Linear ‐ and Cyclo ‐Hexa(amino)hexaboranes: New Routes to Synthesis of B 6 Chain and B 6 Ring

In this work, a linear‐ hexaborane(8) B 6 (NMe 2 ) 6 (CH 2 SiMe 3 ) 2 was synthesized using a new method. By replacing one chlorine atom of Cl 2 B 3 (NMe 2 ) 3 with CH 2 SiMe 3 group, compound ClB 3 (NMe 2 ) 3 CH 2 SiMe 3 was prepared. Reductive dehalogenative coupling of ClB 3 (NMe 2 ) 3 CH 2 SiMe 3 led to linear‐ hexaborane(8). Moreover, the six‐membered boron ring, cyclo ‐hexaborane B 6 (NEt 2 ) 6 was synthesized by reductive dehalogenation of Br 2 BNEt 2 . The first linear ‐hexaborane(8) and cyclo ‐hexaborane B6(NEt 2 ) 6 crystal structures were fully characterized by X‐ray structural analysis and 11 B, 1 H, and 13 C NMR spectroscopy. While the B 1 ⋅⋅⋅B 6 chain in linear‐ hexaborane(8) is strongly twisted at all B−B bonds, the B 6 ring cyclo ‐hexaborane B 6 (NEt 2 ) 6 has a chair conformation similar to cyclohexane.