Reactions of 1,1- and 1,2-bis-boranes with a protic diamine and hydrazine.

The reactions of 1,1- and 1,2-bis-boranes, PhCHCH(B(CF))1 and MeSiCH(B(CF))CHB(CF)2, with -phenylenediamine and hydrazine are reported. The coordination of -phenylenediamine gives the expected adducts, PhCHCH(B(CF)(HN))CH4 and MeSiCH(B(CF))CHB(CF)((HN)CH) 6. Under thermal duress, 4 undergoes retrohydroboration, resulting in the reaction of the diamine with HB(CF) to give (CF)B(NH)(NH)CH5. In contrast, 6 undergoes protolytic loss of CFH, affording MeSiCH(B(CF))CH(B(CF)(NH)(NH)CH) 7. In a related fashion, the bis-boranes react with hydrazine. In the case of bis-borane 1, the isolated adduct PhCHCH(B(CF)(NH))·THF 8 can be deprotonated to give species 9. In contrast, the reaction of 2 proceeds with rapid protonolysis, leading to the formation of MeSiCH(B(CF))CHB(CF)(NH)·THF 10. This study illustrates both the reaction pathways accessible from the adducts of bis-boranes and the impact of coordination to boron on the acidity of NH groups.