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ChemComm
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COMMUNICATION
Conclusions
Journal Name
13 Analogously, Ashley’s group prepared, characterized and
reacted [tBu3PSiiPr3][B(C6F5)4] with H2 to yield
DOI: 10.1039/C6CC07819B
[tBu3PH][B(C6F5)4] and HSiiPr3, a neutral hydride. However,
no catalysis was performed with this system, see: T. J.
Herrington, B. J. Ward, L. R. Doyle, J. McDermott, A. J. P.
White, P. A. Hunt, A. E. Ashley, Chem. Commun., 2014, 50,
12753-12756.
We have developed the first B(C6F5)3-catalyzed transfer 1,4-
hydrostannylation of benzylidene derivatives of 1,3-
dimethylbarbituric acid by employing iPr-tricarbastannatrane.
The products were obtained in good to excellent yields,
following tin enolate hydrolysis with SiO2. A competing
carbostannylation reaction delivering an isopropyl group from
iPr-tricarbastannatrane was also observed. The reaction
mechanism was investigated by 1H, 2H, 11B, 13C, and 119Sn NMR,
mass spectrometry, and labelling experiments. Deuterium-
labelling experiments using iPr-tricarbastannatrane-d6
demonstrated that β-hydride transfer to B(C6F5)3 generated
14 (a) J. M. Blackwell, D. J. Morrison, W. E. Piers, Tetrahedron,
2002, 58, 8247-8254; (b) S. Chandrasekhar, G.
Chandrashekar, M. S. Reddy, P. Srihari, Org. Biomol. Chem.,
2006, 4, 1650-1652; (c) S. Rendler, M. Oestreich, Angew.
Chem., Int. Ed., 2008, 47, 5997-6000.
15 (a) A. Simonneau, M. Oestreich, Angew. Chem., Int. Ed.,
2013, 52, 11905-11907; For reviews on transfer
hydrosilylation, see: (b) M. Oestreich, J. Hermeke, J. Mohr,
Chem. Soc. Rev., 2015, 44, 2202-2220; (c) M. Oestreich,
Angew. Chem., Int. Ed., 2016, 55, 494-499.
16 (a) J. B. Lambert, B. Kuhlmann, J. Chem. Soc, Chem.
Commun., 1992, 931-932; (b) J. B. Lambert, Y. Zhao, S. M.
Zhang, J. Phys. Chem., 2001, 14, 370-379.
17 V. Gevorgyan, J.-X. Liu, Y. Yamamoto, Chem. Commun., 1998,
37-38.
[N(CH2CH2CH2)3Sn][DB(C6F5)3],
which
could
reversibly
hydrostannylate α,β-unsaturated carbonyls. Future work to
expand the scope of this reaction, and to further explore the
reactivity of tricarbastannatrane derivatives in catalysis is in
progress.
This work was supported by the Natural Sciences and
Engineering Research Council of Canada (NSERC), and the
University of Waterloo. C. I. is indebted to NSERC for a USRA
scholarship.
18 M. S. Oderinde, M. G. Organ, Angew. Chem., Int. Ed., 2012,
51, 9834-9837.
19 A. Kavoosi, E. Fillion, Angew. Chem., Int. Ed., 2015, 54, 5488-
5492.
20 For reviews, see: (a) A. Tzschach, K. Jurkschat, Pure Appl.
Chem., 1986, 58, 639-646; (b) N. Srivastav, R. Singh, V. Kaur,
RSC Adv., 2015, 5, 62202-62213.
Notes and references
21 Examples of alkyl-tricarbastannatranes in catalytic reactions,
see: (a) E. Vedejs, A. R. Haight, W. O. Moss, J. Am. Chem.
Soc., 1992, 114, 6556–6558; (b) M. S. Jensen, C. Yang, Y.
Hsiao, N. Rivera, K. M. Wells, J. Y. L. Chung, N. Yasuda, D. L.
Hughes, P. J. Reider, Org. Lett., 2000, 2, 1081-1084; (c) H. L.
