79947-84-5Relevant academic research and scientific papers
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.
Catalytic amide-mediated methyl transfer from silanes to alkenes in Fujiwara-Moritani oxidative coupling
Rauf, Waqar,Brown, John M.
scheme or table, p. 4228 - 4230 (2009/03/12)
(Chemical Equation Presented) Intramolecular assistance: Carbon-bound trimethylsilyl groups are activated intramolecularly by a carbonyl group and can participate in Heck reactions under oxidative conditions. Good stereoselectivities are obtained for a range of di-and trisubstituted alkenes (see example).
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.
Esterification of carboxylic acids catalyzed by in situ generated tetraalkylammonium fluorides
Ooi, Takashi,Sugimoto, Hayato,Doda, Kanae,Maruoka, Keiji
, p. 9245 - 9248 (2007/10/03)
Esterification of carboxylic acids with alkyl halides can be efficiently catalyzed by tetrabutylammonium fluoride (TBAF) generated in situ from tetrabutylammonium hydrogensulfate (TBAHSO4) and KF·2H2O in THF. The general applicability and the characteristic feature of this approach has been amply demonstrated.
