Table 5.

Mechanistic studies via kinetic resolution of unsymmetrical diarylmethanes^a,b

racemic substrate	entry	solvent	k rel
	1	DMF/Tol	5.3
	2	DMF	3.5
	3	DMF/Tol	11.3
	4	DMF	6.9
	5	DMF/Tol	10.3
	6	DMF	4.8

^aReaction conditions: racemic substrate (0.3 mmol), diethyl malonate (1.1 equiv), Cu(MeCN)₄BF₄ (5 mol%), peptide (10 mol%), Cs₂CO₃ (3.2 equiv), DMF/Tol (0.38/0.83 mL) or DMF (1.2 mL).

^bConversions were determined by 1H NMR and enantiomeric ratios were determined by chiral high performance liquid chromatography analysis. See supporting information for details. Results are reported as an average of two runs.