79947-84-5Relevant articles and documents
N-Heterocyclic carbene-catalyzed oxidations
Maki, Brooks E.,Chan, Audrey,Phillips, Eric M.,Scheidt, Karl A.
experimental part, p. 3102 - 3109 (2009/09/05)
N-Heterocyclic carbenes catalyze the oxidation of allylic and benzylic alcohols as well as saturated aldehydes to esters with manganese(IV) oxide in excellent yields. A variety of esters can be synthesized, including protected carboxylates. The oxidation proceeds under mild conditions, with low loadings of a simple triazolium salt pre-catalyst in the presence of base. Substrates containing potentially epimerizable centers are oxidized while preserving stereochemical integrity. The acyl triazolium intermediate generated under catalytic conditions can be employed as a chiral acylating agent in the desymmetrization of meso-diols.
Tandem oxidation of allylic and benzylic alcohols to esters catalyzed by N-heterocyclic carbenes
Maki, Brooks E.,Chan, Audrey,Phillips, Eric M.,Scheidt, Karl A.
, p. 371 - 374 (2007/10/03)
(Chemical Equation Presented) N-Heterocyclic carbenes catalyze the oxidation of allylic, propargylic, and benzylic alcohols to esters with manganese(IV) oxide in excellent yields. A variety of ester derivatives can be synthesized, including protected carboxylates. This one-pot tandem oxidation represents the first organocatalytic oxidation of alcohols to esters. Saturated esters can also be accessed from aldehydes using this method. Through the utilization of a chiral catalyst, the acyl-heteroazolium intermediate becomes a chiral acylating agent, which can desymmetrize meso-1,2-diols.
