Lewis Base Activation of Lewis Acids: Development of a Lewis Base Catalyzed Selenolactonization
作者:Scott E. Denmark、William R. Collins
DOI:10.1021/ol701617d
日期:2007.9.1
Lewis acids has been applied to the selenolactonization reaction. Through the use of substoichiometric amounts of Lewis bases with "soft" donor atoms (S, Se, P) significant rate enhancements over the background reaction are seen. Preliminary mechanistic investigations have revealed the resting state of the catalyst as well as the significance of a weak Bronsted acid promoter.
On the Mechanism of the Selenolactonization Reaction with Selenenyl Halides
作者:Scott E. Denmark、Michael G. Edwards
DOI:10.1021/jo0610457
日期:2006.9.1
The mechanism of selenocyclization reactions of β,γ-unsaturated acids and their derivatives has been studied. The reactions of (E)-4-phenyl-3-butenoic acid 10 and its silyl and alkyl esters with benzeneselenenyl chloride (PhSeCl) and bromide (PhSeBr) have been examined by VT-NMR and in situ IR spectroscopic methods. Whereas the reactions of the acid 10 in the presence of a base were irreproducible