Silver & gold-catalyzed routes to furans and benzofurans

Silver and gold have become incredibly versatile and mild catalysts for numerous transformations, especially in heterocycle synthesis. For the most prominent of them, i.e. furans, silver and gold, with their unique reactivity and mildness, allow numerous possible routes to highly substituted and/or functionalized furans from a large variety of starting materials. Silver and gold catalysis provide thus the most flexible way to this important family of compounds. The present review describes these silver and gold-catalyzed routes, with some emphasis on mechanistic aspects, and proposes a comparison of both the silver and the gold-catalyzed syntheses of furans.

DFT study on the CuBr-catalyzed synthesis of highly substituted furans: effects of solvent DMF, substrate MeOH, trace H2O and the metallic valence state of Cu

Comparing the catalytic abilities of DMF, MeOH, and H₂O for intermolecular nucleophilic addition and H-transfer process.

The mechanism and regioselectivity of gold(i) or platinum(ii) catalyzed intramolecular hydroarylation to pyrrolopyridinones and pyrroloazepinones

Pyrrolopyridinones and pyrroloazepinones can be prepared through gold(i) or platinum(ii) catalysis. These interesting gold(i) or platinum(ii) catalyses are fully supported by a computational study justifying the formation of each intermediate.

How Accurate Can a Local Coupled Cluster Approach Be in Computing the Activation Energies of Late-Transition-Metal-Catalyzed Reactions with Au, Pt, and Ir?

To improve the accuracy of local coupled cluster (LCC) methods in computing activation energies, we propose herein a new computational scheme. Its applications to various types of late-transition-metal-catalyzed reactions involving Au, Pt, and Ir indicate that the new corrective approach for LCC methods can downsize the mean unsigned deviation and maximum deviation, from the CCSD(T)/CBS reference, to about 0.3 and 0.9 kcal/mol. Using this method, we also calibrated the performance of popular density functionals, with respect to the same test set of reactions. It is concluded that the best functional is the general-purpose double hybrid functional B2GP-PLYP. Other well-performing functionals include the "kinetic" functionals M06-2X and BMK, which have a large percentage of HF exchange, and general-purpose functionals like PBE0 and wB97X. Comparatively, general-purpose functionals like PBE0 and TPSSh perform much better than the tested "kinetic" functionals for Pt-/Ir-catalyzed reactions, while the opposite is true for Au-catalyzed reactions. In contrast, wB97X performs more uniformly in these two classes of reactions. These findings hint that even within the scope of late transition metals, different types of reactions may require different types of optimal DFT methods. Empirical dispersion correction of DFT was found to have a small or no effect on the studied reactions barriers.