Cooperative nucleophilic–electrophilic organocatalysis by ionic liquidsw
نویسندگان
چکیده
The anionic and the cationic partners of ionic liquids may act cooperatively and independently as nucleophilic and electrophilic catalysts. This ambiphilic propensity was demonstrated by kinetically discriminating the contributions of the anion (nucleophilic catalyst) and of the cation (electrophilic catalyst) to the solvent-free Baylis– Hillman dimerization of cyclohexenone catalysed by ionic liquids.
منابع مشابه
A cooperative allylic fluorination: combination of nucleophilic and electrophilic fluorine sources
A one step, regioselective allylic fluorination of alkenes is reported in which electrophilic and nucleophilic sources of fluorine act synergistically to afford rearranged allylic fluorides over alternative vicinal dihalides. The reaction occurs under exceptionally mild conditions and without need for prefunctionalization or transition metal catalysts. The fluorination of cyclic alkenes and mon...
متن کاملIonic liquids as transesterification catalysts: applications for the synthesis of linear and cyclic organic carbonates
The use of ionic liquids (ILs) as organocatalysts is reviewed for transesterification reactions, specifically for the conversion of nontoxic compounds such as dialkyl carbonates to both linear mono-transesterification products or alkylene carbonates. An introductory survey compares pros and cons of classic catalysts based on both acidic and basic systems, to ionic liquids. Then, innovative gree...
متن کاملReaction of allene esters with Selectfluor/TMSX (X = I, Br, Cl) and Selectfluor/NH4SCN: Competing oxidative/electrophilic dihalogenation and nucleophilic/conjugate addition
Reaction of benzyl and ethyl allenoates with TMSX (X = I, Br, Cl) and with NH4SCN were investigated in MeCN, DMF, and in imidazolium ionic liquids [BMIM][NTf2] and [BMIM][PF6] as solvent, in the presence and absence of Selectfluor. Comparative product analysis studies demonstrate that the ability of Selectflour to promote oxidative/electrophilic dihalogenation/dithiocyanation with TMSX/NH4SCN (...
متن کاملRecent Advances in the Synthesis of Spiroheterocycles via N-Heterocyclic Carbene Organocatalysis.
Spiroheterocycles are regarded as a privileged framework because of their wide distribution in various natural products and synthetic molecules and promising bioactivities. This review focuses on the recent advances in the synthesis of spiroheterocycles by using the strategy of N-heterocyclic carbene (NHC) organocatalysis, and is organized based on the stereoselectivity and the reactive interme...
متن کامل