(2-Fluoroallyl)boration of Ketones with (2-Fluoroallyl)boronates

Maxim A Novikov; Angelina Yu Bobrova; Igor A Mezentsev; Michael G Medvedev; Yury V Tomilov

doi:10.1021/acs.joc.9b03445

(2-Fluoroallyl)boration of Ketones with (2-Fluoroallyl)boronates

J Org Chem. 2020 May 15;85(10):6295-6308. doi: 10.1021/acs.joc.9b03445. Epub 2020 May 5.

Authors

Maxim A Novikov¹, Angelina Yu Bobrova^{1

2}, Igor A Mezentsev^{1

2}, Michael G Medvedev¹, Yury V Tomilov¹

Affiliations

¹ N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky prosp., 119991 Moscow, Russian Federation.
² Higher Chemical College of the Russian Academy of Sciences, D. I. Mendeleev University of Chemical Technology of Russia, 9 Miusskaya pl., 125047 Moscow, Russian Federation.

PMID: 32309945
DOI: 10.1021/acs.joc.9b03445

Abstract

Efficient routes toward activation of gem-chlorofluorocyclopropane-derived (2-fluoroallyl)boronates for allylboration of various ketones including functionalized and low-reactive ones were developed. Increasing the boron electrophilicity by the transformation of a boronate moiety into a borinic ester with ⁿBuLi/trifluoroacetic anhydride (TFAA) makes (2-fluoroallyl)boration of acetyl arenes/hetarenes and aliphatic ketones possible with high diastereoselectivity. For low-reactive or sterically hindered ketones (e.g., benzophenone, adamantanone), "CuF"-based catalysts were developed: (NHC)CuF·HF and (NHC)CuOTf in the presence of an excess of KHF₂ (NHC = IPr, SIPr, IPr^Cl).