Efficient and highly selective catalytic conditions for the aerobic autoxidation of methylarenes to benzaldehydes, based on N-hydroxyphthalimide (NHPI) and cobalt(II) acetate in 1,1,1,3,3,3-hexafluoropropan-2-ol (HFIP), were developed. The sustainable conditions enable a multigram scale preparation of benzaldehyde derivatives in high efficiency and with excellent chemoselectivity (up to 99 % conversion and 98 % selectivity).

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 β-dicarbonyl compounds. The new conditions were utilized in the synthesis of 2'''-dehydroxycalodenin B in only four synthetic steps.

Biaryl‐bridged cyclic peptides comprise an intriguing class of structurally diverse natural products with significant biological activity. Especially noteworthy are the antibiotics arylomycin and its synthetic analogue G0775, which exhibits potent activity against Gram‐negative bacteria. Herein, we present a simple, flexible, and reliable strategy based on activating‐group‐assisted catalytic oxidative coupling for assembling biaryl‐bridged cyclic peptides from natural amino acids. The synthetic approach was utilized for preparing a number of natural and unnatural biaryl‐bridged cyclic peptides, including arylomycin/G0775 and RP 66453 cyclic cores.

Significant enhancement of both the rate and the chemoselectivity of iron-catalyzedo xidative coupling of phenols can be achieved in fluorinated solvents,such as 1,1,1,3,3,3hexafluoropropan-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 b-dicarbonyl compounds.T he new conditions were utilized in the synthesis of 2'''-dehydroxycalodenin Bi n only four synthetic steps.

In this study, a novel iron-catalyzed oxidative cross-coupling reaction between phenols and 3-alkyloxindole derivatives is reported. The efficient method, which is based on the FeCl3 catalyst and the t-BuOOt-Bu oxidant in 1,2-dichloroethane at 70 °C, affords 3-alkyl-3-(hydroxyaryl)­oxindole compounds with a high degree of selectivity. The generality of the conditions was proven by reacting various substituted phenols, naphthols, and tyrosine derivatives with 3-alkyloxindoles. To apply the chemistry for the conjugation of tyrosine-containing short peptides with oxindolylalanine (Oia) derivatives, the reaction conditions were modified [Fe­(O2CCF3)3 catalyst, t-BuOOt-Bu, HFIP, 70 °C], and amino acids with acid-stable N-protecting groups were used.