Copper-catalyzed cross-coupling of ferrocenyl ketone-derived N-tosylhydrazones with benzo[d]oxazole leads to the direct C-H bond functionalization by a secondary ferrocenyl alkyl group. This direct C-H bond alkylation of azoles with N-tosylhydrazones bearing a ferrocenyl group uses inexpensive CuBr as the catalyst without any ligand. The reaction is operationally simple and conducted under mild conditions, giving the corresponding ferrocenyl-based ligands in moderate to good yields. Furthermore, they were able to act as bidentate ligands, giving rise to the corresponding palladium chelated complex 6a-6c, which were obtained by reaction of 5a-5c with [PdCl2(MeCN)2].

A novel ferrocenyl-naphthalimide multichannel probe 1 was designed and synthesized using a facile method. The color of the solution containing probe 1 changed from yellow to colorless upon the addition of Cu or Hg. Interestingly, probe 1 exhibited highly selective fluorescent turn-on for Cu and turn-off for Hg in aqueous solution. Probe 1 was an electrochemical Cu and Hg ion sensor, in which the Fc/Fc redox couple was significantly shifted (ΔE = 178 mV and ΔE = 53 mV, respectively) upon complexation. Therefore, probe 1 can act as a naked-eye chemosensor, as well as an electrochemical and a fluorescent probe for Cu and Hg. Furthermore, this is the first reported probe that can be used for the bifunctional fluorescent detection of intracellular Cu and Hg by fluorescent imaging studies. These characteristics give this probe considerable potential in the study and analysis of Cu and Hg in complex biosystems.

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We have designed and synthesized 1-substituted and 1,1′-disubstituted ferrocene-based unsymmetrical azines under metal-free conditions. The crystal structures of 3k, 5i, and 5g revealed that conjugative interactions between the ferrocene phenyl rings and the entire azine fragment exist. Furthermore, our electrochemical and optical analysis provided support for extended conjugation, which suggested a larger substituent effect in this system. Density functional theory calculations also supported the results. Thus, these results reflect a stronger conjugative interaction between the ferrocene phenyl rings and the entire azine fragment.

Fusarium wilt (FW), caused by the soil-borne fungal pathogen Fusarium oxysporum f. sp. Tracheiphilum, is a serious threat to cowpea production worldwide. Understanding the genetic architecture of FW resistance is a prerequisite to combatting this disease and developing FW resistance varieties. In the current study, a genetic diversity panel of 99 cowpea accessions was collected, and they were infected by a single strain, FW-HZ. The disease index (DI) based on the two indicators of leaf damage (LFD) and vascular discoloration (VD) varied highly across the population: most accessions were susceptible, and only seven accessions showed resistant phenotypes by both indicators. Through a genome-wide association study (GWAS), 3 and 7 single nucleotide polymorphisms (SNPs) significantly associated with LFD and VD were detected, respectively, which were distributed on chromosomes 3, 4, 5, 6 and 9, accounting for 0.68–13.92% of phenotypic variation. Based on the cowpea reference genome, 30 putative genes were identified and proposed as the likely candidates, including leucine-rich repeat protein kinase family protein, protein kinase superfamily protein and zinc finger family protein. These results provide novel insights into the genetic architecture of FW resistance and a basis for molecular breeding of FW resistant cultivars in cowpea.