Hyper-Cross-Linked Porous Porphyrin Aluminum(III) Tetracarbonylcobaltate as a Highly Active Heterogeneous Bimetallic Catalyst for the Ring-Expansion Carbonylation of Epoxides

Abstract

Development of an industrially viable catalyst for the ring-expansion carbonylation of epoxides remains challenging in the view of facile product separation and recyclability. Herein, we report a heterogenized porous porphyrin Al­(III) tetracarbonylcobaltate bimetallic catalyst for the ring-expansion carbonylation of epoxides. The catalyst was synthesized using a hyper-cross-linking strategy involving methylene bridges introduced by the Friedel–Crafts reaction and incorporated with cobaltate anions. The catalyst effectively converts epoxides into the corresponding β-lactones with an excellent site time yield of 360 h–1, which is comparable to that of the corresponding homogeneous catalysts and is the highest of any heterogeneous catalyst reported so far for this reaction.

Perfectly Alternating Copolymerization of CO and Epoxides to Aliphatic Polyester Oligomers via Cooperative Organoboron–Cobalt Complexes

“…Since then, exploration of reliable catalysts has greatly spurred the development of the carbonylation of the epoxides to cyclic β-lactones and/or polymeric materials. Inspired by the effectiveness of using Al­( i Bu) 3 /H 2 O/cobalt­(III) acetylacetonate for copolymerization of epoxides/CO, a number of catalysts featuring the general formula [Lewis acid] + [Co­(CO) 4 ] − were developed to convert epoxides/CO to PHAs or the corresponding lactones. − The Lewis acid in [Lewis acid] + [Co­(CO) 4 ] − is used for the epoxide activation or stabilization of the alkoxide chain end, and the charge-balancing anionic [Co­(CO) 4 ] − mediates the ring opening of the epoxides and the insertion of CO. Cationic Al, ,− Cr, − Ti, and Co − Lewis acids with elaborate ligands such as salen and porphyrin have been elegantly explored, especially to achieve regio- and/or stereoselective reactions. − In comparison to the above bimetallic catalysts, the monometallic acyl–cobalt complexes have the sustainable benefit of substituting 50% of the metal atom, since they are free of metallic Lewis acid. The successful utilization of monometallic acyl–cobalt complexes for carbonylative polymerization was reported by the research groups of Jia, − Nozaki, and Rieger .…”

Direct Heterogenization of Salphen Coordination Complexes to Porous Organic Polymers: Catalysts for Ring-Expansion Carbonylation of Epoxides

“…19 To overcome these limitations, direct heterogenization of the active homogeneous catalytic system is highly desirable, provided the heterogenization pathway is simple and inexpensive and is capable of producing robust catalytic materials that are dense in active sites. 10 Various synthetic strategies can be used for the direct heterogenization of active homogeneous systems. 9 The synthesis of POPs via Friedel− Crafts reaction (FCR) catalyzed by Lewis acids AlCl 3 and FeCl 3 to knit homogeneous catalysts together through covalent linkages has received considerable attention.…”

Fabrication of O-enriched HyperCross-Linked Polymers and Their Adsorption of Aniline from Aqueous Solution

“…In the past few decades, hyper-cross-linked polymers (HCLPs) have attracted increasing interest because of their high Brunauer–Emmett–Teller (BET) surface area ( S BET ), tunable porosity, and diversified surface chemistry. , Moreover, their synthetic process is very simple with a one-pot Friedel–Crafts reaction, and various aromatic monomers can be applied for their fabrication. , Therefore, the HCLPs are widely used in many fields including gas capture and separation, − energy storage, − organics removal, − and heterogeneous catalysis. ,, The HCLPs were first fabricated from linear polystyrene (PS) or low cross-linked chloromethylated polystyrene (CMPS) by the Friedel–Crafts alkylation reaction . During this process, an extensive cross-linking occurs, and abundant rigid methylene groups connect the polymer chains like the cross-linking bridges.…”

“…3,4 Therefore, the HCLPs are widely used in many fields including gas capture and separation, 4−8 energy storage, 9−11 organics removal, 12−17 and heterogeneous catalysis. 2,18,19 The HCLPs were first fabricated from linear polystyrene (PS) or low cross-linked chloromethylated polystyrene (CMPS) by the Friedel−Crafts alkylation reaction. 20 During this process, an extensive cross-linking occurs, and abundant rigid methylene groups connect the polymer chains like the cross-linking bridges.…”