Phenylene‐bridged β‐Ketoiminate Dilanthanide Aryloxides: Synthesis, Structure, and Catalytic Activity for Addition of Amines to Carbodiimides1. Issue 7 (14th April 2015)

• Record Type: Journal Article
• Authors: Hong, Yubiao; Zheng, Yu; Xue, Mingqiang; Yao, Yingming; Zhang, Yong; Shen, Qi
• Is Part Of: Zeitschrift für anorganische und allgemeine Chemie. Volume 641:Issue 7(2015)
• Page Start: 1230
• Page End: 1237
• Publication Date: 2015-04-14
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry -- Periodicals; 540
• DOI: 10.1002/zaac.201500047
• Languages: English
• ISSNs: 0044-2313

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>The synthesis and reactivity of a series of bimetallic lanthanide aryloxides stabilized by a <italic>p</italic>‐phenylene‐bridged bis(β‐ketoiminate) ligand is presented. The reaction of 1, 4‐diaminobenzene with acetylacetone in a 1:2.5 molar ratio in absolute ethanol gave the compound 1, 4‐bis(4‐imino‐2‐pentanone)benzene (<bold>1</bold>) (LH<sub>2</sub>) in high yield. Compound <bold>1</bold> reacted with (ArO)<sub>3</sub><italic>Ln</italic>(THF)<sub>2</sub> (ArO = 2, 6‐<italic>t</italic>Bu<sub>2</sub>‐4‐MeC<sub>6</sub>H<sub>2</sub>O, THF = tetrahydrofuran) in a 1:2 molar ratio in THF, after workup, to give the corresponding dilanthanide aryloxides L[<italic>Ln</italic>(OAr)<sub>2</sub>(THF)]<sub>2</sub> [<italic>Ln</italic> = Yb (<bold>2</bold>), Y (<bold>3</bold>), Sm (<bold>4</bold>), Nd (<bold>5</bold>), La (<bold>6</bold>)] in high isolated yields. Compound <bold>1</bold> and complexes <bold>2</bold>–<bold>6</bold> were fully characterized, including X‐ray crystal structure analyses for complexes <bold>2</bold>, <bold>3</bold>, <bold>5</bold>, and <bold>6</bold>. Complexes <bold>2</bold>–<bold>6</bold> can be used as efficient pre‐catalysts for catalytic addition of amines to carbodiimides, and the ionic radii of the central metal atoms have a significant effect on the catalytic activity with the increasing sequence of La (<bold>6</bold>) < Nd (<bold>5</bold>) ≈ Sm (<bold>4</bold>) < Y (<bold>3</bold>) ≈ Yb (<bold>2</bold>). The catalytic addition reaction with <bold>2</bold> showed a good scope of substrates including primary and secondary amines.</p> </abstract>