Significant enhancement in the efficiency and selectivity of iron-catalyzed oxidative cross-coupling of phenols by fluoroalcohols.

Significant enhancement of both the rate and the chemoselectivity of iron-catalyzed oxidative coupling of phenols can be achieved in fluorinated solvents, such as 1,1,1,3,3,3-hexafluoropropan-2-ol (HFIP), 2,2,2-trifluoroethanol (TFE), and 1-phenyl-2,2,2-trifluoroethanol. The generality of this effect was examined for the cross-coupling of phenols with arenes and polycyclic aromatic hydrocarbons (PAHs) and of phenol with ß-dicarbonyl compounds. The new conditions were utilized in the synthesis of 2'''-dehydroxycalodenin B in only four synthetic steps.

Ligand-controlled iron-catalyzed coupling of α-substituted ß-ketoesters with phenols.

A chemo-, regio-, and stereoselective FeCl(3)/1,10-phenanthroline-catalyzed cross dehydrogenative coupling (CDC) reaction between phenols and α-substituted ß-ketoesters was developed. The reaction creates a new quaternary carbon center within a polycyclic hemiacetal or polycyclic spirolactone architecture. The applicability of the new method to the synthesis of natural products was demonstrated by a possible biomimetic synthesis of the lachnanthospirone core.