Boron diamide derivatives containing N-N and N-P molecular fragments.

The cationic and neutral boron-diamide precursors are employed to target the inclusion of N and N-P molecular fragments. The species (HCN(Dipp))BNH5, and (HCN(Dipp))BNH6 were prepared. While efforts to oxidize with [NO] gave mixtures of products, reactions with NH gave the salts [(HCN(Dipp))B(NHNH)][OSCF] 7 [(HCN(Dipp))B(NHNH)][OSCF] 8.

The Non-Ancillary Nature of Trimethylsilylamide Substituents in Boranes and Borinium Cations.

The known boranes (R(Me Si)N) BF (R=Me Si 1, tBu 2, C F 3, o-tol 4, Mes 5, Dipp 6) and borinium salts (R(Me Si)N) B][B(C F ) ] (R=Me Si 7, tBu 8) are prepared and fully characterized. Compound 7 is shown to react with phosphines to generate [R PSiMe ] and [R PH] (R=Me, tBu). Efforts to generate related borinium cations via fluoride abstraction from (R(Me Si)N) BF (R=C F 3, o-tol 4, Mes 5) gave complex mixtures suggesting multiple reaction pathways.

Hydroboration without a B-H bond: reactions of the borinium cation [(iPrN)B] with alkyne, nitrile, ketone and diazomethane.

The borinium cation [(iPr2N)2B]+ (1+) is shown to react with PhCCH, PhCN, Ph2CO, and Ph2CN2 to effect a net hydroboration, affording borenium complexes of the form [(iPr2N)B(iPrN[double bond, length as m-dash]CMe2)(L)][B(C6F5)4] (L = CH[double bond, length as m-dash]CHPh 2, N[double bond, length as m-dash]CHPh 3, OCHPh24, NHNCPh25). The nature and reaction of 1+ with PhCCH was probed computationally and the reduction of these unsaturates is shown to occur via hydride transfer from an isopropyl group to the alkyne, thus effecting hydroboration without a B-H bond.