AUTHOR=Tan Jiashen , Zhu Weiqin , Xu Weiping , Jing Yaru , Ke Zhuofeng , Liu Yan , Maruoka Keiji 

TITLE=Hypervalent Iodine-Mediated Diastereoselective α-Acetoxylation of Cyclic Ketones

JOURNAL=Frontiers in Chemistry

VOLUME=8

YEAR=2020

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2020.00467

DOI=10.3389/fchem.2020.00467

ISSN=2296-2646

ABSTRACT=<p>A binary hybrid system comprising a hypervalent iodine(III) reagent and BF<sub>3</sub>•OEt<sub>2</sub> Lewis acid was found to be effective for the diastereoselective α-acetoxylation of cyclic ketones. In this hybrid system, BF<sub>3</sub>•OEt<sub>2</sub> 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<sub>N</sub>2 substitution mechanism via an α-<italic>C</italic>-bound hypervalent iodine intermediate. The diastereoselectivity of the reaction mainly originates from thermodynamic control.</p>