54705-91-8Relevant articles and documents
BORAZANs: Tunable fluorophores based on 2-(pyrazolyl)aniline chelates of diphenylboron
Liddle, Brendan J.,Silva, Rosalice M.,Morin, Tyler J.,Macedo, Felipe P.,Shukla, Ruchi,Lindeman, Sergey V.,Gardinier, James R.
, p. 5637 - 5646 (2007)
(Figure Presented) The reaction between 2-pyrazolyl-4-X-anilines, H(pzAnX), (X = para-OMe (L1), Me (L2), H (L3), Cl (L4), CO 2Et (L5), CF3 (L6), CN (L7)) and triphenylboron in boiling toluene affords the respective, highly emissive N,N′-boron chelate complexes, BPh2(pzAnX) (X = para-OMe (1), Me (2), H (3), Cl (4), CO2Et (5), CF3 (6), CN (7)) in high yield. The structural, electrochemical, and photophysical properties of the new boron complexes can be fine-tuned by varying the electron-withdrawing or -donating power of the para-aniline substituent (delineated by the substituent's Hammett parameter). Those complexes with electron-withdrawing para-aniline substituents such as CO2Et (5), CF3 (6), and CN (7) have more planar chelate rings, more 'quinoidal' disortion in the aniline rings, greater chemical stability, higher oxidation potentials, and more intense (φF = 0.81 for 7 in toluene), higher-energy (blue) fluorescent emission compared to those with electron-donating substituents. Thus, for 1 the oxidation potential is 0.53 V versus Ag/AgCl (compared to 1.12 V for 7), and the emission is tuned to the yellow-green but at an expense in terms of lower quantum yields (φF = 0.07 for 1 in toluene) and increased chemical reactivity. Density functional calculations (B3LYP/6-31G*) on PM3 energy-minimized structures of the ligands and boron complexes reproduced experimentally observed data and trends and provided further insight into the nature of the electronic transitions.
L -(-) -Quebrachitol as a Ligand for Selective Copper(0)-Catalyzed N-Arylation of Nitrogen-Containing Heterocycles
Zhou, Qifan,Du, Fangyu,Chen, Yuanguang,Fu, Yang,Sun, Wenjiao,Wu, Ying,Chen, Guoliang
, p. 8160 - 8167 (2019/06/28)
l-(-)-Quebrachitol (QCT) has been found as a ligand of copper powder for selective N-arylation of nitrogen-containing heterocycles with aryl halides. Furthermore, another potential catalytic system (copper powder/QCT/t-BuOK) was successfully adapted to unactivated aryl chlorides.
Copper(II)-Mediated ortho-Selective C(sp2)-H Tandem Alkynylation/Annulation and ortho-Hydroxylation of Anilides with 2-Aminophenyl-1H-pyrazole as a Directing Group
Lee, Wan-Chen Cindy,Wang, Wei,Li, Jie Jack
, p. 2382 - 2388 (2018/02/23)
2-Aminophenyl-1H-pyrazole has been identified as a viable directing group to promote copper(II)-mediated ortho-selective sp2 C-H bond tandem alkynylation/annulation of anilides with terminal alkynes to offer arylmethylene isoindolinones. Meanwhile, copper(II)-mediated ortho-selective sp2 C-H hydroxylation of anilides has also been optimized as the major reaction pathway by using Cu(OAc)2 as the promoter and 1,1,3,3-tetramethylguanidine as an organic base. Recovery of the directing group was achieved by hydrazinolysis for arylmethylene isoindolinones and basic hydrolysis for the hydroxylation products.