Enantioselective Cyanoethoxycarbonylation of Isatins Promoted by a Lewis Base–Brønsted Acid Cooperative Catalyst

Yoshihiro Ogura, Matsujiro Akakura, Akira Sakakura,* Kazuaki Ishihara* 
Angew. Chem. Int. Ed.2013, 52 (32), 8299–8303.  (Published online: 03 July 2013) 
DOI: 10.1002/anie.201303572 

Teaming up to make it happen: In the title reaction, the Lewis basic site of the catalyst activated ethyl cyanoformate, and the deep and flexible Brønsted acidic cavity stabilized and selectively recognized the key reaction intermediate to promote asymmetric acylation (see scheme).