Borane aminopyridine adduct

Borane (BH3) adducts of some nitrogen heterocyclic bases e.g. quinoline, aminopyridines) have been prepared. Halogenoboranes form boronium salts with such heterocycles, and some containing two different bases attached to a single boron atom, of the type (R -pyridine)(R -pyridine)aBH + 2I, have been identified. The syntheses and molecular structure determinations of complexes of phosphoranes with borane have been reported. The molecular structure of MejP.BCls has been determined by gas electron diffraction. ... 

The BH3 adduct of 2-aminopyridine seems to be very stable to internal hydroboration and polymerisation compared to borane pyridine. We attribute the extra stability to hydride-proton interactions these together with those of fluorine-proton were reported for other amine borane compounds16 (Figure 5). The MM models for the two boron complexes shown in Figure 6, present atomic distances... 

The reaction of N-BH3 adducts of 2-aminopyridine or its monosilylated derivative with an excess of borane afforded a new product, its nB NMR spectrum shows a triplet assigned to an NBH2 group N-coordinated, which could be explained by the formation of a dimer, such structure was supported by calculations (Figures 11-12), similar dimer has been reported17 18 (Figure 13). 

A similar reaction performed with P(NMe2)3 and 2-aminopyridine gives trisaminophosphorus compound. Borane addition gives the corresponding phosphorus and pyridinic adducts (Figure 15). 

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See also in sourсe #XX -- [ ]

See also in sourсe #XX -- [ ]

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