2z' Interestingly, and in contrast to previous observations in silver-catalyzed NT, the counteranion identity was also important, as AgClO4 (entry 7) and AgOTf (entry 8) gave inferior results. This is attributed to the higher binding affinity of the corresponding anions of these salts as compared to AgNTf2. When the temperature was lowered from -10 °C to -20 °C (entry 9), the conversion after 24 h dropped significantly with no improvement in the ee. An attempt to reduce the catalyst loading from 10 mol % to 5 mol % (entry 10) led to decreased yield and ee. Finally, the reaction was amenable to scale-up (entry 11), as a gram-scale (2.5 mmol) reaction afforded 2a in yields (89%) and enantioselectivity (95% ee) comparable to reaction carried out on a 0.1 mmol scale. The absolute stereochemistry of 2a was shown to be (6R,7S) by X-ray crystallography (Supporting Information for details).