Synthesis of diarylalkanes through an intramolecular/intermolecular addition sequence by auto-tandem catalysis with strong Br?nsted base

Article abstract of DOI:10.1039/d0cc04512h

An auto-tandem catalysis with a strong Br?nsted base enabled the synthesis of diarylalkanes containing a benzofuran moiety. Potassiumtert-butoxide efficiently catalyzed both the intramolecular cyclization of less acidicortho-alkynylaryl benzyl ethers and the following intermolecular addition of diarylmethanes to styrenes, demonstrating the high potential of the catalysis in organic synthesis.

Full text of DOI:10.1039/d0cc04512h

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DOI: 10.1039/D0CC04512H
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Synthesis of diarylalkanes through intramolecular/intermolecular
addition sequence by auto-tandem catalysis with strong Brønsted
base
Received 00th January 20xx,
Accepted 00th January 20xx
Azusa Kondoh,*a Chaoyan Ma b and Masahiro Terada *b
DOI: 10.1039/x0xx00000x
An auto-tandem catalysis with a strong Brønsted base enabled a Brønsted base catalysts, we envisioned the development of
synthesis of diarylalkanes containing benzofuran moiety. catalytic reactions consisting of an intramolecular cyclization of
a
Potassium tert-butoxide efficiently catalyzed both the less acidic pronucleophiles and the following intermolecular
intramolecular cyclization of less acidic ortho-alkynylaryl benzyl addition by using a strong Brønsted base as a new type of
ethers and the following intermolecular addition of auto-tandem Brønsted base catalysis. In this study, we
diarylmethanes to styrenes, demonstrating the high potential of designed a reaction of ortho-alkynylaryl benzyl ethers with
the catalysis in organic synthesis.
activated alkenes to provide diarylalkanes as an immediate
goal. Our reaction design is shown in Scheme 1. The first
catalytic process involves the formation of 3-
In recent years, much attention has been paid to the
application of strong Brønsted bases as
a catalyst in
benzylbenzofurans
3
through the intramolecular cyclization of
ortho-alkynylaryl benzyl ethers having an aryl group at the
alkyne terminus and the following aromatization.4 In the
second catalytic process, 3-benzylbenzofurans , which are
nucleophilic addition reactions,1 because the pronucleophiles
applicable to the conventional Brønsted-base-catalyzed
reactions have been mainly limited to highly acidic compounds.
Thus, the method has enabled the direct functionalization of
less acidic pronucleophiles in an atom-economical fashion. In
addition to several intermolecular addition reactions,2,3 the
intramolecular addition to an alkyne as the electrophile was
also achieved, which provides a powerful methods for the
construction of cyclic frameworks that are otherwise difficult
to access.4 Meanwhile, the auto-tandem catalysis is a process
in which one catalyst promotes more than two mechanistically
distinct processes in a single reactor.5 Auto-tandem catalysis
with a Brønsted base catalyst is particularly attractive due to
its operational simplicity and the mildness of the reaction
conditions. However, most of the reactions reported to date
are the reactions that use highly acidic compounds as the
substrate and that limit the accessible structural motifs and
their applications in organic synthesis.6,7 Therefore, the
establishment of an auto-tandem Brønsted base catalysis with
less acidic compounds is highly desirable to expand the scope
of its application and extend its utility in organic synthesis. In
this context, during the course of our study on the
development of new catalytic reactions utilizing strong
1
3
members of diarylmethanes and formed by the first catalytic
process, serve as the pronucleophile, and their catalytic
addition to activated alkenes
2 provides desired diarylalkanes
4
. Diarylalkanes are an important structural motif found in a
large number of bioactive compounds.8,9 The alkylation of
diarylmethanes is one of the straightforward methods for the
synthesis of diarylalkanes. Although nucleophilic substitution
reactions10 and transition-metal-catalyzed allylic alkylation
reactions11 have been developed by using a stoichiometric
amount of a Brønsted base, the addition reactions with a
catalytic amount of a Brønsted base are rare due to the low
acidity of diarylmethanes.12 In addition, all of the precedents
require the pre-synthesis of diarylmethanes. Therefore, we
expected that
