|Title||Substrate-Directable Electron Transfer Reactions. Dramatic Rate Enhancement in the Chemoselective Reduction of Cyclic Esters Using SmI2-H2O: Mechanism, Scope, and Synthetic Utility|
|Publication Type||Journal Article|
|Year of Publication||2013|
|Authors||Szostak M, Spain M, Choquette KA, Flowers RA, Procter DJ|
|Journal||Journal of the American Chemical Society|
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.