ru-Co exhibited a [Ru-
(DBB)(bpy)2]2+ to PPA-Co ratio of ꢀ 1:1 (Figures 2b and S8),
consistent with the proposed molecular formula of Hf12-Ru-
Co. This result indicates complete replacement of TFA groups
by PPA-Co groups on the Hf12-SBUs.
Figure 2. Synthesis and characterization of Hf12-Ru-Co. a) Synthetic
route to Hf12-Ru-Co. b) 1H NMR spectrum of digested Hf12-Ru-Co.
Peaks labeled with blue and yellow stars are assigned to [Ru(DBB)-
(bpy)2]2+ and PPA-Co, respectively c) PXRD patterns of Hf12-Ru and
Hf12-Ru-Co (freshly prepared or after reaction) and the simulated
pattern for the Hf12 MOL. d) Single-crystal X-ray structure of PPA-Co
with thermal ellipsoids set at 50% probability (CCDC number given in
the Supporting Information). e)–h) TEM image (e), HRTEM image (f),
AFM topography (g) and height profile (h) along the white line in (g),
of Hf12-Ru-Co.
model reactions to evaluate the synergistic catalytic perfor-
mance of [Ru(DBB)(bpy)2]2+ photosensitizer and PPA-Co
catalyst in Hf12-Ru-Co. Upon blue LED irradiation, Hf12-Ru-
Co (0.4 mol% based on Co) competently catalyzed dehydro-
genation of indolines and tetrahydroquinolines with turnover
In light of the prevalence of indole and quinoline
derivatives in pharmaceuticals,[57,58] we used acceptorless
dehydrogenation of indolines and tetrahydroquinolines as
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numbers of up to 250 (Table 1). Gas chromatography con-
firmed the generation of H2 as the by-product. A range of
indolines bearing various functional groups including -Me, -F,
-Cl, -Br, and -OMe underwent acceptorless dehydrogenation
smoothly to afford target indoles 2a–2h in > 96% isolated
yields. No obvious electronic and steric effects were observed.
Hf12-Ru-Co also catalyzed more challenging acceptorless
dehydrogenation of tetrahydroquinolines. Halogen-contain-
ing substrates afforded dehydrogenation products 4c and 4d
in 95% and 94% isolated yields, respectively. In contrast, the
relatively electron-deficient substrate 3e bearing the ester
group gave a reduced yield of 42% for 4e, likely due to less
favorable single electron oxidation by the photoexcited
photosensitizer. Although 8- and 2-methyl tetrahydroquino-
lines reacted efficiently to produce 4b and 4 f, respectively,
the use of 4-methyl tetrahydroquinoline led to a mixture of
products 4g and 4g’ in 1:1 ratio. The formation of 4g’ can be
attributed to the cross-coupling between in situ generated
intermediates of 1,4-dihydroquinoline and 3,4-dihydroquino-
line followed by further acceptorless dehydrogenation.
in benzene at room temperature afforded Hf12-Ru-OTf with
a formula of Hf12(m3-O)8(m3-OH)8(m2-OH)6(DBB-Ru)6(OTf)6.
Next, Hf12-Ru-OTf reacted with 3.0 equiv of Co(dmgH)2-
(PPA)Cl (relative to Hf12-SBU) to give Hf12-Ru-Co-OTf of
the formula Hf12(m3-O)8(m3-OH)8(m2-OH)6(DBB-Ru)6(PPA-
Co)3(OTf)3 (Figure 3a).
Both Hf12-Ru-OTf and Hf12-Ru-Co-OTf exhibited similar
PXRD patterns to that of Hf12-Ru (Figure 3d), suggesting
their identical structure. 1H and 19F NMR spectra of digested
Hf12-Ru-OTf showed only one set of signals assignable to
[Ru(DBB)(bpy)2]2+ (Figure S9) and one peak corresponding
to HOTf (Figure S10), respectively, indicating complete
replacement of TFA groups by OTfÀ on the Hf12-SBUs. On
1
the other hand, the H NMR spectrum of digested Hf12-Ru-
Co-OTf showed two sets of signals assignable to [Ru(DBB)-
The excellent dehydrogenation efficiency of Hf12-Ru-Co
shown in Table 1 indicates synergistic catalytic performance
of [Ru(DBB)(bpy)2]2+ photosensitizer and PPA-Co catalyst.