a.Research and Analytical Center for Giant Molecules, Graduate School of Science,
Tohoku University, Aramaki, Aoba-ku, Sendai, 980-8578, Japan. E-mail:
kondoha@tohoku.ac.jp
b.Department of Chemistry, Graduate School of Science, Tohoku University,
Aramaki, Aoba-ku, Sendai 980-8578, Japan. E-mail: mterada@tohoku.ac.jp
Electronic Supplementary Information (ESI) available: experimental procedures,
and characterization data. See DOI: 10.1039/x0xx00000x
Scheme 1 Reaction design
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Table 1 Screening of reaction conditionsa
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DOI: 10.1039/D0CC04512H
Yieldb (%)
Entry
Base
Solvent
4aa
89
<1
<1
87
95 (91)
12
<1
<1
<1
3a
4
<1
<1
4
<1
88
<1
33
<1
<1
<1
<1
1a
<1
95
98
<1
<1
<1
98
66
85
95
99
99
1
2
3
4
5
6
7
8
P4-tBu
P2-tBu
P1-tBu
KHMDS
tBuOK
tBuONa
tBuOLi
tBuOK
tBuOK
tBuOK
tBuOK
tBuOK
DMSO
DMSO
DMSO
DMSO
DMSO
DMSO
DMSO
DMF
Scheme 2 Control experiments
The counter cation of inorganic bases was highly influential to
the reaction outcome. The use of tBuONa instead of tBuOK
provided 4aa in low yield while the use of tBuOLi resulted in
no reaction (entries 6 and 7). The screening of the solvent was
then carried out with tBuOK as the catalyst (entries 8-12). It
revealed that the solvent effect was significant and the use of
DMSO was essential. The use of DMF instead of DMSO
resulted in the formation of 3a in moderate yield, whereas
other solvents including acetonitrile, ethereal solvents, and
9
CH3CN
THF
Et2O
10
11
12
<1
<1
<1
Toluene
a
Reaction conditions: 1a (0.20 mmol), 2a (0.30 mmol), base (0.040 mmol),
solvent (2.0 mL), 40 °C, 3 h. Yields were determined by 1H NMR analysis of the
crude mixture. 1,3-Benzodioxole was used as an internal standard. Isolated yield
is shown in parentheses.
b
toluene, resulted in the recovery of 1a 14
Both high polarity
.
and strong Lewis basicity would be important for promoting
the multi-step reaction.
As a control experiment, 3a was treated with styrene (2a
)
under the optimized conditions. In this case, the addition of 3a
to 2a proceeded smoothly to provide 4aa in good yield
(Scheme 2a). This result confirmed that 3a can serve as an
intermediate for the formation of 4aa from 1a and 2a. On the
other hand, the reaction of 3a and 2a with less basic P2-tBu
did not proceed, suggesting that the high basicity of the
catalyst is responsible for promoting not only the first
intramolecular cyclization process but also the second
our intended reaction would not only provide a new method
for the synthesis of valuable diarylalkanes but also
demonstrate the high potential of auto-tandem catalysis with
a strong Brønsted base catalyst as a new methodology for
organic synthesis. The key for achieving the auto-tandem
catalysis is the establishment of suitable reaction conditions
for mechanistically distinct processes. We were able to
successfully manage this issue, and report herein the reaction
of ortho-alkynylaryl benzyl ethers with styrenes to provide
diarylalkanes containing a benzofuran moiety.
To ascertain the viability of our reaction design, we started our
investigation with the treatment of ortho-alkynylphenyl benzyl
ether 1a having a phenyl group at the alkyne terminus with 1.5
equivalents of styrene (2a) in the presence of 20 mol%
organobases having different basicities in DMSO at 40 °C for 3
h (Table 1, entries 1-3). As a result, phosphazene base P4-tBu
having strong basicity (pKBH+ = 30.3)13 provided desired 4aa in
89% NMR yield along with a small amount of non-alkylated
product 3a, whereas the use of less basic P2-tBu (pKBH+ = 21.5)
and P1-tBu (pKBH+ = 15.7) resulted in the recovery of 1a. These
results suggest that the use of strong Brønsted bases is
essential to promote the designed tandem reaction. Inorganic
bases having strong basicity, such as KHMDS and tBuOK, also
facilitated the reaction (entries 4 and 5), and the use of tBuOK
as the catalyst resulted in the highest yield of 4aa (entry 5).
intermolecular addition process. As
a further control
experiment, the reaction of 1a with 2a was attempted in the
presence of 20 mol% or one equivalent TEMPO to evaluate the
involvement of the radical chain mechanism (Scheme 2b).4e As
a result, 1a was fully consumed and the substantial amount of
4aa was formed along with 3a although the yield was
moderate. This result suggests that each step of the tandem
reaction would not proceed through the radical chain
mechanism but through the anionic mechanism.
