82. Boron hydride derivatives. Part III. Electrophilic substitution in pentaborane and decaborane

Rearrangements in the Nona‐ and Azanonaborane Clusters

“…The RNH 2 moiety exchanges its position from exo to endo as described in the literature [12,13]. This is possibly aided by a weakened bond between B 5 and B 4 .…”

Rearrangements in the nona-and azanonaborane clusters

“…The NMR results show clearly that one deuterium atom is lost (Table 1) while the positions of the other deuterium atoms could be identified unequivocally. Thus, the boron atoms B 3 , B 6 , and B 7 in B 9 cluster end up at the positions B 7 , B 4 , and B 5 in B 8 N, respectively (Fig. 2); B 2 in the B 9 cluster remains B 2 in the B 8 N cluster while B 1 of the B 9 cluster is lost during the conversion.…”

“…A variety of B-substituted B 10 H 14 derivatives are known [4][5][6]. We have prepared some of these compounds where R = Et, Br, and D, respectively.…”

“…With a diamond-square-diamond (DSD) rearrangement [14] Depending on the final stereochemistry of the product, the attack of the initial amine (and probably the second and third amine as well), might also take place on atom B 9 ( Fig. 3), which is equivalent to B 4 . With the resulting compounds being diastereomers, the attack might matter.…”

Chemistry of pentaborane(9)

“…200°, the major product is the 2-alkylpentaborane(9) derivative. 16 Yields are often less than 50%, and the product usually contains appreciable 1alkylpentaborane( 9) impurity. On the other hand, rearrangement of l-alkylpentaborane(9) to the corresponding 2 isomer is essentially quantitative in the presence of Lewis base catalysts such as 2,6dimethylpyridine or hexamethylenetetramine.14 •19 The reaction of BgHg with olefins at ca.…”