Hafnocene dichloride-silver

Matsumoto, T, Katsuki, M, Jona, H, Suzuki, K, Synthetic study toward vineomycins. Synthesis of C-aryl glycoside sector via hafnocene dichloride-silver perchlorate-promoted tactics. Tetrahedron Lett., 30, 6185-6188, 1989. 

The direct linkage of phenolic aromatic rings in the presence of hafnocene dichloride-silver perchlorate as a promoter has been described in the synthesis of gilvocarcin M and V [ 168,295,296]. 

So far, the only examples of O-C migrations have applied to pyranose sugars or derivatives thereof. However, it should be noted that such reactions are applicable to furanose sugars. One particular example, reported by Matsumoto, et al.,101 was used in the total synthesis of gilvocarcin M. The specific reaction, shown in Scheme 2.4.25, utilized the acetoxy activated furanoside shown. Treating this compound with the phenol and using the hafnocene dichloride-silver perchlorate complex as the Lewis acid, the desired C-arylglycoside was obtained in 87% yield with the a anomer favored in a ratio of 8 1. 

Zirconocene dichloridejsilver perchlorate Hafnocene dichloride j silver perchlorate P-Glycosides from p-glycosyl fluorides Solvent effect on stereoselectivity... 

Zirconocene dichloride j silver perchlorate Hafnocene dichloride j silver perchlorate C-Aryl glycosides from glycosyl fluorides Stereospecifle conversion... 

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