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Synfacts 2011(2): 0223-0223  
DOI: 10.1055/s-0030-1259374
Polymer-Supported Synthesis
© Georg Thieme Verlag Stuttgart ˙ New York

Asymmetric Addition of Diethyl Zinc to Benzaldehydes with Ti(Oi-Pr)4 and NS(a)

Contributor(s): Yasuhiro Uozumi, Go Hamasaka
X. Liu, P. Wang, L. Zhang, J. Yang, C. Li*, Q. Yang*
Dalian Institute of Chemical Physics, Graduate School of the Chinese Academy of Sciences, Beijing, China
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Publication History

Publication Date:
19 January 2011 (online)

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Significance

Chiral mesoporous organosilica nanospheres [NS(a)] were prepared by the reaction of BSBINOL with TEOS in the presence of cetyltrimethylammonium bromide (CTAB) followed by aging at 80 ˚C for 48 hours (eq. 1). NS(a) were characterized by SEM, TEM, XRD, N2 adsorption, ¹³C CP/MAS NMR and ²9Si MAS NMR spectroscopy and elemental analyses. The asymmetric addition of diethyl zinc to benzaldehydes 1 readily proceeded in the presence Ti(Oi-Pr)4 and NS(a) to give the corresponding secondary alcohols 2 in 72-99% conversion with 71-94% ee (8 examples, eq. 2).