Bis dimethylamino borane

Submitted by PHILIP C. KELLER Checked by HOWARD D. JOHNSON, Ilf 

Bis(dimethylamino)borane may be prepared by the reduction of CIB[N(CH3)2]21 or by gas-phase exchange of hydride and dimethylamino groups on boron.2,3 The latter method, using diborane(6) and excess B[N(CH3)2]3 and described here, is the most convenient for the synthesis of a few millimoles of product. The basic vacuum-line techniques necessary to carry out this synthesis are detailed in reference 4. 

A dry 500-mL pyrolysis bulb similar to that used for the synthesis of [(CH3)2NBH2]2 (Fig. 5) is evacuated and checked for leaks on the vacuum line. The lower portion of the vessel is cooled with liquid nitrogen, and into 

Shriver, The Manipulation of Air-Sensitive Compounds, McGraw-Hill Book Company, New York, 1969. 

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The reduction of (alkylamino)haloboranes using hydride reagents can provide a convenient route to (alkylamino)boranes for example, LiA1H4 has been utilized to prepare bis(dimethylamino)borane [23884-11-9] from chlorobis(dimethylamino)borane [6562-41-0] (68). When this same strategy is applied to (bis(trimethylsilyl)amino)chloro((trimethylsilyl)amino)borane [10078-93-0], the expected compound is obtained along with the formation of two... 

At the other extreme, the most stable derivatives of the B2X4 type appear to be the tetrakis(dialkylamino) compounds. Thus, tetrakis(dimethylamino)-diborane(4) is stable at its boiling point of 206° C 17). The compound decomposes at 300° C to form bis(dimethylamino)borane and involatile residues containing B—C bonds. It is reported that tetra(A -methylanilino)-borane(4) is pyrolyzed at 300° C by a different mechanism to yield N-methylaniline 18). 

Tris(dimethylamino)silylamino-bis(dimethylamino)-borane (TABB)... 

Bis(dimethylamino)borane, (Me2N)2BH, has been studied by electron diffraction and mofecular orbital calculations. The 6-311-I--I-G basis set was used. 

The compounds 93 (R = Me, Et) are extremely sensitive toward oxidation and moisture and were not isolated in a pure state. Their structures were supported by NMR spectroscopy. Treatment of 93 with pyridine also gives rise to pyridine-l-boraadamantane complex 111 and starting acetylene derivative, via 1,1-deorganoboration. Accordingly, the 1-boraadamantane-TMEDA adduct (TMEDA - bis(dimethylamino)ethane) (along with Me3SnC CSnMc() is formed when the tricyclic borane 93a (R=Me) reacts with TMEDA <2003JOM(687)108>. 

Reaction of l,2-dichloro-l,2-bis(dimethylamino)diborane(4) with N-dilithio bis- or tris(amino)borane derivatives resulted in several derivatives of the system named in the heading, according to the following equation ... 

The reaction of diborane(6) with bis or tris(dimethylamino)borane has recently been shown to be synthetically useful in the stepwise buildup of a boron-nitrogen chain leading to bis( -dimethylamino)triborane(9).7... 

Boran Bis-[dimethylamino]-[2-(dimethylamino-methyl)-phenyl]-XIII/3b, 221... 

Organoboron heterocycles containing the boron-boron bond have also been prepared by the reaction of A -lithio derivatives of alkylbis(alkylamino)-boranes with l,2-dichloro-l,2-bis (dimethylamino)diborane(4) 74) ... 

Thermal decomposition of l,2-dibutyl-l,2-bis (dimethylamino)diborane-(4) at 200°-230°C was found by Noth and Fritz to yield 1-butene and butyl-(dimethylamino)borane, the reaction postulated being... 

A niimber of B-N-Si cyclic systems have been prepared for the first time, by a variety of routes, chiefly (i) the reaction of N-lithio-aminoboranes with bis-(chlorosilylamines), (ii) transamination of (aminoborylamino)silanes, and (iii) condensation of Me2Si(NHMe)2 and alkylbis(dimethylamino)boranes. H, and n.m.r. data suggest that the silaborazine ring in, c.g., (39) is non-planar/ " The crystal structure of (40) shows that the molecule possesses Da symmetry. 

The compound bis-/i-(dimethylamino)-diborane(6), [(CH3)2NBH2]2, has been prepared by the pyrolysis of dimethylamine-borane, (CH3)2NH BH3,1-3 and by a novel iodination-deprotonation of (CH3)2NH BH3,4 The gas-phase pyrolysis described here is the simplest and most convenient method for the preparation of small samples, since no solvent is involved and separation problems are thus minimized. The basic vacuum-line techniques necessary for this synthesis are outlined in reference 7. 

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