Boron azides

Boron azide diiodide, 0148 Boron triazide, 0153 Diazidodichlorosilane, 4092 Diazidodimethylsilane, 0918... 

The synthesis of the amino alcohol (5S,6S)-6-amino-5-decanol begins with reaction of the 1-chloropentylboronic ester (Section 1.1.2.1.3.1.) with sodium azide under phase-transfer conditions to form the a-azido boronic ester, which yields the a-chloro- -azidoalkyl boronic ester (1) [yield 92 % 95 % de] with (dichloromethyl)lithium under the usual conditions. The reaction of 1 with butylmagnesium chloride is unusual in that it requires zinc chloride in order to accomplish the replacement of chlorine by butyl to form /J-azidoalkyl boronic ester 2 without boron-azide /1-elimination. Standard peroxidic deboronation and reduction of the azide complete the synthesis15. 

The expl compdLithium Borazide, LiB(Ng)4, is described under Boron Azide, Vol l,p A525-L... 

Boron Azide A525-L Boron Carbide. See under Acetylides and Carbides A7I-L Boron Triazide A525-L British Ammonals. See under Ammonals A289, A290 A291-R... 

In azido chemistry related to that described above,24 Klapotke et al. have prepared and characterized bis-(pentafluorophenyl)boron azide by treatment of C1B(C6F5)2 with TMSN3.79 The compound is monomeric in solution (nB NMR = 43.9), but crystallizes as a x-N3 dimer, a unique nuclearity for boron azides. The pyridine adduct was also prepared and the compound is an intermediate in the synthesis of various azidoborates.80... 

Unsymmetrically substituted tetra- and penta-n-butyl borazines are obtained by thermal decomposition of dibutylazidoborane 100> with the elimination of butene. Because of the hazards of handling boron azides, this method cannot be recommended. 

In covalent azides, the pseudohalogen azide RN3 has an angular structure as in HN3. Triazidoborazine [H3N3B3(N3)3] and other boron azides, for example, salts of the tetraazidoborate ion B(N3 (4 have been considered as boron nitride precursors (see Boron-Nitrogen Compounds). The M(Ns)3 azido complexes of the other group 13 elements (Al, Ga, In, Tl) and their M(N3)4 tetraazido anions are all known. They and their derivatives are also used as precursors for the nitrides. 

These compounds contain other ligands besides the azide group principal types of the class are basic azides and azide halides. The former are obtained by hydrolysis when preparing the III A through VIII metal azides in aqueous media hence, the stoichiometry of these products fluctuates with experimental circumstances. Nonetheless, stoichiometric phases of 22 basic azides are established, such as nickel hydroxide azide, (OH)Ni(N3), and holmium hydroxide azide, (HO)2Ho—O—Ho(OH)(N3). Azide halides have been made of the III through VII metals and of some adjacent metalloids examples are, lead(II) azide chloride, ClPb(N3), and boron azide dichloride, Cl2B(N3). 

Normal boron azide, B(N3)3, is a white solid and is chemically not very stable. The compound explodes when shocked mechanically or thermally and has a strong tendency to decompose hydrolytically. The only known synthesis starts from hydrazoic acid and diborane and yields the boron azide contaminated with boron hydrogen azides. The compound is ether soluble [231 ] ... 

The properties of lithium tetraazidoborate, Ii[B(N3)4], resemble those of normal boron azide. It is synthesized, apparently in a two-stage reaction, from lithium borohydride and hydrazoic acid ... 

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