137517-06-7Relevant articles and documents
Synthesis of Boron-Halogenated Diborylamines and Diborylhydrazines by Cleavage of Stannazanes
Diemer, Stefan,Noeth, Heinrich,Storch, Wolfgang
, p. 1765 - 1780 (2007/10/03)
The diborylamines R'-N(BRX)2 (3; X=Cl, Br) are obtained by stannazane cleavage of distannylorganylamines R'-N(SnMe3)2 (4) with alkyldihaloboranes RBX2 in a 1:2 molar ratio. The presence of the sterically demanding substituents R and R' also causes carbon-tin bond cleavage, resulting in low yields of 3. However, carbon-tin bond cleavage can be suppressed by the use of bis(dimethylchlorostannyl)organylamines 5 as the nitrogen source for the synthesis of diborylamines. This results in almost quantitative yields of the compounds 3. Treatment of the distannylhydrazines R2N-N(SnMe3)2 (7) with RBX2 in a 1:2 molar ratio leads to the formation of N,N-bis(alkylhaloboryl)hydrazines 8 under mild conditions and in good yield. The molecular structures of 3 and 8 were determined by multinuclear magnetic resonance spectra in solution as well as by X-ray structure analysis in the case of 8d. A typical structural feature of 8d is the intramolecular BN adduct formation. Support for the constitutions of compounds 8c comes from MS fragmentation patterns as well as from IR spectra.
Synthesis und Structure of Bis(trimethylstannyl)- and Bis(dimethylhalostannyl)amines: The Role of the Nitrogen Lone Pair
Diemer, Stefan,Noeth, Heinrich,Polborn, Kurt,Storch, Wolfgang
, p. 389 - 400 (2007/10/02)
Monoaminostannanes RHN-SnMe3 (1) with substitutents R = tBu, Mes, 2,6-iPr2C6H3 are obtained by transmetallation from Me3SnX and RNH-Li, the distannylamines RN(SnMe3)2 (2) by transamination of Et2N-SnMe3 with RNH2, and bis(dimethylhalostannyl)amines R-N(SnMe2X)2 (8) by stannazane cleavage with BX3 (8n, o).Me2Sn(NtBuH)2, prepared from tBuNHLi and Me2SnBr2, decomposes with tBuNH2 elimination into the diazadistannetidine 4 already below room temperature.Information from multinuclear NMR spectra of type 2, 4, and 8 compounds ascertain the proposed relation between the value of the geminal coupling constant 2J(119Sn117Sn) of distannazanes and the Sn-N-Sn bond angle as determined by the X-ray structure analysis of 2c and of (8a)2 as well as the participation of the electron pair at the nitrogen atom with SnN bond lengths of 2.044 Angstroem and an Sn-N-Sn bond angle of 125.0 deg.The aryl group stands perpendicular to the Sn2N plane.These data exclude any ? interaction between the substituents. 2c, therefore, represents an example of a tertiary amine with the lone electron pair at the nitrogen in a p-type orbital.The supposed distannylamine (ClMe2Sn)2NMe (8a) is actually a dimer, whose unexpected structure contains a diazadistannetidine unit bearing two Me2SnCl2 groups at its nitrogen atoms in cis-configuration.This arrangement allows the formation of weak intramolecular SnCl bonds. Key Words: Amines, bis(trimethylstannyl)organyl-, bis(dimethylstannyl)organyl- / Bond cleavage, SnN / 1,3,2,4-Diazastannetidine, hexamethyl- / N,N'-Bis(dichlorodimethylstannane)
