Synthesis of Highly Functionalizable Symmetrically and Unsymmetrically Substituted Triarylboranes from Bench‐Stable Boron Precursors

Abstract

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.

Bithiophene‐Cored,mono‐,bis‐, andtris‐(Trimethylammonium)‐Substituted,bis‐Triarylborane Chromophores: Effect of the Number and Position of Charges on Cell Imaging and DNA/RNA Sensing

“…With all uncharged compounds Neut1 – 3 in hand, their cationic counterparts were synthesized using methyl triflate in CH 2 Cl 2 similar to previous reports[ 26 , 27 , 29 , 35 , 40 ] giving Cat 1+ , Cat 2+ , Cat(i) 2+ , and Cat 3+ in 88 %, 69 %, 49 %, and 57 % yields, respectively. The neutral triarylboranes 5a and 6a were methylated similarly giving 5c and 6c in 89 % and 93 % yields, respectively.…”

“…Triarylboranes 6b [26] and 5b [40] and their para ‐selective C−H borylated analogues were synthesized according to literature procedures. Mono ‐[ 41 , 42 ] and di ‐brominated [42] bithiophenes 2 and 3 were synthesized by routes similar to those in the literature.…”

“…The synthesis of Neut1 , Neut(i)2 , and Neut3 was made possible via a synthetic route to unsymmetrically‐substituted triarylboranes which was previously not well developed, [39] but has been reported very recently by our group. [40] …”

Aggregation‐Induced Dual Phosphorescence from (o‐Bromophenyl)‐Bis(2,6‐Dimethylphenyl)Borane at Room Temperature

“…The compound o ‐ BrTAB was synthesized [24] by reaction of the Grignard reagent (2,6‐Me 2 ‐C 6 H 3 )MgBr with o ‐Br‐C 6 H 4 BF 3 K, whereas m ‐ and p ‐ BrTAB were prepared by the reaction of bis(2,6‐dimethylphenyl)fluoroborane with the respective aryllithium species generated by mono lithium‐halogen exchange of m ‐ or p ‐dibromobenzene with n ‐BuLi (for synthetic details and characterization data, see the Supporting Information). All three compounds showed absorption bands between 270 and 350 nm in hexane which are attributed to B←π transitions with extinction coefficients of ϵ =10000‐16000 M −1 cm −1 (Figure 2a and Table 1).…”

Electron‐Rich EDOT Linkers in Tetracationic bis‐Triarylborane Chromophores: Influence on Water Stability, Biomacromolecule Sensing, and Photoinduced Cytotoxicity

“…Increasing research interest has been focused on triarylboranes over the last three decades and the structural motif has been incorporated in numerous functional materials. [1][2][3][4][5][6][7][8][9][10][11] More recently, several triarylboryl-containing chromophores have been successfully employed in different biological applications. The empty p z -orbital at boron makes it a strong π-acceptor and strong Lewis acid and needs to be protected sufficiently to obtain robust materials.…”