Compounds with Three‐Membered Rings Containing Boron

Three-membered ring systems containing heavier main group elements and almost every combination of elements can now be prepared. The isolobal analogy between C+ and B makes three-membered rings containing boron especially interesting for both theoreticians and synthetic chemists. With the synthesis of oxadiborirane 1 by Paetzold et al. (Angew. Chem. Int. Ed. Engl. 1992, 31, 1040) and boriranes 2 by Berndt et al. (see communication on p. 1384) the synthesis of a diborirane, namely a B2C three-membered ring, appears within reach. The carbon atom in such a molecule is postulated to have a planar bonding geometry. R = tBu and 2,3,5,6-Me4C6H, X = N(SiMe3)2, Cl, Me.