Chiral Bifunctional Metalloporphyrin Catalysts for Kinetic Resolution of Epoxides with Carbon Dioxide

Synthesis and a Catalytic Study of Diastereomeric Cationic Chiral-at-Cobalt Complexes Based on (R,R)-1,2-Diphenylethylenediamine

Here we report the first synthesis of two diastereomeric cationic octahedral Co(III) complexes based on commercially available (R,R)-1,2-diphenylethylenediamine and salicylaldehyde. Both diastereoisomers with opposite chiralities at the metal center (Λ and Δ configurations) were prepared. The new Co(III) complexes possessed both acidic hydrogen-bond donating (HBD) NH moieties and nucleophilic counteranions and operate as bifunctional chiral catalysts for the challenging kinetic resolution of terminal and disubstituted epoxides by the reaction with CO₂ under mild conditions. The highest selectivity factor (s) of 2.8 for the trans-chalcone epoxide was achieved at low catalyst loading (2 mol %) in chlorobenzene, which is the best achieved result currently for this type of substrate.

Synthesis of cyclic carbonates by ruthenium(VI) bis-imido porphyrin/TBACl-catalyzed reaction of epoxide with CO2

The catalytic activity of the ruthenium(VI) bis-imido porphyrin complex/TBACl binary system in promoting the CO[Formula: see text] cycloaddition to epoxides forming cyclic carbonates is here reported. The system was very efficient in catalyzing the conversion of differently substituted epoxides under mild experimental conditions (100 [Formula: see text]C and 0.6 MPa of CO[Formula: see text]. Even if the sole TBACl resulted active under the optimized experimental conditions, the addition of ruthenium species was fundamental to maximizing the reaction productivity both in terms of epoxide conversions and cyclic carbonate selectivities. A preliminary mechanistic study indicated a positive role of ruthenium imido nitrogen atom in activating carbon dioxide.

Mechanistic guidelines in nonreductive conversion of CO2: the case of cyclic carbonates

This perspective provides general mechanistic guidelines for the catalytic formation of cyclic organic carbonates from CO₂ and cyclic ethers.

Aluminum complexes with new non-symmetric ferrocenyl amidine ligands and their application in CO2 transformation into cyclic carbonates

A set of alkyl aluminum complexes supported by non-symmetric ferrocenyl amidine ligands were used as catalysts for the preparation of cyclic carbonates from epoxides and carbon dioxide using Bu₄NI as a co-catalyst.

Central zinc metal-controlled regioselective meso-bromination of zincated β-silylporphyrins—rapid access to meso,β-dual-functionalized porphyrins

A convenient method for preparing meso,β-dual-functionalized porphyrin through a central zinc metal-controlled regioselective bromination of zincated β-silylporphyrin was developed.

1,2,3-Triazolium macrocycles in supramolecular chemistry

In this short review, we describe different pathways for synthesizing 1,2,3-triazolium macrocycles and focus on their application in different areas of supramolecular chemistry. The synthesis is mostly relying on the well-known "click reaction" (CuAAC) leading to 1,4-disubstituted 1,2,3-triazoles that then can be quaternized. Applications of triazolium macrocycles thus prepared include receptors for molecular recognition of anionic species, pH sensors, mechanically interlocked molecules, molecular machines, and molecular reactors.

Recent Advances in the Chemical Fixation of Carbon Dioxide: A Green Route to Carbonylated Heterocycle Synthesis

Carbon dioxide produced by human activities is one of the main contributions responsible for the greenhouse effect, which is modifying the Earth’s climate. Therefore, post-combustion CO2 capture and its conversion into high value-added chemicals are integral parts of today’s green industry. On the other hand, carbon dioxide is a ubiquitous, cheap, abundant, non-toxic, non-flammable and renewable C1 source. Among CO2 usages, this review aims to summarize and discuss the advances in the reaction of CO2, in the synthesis of cyclic carbonates, carbamates, and ureas appeared in the literature since 2017.