Blue Tetrakis(diisopropylamino)‐cyclo‐tetraborane and Yellow Tetrakis(tetramethylpiperidino)tetrabora‐tetrahedrane

The colored boranescloso-1 and cyclo-2 are obtained upon dehalogenation of sterically hindered diaminodichlorodiborane(4) 3. The TMP groups of 1 cause the formation of a tetrahedrane, whereas in 2 the diisopropylamino substituents stabilize the bent four-membered ring. TMP=2,2,6,6-tetramethylpiperidino.