Heterobimetallic dinuclear lanthanide alkoxide complexes Ln2Na8(OCH2CH2NMe2)12(OH)2 [Ln: I (Nd), II (Sm), III (Yb) and IV (Y)] were used as efficient acid–base bifunctional catalysts for the synthesis of carbamates and the N-Boc protection of amines.

A practical heterobimetallic lanthanide‐catalyzed transamidation of primary, secondary and tertiary amides with aliphatic and aromatic amines has been developed. The methodology was also applied to the weakly reactive thioamides to demonstrate its versatility and wide substrate scope. The heterobimetallic lanthanide catalysts showed high catalytic activity and a wide scope of substrates with good to excellent yields under solvent‐free conditions. Efficient activation of the transamidation can be realized by the above complexes acting as cooperative acid–base bifunctional catalysts, which are proposed to be responsible for the higher reactivity in comparison with simple monometallic catalysts.magnified image

A practical lanthanide(III)-catalyzed transesterification of carboxylic esters, weakly reactive carbonates, and much less-reactive ethyl silicate with primary and secondary alcohols was developed. Heterobimetallic dinuclear lanthanide alkoxide complexes [Ln2Na8{(OCH2CH2NMe2)}12(OH)2] (Ln = Nd (I), Sm (II), and Yb (III)) were used as highly active catalysts for this reaction. The mild reaction conditions enabled the transesterification of various substrates to proceed in good to high yield. Efficient activation of transesterification may be endowed by the above complexes as cooperative acid-base difunctional catalysts, which is proposed to be responsible for the higher reactivity in comparison with simple acid/base catalysts.

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