Tetraalkylonium ions

In contrast, the development of asymmetric phase-transfer catalysis based on the use of structurally well-defined chiral, non-racemic catalysts has progressed rather slowly, despite its potential to create a new area of asymmetric catalysis by taking full advantage of structurally and stereochemically modifiable tetraalkylonium ions (Q ). However, recent efforts in this direction have resulted in notable achievements, thus making it feasible to perform various bond-formation reactions under the mild conditions used in phase-transfer catalysis [4],... 

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