Synthesis and characterization of metallatranes with phenyl substituents in atrane cage

A new series of mono- and diphenylsubstituted silatranes and boratranes N(CH2CH2O)2(CHR3CR1R2O)MZ (M = Si, Z = CH2Cl, CCPh, H, OMenth, R1, R2, R3 = H, Ph; M = B, Z = nothing, R1, R2, R3 = H, Ph) have been synthesized. Both transalkoxylation and stepwise modification of a preformed metallatrane skeleton were used. The chloromethyl derivatives N(CH2CH2O)2(CHRCHRO)SiCH2Cl (R = H, Ph) react with tert-BuOK under intramolecular cycle expansion to give 1-tert-butoxy-2-carba-3-oxahomosilatranes N(CH2CH2O)(CH2CH2OCH2)(CHRCHRO)SiOtBu (R = H, Ph). The treatment of boratranes N(CH2CH2O)2(CH2CR1R2O)B (R1,R2 = H, Ph) with triflic acid and trimethylsilyl triflate results in the products of electrophilic attack at the nitrogen atom. The molecular structures of four silatranes and one boratrane bearing phenyl groups in the atrane skeleton were determined by the X-ray structure analysis.

Graphical abstractA series of silatranes and boratranes based on C-phenylsubstituted trialkanolamines has been prepared. Both transalkoxylation and stepwise modification of a preformed metallatrane skeleton were used. The systematic structural study and investigation of chemical behaviour of prepared compounds are presented.Figure optionsDownload full-size imageDownload as PowerPoint slide