Formation of a Hybrid 1‐Bora‐3‐boratabenzene Heteroarene Anion Derivative

Abstract

AbstractThe B(C6F5)2‐substituted borole 2⋅SMe2 was obtained from the phenyl bis(trimethylsilylethynyl) borane SMe2 adduct (1⋅SMe2) by a synthetic sequence containing a rare 1,1‐hydroboration reaction. Subsequent thermolysis at 50 °C converted it to the bicyclic borenium/borate zwitterion 3⋅SMe2. Photolysis of 3⋅SMe2 gave the diboracyclohexadiene derivative 4⋅SMe2, which after ligand exchange with N,N‐dimesitylimidazolylidene and deprotonation gave the 1‐bora‐3‐boratabenzene anion derivative as its potassium salt 6. Some unique follow‐up reactions of the unsaturated diboron containing six‐membered heterocycles were investigated.