With the optimized reaction conditions in hand, the scope of
the substrates was investigated. First, the scope of ortho-
alkynylaryl benzyl ethers
1 was examined (Table 2). The
substrate having an electron-deficient para-chlorophenyl
group on the benzyl moiety underwent the reaction smoothly
to provide 4ba in high yield (entry 1). On the other hand, the
reaction of 1c having an electron-rich para-methoxyphenyl
group was sluggish, and 4ca was obtained in low yield along
with 3c and unreacted 1c (entry 2). Sterically congested 1-
2 | J. Name., 2012, 00, 1-3
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Table 2 Scope of ortho-alkynylaryl benzyl ethers 1
View Article Online
DOI: 10.1039/D0CC04512H
Scheme 3 Reaction of ortho-alkynylphenyl benzyl thioether 1l
Yieldb (%)
4
Time
(h)
Entry
1
Ar1
Ar2
Ph
case.
3
<1
14
3
Next, the scope of activated alkenes was investigated (Table 3).
Styrene derivatives possessing an electron-withdrawing group
and an electron-donating group at the para position
1
1b
1c
1d
1e
1f
1g
1h
1i
4-ClC6H4
4-MeOC6H4 Ph
1-naphthyl
2-pyridyl
2-furyl
Ph
Ph
Ph
Ph
Ph
3
22
22
3
3
3
8
22
3
4ba
4ca
4da
4ea
4fa
4ga
4ha
4ia
96 (92)
2
21c
3d
4
Ph
Ph
Ph
42 (44)
96 (90) <1 underwent the reaction without any problem and the
88 (87)
97 (90)
56 (54) 44
78 (74)
89 (85)
98 (93)
5
6
7
8
9
10
<1
<1
corresponding products were obtained in good yields (entries
1-3). 1-Vinylnaphthalene (2f) underwent the reaction smoothly,
whereas 2e having an ortho-chlorophenyl group provided 4ae
in moderate yield even after 17 h (entries 4 and 5). 2-
Vinylpyridine was also applicable to the reaction albeit the
yield was moderate (entry 6). Interestingly, α-substituted
styrenes, such as 1,1-diphenylethylene
methylstyrene, participated in the reaction to provide 4ah and
4ai in good yields, respectively (entries 7 and 8). Furthermore,
4-ClC6H4
4-MeOC6H4
1-naphthyl
2-pyridyl
2-thienyl
6
<1
<1
1j
1k
4ja
4ka
3
a
Reaction conditions: 1 (0.20 mmol), 2a (0.30 mmol), tBuOK (0.040 mmol),
(
2h
)
and
α-
DMSO (2.0 mL), 40 °C. b Yields were determined by 1H NMR analysis of the crude
mixture. 1,3-Benzodioxole was used as an internal standard. Isolated yields are
shown in parentheses. 1c (38%) recovered. d The reaction was conducted at
c
not only styrene derivatives but also triphenylvinylsilane (2j
)
100 °C.
could be used, and 4aj was obtained in moderate yield (entry
9). The reactions with aliphatic alkenes, trans-stilbene, and
activated alkenes having an electron-withdrawing group, such
as acrylates and acryl amides, were also tested. However, the
desired product was not obtained and instead, 3a was
generated or 1a was recovered in these cases.
naphthyl-substituted 1d required a high temperature to
promote the reaction (entry 3). Compounds 1e and 1f having a
heteroaryl group underwent the reaction without any problem
to provide 4ea and 4fa in high yields (entries 4 and 5). Then, a
screening of the substituent at the alkyne terminus was carried
out (entries 6-10). Various aryl groups including heteroaryl
groups were applicable as the substituent and the
corresponding products were obtained in moderate to high
yields. An alkyl substituent, such as a butyl group, was also
examined. However, a complex mixture was obtained in that
Finally, the reaction system was applied to the synthesis of
diarylalkanes containing
a different heteroaromatic ring
(Scheme 3). Specifically, the reaction of ortho-alkynylphenyl
benzyl thioether 1l as the substrate with styrene (2a) was
attempted. The reaction proceeded to provide diarylalkane 4la
containing a benzothiophene moiety in good yield.15
Table 3 Scope of alkenes 2
In conclusion, we have developed an auto-tandem catalysis
with a strong Brønsted base for the synthesis of diarylalkanes.
