Fig. 3: Scope of aldehydes.

All reactions were performed under N2 atmosphere, dr was determined by analysis of 1H NMR spectra of unpurified mixtures, and er was determined by analysis of HPLC spectra. aThe reaction was performed in the presence of 2.0 equiv of propargyl carbonate and 2.0 equiv of Hantzsch’s ester for 17 h. bYield of pure major diastereomer. cThe reaction was performed in the presence of 5.0 mol % (S,S)-5h. 4CzlPN = 1,2,3,5-tetrakis(carbazole-9-yl)−4,6-dicyanobenzene, Hantzsch’s ester = diethyl 1,4-dihydro-2,6-dimethyl-3,5-pyridinedicarboxylate.