Borylenes as Ligands to Transition Metals

Over the past seven years, complexes of various transition metals with bridged or terminal borylene ligands BR have for the first time been reported and fully characterised. Being closely related to important organometallic compounds, such as carbene, vinylidene, and carbonyl complexes, they have already attracted considerable interest both from experimental and computational points of view. Those studies have provided some detailed information about the nature of the metal−boron bond and about the nature of metal and borylene moieties required for the formation of stable complexes. Various methods for their preparation have been developed and the first studies on their reactivity have demonstrated an interesting chemistry. (© Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2003)

The Chemistry of Borylene Complexes

A periodic hybrid DFT approach (including dispersion) to MgCl2-supported Ziegler–Natta catalysts – 1: TiCl4 adsorption on MgCl2 crystal surfaces

Terminale Borylenkomplexe als Quelle für das Borylen B−N(SiMe3)2: alternative Synthese und Struktur von [(OC)5Cr=B=N(SiMe3)2]

Publisher Summary This chapter reviews that the concept of aromaticity is one of the most general but also controversial constructs. The aim of this chapter is to review a critical analysis of various criteria of aromaticity, and the indices quantifying aromatic or antiaromatic character with an emphasis on the application to heterocyclic compounds. Designed as both an appropriate language for the analysis of specific features of structure, stability, and physical and chemical properties inherent in the conjugated cyclic molecular systems, and for their quantitative or semiquantitative evaluation, the concept of aromaticity has received special attention in the chemistry of heterocyclic compounds. It also emphasized that “it would be inconceivable to attempt to teach or practice heterocyclic chemistry without the use of the concept of aromaticity.” It has been long recognized that despite all its versatility and usefulness, the very idea of aromaticity lacks a secure physical basis. The aromaticity of cyclic systems is, in the first place, manifested in the stabilization (destabilization) effects of cyclic electron (bond), delocalization and non-additivity of the collective properties of a molecule.

The concept of aromaticity in heterocyclic chemistry

https://dspace.library.uu.nl/bitstream/handle/1874/25162/kerk_84_the%20addition%20of%20methylborylene%20to%20acetylenes.pdf?sequence=1

The addition of methylborylene to acetylenes: Synthesis of 1,4-diboracyclohexa-2,5-dienes, and of a borirene and a diboretene derivative

https://dspace.library.uu.nl/bitstream/handle/1874/24519/kerk_80_addition%20of%20methylborylene.pdf;sequence=1

A.L.M. van Eekeren

Papers

The addition of methylborylene to acetylenes: Synthesis of 1,4-diboracyclohexa-2,5-dienes, and of a borirene and a diboretene derivative

The addition of methylborylene to acetylenes