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β-Hydroxy esters are considered as potential building blocks for the production of fine chemicals and potential drug molecules in various industries. Developing an efficient and recyclable catalyst for the synthesis of β-hydroxy esters is challenging. Here we report the first ionic-liquid-based heterogenized cobalt catalyst, [imidazolium-CTF][Co(CO)4], for the direct ring-opening carbonylation of propylene oxide to methyl 3-hydroxybutyrate (MHB) with 86% selectivity (>99% conversion).

Poly (3-hydroxybutyrate) (PHB) is a naturally occurring biodegradable and biocompatible polyester and considered as a class of potentially thermoplastic biopolymers in industry. The alternating copolymerization of cheap and available propylene oxide and carbon monoxide may be an efficient synthetic route for PHB. Here, we studied the base effects on the synthesis of PHB using a well-defined [(salph)Cr(THF)2]+[Co(CO)4]− catalyst combined with various bases. It was found that base not only affects the yield of PHB, but also the molar ratio of each unit in the product.

The synthesis of a unique heterogeneous catalyst that combines the functionality of a homogeneous catalyst and the advantages of a heterogeneous catalytic process is a continuing goal in various industrially applicable reactions. Here, we report heterogenization of homogeneous catalyst for lactone production from epoxide carbonylation through a facile polymerization using Friedel-Crafts reaction. A correlation between reactivity and degree of heterogeneity has been deduced by synthesizing different sized polymeric catalysts. The partially polymerized catalyst showed a remarkable initial turnover frequency of 400 h

Difficulties in product separation and ineffective recycling of the homogenous catalyst deter the mass production of beta-lactones via carbonylation of epoxides. Herein, we address these issues, for the first time, using a recyclable heterogenized catalyst [bpy-CTF-Al(OTf)(2)][Co(CO)(4)] that efficiently converts propylene oxide (PO) to beta-butyrolactone with high selectivity.

Fluorescence imaging is well-suited for the live imaging of biological Zn(II), which has no facile spectroscopic or magnetic signature. The successful application of this methodology requires the development of robust Zn(II) imaging agents that display high sensitivity, selectivity and temporal fidelity. In this study, a N 2 O 2 -type dipyrrin based bimolecular zinc(II) complex was produced and shown to have sharper, blue-shifted and more enhanced fluorescence emission. An approximate three-fold fluorescence enhancement was achieved within the micromolar concentration range, which is an important parameter for Zn(II) detection in vivo. The increase in emission intensity was due to the dominant role of aryl-ring rotation in governing the excited state dynamics and fluorescence properties of the dipyrrin dye. Fluorescence titration showed that the ligand complex exhibited very strong zinc(II) binding affinity when compared to that in the binuclear chloro complex. The fluorescence emission changes in the dipyrrin dye to zinc(II) ion could be observed not only using instruments but also by the naked-eye (violet→sky blue).

Based on theoretical calculations on the effects of molecular orbital energy levels of amines on the fluorescence properties of the fluorophore, aniline-substituted BODIPY motif ( AnB ) with quenched fluorescence was developed as a ‘turn-on’ switch for the qualitative and quantitative detection of formaldehyde with the detection limit (LOD) of ca. 165 nM.

The reported catalytic system demonstrates the possibility of efficient mass production of 3-hydroxybutyric acid (3-HBA) from inexpensive raw materials. The direct coupling of propylene oxide, water, and CO was catalyzed by 1-butyl-3-methylimidazolium cobalt tetracarbonyl ([Bmim][Co(CO)4]) ionic liquid to form 3-HBA with >99% conversion (49% selectivity) under mild conditions.