On this basis, we synthesized trifunctional Hf12-Ru-Co-OTf
MOL consisting of [Ru(DBB)(bpy)2]2+ photosensitizer, Hf-
OTf Lewis acid, and PPA-Co hydrogen transfer catalyst. Hf12-
Ru-Co-OTf was synthesized from Hf12-Ru in two steps.
Treatment of Hf12-Ru with trimethylsilyl triflate (TMS-OTf)
Table 1: Hf12-Ru-Co catalyzed acceptorless dehydrogenation of N-heter-
ocycles.[a]
Figure 3. Synthesis and characterization of Hf12-Ru-Co-OTf. a) Synthetic
route to Hf12-Ru-Co-OTf. b) 1H NMR spectrum of digested Hf12-Ru-Co-
OTf. Peaks labeled with blue and yellow stars are assigned to
[Ru(DBB)(bpy)2]2+ and PPA-Co, respectively c) 19F NMR spectrum of
digested Hf12-Ru-Co-OTf. d) PXRD patterns of Hf12-Ru, Hf12-Ru-OTf,
and Hf12-Ru-Co-OTf (freshly prepared or after reaction) and the
simulated pattern for the Hf12 MOL. e) Fluorescence spectra of free
NMA (black) and NMA bound to Hf12-Ru-OTf (blue) and Hf12-Ru-Co-
OTf (red) in MeCN at 298 K. f) TEM image of Hf12-Ru-Co-OTf.
[a] Reactions at 0.1 mmol scale with 0.4 mol% Hf12-Ru-Co (based on Co)
at room temperature; yields of isolated products and TONs are shown in
parentheses.
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(bpy)2]2+ and PPA-Co in approximately 2:1 molar ratio
benzaldehydes to afford bisindolylmethane (BIM) derivatives
(Figures 3b and S11), consistent with the proposed molecular
formula of Hf12-Ru-Co-OTf. Additionally, the 19F NMR
spectrum of digested Hf12-Ru-Co-OTf exhibited one signal
corresponding to HOTf (Figures 3c and S12). The Lewis
acidity of Hf12-Ru-OTf and Hf12-Ru-Co-OTf was probed by
N-methylacridone (NMA) fluorescence method.[59–60] Upon
coordinating to Hf12-Ru-OTf and Hf12-Ru-Co-OTf, the lmax
values of NMA emissions shifted from 433 nm to 471 nm and
470 nm, respectively (Figure 3e). This result shows that both
Hf12-Ru-OTf and Hf12-Ru-Co-OTf exhibit strong Lewis acid-
ity that is comparable to Sc(OTf)3.[38] Hf12-Ru-Co-OTf
showed similar sizes and morphologies to Hf12-Ru-Co by
TEM and HRTEM analysis (Figures 3 f and S13).
As shown in Scheme S9, Hf12-Ru-Co-OTf retained the
high synergistic catalytic performance of Hf12-Ru-Co for
acceptorless dehydrogenation. Interestingly, the strong Lewis
acid center in Hf12-Ru-Co-OTf efficiently catalyzed electro-
philic substitution of in situ generated indoles with alkenes or
aldehydes to afford 3-alkyl indoles and bisindolylmethanes
(BIMs), respectively, with turnover numbers of up to 500 and
460. In the presence of 0.2 mol% Hf12-Ru-Co-OTf (based
on Co), various indolines with -Cl, -Br, -Me, and -OMe
substituents reacted with 2-butenone smoothly in a stepwise
manner, leading to the corresponding 3-alkyl indoles 5a–5 f in
85% to quantitative isolated yields (Table 2). The dehydro-
genative tandem transformation of indoline with 4-penten-3-
one afforded the coupling product 5g in 94% yield. Impor-
tantly, Hf12-Ru-Co-OTf catalyzed reactions of indolines with
6a–6d in 85–92% isolated yields (Table 2). Methyl- and
fluoro-substituted benzaldehydes also worked well in this
coupling reaction, suggesting the tolerance to substrates with
different electronic properties. It is worth noting that the BIM
scaffold exists prevalently in pharmaceuticals and nature
products.[61] BIM derivatives have found applications as
inhibitors to cancer cell targets.[62]
Hf12-Ru-Co and Hf12-Ru-Co-OTf were stable under
catalytic conditions as illustrated by the maintenance of
PXRD patterns in recovered MOLs (Figure 2c and Fig-
ure 3d). In addition, Hf12-Ru-Co and Hf12-Ru-Co-OTf were
recovered and used in five runs of catalytic reactions with no
significant decrease in product yields (Figures 4a and S16).
