Table 6.

Optimization of Pd Source and Additive for the Asymmetric Oxidative Cyclization.

entry	Pd source	additive	time	convb	eeb
1.	Pd(nbd)Cl2	none	36 h	68%	12%
2.	Pd(COD)Cl2	none	36 h	30%	10%
3.	PdCl2	none	36 h	2%	12%
4.	Pd(CH3CN)2Cl2	none	36 h	53%	12%
5.	PdBr2	none	36 h	32%	8%
6.	Pd(OAc)2	none	36 h	18%	51%
7.	Pd(TFA)2	none	36 h	72%	76%
8.c	(sp)Pd(TFA)2d	none	36 h	83%	77%
9.	Pd(OTf)2(CH3CN)4	none	160 h	20%	16%
10.e	(sp)Pd(TFA)2	Na2CO3	36 h	53%	76%
11.e	(sp)Pd(TFA)2	Ca(OH)2	36 h	87%	81%

^a10 mol% Pd source, 40 mol% (−)-sparteine, 500 mg/mmol MS3Å, 1 atm O₂, toluene (0.1 M), 80 °C.

^bConversion measured by GC or by ¹H NMR.

^c30 mol% (−)-sparteine.

^dsp = (−)-sparteine.

^e10 mol% (sp)Pd(TFA)₂, 100 mol% (−)-sparteine.