Metal-Initiated/Catalyzed Diels-Alder Reaction between Electron Rich Dienes and Dienophiles

Abstract

The Diels-Alder (DA) reaction is one the most used reaction for the construction of organic compounds. However, the DA reactions between electronically mismatched partners are difficult to achieve thermally. A few methods can perform this transformation using a radical cation strategy. These approaches either give low yields of DA products or require the use of expensive materials or specialized setups. We have found that a paperclip can catalyze/initiate a Diels-Alder (DA) reaction at room temperature between electron-rich dienes and electron-rich dienophiles. The reaction gives excellent yields of DA products in a highly regio- and diastereoselective manner. The reaction mechanism is speculated to involve an electron transfer from one of the metals present in the paperclip to the dienophile. The talk will discuss our efforts in testing the hypothesis that certain metal(s) in a paperclip are responsible for the DA reaction and showcase our systematic search for this metal catalyst/initiator in light of suspected reaction mechanisms. Preliminary screening of substrate scope of the reaction will also be presented. The reaction has the potential to become the most economical, sustainable and practical method for the formation of DA products between electron-rich partners, thus expanding the scope of the DA reaction.