5775-58-6Relevant academic research and scientific papers
HETEROCYCLES RELATED TO 2,4-DIBORA 1,3-DIAZAROBENZENE
Allaoud, Smail,Frange, Bernard
, p. 129 - 136 (2007/10/02)
The reaction of ortho-substituted arylamines oY-C6H4NH2 (Y=H, Cl, Br, Me) with BX3, (X=F, Cl, Br, I) was investigated.By suitable choice of Y and X, this reaction may be directed to obtain, in a quantitative way, a new kind of heterocycle I instead of the expected trimeric species (oYC6H4NBX)3.The formation of I was found to be related to the bulk of Y substituent and to the nature of X, increasing in the order BCl3 a tertiary amine added, always gives the corresponding borazines.Some derivatives of I were prepared (X=Me, Y=Br, Me) and characterized by NMR (1H, 13C and 11B) and mass spectra. In connection with this study, we were led to the question of atropisomerism in the N-triarylborazines (oYC6H4NBX)3 when the starting arylamine bears an ortho substituent Y.As far as the compound Y=Me, X=Me is concerned, a sole isomer, the C3t one, could be obtained instead of the two expected.
Atropisomerism in aryl-substituted borazines
Allaoud,Frange
, p. 2520 - 2523 (2008/10/08)
The N,N′,N″-tri-o-tolylborazines (o-CH3C6H4NBX)3 (X = Cl, Br, Me, Et) were prepared and studied by means of 1H and 13C NMR. The methyl derivative (X = Me) resulting from the reaction of CH3MgI on the B,B′,B″-trichloro-N,N′,N″-tri-o-tolyl-borazine (X = Cl) in diethyl ether was shown to be a mixture of the cis isomer alone with B-hydroxy byproducts that were identified. This methylation reaction fails to provide the expected trans isomer for steric reasons: instead, B-hydroxy compounds appear during the hydrolysis step.