Potassium tert-butoxide efficiently catalyzed both the
intramolecular cyclization of less acidic ortho-alkynylaryl
benzyl ethers and the following intermolecular addition of
diarylmethanes to styrene derivatives to provide diarylalkanes
containing a benzofuran moiety. Further studies are in
progress to utilize the high potential of the catalysis as a
methodology for organic synthesis.
Yieldb (%)
Time
Entry
2
R1
R2
(h)
4
3a
3
9
13
33
7
50
18
11
30
1
2
3
4
5
6
2b
2c
2d
2e
2f
2g
2h
2i
4-BrC6H4
4-MeC6H4
4-MeOC6H4
2-ClC6H4
1-naphthyl
2-pyridyl
Ph
H
H
H
H
H
H
Ph
Me
H
3
3
3
17
3
20
25
8
4ab
4ac
4ad
4ae
4af
4ag
4ah
4ai
93 (92)
86 (82)
82 (78)
50 (52)
87 (84)
38
71 (67)
81 (78)f
52 (50)
Conflicts of interest
There are no conflicts to declare.
7c,d
8e
9e
Ph
Ph3Si
Acknowledgements
2j
25
4aj
a
This research was supported by a Grant-in-Aid for Scientific
Research (S) (JP16H06354) from the JSPS.
Reaction conditions: 1a (0.20 mmol), 2 (0.30 mmol), tBuOK (0.040 mmol),
DMSO (2.0 mL), 40 °C. b Yields were determined by 1H NMR analysis of the crude
mixture. 1,3-Benzodioxole was used as an internal standard. Isolated yields are
shown in parentheses. c The reaction was conducted with 0.020 mmol (10 mol%)
of tBuOK. 2.0 equivalents of 2h was used. The reaction was conducted with
0.080 mmol (40 mol%) of tBuOK. 4ai was obtained as a 1:1 mixture of
d
e
f
Notes and references
diastereomers.
This journal is © The Royal Society of Chemistry 20xx
J. Name., 2013, 00, 1-3 | 3
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Journal Name
1
For reviews on Brønsted base catalysis, see: (a) T. Ishikawa,
Superbases for Organic Synthesis, John Wiley & Sons,
Chippenham, 2009; (b) K. Nagasawa, Y. Sohtome, R. P. Singh,
L. Deng, H. B. Jang, J. S. Oh and C. E. Song, Science of
Synthesis: Asymmetric Organocatalysis 2: Brønsted Base and
Acid Catalysis, and Additional Topics, ed. K. Maruoka, Thieme,
Stuttgart, 2012, pp. 1-168; (c) C. Palomo, M. Oiarbide and R.
López, Chem. Soc. Rev., 2009, 38, 632-653; (d) T. Marcelli and
H. Hiemstra, Synthesis, 2010, 1229-1279; (e) B. Teng, W. C.
Lim and C.-H. Tan, Synlett, 2017, 28, 1272-1277.
Bélanger, J. Nat. Prod., 2003, 66, 1280-1283; (f)VCie.wJ.AHrtiiclllesO, Snl.ine
A. Winter and J. A. Balfour, Drugs, 199D8O, 5I:510, .8101339-/8D200C.C04512H
9
Selected recent studies, see: (a) Y. He, C. Liu, L. Yu and S. Zhu,
Angew. Chem. Int. Ed., 2020, 59, 9186-9191; (b) W. Wang, C.
Ding, Y. Li, Z. Li, Y. Li, L. Peng and G. Yin, Angew. Chem. Int.
Ed., 2019, 58, 4612-4616; (c) Shekhar KC, R. K. Dhungana, B.
Shrestha, S. Thapa, N. Khanal, P. Basnet, R. W. Lebrun and R.
Giri, J. Am. Chem. Soc., 2018, 140, 9801-9805; (d) Y.-N. Zhao,
Y.-C. Luo, Z.-Y. Wang and P.-F. Xu, Chem. Commun., 2018, 54
3993-3996; (e) L.-J. Xiao, L. Cheng, W.-M. Feng, M.-L. Li, J.-H.
