Substrate-​Directable Electron Transfer Reactions. Dramatic Rate Enhancement in the Chemoselective Reduction of Cyclic Esters Using SmI2-​H2O: Mechanism, Scope, and Synthetic Utility

TitleSubstrate-​Directable Electron Transfer Reactions. Dramatic Rate Enhancement in the Chemoselective Reduction of Cyclic Esters Using SmI2-​H2O: Mechanism, Scope, and Synthetic Utility
Publication TypeJournal Article
Year of Publication2013
AuthorsSzostak M, Spain M, Choquette KA, Flowers RA, Procter DJ
JournalJournal of the American Chemical Society
Volume135
Issue42
Start Page15702
Pagination3
Abstract

Substrate-​directable reactions play a pivotal role in org. synthesis, but are uncommon in reactions proceeding via radical mechanisms. Herein, we provide exptl. evidence showing dramatic rate acceleration in the Sm-​(II)​-​mediated redn. of cyclic esters that is enabled by transient chelation between a directing group and the lanthanide center. This process allows unprecedented chemoselectivity in the redn. of cyclic esters using SmI2-​H2O and for the first time proceeds with a broad substrate scope. Initial studies on the origin of selectivity and synthetic application to form carbon-​carbon bonds are also disclosed.