Copper-Catalyzed Regio- and Enantioselective Addition of Silicon Grignard Reagents to Alkenes Activated by Azaaryl Groups
Wenbin Mao
Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623 Berlin, Germany
These authors contributed equally to this work.
Search for more papers by this authorWeichao Xue
Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623 Berlin, Germany
These authors contributed equally to this work.
Search for more papers by this authorElisabeth Irran
Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623 Berlin, Germany
Search for more papers by this authorCorresponding Author
Prof. Dr. Martin Oestreich
Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623 Berlin, Germany
Search for more papers by this authorWenbin Mao
Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623 Berlin, Germany
These authors contributed equally to this work.
Search for more papers by this authorWeichao Xue
Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623 Berlin, Germany
These authors contributed equally to this work.
Search for more papers by this authorElisabeth Irran
Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623 Berlin, Germany
Search for more papers by this authorCorresponding Author
Prof. Dr. Martin Oestreich
Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623 Berlin, Germany
Search for more papers by this authorGraphical Abstract
New kid on the block: Silicon Grignard reagents can be used in a new enantioselective copper-catalyzed reaction. With the assistance of BF3⋅OEt2, a CuI-josiphos complex promotes the highly regioselective addition of silicon Grignard reagents to alkenyl-substituted heteroarenes (see scheme). The new method expands the scope of “conjugate addition” type reactions forming C(sp3)−Si bonds.
Abstract
A new application of silicon Grignard reagents in C(sp3)−Si bond formation is reported. With the aid of BF3⋅OEt2, these silicon nucleophiles add across alkenes activated by various azaaryl groups under copper catalysis. An enantioselective version employing benzoxazole-activated alkenes as substrates and a CuI-josiphos complex as catalyst has been developed, forming the C(sp3)−Si bond with good to high enantiomeric ratios (up to 97:3). The method expands the toolbox for “conjugate addition” type C(sp3)−Si bond formation.
Supporting Information
As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed and may be re-organized for online delivery, but are not copy-edited or typeset. Technical support issues arising from supporting information (other than missing files) should be addressed to the authors.
| Filename | Description |
|---|---|
| anie201905934-sup-0001-misc_information.pdf5.3 MB | Supplementary |
Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.
References
- 1
- 1aA. Hensel, M. Oestreich, Top. Organomet. Chem. 2016, 58, 135–167;
- 1bM. Sawamura, H. Ito in Copper-Catalyzed Asymmetric Synthesis (Eds.: ), Wiley-VCH, Weinheim, 2014, pp. 157–177;
10.1002/9783527664573.ch6 Google Scholar
- 1cE. Hartmann, D. J. Vyas, M. Oestreich, Chem. Commun. 2011, 47, 7917–7932.
- 2
- 2aC. Walter, G. Auer, M. Oestreich, Angew. Chem. Int. Ed. 2006, 45, 5675–5677; Angew. Chem. 2006, 118, 5803–5805;
- 2bC. Walter, M. Oestreich, Angew. Chem. Int. Ed. 2008, 47, 3818–3820; Angew. Chem. 2008, 120, 3878–3880;
- 2cC. Walter, R. Fröhlich, M. Oestreich, Tetrahedron 2009, 65, 5513–5520;
- 2dE. Hartmann, M. Oestreich, Angew. Chem. Int. Ed. 2010, 49, 6195–6198; Angew. Chem. 2010, 122, 6331–6334;
- 2eE. Hartmann, M. Oestreich, Org. Lett. 2012, 14, 2406–2409.
- 3
- 3aK.-s. Lee, A. H. Hoveyda, J. Am. Chem. Soc. 2010, 132, 2898–2900;
- 3bH. Y. Harb, K. D. Collins, J. V. Garcia Altur, S. Bowker, L. Campbell, D. J. Procter, Org. Lett. 2010, 12, 5446–5449;
- 3cK.-s. Lee, H. Wu, F. Haeffner, A. H. Hoveyda, Organometallics 2012, 31, 7823–7826;
- 3dV. Pace, J. P. Rae, H. Y. Harb, D. J. Procter, Chem. Commun. 2013, 49, 5150–5152;
- 3eV. Pace, J. P. Rae, D. J. Procter, Org. Lett. 2014, 16, 476–479; see also:
- 3fI. Ibrahem, S. Santoro, F. Himo, A. Córdova, Adv. Synth. Catal. 2011, 353, 245–252 (iminium-ion catalysis);
- 3gT. Kitanosono, L. Zhu, C. Liu, P. Xu, S. Kobayashi, J. Am. Chem. Soc. 2015, 137, 15422–15425 (CuII-bipyridine complex).
