Table 1.

Conditions for Reaction Kinetics Optimization^a

Entry	Ligand	Base	Yield (%)b	ee (%)c
1	(4R,5S)-Bis-Ph-Box	K2CO3	97	90
2	(R,R)-Ph-Box	K2CO3	90	88
3	(R,R)-Ph-Box	NBu4OAc	98	<5
4	(R,R)-Ph-Box	2,6-di-t-butyl-4-methyl- pyridine	75	87
5	(R,R)-Ph-Box	-	87	88
6d	(R,R)-Ph-Box	-	88	87

^aCu(OTf)₂ (20 mol%), (R,R)-Ph-Box (25 mol%) and PhCF₃ (0.07 M w/r to 1a) were combined i a pressure tube and heated to 60 °C for 2 h. Substrate 1a (1 equiv, 0.139 mmol), TEMPO (3 equiv), K₂CO₃ (1 equiv) were added. The reaction mixture was heated to 110 °C for 24 h.

^bYield (%) refers to amount of isolated 2a after purification by flash chromatography on SiO₂.

^cEnantiomeric excesses were determined by chiral HPLC analysis.

^dThe reaction was run using 20 mol% of (R,R)-Ph-Box. OTf = trifluoromethanesulfonyl.