In recent years, research in the fields of optoelectronics, anion sensors and bioimaginga gents have been greatly influenced by novel compounds containing triarylborane motifs. Such compounds possess an empty p-orbital at boron which resultsi nu seful optical and electronic properties. Such ad iversity of applications was not expected when the first triarylboranew as reported in 1885. Synthetic approaches to triarylboranes underwent variousc hanges over the following century,s ome of which are still used in the present day,s uch as the generally applicable routes developedb yK rause et al. in 1922developedb yK rause et al. in , or by Grisdale et al. in 1972 at Eastman Kodak. Some other developments were not pursued further after their initial reports, such as the synthesis of two triarylboranes bearing three different aromatic groups by Mikhailov et al. in 1958. This reviews ummarizes the developmento fs ynthetic approaches to triarylboranes from their first report nearly 135 years ago to the present.2021 The Authors. Chemistry -A European Journal published by Wiley-VCH GmbH. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properlyc ited.Selected by the EditorialO ffice for our Showcaseo fo utstanding Reviewtype articles (www.chemeurj.org/showcase).

The synthesis, photophysical, and electrochemical properties of selectively mono-, bis-and tris-dimethylaminoand trimethylammonium-substituted bis-triarylborane bithiophene chromophores are presented along with the water solubility and singlet oxygen sensitizing efficiency of the cationic compounds Cat 1 + , Cat 2 + , Cat(i) 2 + , and Cat 3 + . Comparison with the mono-triarylboranes reveals the large influence of the bridging unit on the properties of the bistriarylboranes, especially those of the cationic compounds.Based on these preliminary investigations, the interactions of Cat 1 + , Cat 2 + , Cat(i) 2 + , and Cat 3 + with DNA, RNA, and DNApore were investigated in buffered solutions. The same compounds were investigated for their ability to enter and localize within organelles of human lung carcinoma (A549) and normal lung (WI38) cells showing that not only the number of charges but also their distribution over the chromophore influences interactions and staining properties.

Triarylboranes have been known for more than 100 years and have found potential applications in various fields such as anion sensors and optoelectronics, for example in organic light emitting diodes...

A novel and convenient methodology for the onepot synthesis of sterically congested triarylboranes by using bench-stable aryltrifluoroborates as the boron source is reported. This procedure gives systematic access to symmetrically and unsymmetrically substituted triarylboranes of the types BAr 2 Ar' and BArAr'Ar'', respectively. Three unsymmetri-cally substituted triarylboranes as well as their iridiumcatalyzed CÀ H borylation products are reported. These borylated triarylboranes contain one to three positions that can subsequently be orthogonally functionalized in follow-up reactions, such as Suzuki-Miyaura cross-couplings or Sonogashira couplings.

The review article presented by T. B. Marder et al. on page 7043, summarizes the synthetic developments that have been made in the synthesis of triarylboranes throughout the years from their first appearance in 1885 to the present. It is shown that, over time, developments in other fields of research enriched triarylborane chemistry by developing new organometallic reagents or boron sources, which led to new synthetic strategies and opened the door for diverse applications. Investigation of reactivities and other molecular properties of triarylboranes led to the first commercially available products by the middle of the 20th century. With increasing interest in this field of research, new potential applications of such compounds continue to arise. This review article aims to provide guidance for researchers to find the best synthetic strategy for preparing new compounds containing the triarylborane motif.