Table 1. Different Conditions for the Formation of Disulfide-Functionalized Enaminone^a.

entry	catalyst	solvent	T (°C)	yield (%)b
1	I2	EL	90	69
2	no	EL	90	72
3	no	DMF	90	47
4	no	DMSO	90	18
5	no	toluene	90	15
6	no	H2O	90	90
7	no	H2O	70	92
8	no	H2O	50	56

^aGeneral conditions: 1a (0.4 mmol), 2 (0.4 mmol), catalyst (0.12 mmol or no catalyst), and 2 mL of solvent stirred for 12 h at rt under air atmosphere.

^bYield of the isolated product.