,
2
3
For seminal studies, see: (a) H. Pines and W. M. Stalick,
Xie and Q.-L. Zhou, Angew. Chem. Int. Ed., 2018, 57, 461-464;
(f) W. Zhang, P. Chen and G. Liu, J. Am. Chem. Soc., 2017, 139
7709-7712; (g) A. Vasilopoulos, S. L. Zultanski and S. S. Stahl,
J. Am. Chem. Soc., 2017, 139, 7705-7708; (h) K. E. Poremba,
N. T. Kadunce, N. Suzuki, A. H. Cherney and S. E. Reisman, J.
Am. Chem. Soc., 2017, 139, 5684-5687.
Tetrahedron Lett., 1968,
9
, 3723-3726; (b) H. Pines, S. V.
,
Kannan and J. Simonik, J. Org. Chem., 1971, 36, 2311-2315;
(c) A. L. Rodriguez, T. Bunlaksananusorn and P. Knochel, Org.
Lett., 2000,
2, 3285-3287.
For selected recent examples, see: (a) G. Liu, P. J. Walsh and
J. Mao, Org. Lett., 2019, 21, 8514-8518; (b) Y.-F. Liu, L. Zheng, 10 For selected examples, see: (a) J. A. Wilkinson, S. B.
D.-D. Zhai, X.-Y. Zhang and B.-T. Guan, Org. Lett., 2019, 21
5351-5356; (c) I. Sato, Y. Yamashita and S. Kobayashi,
,
Rossington, S. Ducki, J. Leonard and N. Hussain, Tetrahedron,
2006, 62, 1833-1844; (b) L. M. Gooch, S. B. Rossington and J.
A. Wilkinson, Tetrahedron Lett., 2015, 56, 4025-4027; (c) H.
Kawashima, N. Ogawa, R. Saeki and Y. Kobayashi, Chem.
Commun., 2016, 52, 4918-4921; (d) R. Shinohara, N. Ogawa,
H. Kawashima, K. Wada, S. Saito, T. Yamazaki and Y.
Kobayashi, Eur. J. Org. Chem., 2019, 1461-1478; (e) R.
Shinohara, H. Kawashima, N. Ogawa and Y. Kobayashi,
Tetrahedron, 2019, 75, 2717-2725.
Synthesis, 2019, 51, 240-250; (d) X.-Y. Zhang, L. Zheng and B.-
T. Guan, Org. Lett., 2018, 20, 7177-7181; (e) Y. Yamashita, H.
Suzuki, I. Sato, T. Hirata and S. Kobayashi, Angew. Chem. Int.
Ed., 2018, 57, 6896-6900; (f) D.-D. Zhai, X.-Y. Zhang, Y.-F. Liu,
L. Zheng and B.-T. Guan, Angew. Chem. Int. Ed., 2018, 57
,
1650-1653; (g) W. Bao, H. Kossen and U. Schneider, J. Am.
Chem. Soc., 2017, 139, 4362-4365; (h) H. Suzuki, R. Igarashi,
Y. Yamashita and S. Kobayashi, Angew. Chem. Int. Ed., 2017,
56, 4520-4524; (i) H. Suzuki, I. Sato, Y. Yamashita and S.
Kobayashi, J. Am. Chem. Soc., 2015, 137, 4336-4339; (j) Y.
Yamashita, H. Suzuki and S. Kobayashi, Org. Biomol. Chem.,
2012, 10, 5750-5752.
11 (a) S.-C. Sha, H. Jiang, J. Mao, A. Bellomo, S. A. Jeong and P. J.
Walsh, Angew. Chem. Int. Ed., 2016, 55, 1070-1074; (b) S.-C.
Sha, J. Zhang, P. J. Carroll and P. J. Walsh, J. Am. Chem. Soc.,
2013, 135, 17602-17609; (c) B. M. Trost and D. A.
Thaisrivongs, J. Am. Chem. Soc., 2009, 131, 12056-12057.
12 (a) Y.-F. Liu, D.-D. Zhai, X.-Y. Zhang and B.-T. Guan, Angew.