Sebahar, K. Yoshida, L. S. Hegedus, J. Org. Chem., 2002, 67,
3788-3795; (d) E. Fillion, N. J. Taylor, J. Am. Chem. Soc., 2003,
125, 12700-12701; (e) N. Theddu, E. Vedejs, J. Org. Chem.,
2013, 78, 5061-5066; (f) L. Li, L.; C.-Y. Wang, R. Huang, M. R.
Biscoe, Nat. Chem., 2013, 5, 607-612.
22 E. Fillion, S. Carret, L. G. Mercier, V. É. Trépanier, Org. Lett.,
2008, 10, 437-440.
23 A mechanism that proceeds via a 1,4-hydroboration
reaction, followed by transmetallation from B(C6F5)3-enolate
to N(CH2CH2CH2)Sn-enolate cannot be ruled out. The
B(C6F5)3-enolate species was not observed.
24 The exact structure of 10 hasn’t been determined; the
tricarbastannatrane cation could be bound to the urea
moiety.
25 No evidence is available to either support a catalyzed or an
uncatalyzed 1,4-carbostannylation reaction.
26 P. Simidzija, M. J. Lecours, R. A. Marta, V. Steinmetz, T. B.
McMahon, E. Fillion, W. S. Hopkins, Inorg. Chem., 2016, 55,
9579-9585.
1
(a) G. C. Welch, D. W. Stephan, J. Am. Chem. Soc., 2007, 129,
1880-1881; For reviews on FLPs, see: (b) D. W. Stephan, J.
Am. Chem. Soc., 2015, 137, 10018-10032; (c) D. W. Stephan,
G. Erker, Angew. Chem., Int. Ed., 2015, 54, 6400-6441.
P. Spies, S. Schwendemann, S. Lange, G. Kehr, R. Fröhlich, G.
Erker, Angew. Chem., Int. Ed., 2008, 47, 7543-7546.
H. Wang; R. Fröhlich, G. Kehr, G. Erker, Chem. Commun.,
2008, 5966-5968.
2
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(a) L. Greb., P. Oña-Burgos, B. Schirmer, S. Grimme, D. W.
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Org. Biomol. Chem., 2012, 10, 5740-5746; (d) J. Paradies,
Synlett, 2013, 777-780; (e) J. Paradies, Angew. Chem., Int.
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5
Alternate metal-free HB(C6F5)2-catalyzed olefin
hydrogenation, see: Y. Wang, W. Chen, Z. Lu, Z. H. Li, H.
Wang, Angew. Chem., Int. Ed., 2013, 52, 7496-7499.
Hydrogenation of vinylferrocene, see: X. Wang, G. Kehr, C. G.
Daniliuc, G. Erker, J. Am. Chem. Soc., 2014, 136, 3293-3203.
L. Greb, C.-G.Daniliuc, K. Bergander, J. Paradies, Angew.
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(a) G. Erös, H. Mehdi, I. Pápai, T. A. Rokob, P. Király, G.
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Király, G. Tárkányi, T. Soós, Chem. Eur. J., 2012, 18, 574-585;
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Stephan, G. Erker, Organometallics, 2012, 31, 5638-5649.
B. Inés, D. Palomas, S. Holle, S. Steinberg, J. A. Nicasio, M.
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27 The by-product, Ph3CMe was not removed.
28 In this transformation, 5% of starting material 6a was
recovered.
29 No evidence supports the formation of N(CH2CH2CH2)3SnH.
9
10 T. vom Stein, M. Peréz, R. Dobrovetsky, D. Winkelhaus, C. B.
Caputo, D. W. Stephan, Angew. Chem., Int. Ed., 2015, 54,
10178-10182.
11 (a) I. Chatterjee, M. Oestreich, Angew. Chem., Int. Ed., 2015,
54, 1965-1968; (b) I. Chatterjee, Z.-W. Qu, S. Grimme, M.
Oestreich, Angew. Chem., Int. Ed., 2015, 54, 12158-12162.
12 L. Greb, P. Oña-Burgos, A. Kubas, F. C. Falk, F. Breher, K. Fink,
J. Paradies, Dalton Trans., 2012, 41, 9056-9060.
4 | J. Name., 2012, 00, 1-3
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