Search

Samarium metal and samarium diiodide have become important tools as selective cyclopropanating agents in organic synthesis due to their high chemo- and stereoselectivity. Therefore, Sm and SmI2are the ideal reagents to prepare cyclopropane derivatives. This tutorial reviewhighlights C–C multiple bond cyclopropanation processes promoted by samarium or samarium diiodide. [ABSTRACT FROM AUTHOR]

The structure and the composition are two key factors that influence the physical, chemical, and other properties of materials. Correspondingly, structural design and functionalization with inorganic or organic materials provide efficient routes to enhancing some properties. Herein, iron triad nanomaterials, with a wide range of applications in energy, environment and other fields, were chosen as the target materials. This paper reviews various approaches for designing three typical structures (hollow and porous, ultrathin two-dimensional, and complex three-dimensional structures) of iron triad nanomaterials with high specific surface areas as well as their feasible functionalization for special purposes. Furthermore, some amazing work in recent years is introduced and discussed, especially in the energy field including energy transfer, conversion and storage, and in the environment field, including the adsorption and removal of harmful inorganic ions and organic pollutants. This review aims at developing potential applications of the nanomaterials using structural adjustment and functionalization to overcome their intrinsic shortcomings and enhance their performance. [ABSTRACT FROM AUTHOR]

As representative soft materials with widespread applications, gels with various functions have been developed. However, traditional gels are vulnerable to stress-induced formation of cracks. The propagation of these cracks may affect the integrity of network structures of gels, resulting in the loss of functionality and limiting the service life of the gels. To address this challenge, self-healing gels that can restore their functionalities and structures after damage have been developed as "smart" soft materials. In this paper, we present an overview of the current strategies for synthesizing self-healing gels based on the concept of constitutional dynamic chemistry, which involves molecular structures capable of establishing dynamic networks based upon physical interactions or chemical reactions. The characterization methods of self-healing gels and the key factors that affect self-healing properties are analyzed. We also illustrate the emerging applications of self-healing gels, with emphasis on their usage in industry (coatings, sealants) and biomedicine (tissue adhesives, agents for drug or cell delivery). We conclude with a perspective on challenges facing the field, along with prospects for future development. [ABSTRACT FROM AUTHOR]

Transition-metal-catalyzed coupling reactions have become a versatile tool for chemical bond formation. From the variation of the coupling partners, coupling reactions can be classified into three models: traditional coupling, reductive coupling and oxidative coupling. The oxidative coupling, which is different from the traditional coupling, occurs between two nucleophiles. This critical reviewfocuses on transition-metal-catalyzed oxidative coupling reactions involving organometallic reagents as nucleophiles. Since the scope of the oxidative coupling is highly diversified, this paper only reviews the oxidative coupling reactions concerning C–C bond formation, including the coupling between organometal reagents and hydrocarbons as well as coupling between two organometal reagents. Since terminal alkynes are normally activated by metal salts and in situform the alkynyl metal reagents in coupling reactions, they are directly considered as organometal reagents in this review. Intramolecular oxidative couplings and oxidative cyclizations are not included in this critical review. Moreover, there are many examples of oxidative coupling leading to the formation of functional materials, such as the oxidative polymerization of thiophenes. Since several reviews in these areas have been published they are not included in this review either (99 references). [ABSTRACT FROM AUTHOR]

New opportunities for the conversion of glycerol into value-added chemicals have emerged in recent years as a result of glycerol's unique structure, properties, bioavailability, and renewability. Glycerol is currently produced in large amounts during the transesterification of fatty acids into biodiesel and as such represents a useful by-product. This paper provides a comprehensive review and critical analysis on the different reaction pathways for catalytic conversion of glycerol into commodity chemicals, including selective oxidation, selective hydrogenolysis, selective dehydration, pyrolysis and gasification, steam reforming, thermal reduction into syngas, selective transesterification, selective etherification, oligomerization and polymerization, and conversion of glycerol into glycerol carbonate. [ABSTRACT FROM AUTHOR]