Beiträge zur Chemie des Bors, 148. Diamidobor(1+)-Kationen aus Bis(amino)borhalogeniden durch Halogenid-Abspaltung/ Contributions to the Chemistry of Boron, 148.Diamidobor(1+) Cations from Bis(amino)borhalogenides by Halide Abstraction

Bis(amido)boron(1 + ) cations can be generated from bis(amino)-boron halides and an appropriate halide acceptor. The ease of formation of the diethylamido-2.2.6.6-tetramethylpiperidinoboron-( 1 + ) cation 5 from diethylamino-tetramethylpiperidino-boron halides has been studied and found to increase with decreasing strenght of the boron halogen bond. In the case of bis(2.2.6.6- tetramethyl-piperidino)boron fluoride AlCl3, BCl3, BBr3 and even BF3 give access to salts of the bis(tetramethylpiperidino)boron-(1+ ) cation. The tetrabromoborate salt 7c reacts with Ag-triflate to yield the corresponding tetratriflatoborate 7g. Similarly. bis(tetramethylpiperidino)boron chloride 8 , obtained from the tetrachloroborate 7b in boiling pyridine, readily gives bis(tetramethylpiperidino) boron(1 + )-tetrachlorometalates. Bis(tetramethylpiperidino)boron(1 + )-triflate is formed by reaction of 8 with AgOSO2CF3.