Open AccessSubstrate-Directable Electron Transfer Reactions. Dramatic Rate Enhancement in the Chemoselective Reduction of Cyclic Esters Using SmI2–H2O: Mechanism, Scope, and Synthetic Utility
Author(s) -
Michal Szostak,
Malcolm Spain,
Kimberly A. Choquette,
Robert A. Flowers,
David J. Procter
Publication year - 2013
Publication title -
journal of the american chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.115
H-Index - 612
eISSN - 1520-5126
pISSN - 0002-7863
DOI - 10.1021/ja4078864
Subject(s) - chemistry , chemoselectivity , substrate (aquarium) , lanthanide , electron transfer , redox , scope (computer science) , combinatorial chemistry , reaction mechanism , photochemistry , chelation , organic chemistry , catalysis , ion , oceanography , computer science , programming language , geology
Substrate-directable reactions play a pivotal role in organic synthesis, but are uncommon in reactions proceeding via radical mechanisms. Herein, we provide experimental evidence showing dramatic rate acceleration in the Sm(II)-mediated reduction of cyclic esters that is enabled by transient chelation between a directing group and the lanthanide center. This process allows unprecedented chemoselectivity in the reduction 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.