Synthesis of Cyclopropyl Pinacol Boronic Esters from Dibromo­cyclopropanes

Abstract

The synthesis of cyclopropyl pinacol boronic esters from dibromocyclopropanes via Matteson–Pasto rearrangement is reported. The method is readily scalable and shows limited levels of stereoinduction, with a selectivity that is in part complementary to that observed in existing stereoselective borylcyclopropanation strategies. The method can be used to rapidly access borylcyclopropanes as interesting building blocks for diversely functionalized cyclopropanes.

1,2‐Boronate Rearrangement: An Efficient Tool for the Opening, Functionalization and Formation of Strained Cycles

“…This approach has been recently revisited by the group of Neouchy, who published in 2022 the synthesis of stable cyclopropyl pinacol boronic esters 71 [32] . They demonstrated that the chelation of the lithium with an ether oxygen had unfortunately a limited effect on the reaction stereoselectivity (Scheme 15a), while the use of a fused 6‐membered ring 72 led to high level of diastereoselectivity (Scheme 15b).…”