10.1002/adsc.202000290
Advanced Synthesis & Catalysis
enantioselective transformations based on earth-
abundant transition metal complexes bearing salan
ligands.
[2] S. F. McCann, G. D. Annis, R. Shapiro, D. W.
Piotrowski, G. P. Lahm, J. K. Long, K. C. Lee, M. M.
Hughes, B. J. Myers, S. M. Griswold, B. M. Reeves, R.
W. March, P. L. Sharpe, P. Lowder, W. E. Barnette, K.
D. Wing, Pest Manage. Sci. 2001, 57, 153‒164.
Experimental Section
[3] a) P. Y. Toullec, C. Bonaccorsi, A. Mezzetti, A. Togni,
Proc. Natl. Acad. Sci. U. S. A. 2004, 101, 5810‒5814;
b) F. Yang, J. Zhao, X. Tang, G. Zhou, W. Song, Q.
Meng, Org. Lett. 2017, 19, 448‒451; c) T. Ishimaru, N.
Shibata, J. Nagai, S. Nakamura, T. Toru, S. Kanemasa,
J. Am. Chem. Soc. 2006, 128, 16488‒16489; d) A. M.
R. Smith, H. S. Rzepa, A. J. P. White, D. Billen, K. K.
Hii, J. Org. Chem. 2010, 75, 3085‒3096; e) D. S.
Reddy, N. Shibata, J. Nagai, S. Nakamura, T. Toru,
Angew. Chem. Int. Ed. 2009, 48, 803‒806; f) J. Li, G.
Chen, Z. Wang, R. Zhang, X. Zhang, K. Ding, Chem.
Sci. 2011, 2, 1141‒1144; g) A. M. R. Smith, D. Billen,
K. K. Hii, Chem. Commun. 2009, 3925‒3927; h) J.-J.
Jiang, J. Huang, D. Wang, M.-X. Zhao, F.-J. Wang, M.
Shi, Tetrahedron: Asymmetry 2010, 21, 794‒799; i) S.-
H. Cao, M. Shi, Tetrahedron: Asymmetry 2010, 21,
2675‒2680; j) X. Gu, Y. Zhang, Z.-J. Xu, C.-M. Che,
Chem. Commun. 2014, 50, 7870‒7873.
General Procedure for the Synthesis of Ligands
A Schlenk flask (100 mL) equipped with a reflux
condenser, was charged with appropriate diamine (1.0
mmol, 1.0 equiv.), 3-substituted-2-hydroxybenzaldehyde
(2.0 mmol, 2.0 equiv.) and absolute ethanol (60 mL). The
resulting mixture was heated to reflux under an argon
atmosphere overnight and monitored by TLC (petroleum
ether/ethyl acetate = 15/1). The reaction mixture was
cooled to room temperature before NaBH4 (3.0 mmol, 3.0
equiv.) was added in portions with an ice cooling bath. The
mixture was stirred for 3 h at room temperature, after
which the solvent was removed under vacuum and the
residue was quenched by addition of saturated aqueous
NH4Cl. The aqueous layer was extracted with CH2Cl2 (3 ×
15 mL), and the combined organic layers were washed
with H2O (2 × 20 mL), and brine (2 × 20 mL), then dried
over Na2SO4. The dried organic mixture was concentrated
under reduced pressure and the residue was recrystallized
with ethanol to give the aimed product.
General
Procedure
for
Enantioselective
α-
[4] a) M. R. Acocella, O. G. Mancheño, M. Bella, K. A.
Jørgensen, J. Org. Chem. 2004, 69, 8165‒8167; b) Y.
Wang, H. Yin, H. Qing, J. Zhao, Y. Wu, Q. Meng, Adv.
Synth. Catal. 2016, 358, 737‒745; c) H. Yao, M. Lian,
Z. Li, Y. Wang, Q. Meng, J. Org. Chem. 2012, 77,
9601‒9608; d) Y. Wang, Z. Zheng, M. Lian, H. Yin, J.
Zhao, Q. Meng, Z. Gao, Green Chem 2016, 18,
5493‒5499; e) Y. Wang, H. Yin, X. Tang, Y. Wu, Q.
Meng, Z. Gao, J. Org. Chem. 2016, 81, 7042‒7050; f)
Y. Wang, Q. Gao, Z. Liu, S. Bai, X. Tang, H. Yin, Q.
Meng, J. Org. Chem. 2018, 83, 2263‒2273.
