Abstract

A series of 5-sulfurated imidazo[1,5-a]pyridin-3-ylidenes (Imidazo[1,5-a]pyridine carbenes: IPCs) and their Cu and Pd complexes were synthesized. Theoretical investigations of the free carbenes and Cu complexes implied that the IPCs were good π-acceptors. Particularly, Cu complexes of 5-arylsulfonyl IPC were strong π-acids. These complexes were tested as π-acidic catalysts in the Cu-catalyzed hydroboration of an internal alkyne with diboron and the Mizoroki-Heck reaction. As a result, the trend in reactivity corresponded with the theoretical considerations.

Abstract

A one-pot synthesis of 2-acylidene-3-oxindole and azaaurone derivatives starting from O-alkynylanilines and alkynes is presented. By means of oxidative gold catalysis the two starting materials are transferred to reactive intermediates that in situ form the target products. This double oxidation strategy enables a protecting group-free step-economic strategy towards these valuable substrate classes.

Abstract

The Annual Wolf Prize Symposia of the Israel Chemical Society (ICS) have become a significant component of the scientific landscape of the State of Israel. These highly attended events occur annually in late May or early June as part of the Wolf Prize week, usually one day before the award ceremony in the Knesset. This account covers the one-day symposium at the Weizmann Institute of Science on June 14, 2023, the Wolf Prize ceremony in the Knesset on June 15, and several other events in Israel that week, all honoring Chuan He, Jeffrey W. Kelly, and Hiroaki Suga.

The cover picture illustrates symbolically the critical step in π-acid catalysis as a bullfighting scene: a metal catalyst (the toreador) binds an alkyne and activates it for an attack by a nucleophile (the bull). Cover image by Dr. Igor Armiach.

Abstract

Density functional theory (DFT) is a powerful tool that can aid in the exploration and development of synthetic chemistry, and its use is often applied in the chemistry of gold(I) catalysis. In this review, we discuss two different facets of these calculations – namely, the exploration and explanation of anion effects, and the regioselectivity and speciation of gold(I)-catalysed reactions. The research described herein clearly shows the importance of including the anion in DFT studies of Au(I)-catalysed reactions, especially when using low polarity solvents, or where hydrogen-bonding is prevalent. Additionally, we show that whilst using DFT to study the selectivity of reactions can be successful, benchmarking the computational results against experimental data is vitally important for ensuring that the model is accurately describing the observed results.