Search

Herein, we present an accessible aerobic N-heterocyclic carbene (NHC)-catalyzed method that efficiently produces tetrasubstituted benzene rings in a single reaction. The method employs atmospheric oxygen (O2) as the terminal oxidant in a reaction that requires two oxidative steps. The aerobic oxidation is achieved by a selection of electron transfer mediators orchestrating a redox cascade, turning a high-energy aerobic oxidation reaction pathway into a favorable process.

Here we present a polycyclization of oxotriphenylhexanoates. The polycyclization is governed by electronic effects, and three major synthetic paths have been established leading to stereochemically complex tricyclic frameworks with up to five stereogenic centers. The method is compatible with an array of functional groups, allowing pharmacophoric elements to be introduced post cyclization.

We present a highly selective protocol for the orthobenzylation of N-aryl amides. This method offers mild conditions, excellent site specificity, and scalability, enabling the synthesis of diarylmethane amides and dibenzoazepines. The protocol allows for one-pot diagonal dibenzylation of dianilides, creating valuable precursors for pharmaceutically active compounds and addressing limitations in current direct C–H activation methodologies.

An N-heterocyclic carbene (NHC) covalently linked to a quinone introduces a novel avenue for internal oxidations within oxidative NHC catalysis. The deployment of this hybrid NHC class promotes intramolecular electronic flow in the oxidation of the Breslow intermediate to acyl azolium. The use of the redox active NHC as a catalyst is facilitated by employing aerobic regeneration, yielding carboxylic esters with efficiencies of ≤99%, while generating water as the sole byproduct.

A photomediated protocol giving facile access to substituted β-lactam and β-lactones is presented. The method realizes, for the first time, the use of the Zimmerman–O’Connell–Griffin (ZOG) rearrangement in [2 + 2] cycloaddition. Products are obtained in high yield with excellent diastereoselectivity under visible light irradiation and under mild reaction conditions.