Organic Letters
Letter
(7) For a recent example of a noncatalytic hydrohalogenation of
ynones and ynamides, see: Zeng, X.; Lu, Z.; Liu, S.; Hammond, G. B.;
Xu, B. J. Org. Chem. 2017, 82, 13179−13187.
ASSOCIATED CONTENT
* Supporting Information
The Supporting Information is available free of charge on the
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S
(8) For a rare example of an Ir-catalyzed hydroiodination of terminal
alkynes, see: Ez-Zoubir, M.; Brown, J. A.; Ratovelomanana-Vidal, V.;
Michelet, V. J. Organomet. Chem. 2011, 696, 433−441.
Detailed starting material synthesis, general procedures,
characterization data, and NMR spectra for all
(9) (a) Uehling, M. R.; Rucker, R. P.; Lalic, G. J. Am. Chem. Soc. 2014,
136, 8799−8803. This report also contains a single example of a
hydrobromination of internal alkynes. For a theoretical investigation of
this transformation, see: (b) Deng, X.; Dang, Y.; Wang, Z.-X.; Wang, X.
Organometallics 2016, 35, 1923−1930.
Spectra for synthetic intermediates (PDF)
(10) For catalytic alkyne semihydrogenations, see, for example:
(a) Pape, F.; Thiel, N. O.; Teichert, J. F. Chem. - Eur. J. 2015, 21,
15934−15938. (b) Thiel, N. O.; Teichert, J. F. Org. Biomol. Chem.
2016, 14, 10660−10666.
Accession Codes
CCDC 1811522 contains the supplementary crystallographic
data for this paper. These data can be obtained free of charge via
Crystallographic Data Centre, 12 Union Road, Cambridge
CB2 1EZ, UK; fax: +44 1223 336033.
(11) For catalytic alkyne transfer hydrogenations with ammonia
́
borane, see: Korytiakova, E.; Thiel, N. O.; Pape, F.; Teichert, J. F. Chem.
Commun. 2017, 53, 732−735.
(12) For related H2-mediated reductive couplings, see: (a) Hassan, A.;
Krische, M. Org. Process Res. Dev. 2011, 15, 1236−1242. (b) Bower, J.
F.; Kim, I. S.; Patman, R. L.; Krische, M. J. Angew. Chem., Int. Ed. 2009,
48, 34−46.
AUTHOR INFORMATION
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Corresponding Author
ORCID
(13) For characterization of vinylcopper(I)/NHC compounds, see:
Mankad, N. P.; Laitar, D. S.; Sadighi, J. P. Organometallics 2004, 23,
3369−3371.
(14) For use of vinylcopper intermediates in catalysis, see, for
example: (a) Fujihara, T.; Xu, T.; Semba, K.; Terao, J.; Tsuji, Y. Angew.
Chem., Int. Ed. 2011, 50, 523−527. (b) Miki, Y.; Hirano, K.; Satoh, T.;
Miura, M. Angew. Chem., Int. Ed. 2013, 52, 10830−10834. (c) Uehling,
M. R.; Suess, A. M.; Lalic, G. J. Am. Chem. Soc. 2015, 137, 1424−1427.
(d) Sidera, M.; Fletcher, S. P. Chem. Commun. 2015, 51, 5044−5047.
(e) Shi, S.-L.; Wong, Z. L.; Buchwald, S. L. Nature 2016, 532, 353−356.
(15) An exception to this is the syn hydrochlorination of internal
alkynes given in ref 5.
Notes
The authors declare no competing financial interest.
ACKNOWLEDGMENTS
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This work was supported by the Fonds der Chemischen
Industrie (Liebig-Stipendium for J.F.T.), the German Research
Council (DFG, Emmy Noether Fellowship to J.F.T.), and the
Boehringer Ingelheim Stiftung (Exploration Grant to J.F.T.).
We thank Dr. Sebastian Kemper (NMR analysis), Dr. Elisabeth
Irran (elucidation of the crystal structure), Sebastian Mohle
(initial experiments), and Prof. Dr. Martin Oestreich (all TU
Berlin) for generous support.
(16) For a review on copper/NHC catalysts, see: Lazreg, F.; Cazin, C.
S. J. In N-Heterocyclic Carbenes: Effective Tools for Organometallic
Synthesis; Nolan, S. P.. Ed.; Wiley-VCH: Weinheim, 2014; pp 199−242.
(17) Presumably, a copper(I) hydroxide complex is formed in situ:
Fortman, G. C.; Slawin, A. M. Z.; Nolan, S. P. Organometallics 2010, 29,
3966−3972.
̈
(18) For the use of 9 as electrophilic brominating agent, see, for
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Chem., Int. Ed. 2002, 41, 351−352. (b) Soderman, S. C.; Schwan, A. L. J.
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