Four-Component Catalytic Machinery: Reversible Three-State Control of Organocatalysis by Walking Back and Forth on a Track

• Published in: Inorganic chemistry Vol. 57; no. 7; pp. 3579 - 3586
• Main Authors: Mittal, Nikita, Özer, Merve S, Schmittel, Michael
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 02.04.2018
• ISSN: 0020-1669; 1520-510X
• DOI: 10.1021/acs.inorgchem.7b02703

A three-component supramolecular walker system is presented where a two-footed ligand (biped) walks back and forth on a tetrahedral 3D track upon the addition and removal of copper­(I) ions, respectively. The addition of N-methylpyrrolidine as a catalyst to the walker system generates a four-component catalytic machinery, which acts as a three-state switchable catalytic ensemble in the presence of substrates for a conjugate addition. The copper­(I)-ion-initiated walking process of the biped ligand on the track regulates the catalytic activity in three steps: ON versus int ON (intermediate ON) versus OFF. To establish the operation of the four-component catalytic machinery in a mixture of all constituents, forward and backward cycles were performed in situ illustrating that both the walking process and catalytic action are fully reversible and reproducible.