N-Heterocyclic olefins as efficient phase-transfer catalysts for base-promoted alkylation reactions

Abstract

N-Heterocyclic olefins (NHOs) have very recently emerged as efficient promoters for several chemical reactions due to their strong Brønsted/Lewis basicities. Here we report the novel application of NHOs as efficient phase-transfer organocatalysts for synthetically important alkylation reactions on a wide range of substrates, further demonstrating the great potential of NHOs in organic chemistry.

N‐Heterocyclic Olefin–Carbon Dioxide and –Sulfur Dioxide Adducts: Structures and Interesting Reactivity Patterns

“…The NHOs, which are generated in situ and most likely the active species in these catalytic cycles, have also been employed as highly basic starting materials for the synthesis of ionic liquids and as polymerization catalysts for propylene oxide, methyl methacrylate, and lactones . They are also versatile organocatalysts for transesterification and base‐promoted alkylation reactions . Furthermore, they are interesting ligands in main‐group and transition‐metal complexes…”

“…[24] They are also versatile organocatalysts for transesterification [25] and base-promoted alkylation reactions. [26] Furthermore, they are interesting ligandsinm ain-group andt ransition-metalcomplexes. [27] During our investigations,w hich were primarily concerned with the preparation of organic salts with hydrochalcogenide and trimethylsilylchalcogenolate anions, [1i, j] we noticedaselective and easy access to imidazolium-2-carboxylates and discovered that 1,3-dialkyl-2-methylimidazolium methyl carbonate salts form carboxylate zwitterions as well.…”

Promotion of Organic Reactions by Non‐Benzenoid Carbocyclic Aromatic Ions

“…[56] Apart from the traditional tetraalkyl ammonium and phosphonium salts,i midazolium, triazolium, and tetraaminophosphonium salts have recently been utilized. [56] Apart from the traditional tetraalkyl ammonium and phosphonium salts,i midazolium, triazolium, and tetraaminophosphonium salts have recently been utilized.…”

CO2 Sequestration by Triazolylidene-Derived N-Heterocyclic Olefins: A Computational Study

“…A particular class of chemical systems that allows the exploration of the CO 2 as a C1 source is the N‐heterocyclic carbenes (NHCs). During the last years, the NHC systems and related derivatives were seen to promote different reactions . For instance, the recent N‐ heterocyclic olefins (NHOs) compounds, as well as the NHCs, react with CO 2 yielding NHO carboxylates (NHO‐CO 2 ) (Figure A and 1B).…”

“…For instance, the recent N‐ heterocyclic olefins (NHOs) compounds, as well as the NHCs, react with CO 2 yielding NHO carboxylates (NHO‐CO 2 ) (Figure A and 1B). Both NHOs and NHO‐CO 2 are considered powerful nucleophiles for a large range of chemical reactions ,,,…”