Solid-Supported Reagents in Organic Synthesis David H. Drewry,1 Diane M. Coe,2 Steve Poon1 ... The reactiv- ity of NaBH4 can be enhanced by combining it with certain transition metal salts. ... hexanal 10 1 6.5% p-NO2 benzaldehyde 10 1 92.3% p-MeO benzaldehyde 10 1 5.2% ...