Facile construction of diverse diarylmethane scaffolds via uranyl-catalyzed 1,6-addition reaction

Article abstract of DOI:10.1016/j.tetlet.2020.152076

A direct 1,6-addition route of p-QMs to synthesize substituted diarylmethanes catalyzed by uranyl ion was developed. In our approach, the salient feature of this transformation is that abundant, underexploited, neglected and sequestrable depleted uranium made the reaction more sustainable. Moreover, diarylmethane derivatives were delivered in moderate to high yields with broad scope and functional group tolerance. Facile operation and mild conditions offer a practical and attractive protocol.

Full text of DOI:10.1016/j.tetlet.2020.152076

Journal Pre-proofs
Facile Construction of Diverse Diarylmethane Scaffolds via Uranyl-Catalyzed
1,6-Addition Reaction
Jipan Yu, Siyu Chen, Kang Liu, Liyong Yuan, Yubao Zhao, Zhifang Chai,
Lei Mei
PII:
S0040-4039(20)30526-8
DOI:
Reference:
https://doi.org/10.1016/j.tetlet.2020.152076
TETL 152076
To appear in:
Tetrahedron Letters
Received Date:
Revised Date:
Accepted Date:
14 February 2020
15 May 2020
22 May 2020
Please cite this article as: Yu, J., Chen, S., Liu, K., Yuan, L., Zhao, Y., Chai, Z., Mei, L., Facile Construction of
Diverse Diarylmethane Scaffolds via Uranyl-Catalyzed 1,6-Addition Reaction, Tetrahedron Letters (2020), doi:
https://doi.org/10.1016/j.tetlet.2020.152076
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Facile Construction of Diverse
Diarylmethane Scaffolds via Uranyl-
Catalyzed 1,6-Addition Reaction
Leave this area blank for abstract info.
Jipan Yu,‡a Siyu Chen,‡b Kang Liu,a Liyong Yuan,a Yubao Zhao,b Zhifang Chaic and Lei Mei*a
OH
O
OH
R1
R1
R1
R1
t-Bu
t-Bu
2+
UO2
r.t.
+
H XRn
XRn
OCH3
R'
R2
R'
X = O, S
R2
31 examples
up to 98% yield
uranyl catalysis mild conditions simple operation broad tolerance
gram scale in one step

1
Tetrahedron Letters
journal homepage: www.elsevier.com
Facile Construction of Diverse Diarylmethane Scaffolds via Uranyl-Catalyzed
1,6-Addition Reaction
Jipan Yu,‡a Siyu Chen,‡b Kang Liu,a Liyong Yuan,a Yubao Zhao,b Zhifang Chai,a,c Lei Meia
a Laboratory of Nuclear Energy Chemistry, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, P. R. China.
b College of Chemistry and Chemical Engineering, University of South China, Hengyang, Hunan, 421001, P. R. China
c Engineering Laboratory of Advanced Energy materials, Institute of Industrial Technology, Chinese Academy of Sciences, Ningbo, 315201, P. R. China
Abstract
A direct 1,6-addition route of p-QMs to synthesize substituted diarylmethanes catalyzed by uranyl ion was developed. In our approach, the salient
feature of this transformation is that abundant, underexploited, neglected and sequestrable depleted uranium made the reaction more sustainable.
Moreover, diarylmethane derivatives were delivered in moderate to high yields with broad scope and functional group tolerance. Facile operation and
mild conditions offer a practical and attractive protocol.
Keywords:Uranyl, p-QMs, Diarylmethane, 1,6-addition
———
‡
The first two authors contributed equally to this work.
* Corresponding author. E-mail address: meil@ihep.ac.cn (L. Mei)
The diarylmethane derivatives are interesting structural motifs and widely exist in natural products, pharmaceuticals and
functional materials. For example, Tolterodine exhibits antimuscarinic activities (Scheme 1)[1]. In addition, DABOs and
DAMNI derivatives were found to potently inhibit HIV-1 reverse transcriptase (RT) (Scheme 1)[2]. Obviously, since the
important pharmaceutical activities and other peculiar properties of diarylmethane unit are in connection with different
substituents on the aromatic rings and methylene, it is highly imperative that the investigation of synthetic methods enabling
their efficient construction to expand structural diversity with bioactive properties is a topic of continuing scientific
advancement.
