Christian Hering-Junghans

Encapsulating Inorganic Acetylene, HBNH, Using Flanking Coordinative Interactions

A stable donor-acceptor coordination complex of the elusive parent inorganic iminoborane HBNH (a structural analogue of acetylene) is reported. This species was generated via thermally induced N2 elimination/1,2-H migration from a hydrido(azido)borane adduct NHC⋅BH2N3 (NHC=N-heterocyclic carbene) in the presence of a fluorinated triarylborane. The mechanism of this process was also investigated by computational and isotopic labeling studies. This transformation represents a new and potentially modular route to unsaturated inorganic building blocks for advanced material synthesis.

Synthesis of elusive chloropnictenium ions.

This work describes the synthesis and full characterization of elusive chloropnictenium ion salts of the type [(R)Ar*N(SiMe)ECl][A] ((R)Ar* = 2,6-(CHPh2)-4-R-C6H2, R = Me, tBu; E = Sb, Bi; A(-) = GaCl4, Al(OCH(CF3)2)4). In these species the cation is significantly stabilized by weak arene interactions to flanking phenyl groups of the (R)Ar* moiety. In this context the bonding situation has been studied by computational means and the reactivity towards the Lewis base 4-dimethylaminopyridine (dmap) was investigated.

Using N-Heterocyclic Vinyl Ligands to Access Stable Divinylgermylenes and a Germylium Cation

Two efficient methods are presented to install σ- and π-electron-donating N-heterocyclic vinyl groups onto main-group elements (E): halosilane elimination and base-induced E-C bond formation. Placement of two NHC=CH- ligands (NHC=N-heterocyclic carbene) onto a GeII center affords a two-coordinate germylene, a heavy congener of the elusive divinyl carbenes. The π-donating ability of this vinylic ligand scaffold was further demonstrated by the synthesis of a three-coordinate germylium cation R3 Ge+ .

Synthesis of arylated coumarins by Suzuki–Miyaura cross-coupling. Reactions and anti-HIV activity

Arylated coumarins were prepared by site-selective Suzuki-Miyaura cross-coupling reaction of the bis(triflate) of 4-methyl-6,7-dihydroxycoumarin. Triarylated coumarins were prepared by Suzuki-Miyaura cross-coupling reactions of 3-bromo-4-methyl-2-oxo-2H-chromene-6,7-diylbis(trifluoromethanesulfonate). The in vitro anti-HIV activity of the products was investigated. Two lead structures with considerable activities were identified.

Oxoborane (RBO) Complexation and Concomitant Electrophilic Bond Activation Processes

Donor-acceptor complexes of the oxoboranes ClB=O and HOB=O were synthesized and each feature short multiply bonded B=O linkages. The retention of high Lewis acidic character within these encapsulated monomeric oxoboranes was manifested by their ability to support C-F and Si-O bond activation/functionalization. The reported ClB=O complexes can be regarded as synthetic surrogates of the [BO]+ cation, an inorganic analogue of CO.

Metal‐Free Nitrogen Fixation at Boron

No metal needed: Boron does the job! The activation of the inert dinitrogen molecule has fascinated chemists for ages. In a ground-breaking study Braunschweig and co-workers have now demonstrated that N2 activation can be achieved with the aid of the p-block element boron-a reactivity previously restricted to transition metals.

CCDC 1514190: Experimental Crystal Structure Determination

Related Article: Anindya K. Swarnakar, Christian Hering-Junghans, Michael J. Ferguson, Robert McDonald, Eric Rivard|2017|Chemical Science|8|2337|doi:10.1039/C6SC04893E

CCDC 1514195: Experimental Crystal Structure Determination

Related Article: Anindya K. Swarnakar, Christian Hering-Junghans, Michael J. Ferguson, Robert McDonald, Eric Rivard|2017|Chemical Science|8|2337|doi:10.1039/C6SC04893E