η⁶‐Metalated Aryl Iodides in Diels‐Alder Cycloaddition Reactions: Mode of Activation and Catalysis

Abstract

The potential application of η 6 -metalated aryl iodides as organocatalyst has been explored by means of computational methods. It is found that the enhanced halogen bonding donor ability of these species, in comparison with their demetalated counterparts, translates into a significant acceleration of the Diels-Alder cycloaddition reaction involving cyclohexadiene and methyl vinyl ketone.The factors behind this acceleration, the endo-exo selectivity of the process and the influence of the nature of the transition metal fragment in the activity of these species are quantitatively explored in detail by means of the combination of the Activation Strain Model of reaction and the Energy Decomposition Analysis methods.

Not antiaromaticity gain, but increased asynchronicity enhances the Diels–Alder reactivity of tropone

“…Similar conclusions were found by us and others when studying catalyzed DA reactions. 5 In this work, we challenge the frequently used antiaromaticity-induced HOMO-raising rationale . We computationally studied the DA reaction between maleimide and tropone ( 1 ) and hydrazone analogs 2-prot , 2 , 3-prot , and 3 (Scheme 1) using the activation strain model (ASM) 6 with a matching energy decomposition analysis (EDA) 7 and quantitative Kohn-Sham molecular orbital theory.…”