O
HN
O
N
S
N
F
NH
Me
iPr
F
N
O2N
H
iPr
OH
Tolterodine
DABOs
DAMNI Derivative
Scheme 1. Representative examples of bioactive diarylmethane derivatives
para-Quinone Methides (p-QMs), which are known as potential building block with the unique assembly of carbonyl and
o l e f i n i c m o i e t i e s , h a v e b e e n e m p l o y e d f o r
preparing diarylmethane derivatives. 1,6-Michael addition, as classical synthetic process, is one of the most effective and
atom-economic methods to construct a variety of structurally complicated diarylmethane compounds with great practical
worth starting from the simple materials. Recently, Fan and co-workers[3] reported an asymmetric 1,6-conjugate
addition/aromatization of p-QMs for enantioselective construction of functionalized diarylmethane derivatives. Afterwards,
Jørgensen[4], Liao[5], Cheng[6], Tortosa[7], Lu[8], Deng[9], Li[10], Xu[11] and Enders[12] independently developed the
asymmetric synthesis of diarylmethane derivatives via 1,6-Michael addition of p-QMs, which serve as the versatile synthetic
scaffold. Moreover, visible-light-promoted[13-17] radical process or transition-metal/Lewis acid[7, 18-25] catalyzed
conjugate addition represent powerful route access to alkylboranes[7], silanization[18], fluoromethylation[13, 15, 19],
arylation[10, 20], alkylation[14, 16, 17, 21, 23, 24, 26, 27], alkynylation[25], sulfonylation[15, 28] and so on. Besides this, N-
heterocyclic carbene (NHC)-catalyzed 1,6-conjugate addition of p-QMs for the synthesis α,α′-diarylated ketone and
phosphorylation derivatives has been investigated by Anand group (Scheme 2a)[29, 30]. Although these classical approaches
are widely utilized, there still exists a scope of improvement in terms of generality of reaction, functional-group tolerance and
diversity, and green and sustainable chemistry. Furthermore, the development of green and straightforward synthetic
strategies to construct multi-substituted diarylmethane derivatives is of growing fundamental interest and urgent desire in

2
Tetrahedron
synthetic chemistry. Consequently, even though the synthesis of diarylmethane derivatives by using p-QMs has been
documented so far, there is still much to do.
To address the above-referred topic, the incorporation of other functional groups into the diarylmethane skeleton probably enhances
the diversified bioactivities of diarylmethane derivatives. Therefore, the development of novel methodology to construct diverse
molecular structure is extremely pivotal due to fundamental issue regarding the relationship between structure and properties.
Meanwhile, we proclaim that uranyl can be employed as a high-efficient catalyst for the 1,6-conjugate addition of p-QMs with O, S-
nucleophiles.
Uranium, one of the most important elements in nuclear fuel cycle, has contributed tremendously to the progress of
mankind. Accordingly, the less abundant 235U isotope is employed for the generation of nuclear power, while large amounts of depleted
uranium (238U isotope UO22+, as the most common form of uranium
) with neglected radioactivity and toxicity is underexplored.
element, has been exploited to catalyze the organic reaction due to the high Lewis acidity and strong coordination mode. In
this field, Mandolini[31], Enthaler[32] and Takao[33] have independently developed uranyl-catalyzed conjugate addition,
dehydration and acyl substitution reactions. In addition, uranyl as photocatalyst has received much attention on C-H bond
activation[34-36] and photocatalytic oxidation[37] recently. These pioneering works uncovered that uranyl ions possess great
catalytic potential in organic transformations, but their applications in synthetic organic transformations remain largely
undeveloped. Thus, expanding the boundaries of uranyl-catalyzed organic processes is extremely necessary. Herein, we
present the report on a uranyl-catalyzed 1,6-addition of p-QMs to synthesize diarylmethane derivatives (Scheme 2b).
