Table 3.

Reaction Optimization for Aromatic Aldehydes^a

entry	solvent	yieldb (%)
1	DCE	23
2	EtOH	trace
3	i-PrOH	20
4	CF3CH2OH	50
5	CH3CN	trace
6	DMF	17
7	EtOAc	63
8	Dioxane	53
9	HOAc	78
10	THF	78

^[a]Conditions: 1b (0.10 mmol), aldehyde 5a (0.20 mmol) in 0.33 mL of solvent

^[b]Determined by ¹H NMR analysis relative to 1,3,5-trimethoxybenzene as an internal standard.