Synthesis of Fluoromethyl‐substituted Cyclopropanes by Electrophilic Cyclization of Homoallylic Boronate Intermediates

Abstract

The electrophilic cyclization via the boronate complex between various homoallylic boronates and Selectfluor® is reported. This reaction provides a fluoromethylated cyclopropane ring that was difficult to synthesize by previous methods. The use of phenyl lithium, which activates the homoallylic boronate, is important for the reaction. The intermediate boronate species in this reaction was observed through <sup>11</sup>B NMR experiments. We also demonstrate the synthesis of a building block including fluoromethyl‐substituted cyclopropane for a bioactive compound.