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The effectiveness of a series of chiral phase transfer catalysts in cascade reactions of active methylene compounds with 2‐cyanobenzaldehyde leading to chiral 3‐substituted isoindolinones and fused benzoindolizidinones has been investigated. High yields and moderate enantiomeric excesses (e.e.s) were achieved employing a chiral phase‐transfer catalyst derived from bifunctional urea–quinine. Moreover, an efficient process of heterochiral crystallization, performed on moderately enantioenriched compounds, led to an impressive increase of the enantiopurity up to 93% e.e.s.

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A chiral phase transfer catalyst is used in the reaction of 2-cyanobenzaldehyde with active methylene compounds. The products (III) and (VII) are obtained in high yield but only moderate enantiomeric excess. (III) and (VII) react with acrolein to give tricyclic compounds (V) and (VIII). A method is given to obtain the products in higher enantiomeric excesses (up to 93%) by a heterochiral crystallization process. -(TISO, S.; MASSA*, A.; J. Heterocycl. Chem. 52 (2015) 5, 1570-1575, http://dx.doi.org/10.1002/jhet.2170 ; Dip. Chim. Biol., Univ. Salerno, I-84084 Fisciano, Salerno, Italy; Eng.) -M. Bohle 08-134