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The first catalytic asymmetric addition of diethylzinc to aldehyde promoted by chiral thiourea |
Zhi Guo Qiao, Tian Hua Shen, Zhen Fang Fu, Jun Qi Li, Hong Wang, Qing Bao Song |
The State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, College of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310032, China |
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Abstract A series of C2-symmetric and asymmetric chiral thiourea derivatives were synthesized from commercial L-phenylalanine. All of the new compounds have been fully characterized by IR, 1H NMR, 13C NMR, MS spectra and elemental analyses. The chiral thioureas were used as chiral ligands in the catalytic enantioselective ethylation of aldehydes with diethylzinc, the corresponding sec-alcohols were gained with excellent enantioselectivities (up to 87.1% ee) and high yields (up to 76.7%) after the conditions were optimized.
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Received: 01 April 2011
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Fund:Open-Ended Fund of the State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, Zhejiang University of Technology is gratefully acknowledged. |
Corresponding Authors:
Qing Bao Song,E-mail address:qbsong@zjut.edu.cn
E-mail: qbsong@zjut.edu.cn
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