Previous work
O
OH
R1
R1
R1
R1
Transition metal/Lewis acid
catalyzed organic transformation
+
(a)
Nu
Visible-light-enable radical
reaction and others
Nu
R2
R2
Nu = Ar, Alkynyl, Alkyl, Bpin, SiR3, CF3, CFnH2-nR, CN, SO2Ar, OPR2
This work:
R1
OH
O
R1
R1
R1
Catalytic in uranyl
C-O, C-S bonds
formation
2+
UO2
r.t.
+
H
XRn
(b)
XRn
R'
R2
R'
R2
X = O, S
Scheme 2. p-QMs as diarylmethane derivatives precursors
We initially initiated our investigation with 4-benzylidene-2,6-di-tert-butylcyclohexa-2,5-dien-1-one 1a and methanol 2a as the
model substrate in CH3CN at room temperature to measure the metal salt/Lewis acid suitable for facilitating the reaction. The result
indicated that no reaction occurred without the catalyst (Entry 1, Table 1). What's comforting is that a 66% yield of 3a was
obtained with Fe(NO3)3·6H2O (5 mol%) as catalyst (Entry 2, Table 1). Different catalysts were systematically investigated by screening
of other Lewis acids (e.g., Al(NO3)3·6H2O, Cu(NO3)2·6H2O, CeCl3, B(C6F5)3), and all gave poor results (Entries 3-6, Table 1). No
reaction occurred using Cd(NO3)2·6H2O, Co(NO3)2·6H2O, Sr(NO3)3·6H2O (Entries 7-9, Table 1). Gratifyingly, when the reaction was
carried out in the presence of UO2(NO3)2·6H2O (5 mol%), the 1a led to 3a in excellent yield of 95% (Entry 10, Table 1). In addition,
when 10 mol% UO2(NO3)2·6H2O was used, no significant effect was observed on the yield (Entry 11, Table 1). But the transformation
obviously decreased by reducing the amount of UO2(NO3)2·6H2O, even if increasing the reaction time (Entry 12, Table 1). Next, other
uranyl salts were screened, and UO2(NO3)2·6H2O provided the highest yield (Entries 10, 13-14, Table 1). The effect of solvents was
investigated, and the outcome showed that other solvents was inferior to CH3CN (Entries 10, 15-19, Table 1). Therefore, the optimum
conditions for the uranyl-catalyzed 1,6-Machiel addition reaction of p-QMs are as follows: 5 mol% UO2(NO3)2·6H2O as catalyst in
CH3CN solvent at room temperature under air atmosphere.
Table 1 Optimization of reaction conditions
O
OH
Cat
+
HOCH3
OCH3
3a
solvent, rt
1a
2a
Entry Catalyst
Solvent
CH3CN
CH3CN
CH3CN
CH3CN
CH3CN
CH3CN
CH3CN
Yield (%)b
0
1
2
3
4
5
6
7
-
Fe(NO3)3·6H2O (5 mol%)
Al(NO3)3·6H2O (5 mol%)
Cu(NO3)2·6H2O (5 mol%)
CeCl3 (5 mol%)
B(C6F5)3 (5 mol%)
Cd(NO3)2·6H2O (5 mol%)
66
61
58
20
34
trace

3
8
9
Co(NO3)2·6H2O (5 mol%)
Sr(NO3)2·6H2O (5 mol%)
UO2(NO3)2·6H2O (5 mol%)
UO2(NO3)2·6H2O (10 mol%)
UO2(NO3)2·6H2O (1 mol%)
UO2SO4·4H2O (5 mol%)
UO2(OAc)2·4H2O (5 mol%)
UO2(NO3)2·6H2O (5 mol%)
UO2(NO3)2·6H2O (5 mol%)
UO2(NO3)2·6H2O (5 mol%)
UO2(NO3)2·6H2O (5 mol%)
UO2(NO3)2·6H2O (5 mol%)
CH3CN
CH3CN
CH3CN
CH3CN
CH3CN
CH3CN
CH3CN
CH3COCH3 31
THF
toluene
CH2Cl2
EtOAc
trace
trace
95
95
66
10
11
12c
13c
14c
15
16
17
18c
70
57
10
trace
68
19
trace
a
Reaction conditions: 1a (0.2 mmol), 2a (1.0 mmol, 5.0 eq.),
UO2(NO3)2·6H2O (5 mol%), solvent (2 mL), time (12 h), at room
temperature in air.
b Isolated yield.
c Reaction for 48 h.