Hf12-Ru-Co and Hf12-Ru-Co-OTf exhibited better synergistic
catalytic performance over the homogeneous counterparts
(Figure 4b, Schemes S11–S13). The isolation of three differ-
ent catalytic sites in Hf12-Ru-Co-OTf prevents their delete-
rious mutual deactivation, the foremost challenge in homo-
geneous ternary catalysis,[55] resulting in excellent synergistic
tandem catalytic performance.
We conducted several control experiments to probe the
reaction mechanism. No reaction was observed in the absence
of light (Figure 4c, top), suggesting the photocatalytic nature
of this synergistic catalysis. Only a trace amount of dehydro-
genation product 2a was obtained with Hf12-Ru as catalyst
Table 2: Hf12-Ru-Co-OTf catalyzed dehydrogenative tandem transforma-
tions of indolines.[a]
Figure 4. a) Yields of 2a with recovered Hf12-Ru-Co in five consecutive
runs. b) Time-dependent yields of 2a with different catalysts. c) Con-
trol experiments under different conditions. d) Proposed reaction
mechanism.
[a] Reactions at 0.1 mmol scale with 0.2 mol% Hf12-Ru-Co-OTf (based on
Co) at room temperature; yields of isolated products and TONs are
shown in parentheses.
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(Figure 4c, middle), indicating the crucial role of cobaloxime
Acknowledgements
as a hydrogen transfer catalyst. Hf12-Ru-Co catalyzed hydro-
gen transfer from indoline to 1,1-diphenylethene
(Scheme S10), which supports the involvement of metal-
hydride intermediate in the reaction. Without the strong
Lewis acidic site, Hf12-Ru-Co only catalyzed the acceptorless
dehydrogenation of indoline but did not mediate subsequent
electrophilic alkylation (Figure 4c, bottom). These control
experiments support the critical role of [Ru(DBB)(bpy)2]2+
photosensitizer, Hf-OTf Lewis acid, and PPA-Co hydrogen
transfer catalyst in Hf12-Ru-Co-OTf.
We acknowledge the National Science Foundation and the
University of Chicago for founding support and the MRSEC
Shared User Facilities at the University of Chicago (NSF
DMR-1420709) for instrument access. XAS analysis was
performed at Beamline 10-BM, supported by the Materials
Research Collaborative Access Team (MRCAT). Use of the
Advanced Photon Source, an Office of Science User Facility
operated for the U.S. DOE Office of Science by ANL, was
supported by the U.S. DOE under Contract No. DE-AC02-
06CH11357.
On the basis of these experimental results and literature
precedents,[47,48] we propose a plausible reaction mechanism
in Figure 4d. Upon blue LED irradiation, the photoexcited
[RuII]* delivers one electron to the [CoIII] species to generate
the [CoII] compound and strongly oxidizing [RuIII] complex.
Single electron oxidation of indoline by [RuIII] affords [RuII]
and radical cation intermediate A. Deprotonation of A forms
a-carbon radical B. The [RuII] photocatalyst is excited by blue
LED to restart the photocatalytic cycle. Radical addition
Conflict of interest
The authors declare no conflict of interest.
Keywords: dehydrogenation · metal–organic layers ·
photocatalysis · tandem catalysis · trifunctional materials
II
III
À
reaction of B to [Co ] gives the [Co ] C bonded intermedi-
ate C. Subsequent b-H elimination of C yields indole 3 and
the [CoIII]-H intermediate. Protonation of [CoIII]-H produces
H2 and regenerates [CoIII] hydrogen transfer catalyst to finish
the Co-catalytic cycle. In the meantime, upon coordinating to
the strongly Lewis acidic Hf12-SBU, vinyl ketone becomes
electron deficient and attacks indole 3 at the most electron-
rich b-position. The resulting intermediate E reacts with an
incoming vinyl ketone to release product 5 and restart the
Lewis acid catalytic cycle. The hierarchical integration of
three different catalytic centers into the MOL not only
prevents mutual deactivation but also facilitates electron and
radical transfer to enhance the synergistic tandem catalytic
activity.
[1] H. Furukawa, K. E. Cordova, M. OꢀKeeffe, O. M. Yaghi, Science
2013, 341, 1230444.
[2] J. R. Long, O. M. Yaghi, Chem. Soc. Rev. 2009, 38, 1213 – 1214.
[3] O. K. Farha, J. T. Hupp, Acc. Chem. Res. 2010, 43, 1166 – 1175.
