Scheme 2. Substrate scope^a. [a] Unless otherwise noted, all reactions were carried out with A (0.1 mmol) and L₃-TQCp/Co(BF₄)₂·6H₂O (1 : 1, 10 mol%) in 1,1,2,2-TCE (0.1 M). Yields of the isolated product. ee was determined by HPLC or UPC² analysis on a chiral stationary phase. [b] 3.0 mmol A1 was used.