Having obtained the optimized reaction conditions in hand (Entry 10, Table 1), we further investigated the substrate scope
of p-QMs and probed the generality of this protocol, delivering a wide range of diarylmethane derivatives. As shown in Table
2, plenty of p-QMs performed well, affording the corresponding diarylmethane products in moderate to excellent yields (3a-
3r). Electron-rich (4-Me, 3-OMe, 4-OMe, 3-OMe-4-OMe) aryl substituents were all suitable substrate, leading to the desired
products 3b-3e in 48-66% yields. As for condensed ring aromatic molecule, naphthalene-substituted product 3f could be
obtained in 71% yield. The reaction processes were also tolerant of halogen functionality, and the products 3g-3l were readily
achieved in high yields (58-98%). Notably, electron-withdrawing groups such as -CN, -CF3 and -NO2 at meta- or para-
position could undergo and afford the corresponding target molecular 3m-3p in 42-76% yields. para-SMe substrate also
showed good functional tolerance in this transformation, providing 3q in 52% yield. Apart from aromatic group,
heteroaromatic motifs including indolyl and thienyl were also compatible with the established reaction conditions, but only
resulting in 44% and 18% yields (3r and 3s). With respect to methyl-substituted p-QMs, we found that 1t was suitable for this
reaction system and gave desired product 3t with high yield. To our delight, isopropyl-substituted indolin-2-one derivatives
3u with the carbon quaternary center was also constructed with 57% yield.
Table 2 1,6-Michael addition of 4-arylidene-2,6-dialkyl-cyclohexa-2,5-dien-1-one (1) with methanol (2a) by using UO2(NO3)2·6H2O as the catalyst

4
Tetrahedron
O
OH
R1
R1
R1
R1
UO2(NO3)2 6H2O (5 mol%)
+
HOCH3
CH3CN, 12 h, r.t.
OCH3
OH
R'
R2
R'
1
2a
R2
3
OH
OH
OH
t-Bu
t-Bu
t-Bu
t-Bu
t-Bu
t-Bu
t-Bu
t-Bu
MeO
OCH3
OCH3
OCH3
OCH3
Me
MeO
3a
3b
3c
3d
, 95%
OH
, 49%
, 66%
OH
,
48%
OH
OH
t-Bu
t-Bu
t-Bu
t-Bu
t-Bu
t-Bu
t-Bu
t-Bu
OCH3
OCH3
OCH3
OCH3
MeO
F
Cl
OMe
3e
3f
3g
3h
, 63%
OH
, 71%
OH
, 62%
OH
, 98%
OH
t-Bu
t-Bu
t-Bu
t-Bu
t-Bu
t-Bu
t-Bu
t-Bu
Br
OCH3
OCH3
OCH3
OCH3
Cl
Br
I
3i
3j
3k
3l
, 81%
OH
, 59%
OH
, 76%
, 58%
OH
OH
t-Bu
t-Bu
t-Bu
t-Bu
t-Bu
t-Bu
t-Bu
t-Bu
NC
OCH3
OCH3
OCH3
OCH3
NC
F3C
R
3p
R = NO2, , 42%
3m
3n
3o
, 53%
, 76%
, 74%
3q
R = MeS, , 52%
OH
OH
OH
OH
t-Bu
t-Bu
t-Bu
t-Bu
H3C
CH3
iPr
iPr
OCH3
O
OCH3
OCH3
OCH3
OCH3
N
S
N
Ts
CH3
3r
3s
3t
3u
, 57%
, 44%
, 18%
, 92%
Moving forward, a series of alcohols was introduced to produce the oxo-diarymethane derivatives with the p-QMs via 1,6-
Machael addition process. As depicted in Table 3, functional products were synthesized in moderated yields under the
standard reaction conditions (3v-3ab). The results indicated that there was no direct relationship among steric hindrance,
electronic effect and the reaction efficiency. It is worth mentioning that thiol instead of alcohol was successfully implanted
into the diarymethane skeleton. Due to the weak nucleophilicity of thiol in this system, the relevant transformation cannot
occur very well under this condition (3ac-3ae). To the best of our knowledge, the present approach based on uranyl-induced
1,6-conjugate addition reaction represents one of the most efficient methods to prepare diarymethane derivatives.
