Direct Spectroscopic Identification of BN-Arynes and Subtle Steric Effects on Nitrogen Fixation.

1,2-Azaborinines are the BN analogues of arynes through exchange of the formal CC triple bond by an isoelectronic BN bond. The BN-arynes are an underexplored class of reactive intermediates. Dibenzo[c,e][1,2]azaborinine (10,9-BN-phenanthryne) 1 was inferred as reactive intermediate by trapping reactions.

Solution Phase Reactivity of Dibenzo[c,e][1,2]azaborinine: Activation and Insertion into Si-E Single Bonds (E=H, OSi(CH ) , F, Cl) by a BN-Aryne.

The boron-nitrogen analogue of ortho-benzyne, 1,2-azaborinine, is a reactive intermediate that features a formal boron-nitrogen triple bond. We here show by combining experimental and computational techniques that the Lewis acidity of the boron center of dibenzo[c,e][1,2]azaborinine allows interaction with the silicon containing single bonds Si-E through the silicon bonding partner E (E=F, Cl, OR, H). The binding to boron activates the Si-E bonds for subsequent insertion reaction.

Photo electron transfer induced desilylation of N,N-bis(trimethylsilyl)aminodibenzoborole to aminodibenzoborole.

The synthesis of 9-amino-9-borafluorene is described using a photoinduced twofold desilylation of the N,N-bis(trimethylsilyl) derivative 2. The mechanistic analysis suggests an initial single electron transfer step from 2 to the halogen containing solvent. 9-Amino-9-borafluorene undergoes a photoinduced cyclooligomerization, most reasonably to the dimer.

Thermal dehydrochlorination in the 4-fluoroaniline-trichloroborane system: identification of reactive intermediates involved in the formation of B,B',B''-trichloro-N,N',N''-tri((4-fluoro)phenyl)borazine.

Borazines are used in chemical vapor deposition processes to produce hybrid graphene-boron nitride nanostructures. As the knowledge on the mechanism of borazine formation is scarce, we studied the mechanism of formation of B,B',B''-trichloro-N,N',N''-tri(p-fluorophenyl)borazine (3a) from p-fluoroaniline and boron trichloride employing NMR spectroscopy, X-ray single crystal structure analysis, trapping experiments, and computational chemistry methods up to the coupled cluster CCSD(T) level of theory. These studies suggest the initial formation of the 1 : 1 adduct 1a (ArNHBCl, Ar = 4-fluorophenyl) with a dative B-N bond that could be fully characterized including single crystal X-ray diffraction.

Synthesis and Ring Strain of a Benzoborirene-N-Heterocyclic Carbene Adduct.

The reduction of an N-heterocyclic carbene (1,3-diisopropyl-4,5-dimethylimidazolin-2-ylidene, IiPr ) adduct of dichloro(ortho-bromophenyl)borane by tert-butyl lithium at low temperature yields the IiPr adduct A of parent benzoborirene, a highly strained boron-containing bicyclic compound. A is unstable at room temperature and dimerizes at low temperature to the bis-IiPr adduct of 9,10-dihydro-9,10-diboraanthracene, characterized by single-crystal X-ray crystallography.