A simple but effective copper-catalyzed borylation of aryl halides, including electron-rich and sterically hindered aryl bromides, with alkoxy diboron reagents occurs under mild conditions (see scheme). Preliminary DFT studies of the mechanism suggest that sigma-bond metathesis between a copper-boryl intermediate and the aryl halide generates the aryl boronate product.

A Facile Route to Aryl Boronates: Room‐Temperature, Copper‐Catalyzed Borylation of Aryl Halides with Alkoxy Diboron Reagents

Synthesis, Structure, and Reactions of Hydride, Borohydride, and Aluminohydride Compounds of the f-Elements.

A wide variety of metal borohydrides, MBH4, have been discovered and characterized during the past decade, revealing an extremely rich chemistry including fascinating structural flexibility and a wide range of compositions and physical properties. Metal borohydrides receive increasing interest within the energy storage field due to their extremely high hydrogen density and possible uses in batteries as solid state ion conductors. Recently, new types of physical properties have been explored in lanthanide-bearing borohydrides related to solid state phosphors and magnetic refrigeration. Two major classes of metal borohydride derivatives have also been discovered: anion-substituted compounds where the complex borohydride anion, BH4−, is replaced by another anion, i.e. a halide or amide ion; and metal borohydrides modified with neutral molecules, such as NH3, NH3BH3, N2H4, etc. Here, we review new synthetic strategies along with structural, physical and chemical properties for metal borohydrides, revealing a number of new trends correlating composition, structure, bonding and thermal properties. These new trends provide general knowledge and may contribute to the design and discovery of new metal borohydrides with tailored properties towards the rational design of novel functional materials. This review also demonstrates that there is still room for discovering new combinations of light elements including boron and hydrogen, leading to complex hydrides with extreme flexibility in composition, structure and properties.

Metal borohydrides and derivatives – synthesis, structure and properties

Structures of high coordination complexes

Transition metal complexes in which hydrocarbons serve as σ,σ-, σ,π- or π,π-bound bridging ligands are currently of great interest. This review presents efficient and directed syntheses for such compounds, which often have very aesthetic structures. These reactions are among the most important reaction types in modern organometallic chemistry. They can be a useful aid for the synthesis of tailor-made compounds, for example, for models of catalytic processes and, specifically, for the construction of heterometallic compounds. We will discuss reactions of electrophilic complexes with nucleophilic ones, numerous transformations of (functionalized) hydrocarbons with metal complexes, the currently very topical complexes with bridging acetylide and carbide ligands, and organometallic polymers, which can be expected to have interesting and novel materials properties. Chisholm1 has described the importance of these complexes as follows: “Central to the development of polynuclear and cluster chemistry are bridging ligands and central to organometallic chemistry are metal–carbon bonds. Thus bridging ligands hold a pivotal role ins the development of Binuclear and polynuclear organometallic chemistry”.

Methods for the Synthesis of μ‐Hydrocarbon Transition Metal Complexes without Metal–Metal Bonds

Structural determinations of four mono- and binuclear tertiary phosphine and arsine complexes of copper(I) chloride

14-Coordinate Uranium(IV). The structure of uranium borohydride by single-crystal neutron diffraction

Behavior of tertiary phosphine and arsine complexes of copper(I) in chloroform solution

.eta.5-Benzyl: crystal structure, nucleophilic properties, and electron-transfer reactions of CpFe(.eta.5-C6Me5CH2), an intermediate in carbon-hydrogen activation by oxygen via O2-

James J. Mayerle

Papers

Structural determinations of four mono- and binuclear tertiary phosphine and arsine complexes of copper(I) chloride

14-Coordinate Uranium(IV). The structure of uranium borohydride by single-crystal neutron diffraction

Behavior of tertiary phosphine and arsine complexes of copper(I) in chloroform solution

.eta.5-Benzyl: crystal structure, nucleophilic properties, and electron-transfer reactions of CpFe(.eta.5-C6Me5CH2), an intermediate in carbon-hydrogen activation by oxygen via O2-

Structure of uranium borohydride by single-crystal x-ray diffraction.