- 4J. M. O'Brien, A. H. Hoveyda, J. Am. Chem. Soc. 2011, 133, 7712–7715.
- 5
- 5aL. B. Delvos, M. Oestreich in Science of Synthesis Knowledge Update 2017/1 (Ed.: ), Thieme, Stuttgart, 2017, pp. 65–176;
- 5bM. Oestreich, E. Hartmann, M. Mewald, Chem. Rev. 2013, 113, 402–441; for the preparation of Si-B reagents, see:
- 5cM. Suginome, T. Matsuda, Y. Ito, Organometallics 2000, 19, 4647–4649.
- 6For an authoritative perspective, see: D. Best, H. W. Lam, J. Org. Chem. 2014, 79, 831–845.
- 7A. Hensel, Master Thesis, Westfälische Wilhelms-Universität Münster (Germany), 2012.
- 8M. Lautens, A. Roy, K. Fukuoka, K. Fagnou, B. Martín-Matute, J. Am. Chem. Soc. 2001, 123, 5358–5359.
- 9
- 9aG. Pattison, G. Piraux, H. W. Lam, J. Am. Chem. Soc. 2010, 132, 14373–14375;
- 9bI. D. Roy, A. R. Burns, G. Pattison, B. Michel, A. J. Parker, H. W. Lam, Chem. Commun. 2014, 50, 2865–2868.
- 10See also: R. Amengual, V. Michelet, J.-P. Genêt, Tetrahedron Lett. 2002, 43, 5905–5908.
- 11
- 11aR. P. Jumde, F. Lanza, M. J. Veenstra, S. R. Harutyunyan, Science 2016, 352, 433–437;
- 11bR. P. Jumde, F. Lanza, T. Pellegrini, S. R. Harutyunyan, Nat. Commun. 2017, 8, 2058.
- 12
- 12aW. Xue, R. Shishido, M. Oestreich, Angew. Chem. Int. Ed. 2018, 57, 12141–12145; Angew. Chem. 2018, 130, 12318–12322; these silicon Grignard reagents have already been applied to allylic substitution and ring opening of aziridines, respectively:
- 12bW. Xue, M. Oestreich, Synthesis 2019, 51, 233–239;
- 12cH. Yi, M. Oestreich, Chem. Eur. J. 2019, 25, 6505–6507.
- 13Meng and co-workers recently reported a broadly applicable borylation using B2(pin)2 as the boron pronucleophile and a CuI-1,2-bis[(2R,5R)-2,5-diphenylphospholan-1-yl]ethane [(R,R)-Ph-BPE] complex as catalyst. Subsequent oxidation established a hydroxy group β to the heteroaryl group. L. Wen, Z. Yue, H. Zhang, Q. Chong, F. Meng, Org. Lett. 2017, 19, 6610–6613. Our approach with silicon as a placeholder for oxygen is related to this work (cf. Ref. [1c]).
- 14According to Harutyunyan, Lewis acid additives are thought to further activate the azaaryl group (see Ref. [11]).
- 15A. Weickgenannt, M. Oestreich, Chem. Eur. J. 2010, 16, 402–412, and references therein.
- 16The role of magnesium cations in related copper-catalyzed conjugate addition reactions was studied by Minnaard, Feringa, and co-workers, and their model has been adopted by Harutyunyan (Ref. [11a]). S. R. Harutyunyan, F. López, W. R. Browne, A. Correa, D. Peña, R. Badorrey, A. Meetsma, A. J. Minnaard, B. L. Feringa, J. Am. Chem. Soc. 2006, 128, 9103–9118.
- 17Aside from benzoxazole-containing 1, all other alkenyl-substituted azaarenes 3–6 with the exception of 2 did not react (<5 % yield). Acceptor 2 activated by a benzothiazole furnished 29 % yield but with low enantioinduction (e.r. 60:40).
- 18T. Robert, J. Velder, H. G. Schmalz, Angew. Chem. Int. Ed. 2008, 47, 7718–7721; Angew. Chem. 2008, 120, 7832–7835.
- 19CCDC 1913584 and 1913585 ([(S)-8 d] and [(S)-16 a]) contain the supplementary crystallographic data for this paper. These data can be obtained free of charge from The Cambridge Crystallographic Data Centre.
- 20R. Shintani, K. Okamoto, T. Hayashi, Org. Lett. 2005, 7, 4757–4759.
- 21L. Rupnicki, A. Saxena, H. W. Lam, J. Am. Chem. Soc. 2009, 131, 10386–10387.
Citing Literature
