High-Speed Reduction of Triarylpyrylium Salts Using Zn(BH₄)₂/SiO₂ as an Efficient and Regiospecific Reducing Reagent

Table 2

Reaction of pyrylium salts with Zn(BH₄)₂/SiO₂.

Entry	Substrate	Product	Yield (%)	Time ( min)
1			98	5
2			85	3
3			92	3
4			97	Imm.
5			79	Imm.
6			92	Imm.
7			89	Imm.
8			90	Imm.
9			82	Imm.

Imm: immediately (1 min).