Asymmetric Phase-Transfer-Catalyzed Intramolecular N-Alkylation of Indoles and Pyrroles: A Combined Experimental and Theoretical Investigation
Asymmetric phase-transfer catalysis (PTC) has risen to prominence over the last decade as a straightforward synthetic methodology for the preparation of pharmacologically active compounds in enantiomerically pure form. However, the complex interplay of weak nonbonded interactions (between catalyst and substrate) that could account for the stereoselection in these processes is still unclear, with tentative pictorial mechanistic representations usually proposed. Here we present a full account dealing with the enantioselective phase-transfer-catalyzed intramolecular aza-Michael reaction (IMAMR) of indolyl esters, as a valuable synthetic tool to obtain added-value compounds, such as dihydro- pyrazinoindolinones. A combined computational and experimental investigation has been carried out to elucidate the key mechanistic aspects of this process.
Keywords: asymmetric catalysis ; computational chemistry ; indoles ; Michael addition ; phase-transfer catalysis ; Friedel-Crafts Reaction ; Aza-Michael Reaction ; Enantioselective Total-Synthesis ; Quaternary Ammonium-Salts ; Chiral Bronsted Acids ; Allylic Alkylation ; Thermochemical Kinetics ; Density Functionals ; Carbonyl-Compounds ; Natural-Products
Record created on 2010-09-24, modified on 2016-08-08