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ChemComm
Page 4 of 4
DOI: 10.1039/C8CC02558D
COMMUNICATION
Journal Name
R. K. Mylavarapu, K. GCM, N. Kolla, R. Veeramalla, P.
Koilkonda, A. Bhattacharya and R. Bandichhor, Org. Process
Res. Dev., 2007, 11, 1065; (i) I. Georgiou, G. Ilyashenko and
A. Whiting, Acc. Chem. Res., 2009, 42, 756; (j) R. M. Al‐Zoubi,
D. G. Hall, Org. Lett., 2010, 12, 2480; (k) A. Sakakura, T.
Ohkubo, R. Yamashita, M. Akakura and K. Ishihara, Org. Lett.
2011, 13, 892; (l) A. Sakakura, R. Yamashita, M. Akakura and
K. Ishihara, Austr. J. Chem., 2011, 64, 1458; (m) N. Gernigon,
H. Zheng and D. G. Hall, Tetrahedron Lett., 2013, 54, 4475;
(n) S. Liu, Y. Yang, X. Liu, F. K. Ferdousi, A. S. Batsanov and A.
Whiting, Eur. J. Org. Chem., 2013, 2013, 5692; (o) R.
stability and lowers its reactivity, thus suppressing
amidation.2q
To obtain more mechanistic insights, we
conducted the initial rate kinetic experiments to determine
rate orders in 1c‐catalyzed amidation between 2a and 3a 17
.
Although the formation of ammonium carboxylate salt slightly
complicated this system, we obtained approximate first orders
for 1c and 3a, and a zero order for 2a
.
Moreover, as Hall’s previous report,3d we also found the pre‐
mixing of 1c and 2a in the presence of molecular sieves for
several minutes is indispensable. Control reactions with a
simultaneous addition of both substrates with the catalyst
provided less than 5% yield of amide product after several
Yamashita, A. Sakakura and K. Ishihara, Org. Lett., 2013, 15
3654; (p) K. Ishihara and Y. Lu, Chem. Sci., 2016, , 1276.
,
7
3
For ortho‐basic group‐substituted phenylboronic acid‐
catalysed amidations: (a) K. Arnold, A. S. Batsanov, B. Davies
and A. Whiting, Green Chem., 2008, 10, 124; (b) R. M. Al‐
Zoubi, O. Marion and D. G. Hall, Angew. Chem. Int. Ed., 2008,
47, 2876; (c) I. Georgiou, G. Ilyashenko and A. Whiting, Acc.
Chem. Res., 2009, 42, 756; (d) N. Gernigon, R. M. Al‐Zoubi
and D. G. Hall, J. Org. Chem., 2012, 77, 8386; (e) L. Gu, J. Lim,
J. L. Cheong and S. S. Lee, Chem. Commun., 2014, 50, 7017;
(f) T. Mohy El Dine, W. Erb, Y. Berhault, J. Rouden and J.
Blanchet, J. Org. Chem., 2015, 80, 4532; (g) E. K. W. Tam,
hours. A coherent explanation for this initiation step asserts
as the actual catalytic species (Scheme 1).12 Once formed,
can react with the added amine to give active intermediate
6
6
7
,
which gives amide
5 quickly. The formation of 7 should be the
rate‐determining step according to the kinetics studies.
Moreover, steric effect of 1c helped to suppress the formation
of inactive complexes 8 and 9.
In summary, 2,4‐bis(trifluoromethyl)phenylboronic acid 1c
Rita, L. Y. Liu and A. Chen, Eur. J. Org. Chem., 2015, 2015,
1100; (h) S. Fatemi, N. Gernigon and D. G. Hall, Green Chem.,
2015, 17, 4016.
serves as a highly effective catalyst for direct amidation under
mild conditions. A variety of amides including
‐dipeptides
4
(a) H. Noda, M. Furutachi, Y. Asada, M. Shibasaki and N.
can be successfully constructed through this catalysis.
Moreover, the in situ IR experiments proved that the ortho‐
Kumagai, Nature Chem. 2017, 9, 57; (b) Z. Liu, H. Noda, M.
Shibasaki and N. Kumagai, Org. Lett., 2018, 20, 612.
M. T. Sabatini, L. T. Boulton and T. D. Sheppard, Sci. Adv.
2017, 3:e1701028.
substituent of boronic acid
coordination of amines to the boron atom of 2:2 mixed
anhydride , thus accelerating the amidation.