Hydroxylation of β-Keto Esters
Under an argon atmosphere, to a dried Schlenk tube (10
mL) equipped with a magnetic stir bar was charged with
Zr(acac)4 (2.4 mg, 5.0 × 10-3 mmol, 5.0 mol%), L2c (3.5
mg, 5.5 × 10-3 mmol, 5.5 mol%) and toluene (2.0 mL). The
mixture was stirred at room temperature for 30 min. Then,
1a‒1r (0.1 mmol, 1.0 equiv.) and cumene hydroperoxide
(80% wt, 28.5 mg, 0.15 mmol, 1.5 equiv.) were added
sequentially. The resulting solution was stirred at room
temperature for 4 h. Afterwards, the solution of the crude
product was concentrated in vacuo and the residue was
purified by column chromatography on silica gel to afford
the product 2a‒2r. Enantiomeric excess was determined by
chiral HPLC analysis. The absolute configuration was
determined by comparison with the optical rotation or the
HPLC retention time of an authentic sample which has
been previously reported.
[5] a) L. Zou, B. Wang, H. Mu, H. Zhang, Y. Song, J. Qu,
Org. Lett. 2013, 15, 3106‒3109; b) X. Lin, S. Ruan, Q.
Yao, C. Yin, L. Lin, X. Feng, X. Liu, Org. Lett. 2016,
18, 3602‒3605.
[6] J. Novacek, J. A. Izzo, M. J. Vetticatt, M. Waser, Chem.
Eur. J. 2016, 22, 17339‒17344.
Acknowledgements
[7] M. Odagi, K. Furukori, T. Watanabe, K. Nagasawa,
We acknowledge financial support of this work from the National
Natural Science Foundation of China (21771087 to B.W and
21703080 to J.C), the NSF of Shandong Province
(ZR2017MB007 to B.W and ZR2017BB010 to J.C), Taishan
Scholar Program of Shandong Province (tsqn201812078 to B.W.),
the NRF of Korea through CRI (NRF-2012R1A3A2048842 to
W.N.).
Chem. Eur. J. 2013, 19, 16740‒16745.
[8] M. Lu, D. Zhu, Y. Lu, X. Zeng, B. Tan, Z. Xu, G.
Zhong, J. Am. Chem. Soc. 2009, 131, 4562‒4563.
[9] F. Yang, J. Zhao, X. Tang, Y. Wu, Z. Yu, Q. Meng,
Adv. Synth. Catal. 2019, 361, 1673‒1677.
[10] W. Ding, L.-Q. Lu, Q.-Q. Zhou, Y. Wei, J.-R. Chen,
References
W.-J. Xiao, J. Am. Chem. Soc. 2017, 139, 63‒66.
[11] T. P. Yoon, E. N. Jacobsen, Science, 2003, 299,
[1] a) G. Buechi, K. E. Matsumoto, H. Nishimura, J. Am.
Chem. Soc. 1971, 93, 3299‒3301; b) K. D. Wellington,
R. C. Cambie, P. S. Rutledge, P. R. Bergquist, J. Nat.
Prod. 2000, 63, 79‒85; c) M. Nakayama, Y. Fukuoka,
H. Nozaki, A. Matsuo, S. Hayashi, Chem. Lett. 1980, 9,
1243‒1246; d) J. Zhu, A. J. H. Klunder, B.
Zwanenburg, Tetrahedron Lett. 1994, 35, 2787‒2790;
e) J. Christoffers, T. Werner, W. Frey, A. Baro, Chem.
Eur. J. 2004, 10, 1042‒1045; f) J. Christoffers, A. Baro,
T. Werner. Adv. Synth. Catal. 2004, 346, 143‒151.
1691‒1693.
[12] K. Matsumoto, B. Saito, T. Katsuki, Chem. Commun.
2007, 3619‒3627.
[13] R. Lu, L. Cao, H. Guan, L. Liu, J. Am. Chem. Soc.
2019, 141, 6318‒6324.
[14] a) Y. Sawada, K. Matsumoto, S. Kondo, H. Watanabe,
T. Ozawa, K. Suzuki, B. Saito, T. Katsuki, Angew.
7
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