79598-03-1Relevant academic research and scientific papers
Cross dehydrogenative C-O coupling catalysed by a catenane-coordinated copper(i)
Au-Yeung, Ho Yu,Li, Jiasheng,Yang, Jun,Zhu, Lihui
, p. 13008 - 13014 (2020)
Catalytic activity of copper(i) complexes supported by phenanthroline-containing catenane ligands towards a new C(sp3)-O dehydrogenative cross-coupling of phenols and bromodicarbonyls is reported. As the phenanthrolines are interlocked by the strong and flexible mechanical bond in the catenane, the active catalyst with an open copper coordination site can be revealed only transiently and the stable, coordinatively saturated Cu(i) pre-catalyst is quickly regenerated after substrate transformation. Compared with a control Cu(i) complex supported by non-interlocked phenanthrolines, the catenane-supported Cu(i) is highly efficient with a broad substrate scope, and can be applied in gram-scale transformations without a significant loss of the catalytic activity. This work demonstrates the advantages of the catenane ligands that provide a dynamic and responsive copper coordination sphere, highlighting the potential of the mechanical bond as a design element in transition metal catalyst development.
Stable Enols of α-dibenzoylmethanes
Regitz, Manfred,Schaefer, Ansgar
, p. 1172 - 1185 (2007/10/02)
The enols 13a-m of α-(aryloxy)- and α-(alkyloxy)dibenzoylmethanes 4a-m are obtained by decomposition of the copper chelates 11a-m with sulfuric acid.The copper compounds are synthesized either by ester condensation of the acetophenones 6h-m with phenyl benzoate (7) or by nucleophilic substitution of α-bromodibenzoylmethane (9) with the phenols 10a-g.The enolates 8, primarily formed in the presence of sodium hydride or triethylamine, respectively, are directly converted into the chelates 11 with copper(II) acetate.The enols 13 are characterized by isomerization to the β-diketones 4 as well as by bromination to 12.