1 plays a key role in preventing the
5
6
For borinic acid catalysts, see: (a) T. Mohy El Dine, J. Rouden
and J. Blanchet, Chem. Commun., 2015, 51, 16084; (b) T.
Mohy El Dine, D. Evans, J. Rouden and J. Blanchet, Chem.
Eur. J., 2016, 22, 5894. However, Whiting et al. recently
reported that borinic acids do not catalyze amidation
without prior protodeboronation to give boronic acids in
situ, which are active.7
6
This work was financially supported by JSPS KAKENHI Grant
Numbers JP15H05755 and JP15H05810 in Precisely Designed
Catalysts with Customized Scaffolding, and the Program for
Leading Graduate Schools: IGER Program (MEXT).
7
S. Arkhipenko, M. T. Sabatini, A. S. Batsanov, V. Karaluka, T.
D. Sheppard, H. S. Rzepa and A. Whiting, Chem, Sci., 2018, 9,
Conflicts of interest
1058.
8
9
S. Soundararajan, E. N. Duesler and H. Hageman, J. Acta
Crystallogr. C, 1993, 49, 690.
There are no conflicts to declare.
According to ref. 3d, it is noted that the catalytic activity of
1m with MS 3Å is much lower than with MS 4Å. In sharp
contrast, MS 3Å was much more effective than MS 4Å for the
Notes and references
1c‐catalyzed synthesis of ‐peptides.
1
For selected reviews, see: (a) I. Georgiou, G. Ilyashenko and
A. Whiting, Acc. Chem. Res., 2009, 42, 756; (b) K. Ishihara,
Tetrahedron, 2009, 65, 1085; (c) H. Charville, D. Jackson, G.
Hodges and A. Whiting, Chem. Commun., 2010, 46, 1813; (d)
10 Bortezomib is the first FDA‐approved proteasome inhibitor
drug for the treatment of multiple myeloma and mantle cell
lymphoma. (a) For a recent review of proteasome inhibitors,
see: L. Borissenko and M. Groll, Chem. Rev., 2007, 107, 687;
(b) M. A. Beenen, C. An and J. A. Ellman, J. Am. Chem. Soc.,
2008, 130, 6910.
11 (a) C. W. Gray, Jr. and T. A. Houston, J. Org. Chem. 2002, 67
5426; (b) T. Harada and T. Kusukawa, Synlett, 2007, 2007
1823.
E. Dimitrijevi´c and M. S. Taylor, ACS Catal., 2013, 3, 945; (e)
H. Zheng and D. G. Hall, Aldrichmica Acta, 2014, 47, 41; (f) K.
Ishihara, in Synthesis and Application of Organoboron
Compounds, Topics in Organometallic Chemistry, Vol. 49
(Eds.: E. Ferna´ndez and A. Whiting), Springer, Heidelberg,
2015, pp. 243; (g) R. M. de Figueiredo, J.‐S. Suppo and J.‐M.
Campagne, Chem. Rev., 2016, 116, 12029; (h) A. O. Porras
,
,
12 See details for screening of protective groups in ESI.
13 According to ref. 7, it was proposed that destabilizeation of
and D. G. Sanchez, J. Org. Chem., 2016, 81, 11548.
́
boroxines is a key effect of ortho‐group of
significant difference on the stability of boroxines was not
observed between 1b and 1c
1. However, the
2
For selected reports of boronic acid‐catalysed amide
condensations, see: (a) K. Ishihara, S. Ohara and H.
Yamamoto, J. Org. Chem., 1996, 61, 4196; (b) K. Ishihara, S.
Ohara and H. Yamamoto, Macromolecules, 2000, 33, 3511;
(c) K. Ishihara, S. Ohara and H. Yamamoto, Org. Synth., 2002,
79, 176; (d) T. Maki, K. Ishihara and H. Yamamoto, Synlett,
2004, 2004, 1355; (e) P. Tang, Org. Synth., 2005, 81, 262; (f)
.
14 T. Marcelli, Angew. Chem. Int. Ed., 2010, 49, 6840.
15 C. Wang, H.‐Z. Yu, Y. Fu and Q‐X. Guo, Org. Biomol. Chem.,
2013, 11, 2140.
16 See reference peaks of in situ IR in ESI.
17 See details of IRKE in ESI.
T. Maki, K. Ishihara and H. Yamamoto, Org. Lett., 2006, 8,
1431; (g) K. Arnold, B. Davies, R. L. Giles, C. Grosjean, G. E.
Smith and A. Whiting, Adv. Synth. Catal., 2006, 348, 813; (h)
4 | J. Name., 2012, 00, 1‐3
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