Compounds with Planar Tetracoordinate Boron Atoms: Anti van't Hoff/Le Bel Geometries without Metal Centers

Electropositive elements are prerequisites for the formation of anti van't Hoff/Le Bel geometries, as evident in compounds 1, which contain planar tetracoordinate boron atoms in the CB2H framework. These compounds extend the range of molecules of this structural type to include those without metal atoms. R = CH(SiMe3)2, R′ = 2,3,5,6-Me4C6H.