Table 3.

LSA-Sc³⁺ catalyzed electrophilic ring-opening reactions of 2-butoxy-3,4-dihydropyrans with indoles [33] ¹.

Entry	R1	R2	R3	R4	Yield (%) 2
1	OEt	Me	H	H	89 (88)
2	OEt	Me	Br	H	86
3	OEt	Ph	H	H	89
4	OEt	Ph	Br	H	63
5	OMe	Me	H	H	87
6	OMe	Me	H	Me	80
7	OMe	Me	Br	H	90
8	Me	Me	H	H	95
9	Me	Me	Br	H	96
10	OCH2CH2OMe	Me	H	H	87

¹ Reaction conditions: 2-butoxy-3,4-dihydropyran derivative (0.5 mmol), indole derivative (1.25 mmol), LSA-Sc³⁺ (10 mol%), CH₃CN₂ (1 mL), 100 °C, 11 h. Isolated yields. The yield in parentheses shows reuse of the catalyst in the third run. ² Isolated yield.