A Dinuclear Dysprosium Complex as an Air‐Stable and Recyclable Catalyst: Applications in the Deacetylation of Carbohydrate, Aliphatic, and Aromatic Molecules

Two dinuclear DyIII complexes, [Dy2(hmb)2(OTf)2(H2O)4]⋅HOTf⋅2 THF (A⋅HOTf⋅2 THF) and [Dy2(hmi)3(H2O)2]⋅2 HOTf (B⋅2 HOTf), have been synthesized by the reaction of Dy(OTf)3 and the Schiff‐base ligands H2hmb (N′‐(2‐hydroxy‐3‐methoxybenzylidene)benzohydrazide) or H2hmi ((2‐hydroxy‐3‐methoxyphenyl)methylene isonicotinohydrazine). Disarmed glycosyl trichloroacetimidates can be activated by complex A in the synthesis of 1,2‐trans‐glycosides with primary and secondary acceptors. This method offers an efficient route to selectively deacetylated monosaccharides and disaccharides in high yields and a green catalyst that can be easily recycled and reused. Dysprosium deacetylation: Disarmed glycosyl trichloroacetimidates can be activated by a dinuclear dysprosium complex ([Dy2(hmb)2(OTf)2(H2O)4]⋅HOTf⋅2 THF; H2hmb=N′‐(2‐hydroxy‐3‐methoxybenzylidene)benzohydrazide) in the synthesis of 1,2‐trans‐glycosides with primary and secondary acceptors (see scheme). This offers an efficient route to selectively deacetylated saccharides in high yields with a green catalyst that is easily recycled and reused.