Reactivity of Diphenylberyllium as a Brønsted Base and Its Synthetic Application

Abstract

Diphenylberyllium [Be3Ph6] is shown here to react cleanly as a Brønsted base with a vast variety of protic compounds. Through the addition of the simple molecules tBuOH, HNPh2 and HPPh2, as well as the more complex 1,3‐bis‐(2,6‐diisopropylphenyl)imidazolinium chloride, one or two phenyl groups in diphenylberyllium were protonated. As a result, the long‐postulated structures of [Be3(OtBu)6] and [Be(μ‐NPh2)Ph]2 have finally been verified and shown to be static in solution. Additionally [Be(μ‐PPh2)(HPPh2)Ph]2 was generated, which is only the second beryllium‐phospanide to be prepared; the stark differences between its behaviour and that of the analogous amide were also examined. The first crystalline example of a beryllium Grignard reagent with a non‐bulky aryl group has also been prepared; it is stabilised with an N‐heterocyclic carbene.

Tricoordinate Beryllium Radicals and Their Reactivity

“…The heteroleptic bromo­(duryl)beryllium complex, 1 , was synthesized by salt metathesis of CAAC-stabilized beryllium dibromide with duryllithium. It is noteworthy that unlike heteroleptic heavier Ae aryl Grignards (AeArX), which are highly susceptible to Schlenk-type disproportionation into AeAr 2 and AeX 2 , beryllium-based aryl Grignards, both base-free and base-stabilized, show a marked preference for heterolepticity and can be synthesized by comproportionation, in particular when using sterically demanding ligands. − In line with these observations, complex 1 does not disproportionate into [(CAAC)­BeDur] 2 (Dur = 2,3,5,6-triphenylmethyl = duryl) and [(CAAC)­BeBr 2 ] even after prolonged heating in toluene up to 100 °C.…”

Gauging ambiphilicity of pseudo-halidesviaberyllium-trispyrazolylborato compounds

“…Typically only line broadening but no resolved 1 J CBe coupling is observed in beryllium organic compounds with anionic or neutral C-ligands. 32–36 Thus, the presence of 1 J CBe coupling is evidence for little to no dissociation of the cyanide ligand and of a strong Be–C bond. This is further supported by the lack of exchange cross peaks in EXSY NMR experiments (ESI Fig.…”

Cesium Reduction of a Lithium Diamidochloroberyllate

“…Following a period of relative dormancy, the molecular chemistry of beryllium has experienced something of a renaissance during the past decade. While the solution behavior and toxicity of organo- and inorganic beryllium­(II) compounds continues to provide a significant conventional focus, − noteworthy effort has also been applied to the pursuit of lower oxidation state Be species. − In this latter regard, the groups of Braunschweig and Gilliard have succeeded in the isolation of several cyclic alkyl­(amino)­carbene (CAAC)-supported compounds in which formal Be(0) or Be­(I) oxidation states may be ascribed to an isolated beryllium center. − Notably, and very recently, the long sought , and predicted , isolation of a Be–Be bonded species has been realized through Aldridge and co-workers’ isolation of CpBeBeCp. , …”