One‐Component Aluminum(heteroscorpionate) Catalysts for the Formation of Cyclic Carbonates from Epoxides and Carbon Dioxide

• DOI: 10.1002/cssc.201601370
• Publication Date: 2016-11-10T16:01:29Z
• Authors: Javier Martínez; José A. Castro‐Osma; Carlos Alonso‐Moreno; Antonio Rodríguez...; Michael North; Antonio Otero; Agustín Lara‐Sánchez
• Keywords: Cationic polymerization; Bimetallic strip; Benzyl bromide

New neutral and zwitterionic chiral NNO-donor scorpionate ligands 1 2 were designed to obtain new mononuclear dinuclear NNO-heteroscorpionate aluminum complexes. Reaction of with [AlR3 ] (R=Me, Et) in a 1:1 or 1:2 molar ratio afforded the alkyl complexes [AlR2 (κ2 -bpzappe)] {R=Me (3), Et (4); bpzappeH=2,2-bis(3,5-dimethylpyrazol-1-yl)-1-[4-(dimethylamino)phenyl]-1-phenylethanol} bimetallic [{AlR2 -bpzappe)}(μ-O){AlR3 }] [R=Me (5), (6)]. By reaction 3-6 PhCH2 Br, cationic -bbpzappe)]Br (7), (8); bbpzappeH=N-benzyl-4-[2,2-bis(3,5-dimethyl-1H-pyrazol-1-yl)-1-hydroxy-1-phenylethyl]-N,N-dimethylbenzenaminium bromide} -bbpzappe)}(μ-O){AlR3 }]Br (9), (10)] synthesized. Both presence Bu4 NBr investigated as catalysts for cyclic carbonate formation from epoxides carbon dioxide. Amongst them, complex 10 was found be an efficient one-component catalyst synthesis carbonates both monosubstituted internal shown have broad substrate scope.