July 6, 2009

Building Addressable Libraries: Site-Selective Lewis-Acid (Sc(III)) Catalyzed Reactions

Bo Bi, Karl Maurer, and Kevin D. Moeller.
Angew. Chem. Int. Ed. Eng. 2009, 48, 5872

Lewis acid-catalyzed reactions have been site-selectively conducted on arrays having either 1024 microelectrodes cm-2 or 12,544 microelectrodes cm-2. The reactions employ Sc(III) generated at the microelectrodes as the Lewis acid, and confine the reagent to the electrodes utilized in its generation with the use of  2-phenylbenzthiazole  as a solution phase reductant. A multicomponent synthesis of a tetrahydropyran, a Diels-Alder reaction, and an esterification reaction were all shown to be compatible with the electrochemical generation of the Sc(III) and the confinement strategy.