[4] D. Dang, P. Wu, C. He, Z. Xie, C. Duan, J. Am. Chem. Soc. 2010,
132, 14321 – 14323.
[5] S. I. Swamy, J. Bacsa, J. T. A. Jones, K. C. Stylianou, A. Steiner,
L. K. Ritchie, T. Hasell, J. A. Gould, A. Laybourn, Y. Z.
Khimyak, D. J. Adams, M. J. Rosseinsky, A. I. Cooper, J. Am.
Chem. Soc. 2010, 132, 12773 – 12775.
[6] M. Yoon, R. Srirambalaji, K. Kim, Chem. Rev. 2012, 112, 1196 –
1231.
[7] J.-P. Zhang, Y.-B. Zhang, J.-B. Lin, X.-M. Chen, Chem. Rev. 2012,
112, 1001 – 1033.
[8] S. Horike, D. Umeyama, S. Kitagawa, Acc. Chem. Res. 2013, 46,
2376 – 2384.
Conclusion
[9] D. J. Xiao, E. D. Bloch, J. A. Mason, W. L. Queen, M. R.
Hudson, N. Planas, J. Borycz, A. L. Dzubak, P. Verma, K. Lee,
F. Bonino, V. Crocellꢁ, J. Yano, S. Bordiga, D. G. Truhlar, L.
Gagliardi, C. M. Brown, J. R. Long, Nat. Chem. 2014, 6, 590 –
595.
In summary, we have prepared the new bifunctional Hf12-
Ru-Co MOL by linking cobaloxime-capped Hf12-SBUs with
Ru-photosensitizer-based bridging ligands. Hf12-Ru-Co ex-
hibited excellent synergistic catalytic performance in accept-
orless dehydrogenation of indolines and tetrahydroquino-
lines. We further designed the new trifunctional Hf12-Ru-Co-
OTf MOL containing Ru-photosensitizer, Co-hydrogen
transfer catalyst, and strong Lewis acid catalyst for dehydro-
genative tandem catalysis. Hf12-Ru-Co-OTf efficiently cata-
lyzed dehydrogenative tandem transformations of indolines
with vinyl ketones or aldehydes to afford a variety of 3-
alkylindoles and bisindolylmethanes (BIMs) with turnover
numbers of up to 500 and 460, respectively. The integration of
three isolated, uniform, and well-defined catalytic centers
into the MOL enhances the multicatalytic performance by
preventing mutual deactivation and increasing local concen-
trations. This work highlights the potential of MOLs as a 2D
material platform for designing multi-catalytic systems for
tandem catalysis.
[10] J. A. Johnson, B. M. Petersen, A. Kormos, E. Echeverrꢂa, Y.-S.
Chen, J. Zhang, J. Am. Chem. Soc. 2016, 138, 10293 – 10298.
˘
[11] L. Sun, M. G. Campbell, M. Dinca, Angew. Chem. Int. Ed. 2016,
55, 3566 – 3579; Angew. Chem. 2016, 128, 3628 – 3642.
[12] L. Zhu, X.-Q. Liu, H.-L. Jiang, L.-B. Sun, Chem. Rev. 2017, 117,
8129 – 8176.
[13] C.-D. Wu, M. Zhao, Adv. Mater. 2017, 29, 1605446.
[14] A. Kirchon, L. Feng, H. F. Drake, E. A. Joseph, H.-C. Zhou,
Chem. Soc. Rev. 2018, 47, 8611 – 8638.
[15] K. Shen, L. Zhang, X. Chen, L. Liu, D. Zhang, Y. Han, J. Chen, J.
Long, R. Luque, Y. Li, B. Chen, Science 2018, 359, 206.
[16] X. Zhao, Y. Wang, D.-S. Li, X. Bu, P. Feng, Adv. Mater. 2018, 30,
1705189.
[17] L. Jiao, Y. Wang, H.-L. Jiang, Q. Xu, Adv. Mater. 2018, 30,
1703663.
[18] D. Yang, B. C. Gates, ACS Catal. 2019, 9, 1779 – 1798.
[19] V. Pascanu, G. Gonzꢃlez Miera, A. K. Inge, B. Martꢂn-Matute, J.
Am. Chem. Soc. 2019, 141, 7223 – 7234.
[20] A. Bavykina, N. Kolobov, I. S. Khan, J. A. Bau, A. Ramirez, J.
Gascon, Chem. Rev. 2020, https://doi.org/10.1021/acs.chemrev.