Table 3 1,6-Michael addition of 4-benzylidene-2,6-di-tert-butylcyclohexa-2,5-dien-1-one (1a) with various of nucleophiles (2) by using UO2(NO3)2·6H2O as the
catalyst

5
O
OH
t-Bu
t-Bu
t-Bu
t-Bu
UO2(NO3)2 6H2O (5 mol%)
CH3CN, 12 h, r.t.
+
HXR
XR
1a
2
3
OH
OH
OH
OH
t-Bu
t-Bu
t-Bu
t-Bu
t-Bu
t-Bu
t-Bu
t-Bu
t-Bu
t-Bu
OC2H5
OiPr
OnBu
OC8H17
3v
3w
3x
3y
, 54%
, 56%
OH
, 60%
OH
, 51%
OH
OH
t-Bu
t-Bu
t-Bu
t-Bu
t-Bu
t-Bu
t-Bu
O
O
O
S
3z
3ab
3ac
, 26%
, 77%
, 89%
3aa
, 61%
OH
OH
t-Bu
t-Bu
t-Bu
t-Bu
OH
S
S
S
t-Bu
3ad
3ae
, 30%
, 53%
The synthetic utility of this protocol by using the optimization method was further investigated through a gram scale
synthesis of 2,6-di-tert-butyl-4-(methoxy(phenyl)methyl)phenol, which is ubiquitous in natural products and biologically and
pharmaceutically active molecules. Under the standard conditions, the reaction provided the target molecular 3a in a high
yield (1.48 g, 91%). Therefore, the established method is effective for the synthesis of diarymethane derivatives with potential
biological activity.
O
OH
t-Bu
t-Bu
t-Bu
t-Bu
UO2(NO3)2 6H2O (5 mol%)
CH3CN, 12 h, r.t.
+
HOCH3
OCH3
1a
2a
3a
1.48 g, 91%
1.47 g, 5.0 mmol
Scheme 3. Scale synthesis of 2,6-di-tert-butyl-4-(methoxy(phenyl)methyl)phenol.
In addition, to further investigate the more mechanistic information, controlled deuterium labelling experiment was carried
out (Scheme 4). To our surprise, phenol-H 3a' was obtained as the final product with 90% yield, while no phenol-D 3a'' was
incorporated in the product when 1a reacted with CD3OD 2a' under standard condition. The result indicates that the source of
hydrogen atoms at phenol oxygen site of product arise from trace water in the reaction system.
OH
OD
O
t-Bu
t-Bu
t-Bu
t-Bu
t-Bu
t-Bu
"standard condition"
CD3OD
+
OCD3
OCD3
3a'
90% yield
3a''
not detected
1a
2a'
Scheme 4. Control deuterium labelling experiment.
Based on the experimental results above and literature reports[38, 39], the possible mechanistic pathway of the 1,6-Michael
addition reaction of p-QMs and alcohol catalyzed by UO2(NO3)2·6H2O is illustrated in Scheme 5. Firstly, the UO22+ occupied
the coordination site on the oxygen atom of substrate 1a via chelated transition state A. Then, the ketone oxygen position of
species A coordinated with proton and the interaction enabled the molecular polarization followed by aromatization, and
would afford the intermediate B with more electropositive feature. Next, the resulting species B underwent intermolecular
typical nucleophilic addition reaction by methanol 2a to give C. Finally, deprotonation of C occurred, affording the target
product 3a with regenerating the UO22+ catalyst.

6
Tetrahedron
O
t-Bu
t-Bu
H+
O
U
O
2+
OH
1a
OCH3
3a
O
O
2+
2+
O
O
U
U
O
O
t-Bu
t-Bu
t-Bu
t-Bu
CH3
O
H
A
2+
O
C
U
H
O
O
t-Bu
t-Bu
H+
δ+
H
OCH3
2a
B
Scheme 5. The possible mechanistic pathway for the reaction.
