Wu, Kai published the artcileTransition-Metal-Free C(sp2)-C(sp2) Cross-Coupling of Diazo Quinones with Catechol Boronic Esters, Name: 5-(6-Hydroxybenzofuran-2-yl)benzene-1,3-diol, the publication is Angewandte Chemie, International Edition (2020), 59(37), 16202-16208, database is CAplus and MEDLINE.
A transition-metal-free C(sp2)-C(sp2) bond formation reaction by the cross-coupling of diazo quinones with catechol boronic esters was developed. With this protocol, a variety of biaryls and alkenyl phenols were obtained in good to high yields under mild conditions [e.g., ortho-diazo quinone I + catechol boronic ester II → III (94%) using K2CO3 as base and MeCN/DCM mixed solvent]. The reaction tolerates various functionalities and is applicable to the derivatization of pharmaceuticals and natural products. The synthetic utility of the method was demonstrated by the short synthesis of multi-substituted triphenylenes and three bioactive natural products, honokiol, moracin M, and stemofuran A. Mechanistic studies and d. functional theory (DFT) calculations revealed that the reaction involves attack of the boronic ester by a singlet quinone carbene followed by a 1,2-rearrangement through a stepwise mechanism. Safety: diazo quinones are potentially explosive.
Angewandte Chemie, International Edition published new progress about 56317-21-6. 56317-21-6 belongs to benzofurans, auxiliary class Metabolic Enzyme,PDE,Natural product, name is 5-(6-Hydroxybenzofuran-2-yl)benzene-1,3-diol, and the molecular formula is C7H8FNO2S, Name: 5-(6-Hydroxybenzofuran-2-yl)benzene-1,3-diol.