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

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.

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