1029b00685.
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These are not the final page numbers!

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Research Articles
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[21] Y.-S. Wei, M. Zhang, R. Zou, Q. Xu, Chem. Rev. 2020, https://
[42] M. N. Hopkinson, B. Sahoo, J.-L. Li, F. Glorius, Chem. Eur. J.
doi.org/10.1021/acs.chemrev.1029b00757.
[22] A. Bꢄtard, R. A. Fischer, Chem. Rev. 2012, 112, 1055 – 1083.
[23] C. Tan, G. Liu, H. Li, Y. Cui, Y. Liu, Dalton Trans. 2020, https://
doi.org/10.1039/d1030dt01359e.
[24] L. Cao, Z. Lin, F. Peng, W. Wang, R. Huang, C. Wang, J. Yan, J.
Liang, Z. Zhang, T. Zhang, L. Long, J. Sun, W. Lin, Angew.
Chem. Int. Ed. 2016, 55, 4962 – 4966; Angew. Chem. 2016, 128,
5046 – 5050.
2014, 20, 3874 – 3886.
[43] K. L. Skubi, T. R. Blum, T. P. Yoon, Chem. Rev. 2016, 116,
10035 – 10074.
[44] J. Twilton, C. Le, P. Zhang, M. H. Shaw, R. W. Evans, D. W. C.
MacMillan, Nat. Rev. Chem. 2017, 1, 0052.
[45] C. Gunanathan, Y. Ben-David, D. Milstein, Science 2007, 317,
790.
[46] C. Gunanathan, D. Milstein, Science 2013, 341, 1229712.
[47] K.-H. He, F.-F. Tan, C.-Z. Zhou, G.-J. Zhou, X.-L. Yang, Y. Li,
Angew. Chem. Int. Ed. 2017, 56, 3080 – 3084; Angew. Chem.
2017, 129, 3126 – 3130.
[48] S. Kato, Y. Saga, M. Kojima, H. Fuse, S. Matsunaga, A. Fukatsu,
M. Kondo, S. Masaoka, M. Kanai, J. Am. Chem. Soc. 2017, 139,
2204 – 2207.
[49] B. Chen, L.-Z. Wu, C.-H. Tung, Acc. Chem. Res. 2018, 51, 2512 –
2523.
[50] H. Wang, X. Gao, Z. Lv, T. Abdelilah, A. Lei, Chem. Rev. 2019,
119, 6769 – 6787.
[51] J. G. West, D. Huang, E. J. Sorensen, Nat. Commun. 2015, 6,
10093.
[52] X. Sun, J. Chen, T. Ritter, Nat. Chem. 2018, 10, 1229 – 1233.
[53] H. Cao, Y. Kuang, X. Shi, K. L. Wong, B. B. Tan, J. M. C. Kwan,
X. Liu, J. Wu, Nat. Commun. 2020, 11, 1956.
[54] H. Fuse, H. Mitsunuma, M. Kanai, J. Am. Chem. Soc. 2020, 142,
4493 – 4499.
[25] P. Garcꢂa-Garcꢂa, J. M. Moreno, U. Dꢂaz, M. Bruix, A. Corma,
Nat. Commun. 2016, 7, 10835.
[26] M. Xu, S. Yuan, X.-Y. Chen, Y.-J. Chang, G. Day, Z.-Y. Gu, H.-C.
Zhou, J. Am. Chem. Soc. 2017, 139, 8312 – 8319.
[27] W. Shi, L. Cao, H. Zhang, X. Zhou, B. An, Z. Lin, R. Dai, J. Li, C.
Wang, W. Lin, Angew. Chem. Int. Ed. 2017, 56, 9704 – 9709;
Angew. Chem. 2017, 129, 9836 – 9841.
[28] C. Tan, K. Yang, J. Dong, Y. Liu, Y. Liu, J. Jiang, Y. Cui, J. Am.
Chem. Soc. 2019, 141, 17685 – 17695.
[29] L. Chen, Y. Wang, F. Yu, X. Shen, C. Duan, J. Mater. Chem. A
2019, 7, 11355 – 11361.
[30] F. Zhang, J. Zhang, B. Zhang, L. Zheng, X. Cheng, Q. Wan, B.
Han, J. Zhang, Nat. Commun. 2020, 11, 1431.
[31] C. Huang, Z. Guo, X. Zheng, X. Chen, Z. Xue, S. Zhang, X. Li,
B. Guan, X. Li, G. Hu, T. Wang, J. Am. Chem. Soc. 2020, 142,
9408 – 9414.
