Hypervalent Iodine-Mediated Diastereoselective α-Acetoxylation of Cyclic Ketones

Jiashen Tan; Weiqin Zhu; Weiping Xu; Yaru Jing; Zhuofeng Ke; Yan Liu; Keiji Maruoka

doi:10.3389/fchem.2020.00467

Hypervalent Iodine-Mediated Diastereoselective α-Acetoxylation of Cyclic Ketones

Front Chem. 2020 Jul 10:8:467. doi: 10.3389/fchem.2020.00467. eCollection 2020.

Authors

Jiashen Tan¹, Weiqin Zhu¹, Weiping Xu¹, Yaru Jing^{1

2}, Zhuofeng Ke², Yan Liu¹, Keiji Maruoka^{1

3}

Affiliations

¹ School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou, China.
² PCFM Lab, School of Materials Science and Engineering, Sun Yat-sen University, Guangzhou, China.
³ Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan.

Abstract

A binary hybrid system comprising a hypervalent iodine(III) reagent and BF₃•OEt₂ Lewis acid was found to be effective for the diastereoselective α-acetoxylation of cyclic ketones. In this hybrid system, BF₃•OEt₂ Lewis acid allowed the activation of the hypervalent iodine(III) reagent and cyclic ketones for smooth α-acetoxylation reaction, achieving high diastereoselectivity. This hypervalent iodine-mediated α-acetoxylation of the cyclic ketone reaction plausibly undergoes an S_N2 substitution mechanism via an α-C-bound hypervalent iodine intermediate. The diastereoselectivity of the reaction mainly originates from thermodynamic control.

Keywords: cyclic ketones; density functional theory; diastereoselectivity; hypervalent iodine (III) reagent; α-acetoxylation.