Carboberyllation: addition of organoberyllium species to alkenes and alkynes. A comparison with carboboration.

The potential for carbometallation reactions between organoberyllium and model alkenes and alkynes has been investigated in a computational study. Results indicate that barriers for carbometallation reactions between BeR and alkynes are as low as 100 kJ mol, and much lower than corresponding reactions with MgR. In contrast to carboboration reactions with BR, with organoberyllium 1,2-addition is favoured over 1,1-addition.

Reactions of imines, nitriles, and isocyanides with pentaphenylborole: coordination, ring expansion, C-H bond activation, and hydrogen migration reactions.

The reactions of pentaphenylborole with imines, isocyanides, and acetonitrile were investigated experimentally and theoretically. On the basis of literature precedent, we envisioned that the dipolar substrates would undergo facile ring expansion reactions to yield new BNC5 heterocycles. For acetonitrile and one particular imine, this ring expansion process was observed.

Investigating the ring expansion reaction of pentaphenylborole and an azide.

The reaction between trimethylsilyl azide and pentaphenylborole was recently shown to produce the corresponding 1,2-azaborine. Investigating this transformation theoretically suggests that the reaction proceeds via coordination of the azide to the borole, rearrangement to a bicyclic species, and conversion to a kinetically favoured eight-membered BN3C4 heterocycle or expulsion of N2 to furnish the thermodynamically favoured 1,2-azaborine. The eight-membered species was structurally characterized as a borole adduct and represents an unusual analogue of cyclooctatetraene.

Beryllium chemistry the safe way: a theoretical evaluation of low oxidation state beryllium compounds.

A theoretical study of compounds containing Be in the +1 or 0 oxidation state has been carried out. The molecules considered containing Be in the +1 oxidation state are analogues of the important Mg(I)-Mg(I) dimer supported by the β-diketiminate ligand. The molecules in the 0 oxidation state are NHC supported compounds analogous to "molecular allotropes" which has recently become a topic of importance in p-block chemistry.

Diverse reactions of PhI(OTf)2 with common 2-electron ligands: complex formation, oxidation, and oxidative coupling.

The crystal structures of bis-pyridine stabilized iodine dications [PhI(pyr)(2)](2+) are reported as triflate salts, representing the first ligand supported iodine dications to be structurally characterized. The pyridine complexes are susceptible to ligand exchange in reaction with stronger N-based donors such as 4-dimethylaminopyridine. Attempts to extend this reactivity to N-heterocyclic carbene and phosphine ligands, as has been accomplished in the earlier p-block groups, resulted in redox chemistry, with oxidation of the ligands rather than coordination.

Are N-heterocyclic carbenes "better" ligands than phosphines in main group chemistry? A theoretical case study of ligand-stabilized E2 molecules, L-E-E-L (L = NHC, phosphine; E = C, Si, Ge, Sn, Pb, N, P, As, Sb, Bi).

A theoretical examination of the L-E-E-L class of molecules has been carried out (E = group 14, group 15 element; L = N-heterocyclic carbene, phosphine), for which Si, Ge, P, and As-NHC complexes have recently been synthesized. The focus of this study is to predict whether it is possible to stabilize the elusive E(2) molecule via formation of L-E-E-L beyond the few known examples, and if the ligand set for this class of compounds can be extended from the NHC to the phosphine class of ligands. It is predicted that thermodynamically stable L-E-E-L complexes are possible for all group 14 and 15 elements, with the exception of nitrogen.