Synthesis and crystal structures of guanidinatoaluminum complexes and catalytic study for MPV reduction. (18th April 2017)

• Record Type: Journal Article
• Authors: Han, Hongfei; Guo, Zhiqiang; Zhang, Shaofeng; Hua, Yupeng; Wei, Xuehong
• Is Part Of: Polyhedron. Volume 126(2017)
• Page Start: 214
• Page End: 219
• Publication Date: 2017-04-18
• Subjects: Guanidinato complexes -- Oxygen -- Crystal structure -- Catalysts -- MPV reaction; Chemistry, Inorganic -- Periodicals; Chimie inorganique -- Périodiques; Organometaalverbindingen; Anorganische chemie; 546.05
• DOI: 10.1016/j.poly.2017.01.030
• Languages: English
• ISSNs: 0277-5387

Abstract

Graphical abstract: The synthesis of four guanidinatoaluminum complexes is described. The molecular structures of four guanidinatoaluminuml complexes were confirmed by a single crystal X-ray diffraction study. In addition, the guanidinatoaluminuml complexes were also used to catalyze the Meerwein–Ponndorf–Verley (MPV) reaction of a series of aromatic and aliphatic aldehydes to the corresponding alcohols. Abstract: Treatment of a secondary amine (piperidine or N -benzylmethylamine) with sequentially trimethylaluminum and carbodiimide CyNCNCy in a molar ratio of 1:1:1 afforded two mononuclear guanidinatoaluminum complexes, [{(C5 H10 N)C(NCy)2 }AlMe2 ] (1 ) and. [{(Bz(Me)N)C(NCy)2 }AlMe2 ] (2 ). Introducing dry oxygen slowly into the solution of1 or2, [{(C5 H10 N)C(NCy)2 }AlMe( μ -OMe)]2 (3 ) and [{(Bz(Me)N)C(NCy)2 }AlMe( μ -OMe)]2 (4 ) were obtained, respectively. Both of3 and4 were also prepared by treatment of piperidine or N-benzylmethylamine with trimethylaluminum and carbodiimide CyNCNCy in the presence of O2 . The complexes1 –4 were characterized by 1 H, 13 C NMR spectra and single crystal X-ray diffraction analysis.1 –4 were also used to catalyze the Meerwein–Ponndorf–Verley (MPV) reaction.