In conclusion, we have described a practical protocol toward the synthesis of diverse diarylmethane derivatives from p-
QMs and alcohol/thiol via 1,6-Machiel addition reaction under mild reaction conditions, in which the UO22+ was employed as
the excellent catalyst. The reaction shows superior results in terms of good functional-group compatibility and broad substrate
scope. The reaction process was proposed to proceed via a plausible chelated uranyl-carbonyl transition state, which could be
2+
attributed to the origin of the activation. Given the high catalytic activity of UO2 for the 1,6-addition of p-QMs, this
appeared to be a potentially useful strategy for the synthesis of diarylmethane complexes. Studies on other uranyl-catalyzed
organic transformations are currently underway in our lab.
Declaration of Competing Interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to
influence the work reported in this paper.
Acknowledgements
This work was supported by the National Natural Science Foundation of China (No. 21806167 and 21671191), the National Science
Fund for Distinguished Young Scholars (No. 21925603), the Science Challenge Project (TZ2016004), and the Youth Innovation
Promotion Association of CAS (2017020).
Appendix A. Supplementary data
Supplementary data to this article can be found online at https://doi.org/10.1016/j.tetlet.2020.XXXXXX.
References
[1] P. Abrams, R. Freeman, C. Anderstrom, A. Mattiasson, Brit J Urol 81 (1998) 801-810.
[2] M. Nilsson, M. Hamalainen, M. Ivarsson, J. Gottfries, Y. F. Xue, S. Hansson, R. Isaksson, T. Fex, J. Med. Chem. 52 (2009) 2708-2715.
[3] W. D. Chu, L. F. Zhang, X. Bao, X. H. Zhao, C. Zeng, J. Y. Du, G. B. Zhang, F. X. Wang, X. Y. Ma, C. A. Fan, Angew. Chem. Int. Ed. 52 (2013)
9229-9233.
[4] L. Caruana, F. Kniep, T. K. Johansen, P. H. Poulsen, K. A. Jorgensen, J. Am. Chem. Soc. 136 (2014) 15929-15932.
[5] Y. Z. Lou, P. Cao, T. Jia, Y. L. Zhang, M. Wang, J. Liao, Angew. Chem. Int. Ed. 54 (2015) 12134-12138.
[6] N. Dong, Z. P. Zhang, X. S. Xue, X. Li, J. P. Cheng, Angew. Chem. Int. Ed. 55 (2016) 1460-1464.
[7] C. Jarava-Barrera, A. Parra, A. Lopez, F. Cruz-Acosta, D. Collado-Sanz, D. J. Cardenas, M. Tortosa, ACS Catal. 6 (2016) 442-446.
[8] G. B. Huang, W. H. Huang, J. Guo, D. L. Xu, X. C. Qu, P. H. Zhai, X. H. Zheng, J. Weng, G. Lu, Adv. Synth. Catal. 361 (2019) 1241-1246.
[9] F. S. He, J. H. Jin, Z. T. Yang, X. X. Yu, J. S. Fossey, W.P. Deng, ACS Catal. 6 (2016) 652-656.
[10] Y. Y. Cheng, Z. Q. Fang, Y. W. Jia, Z. Y. Lu, W. J. Li, P. F. Li, RSC Adv. 9 (2019) 24212-24217.
[11] D. Wang, Z. F. Song, W. J. Wang, T. Xu, Org. Lett. 21 (2019) 3963-3967.
[12] K. Zhao, Y. Zhi, A. Wang, D. Enders, ACS Catal. 6 (2016) 657-660.
[13] Y. N. Zhao, Y. C. Luo, Z. Y. Wang, P. F. Xu, Chem. Commun. 54 (2018) 3993-3996.
[14] Q. Y. Wu, Q. Q. Min, G. Z. Ao, F. Liu, Org. Biomol. Chem. 16 (2018) 6391-6394.
[15] Q. Y. Wu, G. Z. Ao, F. Liu, Org. Chem. Front. 5 (2018) 2061-2064.
[16] J. Guo, G. B. Huang, Q. L. Wu, Y. Xie, J. Weng, G. Lu, Org. Chem. Front. 6 (2019) 1955-1960.
[17] W. Zhang, C. Yang, Z. P. Zhang, X. Li, J. P. Cheng, Org. Lett. 21 (2019) 4137-4142.

