Aminoborane

Synthesis. One of the more common routes for the synthesis of aminoboranes involves the aminolysis of the appropriate boron hahde. Trisaminoboranes are most convenientiy prepared by adding BCI3 to an excess of amine in an inert solvent at low temperatures (42). For example for tris(dimetby1amino)borane [4375-83-1]. ... 

A widely used reaction for preparing unsymmetrical aminoboranes is the treatment of an aminoborane B(NR2)3 with another boron compound BX3 to induce an exchange of the substituents an example is given in equation 12 (43). 

The chemistry and stereochemistry of aminoboranes containing the siLicon—nitrogen—boron linkage have been the subject of numerous studies. Many of these compounds are useful precursors to other B—N systems including diboryl-amines (45) and B—H substituted aminoboranes (46). A series of... 

The /-butyl derivative [87487-06-9] reacts with ammonia as shown in equation 15 to yield a stable primary aminoborane [99748-68-2] (48). The stabiUty of primary aminoboranes has been attributed to the presence of a bulky substituent on boron (49). 

This primary aminoborane is a useful reagent for attaching B—N moieties to other elements, eg, (borylarnino)phosphines, or for extending short B—N chains, eg, diborylamines. 

A series of lithium complexes have been utilized as synthons in the preparation of aminoborane complexes. (/V-Tlthiomethy1amino)dimethy1horane is used as a reagent for the preparation of borylarnino(arnino)boranes and diborylamines (50). Lithium benzyl-/ f/-butylamide reacts with BCl to yield the bisaminoborane [91573-50-1] shown in equation 16 (51). 

The bonding in aminoboranes has been represented as 2 BR2 X2N i m 2 show the contribution of some 7t-orbital interaction... 

The emphasis in the approaches to boron nitride [10043-11 -5] BN, precursors has been concentrated on cycHc compounds. There have been recent reports of trimethylsilyl-substituted aminoboranes being evaluated as B—N precursors. These are linear borylamines containing up to four boron atoms. Compounds were also synthesized with free —NH2 groups amenable to condensation with either dihaloboranes or dihaloborazines (65) and offering suitable monomers for linear B—N polymer synthesis and borazine-ring-linking appHcations. 

Aminoboranes have been used as ligands in complexes with transition metals (66) in one instance giving a rare example of two-coordinate, non-t/ transition-metal complexes. The molecular stmcture of the iron complex Fe[N(Mes)B(Mes)2]2 where Mes = is shown in Figure 1. The... 

Aminoboranes can be prepared from diborane to protect a tertiary amine during oxidation they are cleaved by refluxing in ethanol or methanolic sodium carbonate. ... 

They are cleaved by refluxing in ethanol," methanolic sodium carbonate, TFA, or ammonium chloride. The aminoborane was found to be stable to LDA and KHMDS."... 

A similar situation obtains in the aminoboranes where one or more of the substituents on B is an R2N group (R = alkyl, aryl, H), e.g. Me2N-BMc2. Reference to Fig. 6.22 indicates the possibility of some p, interaction between the lone pair on N and the vacant orbital on trigonal B. This is frequently indicated as... 

The reaction takes place in an excess of the liquid aminoborane as solvent. 

In one compound iron carbonyl moieties serve as electron donors to the B of a simple aminoborane, whereas the N atoms have donor functions to Fe ... 

It is well known that some silylamines, in combination with haloboranes, provide a facile route to aminoboranes (Equation 1) (26). Meller and Fullgrabe (19.) have previously reported that a... 

The Amine Complexes of Aluminium Hydride, IV. Bis-(dimethyl-aminoborane)-bis-(dimethylamino)-alane. Inorg. Chem. 1, 612 (1962). 

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