Electrophilic activation of difunctional aminoboranes: B-N coupling versus intramolecular Cl/Me exchange.

Treatment of an N -silyl- B -chloro-aminoborane with substoichio-metric quantities of Me 3 SiOTf afforded B-N coupling, whereas activation with 5 mol% of Ag[Al{OC(CF 3 ) 3 } 4 ] led to Cl/Me exchange between the boron and the silicon center. Combined experimental and computational studies of the latter process support a chain reaction that is initiated by nucleation-limited chloride abstraction.