Powerful Amide Synthesis from Alcohols and Amines under Aerobic Conditions Catalyzed by Gold or Gold/Iron, -Nickel or -Cobalt Nanoparticles

Considering the importance of the development of powerful green catalysts and the omnipresence of amide bonds in natural and synthetic compounds, we report here on reactions between alcohols and amines for amide bond formation in which heterogeneous gold and gold/iron, -nickel, or -cobalt nanoparticles are used as catalysts and molecular oxygen is used as terminal oxidant. Two catalysts show excellent activity and selectivity, depending on the type of alcohols used. A wide variety of alcohols and amines, including aqueous ammonia and amino acids, can be used for the amide synthesis. Furthermore, the catalysts can be recovered and reused several times without loss of activity

Synthesis of 2‑Pyridinemethyl Ester Derivatives from Aldehydes and 2‑Alkylheterocycle <i>N</i>‑Oxides via Copper-Catalyzed Tandem Oxidative Coupling–Rearrangement

Successful benzylic C­(sp³)–H acyloxylation of 2-alkylpyridine, 2-alkylpyrazine, and 2-alkylthiazole compounds was achieved using simple aldehydes. This was carried out via a copper-catalyzed tandem reaction, involving oxidative esterification followed by O-atom transfer of the resultant high yield formed Boekelheide intermediate. The method enables the preparation of functional heterocycles and the desymmetrization of 2,6-dialkylpyridines for efficient synthesis of dissymmetric pincer ligands, thus offering a new life for more practical Boekelheide rearrangement

Remarkable Stereoselectivity in Intramolecular Borono-Mannich Reactions: Synthesis of Conduramines

An unprecedented intramolecular Petasis condensation provides a novel approach to biologically important conduramines. The compounds are produced with an exclusive <i>anti</i> stereoselectivity for the newly created β-amino alcohol motif. The stereochemical outcome of the reaction is opposite to the one usually observed in the intermolecular reaction

Palladium-Catalyzed Regioselective C–H Bond Arylations of Benzoxazoles and Benzothiazoles at the C7 Position

We report herein, a very simple catalytic system for the direct arylation of benzoxazole and benzothiazole derivatives at C7 position, namely, phosphine-free PdCl₂ associated with PivOK in NMP at 150 °C. (Thio)­phenoxy chelation-assisted Pd-catalyzed C–H bond cleavage, from an opened intermediate, was proposed to explain this unique regioselectivity. This reaction allows the synthesis of 2-amino-6-arylphenols through the ring opening of the benzoxazole

Remarkable Stereoselectivity in Intramolecular Borono-Mannich Reactions: Synthesis of Conduramines

An unprecedented intramolecular Petasis condensation provides a novel approach to biologically important conduramines. The compounds are produced with an exclusive <i>anti</i> stereoselectivity for the newly created β-amino alcohol motif. The stereochemical outcome of the reaction is opposite to the one usually observed in the intermolecular reaction

Remarkable Stereoselectivity in Intramolecular Borono-Mannich Reactions: Synthesis of Conduramines

An unprecedented intramolecular Petasis condensation provides a novel approach to biologically important conduramines. The compounds are produced with an exclusive <i>anti</i> stereoselectivity for the newly created β-amino alcohol motif. The stereochemical outcome of the reaction is opposite to the one usually observed in the intermolecular reaction