Scheme 2. Substrate scope of anti-selective Mannich reaction. ^a Unless otherwise noted, all reactions were performed with catalyst/acid (1 : 1, 20 mol%), 1 (0.20 mmol), 2 (0.2 mL) and 4 Å MS (20 mg) in CH₂Cl₂ (0.6 mL) at 35 °C. All yields were the isolated products of the two diastereomers. The ee values were detected by SFC analysis on a chiral stationary phase and dr values were determined by ¹H NMR analysis. ^b CH₂Cl₂ (1.0 mL) as the solvent. ^c CH₂ClCH₂Cl (0.6 mL) as the solvent at 40 °C. ^d CH₂ClCH₂Cl (1.0 mL) as the solvent at 40 °C. ^e Solid ketones were 1.0 mmol.