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DOI: 10.1039/C8CC06153J
COMMUNICATION
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Scheme 4. Cross-coupling of 1,2,3-triborated products with 1-iodo-4-
methylbenzene and 1-iodo-4-methoxybenzene in the presence of
B. Marder, J. M. Murphy, J. F. Hartwig, Chem. Rev., 2010,
110, 890; e) H. E. Burks, J. P. Morken, Chem. Commun., 2007,
4717.
Pd(OAc)2/RuPhos, and in situ oxidation of 36
.
2
a) G. Lesley, P. Nguyen, N. J. Taylor, T. B. Marder, A. J. Scott,
W. Clegg, N. C. Norman, Organometallics 1996, 15, 5137; b)
H. Abu Ali, A. E. A. Al Quntar, I. Goldberg, M. Srebnik,
Organometallics 2002, 21, 4533.
Unlike to the functionalisation of the terminal C-B bond in 1,2-
diborated vicinal products observed by Morken et al.,22 in our
hands the 1,2,3-triborated species allows a selective cross-
coupling at the internal B2, under the same reaction
conditions. The reaction has been extended to the cross-
coupling between 1-iodo-4-methylbenzene and the 1,2,3-
3
4
K. Hyodo, M. Suetsugu, Y. Nishihara, Org. Lett. 2014, 16, 440.
C.-I. Lee, W.-C. Shih, J. Zhou, J. H. Reibenspies, O. V. Ozerov,
Angew. Chem., Int. Ed. 2015, 54, 14003.
Y. Gu, H. Pritzkow, W. Siebert, Eur. J. Inorg. Chem. 2001, 373.
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a) W. N. Palmer, J. V. Obligacion, I. Pappas, P. J. Chirik, J. Am.
Chem. Soc., 2016, 138, 766; b) W. N. Palmer, C. Zarate, P. J.
Chirik, J. Am. Chem. Soc., 2017, 139, 2589.
S. Krautwald, M. J. Bezdek, P. J. Chirik, J. Am. Chem. Soc.,
2017, 139, 3868.
5
6
triborated compounds 14
general for para- and ortho- substituted aryl systems as well as
the furyl group forming the desired products 38 39 and 41
, 16 and 18 making the protocol
7
,
respectively (Scheme 4). Product 38 could be full characterised
by X-Ray diffraction (Figure 1). Following with the attempt to
fully functionalise the triborated compounds, we proceeded
towards the in situ oxidation of the diborated product 36, in
the presence of H2O2/NaOH, forming the corresponding 1,3-
butanediol 2,4-diaryl system 40 (Scheme 4).
8
9
H. Yoshida, S. Kawashima, Y. Takemoto, K. Okada, J. Ohshita,
K. Takaki, Angew. Chem. Int. Ed., 2012, 51, 235.
10 Z. Yang, T. Cao, Y. Han, W. Lin, Q. Liu, Y. Tang, Y. Zhai, M. Jia,
W. Zhang, T. Zhu, S. Ma, Chin. J. Chem. 2017, 35, 1251.
11 N. Miralles, R. Alam, K. Szabó, E. Fernández, Angew. Chem.
Int. Ed., 2016, 55, 4303.
12 J. Cid, H. Gulyás, J. J. Carbó, E. Fernández, Chem. Soc. Rev.
2012, 41, 3558.
13 A. B. Cuenca, R. Shishido, H. Ito, E. Fernández, Chem. Soc.
Rev. 2017, 46, 415.
14 Y. Cao, Y. Zhang, L. Zhang, D. Zhang, X. Leng, Z. Huang, Org.
Chem. Front., 2014,
15 a) R. J. Ely, J. P. Morken, J. Am. Chem. Soc., 2010, 132, 2534;
1,1101.
38
Figure 1. X-Ray Diffraction Data for compound 38
b) R. J. Ely,, Z. Yu, J. P. Morken, Tetrahedron Lett., 2015, 56
3402.
,
.
16 K. Semba, M. Shinomiya, T. Fujihara, J. Terao, Y. Tsuji, Chem.
Eur. J. 2013, 19, 7125.
17 M. Zaidlewicz, J. Meller, Tetrahedron Lett., 1997, 38, 7279.
18 Competitive copper catalyzed 1,2- versus 1,4-arylborylation:
In conclusion, we have been able to perform a direct 1,2,3-
triboration reaction in a transition metal-free context, by 1,4-
hydroboration of 1,3-dienes followed by in situ diboration
reaction of the internal double bond. In order to confirm the
S. R. Sardini, M. K. Brown, J. Am. Chem. Soc., 2017, 139
9823.
19 J. Y. Wu, B. Moreau, T. Ritter, J. Am. Chem. Soc., 2009, 131
12915.
20 C. Zhu, B. Yang, Y. Qiu, J.-E. Bäckvall, Chem. Eur. J., 2016, 22
2939.
,
,
,
suggested mechanism, the 1,4-hydroborated intermediate
was isolated and a consequent diboration under the same
reaction conditions took place to form exclusively product
2
3.
The reactions are carried out with quantitative conversion for
terminal 1,2-dienes, and moderate yields for internal 1,3-
dienes, with tolerance to heterofunctional groups. When the
1,2,3-triborated compounds were exposed to cross coupling
conditions, only the internal C-B bond could be arylated in a
selective way, as a plausible double assistance of the two
vicinal boryl moieties. This is an unprecented access to 1,2,3-
triborated compounds but also the fact that they can be
exclusively functionalised makes this methodology of great
applicability in synthetic organic purposes.
21 a) G. Desurmont, R. Klein, S. Uhlenbrock, L. Laloe, L. Deloux
D. M. Giolando, J. M. Kim, S. Pereira, M. Srebnik M.
Organometallics 1996, 15, 3323; b) A. Shibli, H. Abu Ali, I.
Goldberg, M. Srebnik, Appl. Organomet. Chem., 2005, 19
171.
,
22 S. N. Mlynarski, C. H. Schuster, J. P. Morken, Nature, 2014,
505, 386.
The present research was supported by the Spanish Ministerio
de Economia y competitividad (MINECO) through project
FEDER-CTQ2016-80328-P. We thank AllyChem for the gift of
diboranes
Notes and references
1
a) E. C. Neeve, S. J. Geiger, I. A. I. Mkhalid, S. A. Westcott, T.
B. Marder, Chem. Rev., 2016, 116, 9091; b) J. Takaya, N.
Iwasawa, ACS Catal., 2012, 2, 1993; c) J. F. Hartwig, Chem.
Soc. Rev., 2011, 40, 1992; d) I. A. I. Mkhalid, J. H. Barnard, T.
4 | J. Name., 2012, 00, 1-3
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