Synthetic and structural studies of phosphine coordinated boronium salts

Syntheses, Structures, and Reactivities of N-Heterocyclic Carbene-Coordinated Aminoborane Complexes

Recent research has attracted considerable attention toward N-heterocyclic carbene-coordinated boranes (NHC-borane) and their B-substituted derivatives because of their unique characteristics. In the present work, we focused on the syntheses, structures, and reactivities of such types of amine complexes, [NHC·BH₂NH₃]X ((NHC = IPr (1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene) and IMe (1,3-dimethylimidazol-2-ylidene); X = Cl, I, OTf). We have developed a synthetic method to access NHC·BH₂NH₂ through the reaction of NaH with [IPr·BH₂NH₃]I, which was synthesized by the reaction of IPr·BH₂I with NH₃. As a Lewis base, NHC·BH₂NH₂ could further react with HCl or HOTf to produce the corresponding salts of [IPr·BH₂NH₃]⁺. IPr·BH₂NH₂BH₂X (X = Cl, I) were synthesized by the reaction of HCl/I₂ with IPr·BH₂NH₂BH₃ and then converted to [IPr·BH₂NH₂BH₂·IPr]X (X = Cl, I) by reacting with IPr. The IMe-coordinated boranes reacted quite similarly. The preliminary results revealed that the introduction of the NHC molecule has a considerable impact on the solubility and reactivities of aminoboranes.

Crystalline phosphino-functionalized mesoionic olefins (p-MIOs)

Phosphino-functionalized mesoionic olefins (p-MIOs), (iMIC)CHR (iMIC = PhC{N(Dipp)}2C(PPh2)C, Dipp = 2,6-iPr2C6H3; R = H 4a or Ph 4b) derived from a 1,3-imidazole based mesoionic carbene (iMIC) are reported. The p-MIOs...