7
[18] A. Lopez, A. Parra, C. Jarava-Barrera, M. Tortosa, Chem. Commun. 51 (2015) 17684-17687.
[19] M. L. Ke, Q. L. Song, Adv. Synth. Catal. 359 (2017) 384-389.
[20] R. J. Zhuge, L. Wu, M. Quan, N. Butt, G. Q. Yang, W. B. Zhang, Adv. Synth. Catal. 359 (2017) 1028-1036.
[21] Z. P. Zhang, N. Dong, X. Li, Chem. Commun. 53 (2017) 1301-1304.
[22] N. Molleti, J. Y. Kang, Org. Lett. 19 (2017) 958-961.
[23] B. B. Yang, W. Yao, X. F. Xia, D. W. Wang, Org. Biomol. Chem. 16 (2018) 4547-4557.
[24] R. Li, Y. Chen, K. Jiang, F. Y. Wang, C. F. Lu, J. Q. Nie, Z. X. Chen, G. C. Yang, Y. C. Chen, Y. Zhao, C. Ma, Chem. Commun. 55 (2019) 1217-
1220.
[25] Z. L. Liu, H. F. Xu, T. F. Yao, J. L. Zhang, L. Liu, Org. Lett. 21 (2019) 7539-7543.
[26] A. S. Jadhav, R. V. Anand, Org. Biomol. Chem. 15 (2017) 56-60.
[27] Y. Y. Shen, J. F. Qi, Z. J. Mao, S. L. Cui, Org. Lett. 18 (2016) 2722-2725.
[28] X. Y. Guan, L. D. Zhang, P. S. You, S. S. Liu, Z. Q. Liu, Tetrahedron Lett 60 (2019) 244-247.
[29] P. Goswami, G. Singh, R. V. Anand, Org. Lett. 19 (2017) 1982-1985.
[30] P. Arde, R. V. Anand, Org. Biomol. Chem. 14 (2016) 5550-5554.
[31] V. V. Castelli, A. Dalla Cort, L. Mandolini, D. N. Reinhoudt, L. Schiaffino, Eur. J. Org. Chem. (2003) 627-633.
[32] S. Enthaler, Chem. -Eur J. 17 (2011) 9316-9319.
[33] K. Takao, S. Akashi, RSC Adv. 7 (2017) 12201-12207.
[34] J. G. West, T. A. Bedell, E. J. Sorensen, Angew. Chem. Int. Ed. 55 (2016) 8923-8927.
[35] L. Capaldo, D. Merli, M. Fagnoni, D. Ravelli, ACS Catal. 9 (2019) 3054-3058.
[36] M. Azam, S. I. Al-Resayes, A. Trzesowska-Kruszynska, R. Kruszynski, P. Kumar, S. L. Jain, Polyhedron 124 (2017) 177-183.
[37] Y. M. Li, S. a.E.A. Rizvi, D. Q. Hu, D.W. Sun, A. H. Gao, Y. B. Zhou, J. Li, X. F. Jiang, Angew. Chem. Int. Ed. 58 (2019) 13499-13506.
[38] J. P. Yu, X. N. Zhao, Z. W. Miao, R. Y. Chen, Org. Biomol. Chem. 9 (2011) 6721-6726.
[39] S. Park, H. Lee, Y. Lee, Adv. Synth. Catal. 362 (2019) 572-584.
Declaration of interests
☒ The authors declare that they have no known competing financial interests or personal relationships that
could have appeared to influence the work reported in this paper.
☐The authors declare the following financial interests/personal relationships which may be considered as potential
competing interests:
Highlights
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A direct 1,6-addition route of p-QMs to diarylmethanes was catalyzed by uranyl ion.
Abundant, and sequestrable depleted uranium made the reaction more sustainable.
Moderate to high yields with broad scope and functional group tolerance.
Facile operation and mild conditions as a practical and attractive protocol.

8
Tetrahedron
OH
O
OH
R1
R1
R1
R1
t-Bu
t-Bu
2+
UO2
r.t.
+
H XRn
OCH3
XRn
R2
R2
X = O, S
gram scale in one step