[32] Y.-B. Huang, J. Liang, X.-S. Wang, R. Cao, Chem. Soc. Rev. 2017,
46, 126 – 157.
[33] B. Li, H.-M. Wen, Y. Cui, W. Zhou, G. Qian, B. Chen, Adv.
Mater. 2016, 28, 8819 – 8860.
[55] S. P. Sancheti, Urvashi, M. P. Shah, N. T. Patil, ACS Catal. 2020,
10, 3462 – 3489.
[56] G. Lan, Z. Li, S. S. Veroneau, Y.-Y. Zhu, Z. Xu, C. Wang, W. Lin,
J. Am. Chem. Soc. 2018, 140, 12369 – 12373.
[57] A. J. Kochanowska-Karamyan, M. T. Hamann, Chem. Rev. 2010,
110, 4489 – 4497.
[34] Y. Huang, M. Zhao, S. Han, Z. Lai, J. Yang, C. Tan, Q. Ma, Q. Lu,
J. Chen, X. Zhang, Z. Zhang, B. Li, B. Chen, Y. Zong, H. Zhang,
Adv. Mater. 2017, 29, 1700102.
[35] P. Ling, C. Qian, F. Gao, J. Lei, Chem. Commun. 2018, 54, 11176 –
11179.
[58] A. P. Gorka, A. de Dios, P. D. Roepe, J. Med. Chem. 2013, 56,
5231 – 5246.
[36] J. Nicks, J. Zhang, J. A. Foster, Chem. Commun. 2019, 55, 8788 –
8791.
[59] P. Ji, T. Drake, A. Murakami, P. Oliveres, J. H. Skone, W. Lin, J.
Am. Chem. Soc. 2018, 140, 10553 – 10561.
[37] G. Lan, Y. Quan, M. Wang, G. T. Nash, E. You, Y. Song, S. S.
Veroneau, X. Jiang, W. Lin, J. Am. Chem. Soc. 2019, 141, 15767 –
15772.
[38] Y. Quan, G. Lan, Y. Fan, W. Shi, E. You, W. Lin, J. Am. Chem.
Soc. 2020, 142, 1746 – 1751.
[60] P. Ji, X. Feng, P. Oliveres, Z. Li, A. Murakami, C. Wang, W. Lin,
J. Am. Chem. Soc. 2019, 141, 14878 – 14888.
[61] M. Shiri, M. A. Zolfigol, H. G. Kruger, Z. Tanbakouchian,
Chem. Rev. 2010, 110, 2250 – 2293.
[62] S. Safe, S. Papineni, S. Chintharlapalli, Cancer Lett. 2008, 269,
326 – 338.
[39] D. Ma, Y. Zhang, S. Jiao, J. Li, K. Liu, Z. Shi, Chem. Commun.
2019, 55, 14347 – 14350.
[40] D. Kornitzer, A. Ciechanover, J. Cell. Physiol. 2000, 182, 1 – 11.
[41] J.-C. Wasilke, S. J. Obrey, R. T. Baker, G. C. Bazan, Chem. Rev.
2005, 105, 1001 – 1020.
Manuscript received: August 22, 2020
Version of record online: && &&
,
&&&&
Angew. Chem. Int. Ed. 2020, 59, 2 – 8
ꢀ 2020 Wiley-VCH GmbH
www.angewandte.org
&&&&
These are not the final page numbers!

Angewandte
Research Articles
Chemie
Research Articles
Tandem Catalysis
A tri-functional metal–organic layer with
[Ru(DBB)(bpy)2]2+ photosensitizers and
Hf12 secondary building units capped
with triflate groups as strong Lewis acid
sites and PPA-Co groups as hydrogen-
transfer catalysts synergistically catalyzed
dehydrogenative tandem transformations
of indolines with alkenes or aldehydes to
afford 3-alkylindoles and bisindolyl-
methanes, respectively.
Y. Quan, G. Lan, W. Shi, Z. Xu, Y. Fan,
E. You, X. Jiang, C. Wang,
W. Lin*
&&&& — &&&&
Metal–Organic Layers Hierarchically
Integrate Three Synergistic Active Sites
for Tandem Catalysis
&&&&
www.angewandte.org
ꢀ 2020 Wiley-VCH GmbH
Angew. Chem. Int. Ed. 2020, 59, 2 – 8
These are not the final page numbers!