Intramolecular cyclization–decyclization of new sterically hindered diiminophenol. Synthesis and coordination abilities

Abstract

The novel benzoxazole I undergoes a fast intramolecular decyclization and demonstrates either a neutral or anionic coordination type in cadmium complexes.

2-Imino-2,3-dihydrobenzoxazole—a useful platform for designing rare- and alkaline earth complexes with variable di- and trianionic O,N,N, ligands

“…were dried with sodium/benzophenone ketyl and condensed under vacuum prior to use. [(Me 3 Si) 2 N] 2 M(THF) 2 (M = Yb 58 and Ca 59 ), Y(CH 2 SiMe 3 ) 3 THF 2 60 and LH 12,13 were prepared according to the literature procedures.…”

“…[3][4][5][6] Schiff base ligands have been extensively studied mainly due to their coordination abilities, facile syntheses, easily tunable steric factors, and electronic properties. [7][8][9][10][11] In 2014, Abakumov and co-workers reported on the synthesis, structure and intramolecular cyclization-decyclization of new sterically hindered diiminophenol 12,13 and complexation of the cyclic tautomer 2-imino-2,3-dihydrobenzoxazole LH (Scheme 1) with 12 and 13 group metals was investigated. 12,13 The combination of a variety of possible coordination modes of cyclic and acyclic tautomers of LH 12,13 with large sizes characteristic of rare-earth ions 3 provides a basis for rich coordination chemistry.…”

“…[7][8][9][10][11] In 2014, Abakumov and co-workers reported on the synthesis, structure and intramolecular cyclization-decyclization of new sterically hindered diiminophenol 12,13 and complexation of the cyclic tautomer 2-imino-2,3-dihydrobenzoxazole LH (Scheme 1) with 12 and 13 group metals was investigated. 12,13 The combination of a variety of possible coordination modes of cyclic and acyclic tautomers of LH 12,13 with large sizes characteristic of rare-earth ions 3 provides a basis for rich coordination chemistry. Moreover, due to the presence in the acyclic form of a pendant redox active diimino fragment able to oxidize electropositive Ln(II) [14][15][16][17][18] centres unique redox reactivity can be expected in the case of Ln metals possessing two stable oxidation states.…”

Structural, Non-Covalent Interaction, and Natural Bond Orbital Studies on Bromido-Tricarbonyl Rhenium(I) Complexes Bearing Alkyl-Substituted 1,4-Diazabutadiene (DAB) Ligands

“…By changing the electronic and steric effects in the DAB ligands in their Ni(II) and Pd(II) complexes, they can be utilized as efficient catalysts in alkene polymerization [17,18]. The tuning of such electronic and steric effects has been examined before in some iminophenol complexes [19,20]. Besides all the aforementioned properties, one of the interesting features of metal carbonyl complexes is the presence of intra-and/or intermolecular n .…”

The group 13 metal complexes of sterically-hindered substituted iminophenol: synthesis and structure

“…It have been shown that the compound a in solution exists in equilibrium with the enamine form containing hydroxy group. 17 In this paper we describe the synthetic details, spectral characteristics, X-ray crystal structures and luminescence properties of new group 13 metal complexes with aforementioned ligand a.…”