Chem. Int. Ed., 2018, 57, 8245-8249; (b) Q. Hu, A. Kondoh
4
For a review, see: (a) F. Dénès, A. Pérez-Luna and F. Chemla,
Chem. Rev., 2010, 110, 2366-2447; For selected examples,
see: (b) C. Koradin, A. Rodriguez and P. Knochel, Synlett,
2000, 1452-1454; (c) C. Kanazawa, K. Goto and M. Terada,
Chem. Commun., 2009, 5248-5250; (d) A. Kondoh, K. Ando
and M. Terada, Chem. Commun., 2013, 49, 10254-10256; (e)
Y.-y. Chen, J.-h. Chen, N.-n. Zhang, L.-m. Ye, X.-J. Zhang and
M. Yan, Tetrahedron Lett., 2015, 56, 478-481; (f) A. Kondoh,
H. T. Q. Tran, K. Kimura and M. Terada, Chem. Commun.,
2016, 52, 5726-5729.
and M. Terada, Chem. Sci., 2018, 9, 4348-4351.
13 R. Schwesinger, H. Schlemper, C. Hasenfratz, J. Willaredt, T.
Dambacher, T. Breuer, C. Ottaway, M. Fletschinger, J. Boele,
H. Fritz, D. Putzas, H. W. Rotter, F. G. Boldwell, A. V. Satish,
G.-Z. Ji, E. M. Peters, K. Peters, H. G. von Schnering and L.
Walz, Liebigs Ann., 1996, 1055-1081.
14 Reduction of the catalyst loading to 10 mol% or reduction of
reaction temperature to 25 °C caused insufficient
reproducibility.
15 The synthesis of diarylalkanes containing an indole moiety
was failed. Although the intramolecular cyclization of ortho-
alkynyl-N-benzylanilines proceeded smoothly, the
intermolecular addition of the corresponding diarylmethanes
to styrenes was sluggish.
5
6
For selected reviews on auto-tandem catalysis, see: (a) D. E.
Fogg and E. N. dos Santos, Coord. Chem. Rev., 2004, 248
,
2365-2379; (b) N. Shindoh, Y. Takemoto and K. Takasu, Chem.
Eur. J., 2009, 15, 12168-12179; (c) J. E. Camp, Eur. J. Org.
Chem., 2017, 425-433.
For reviews, see: (a) C. M. R. Volla, I. Atodiresei and M.
Rueping, Chem. Rev., 2014, 114, 2390-2431; (b) S. Nayak, P.
Panda, S. Bhakta, S. K. Mishra and S. Mohapatra, RSC Adv.,
2016,
6, 96154-96175. For selected examples, see: (c) Z.-X.
Jia, Y.-C. Luo and P.-F. Xu, Org. Lett., 2011, 13, 832-835; (d) H.
R. Tan, H. F. Ng, J. Chang and J. Wang, Chem. Eur. J., 2012, 18
3865-3870; (e) A. Quintavalla, M. Lombardo, S. P. Sanap and
C. Trombini, Adv. Synth. Catal., 2013, 355, 938-946; (f) C.
,
Feng, Y. Li, Q. Xu, L. Pan, Q. Liu and X. Xu, J. Org. Chem., 2018,
83, 1232-1240.
A. Kondoh and M. Terada, Org. Lett., 2018, 20, 5309-5313.
For reviews, see: (a) D. Ameen and T. J. Snape, Med. Chem.
Commun., 2013, 4, 893-907; (b) M. Gordaliza, P. A. García, J.
7
8
M. M. del Corral, M. A. Castro and M. A. Gómez-Zurita,
Toxicon, 2004, 44, 441-459. For selected examples, see: (c) S.
Messaoudi, A. Hamze, O. Provot, B. Tréguier, J. R. De Losada,
J. Bignon, J.-M. Liu, J. Wdzieczak-Bakala, S. Thoret, J. Dubois,
J.-D. Brion and M. Alami, ChemMedChem, 2011, 6, 488-497;
(d) M. Kainuma, J. Kasuga, S. Hosoda, K. Wakabayashi, A.
Tanatani, K. Nagasawa, H. Miyachi, M. Makishima and Y.
Hashimoto, Bioorg. Med. Chem. Lett., 2006, 16, 3213-3218;
(e) D. J. McNally, K. V. Wurms, C. Labbé, S. Quideau and R. R.
4 | J. Name., 2012, 00, 1-3
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DOI: 10.1039/D0CC04512H
An auto-tandem catalysis with a strong Brønsted base enabled an efficient synthesis of
diarylalkanes containing a benzofuran moiety.