Two-phase reactions in the chemistry of carbanions and halocarbenes. A useful tool in organic synthesis
Abstract
Interfacial Generation of a Carbanion: The Key Step of PTC Reaction Directly Observed by Second Harmonic Generation.
We present the first unambiguous evidence of the interfacial mechanism of phase-transfer catalysis (PTC) by direct observation of the formation of carbanions in the interfacial region between the aqueous and the organic phase by using a surface-sensitive spectroscopic method known as second harmonic generation (SHG). Ion exchange of carbanions adsorbed at the surface after addition of lipophilic tetraalkylammonium salts (TAA) to organic phase and transport of the lipophilic ion-pairs to the organic phase is observed. Results allow for the formulation of a more detailed mechanism of PTC.
Condensation of acetone with sym-trinitrobenzene. Structure of the bicyclic product
Red bicyclic condensation product from reaction of acetone with sym-trinitrobenzene and diethylamine