In 2008,Reisner, Erwin; Lippard, Stephen J. published 《Synthesis of dicarboxylate “”C-clamp”” 1,2-diethynylarene compounds as potential transition-metal ion hosts》.European Journal of Organic Chemistry published the findings.Formula: C7H6BrNO2 The information in the text is summarized as follows:
An efficient convergent synthesis is reported for a new type of C-clamp ligand with a 1,2-diethynylarene scaffold involving a chelate host capable of binding a guest mol. in its endo-dicarboxylate pocket. The chem. involves a combination of palladium-catalyzed Sonogashira, Heck, and Suzuki cross-coupling reactions. The compounds 2,3-bis[2-(2′-carboxybiphenyl-4-yl)ethynyl]triptycene and 4,5-bis[2-(2′-carboxybiphenyl-4-yl)ethynyl]veratrole and their 2′-carboxy-m-terphenyl-4-yl analogs were designed as dinucleating ligands to assemble carboxylate-bridged transition-metal complexes with a windmill geometry. The X-ray crystal structure of one such C-clamp compound containing co-crystallized water mols. reveals strong hydrogen bonds of the aqua guest to the endo-oriented carboxylic acid entities of the C-clamp host. In addition, two syn-N-donor ligands were prepared as a synthetic scaffold to mimic the geometric arrangement of N-donor atoms in carboxylate-bridged dinuclear proteins. In the experiment, the researchers used many compounds, for example, Methyl 5-bromopicolinate(cas: 29682-15-3Formula: C7H6BrNO2)
Methyl 5-bromopicolinate(cas: 29682-15-3) belongs to pyridine. Pyridine is very deactivated towards electrophilic substitution with respect to benzene. For this reason classical formylation, using methods such as the Gattermann or Vilsmeier reactions, are not generally successful. Formula: C7H6BrNO2