Carbon Nanotubes (CNTs) from Synthesis to Functionalized (CNTs) Using Conventional and New Chemical Approaches

Carbon nanotubes (CNTs) have emerged worldwide because of their remarkable properties enlarging their field of applications. Functionalization of CNTs is a convenient strategy to tackle low dispersion and solubilization of CNTs in many solvents or polymers. It can be done by covalent or noncovalent surface functionalization that is briefly discussed regarding the current literature. Endohedral and exohedral are conventional methods based on covalent and van der Waals bonding forces that are created through CNT functionalization by various materials. In this paper, a review of new approaches and mechanisms of functionalization of CNTs is proposed, including amidation, fluorination, bromination, chlorination, hydrogenation, and electrophilic addition. Our analysis is supported by several characterization methods highlighting recent improvements hence extending the range of applicability of CNTs.

Recent advances of the tandem difunctionalization of alkynes via five kinds of mechanisms

Recent advances of the tandem difunctionalization of alkynes in decade (2010-2020) were summarized via five categories by triggered mechanisms: (1) radical addition and coupling for the synthesis of polysubstituted ketones and alkenes; (2) electrophilic addition of alkynes; (3) haloalkyne or copper acetylide-mediated reactions; (4) preparation of cyclic compounds via radical process, palladium-catalyzed reactions or conjugate addition; (5) cyclic compounds as intermediates in ring openings. Herein, radical, electrophilic and nucleophilic reactions were well discussed. We hope this review will promote future research in this area.

REACTION OF CHLOROANHYDRIDES OF CYCLOALKANECARBOXILIC ACIDS WITH SOME ALLYLIC CHLORIDES

The reactions of electrophilic addition of cycloalkane carboxylic acid chlorides with allyl chlorides were studied. It was found, that depending on the chloride structures, 2- and 2,4-substituted furans, 1-R-3,4- dichloro-2-butene-1-ones and 1-R-3,4,4-trichloro-1-butanones were obtained.

Metal-free synthesis of 1H-isochromenes via benzyl ether-assisted, electrophilic addition of diaryl acetylenes

Bromotrimethylsilane (TMSBr) promoted, intramolecular cyclization of (o-arylethynyl)benzyl ethers to form 1H-isochromenes at room temperature is reported. Further studies indicated that the stability of vinyl carbocations is crucial, similar to the...

A Dynamic Picture of the Halolactonization Reaction through a Combination of ab-initio Metadynamics and Experimental Investigations .

The halolactonization reaction is one of the most common electrophilic addition reactions to alkenes. The mechanism is generally viewed as a two-step pathway, which involves the formation of an ionic...

Synthesis of dibenzocyclohepta[1,2-a]naphthalene derivatives from phenylacetaldehyde and alkynyl benzyl alcohols via sequential electrophilic addition and double Friedel–Crafts reactions

A simple methodology for the regioselective synthesis of substituted dibenzocyclohepta[1,2-a]naphthalenes from phenylacetaldehydes and ortho-alkynyl benzyl alcohols in the presence of a Lewis acid has been developed.

Squalene interactions with some hydrosilanes and hydrogermans

Squalene hydrosilylation by a number of organohydrosilanes R3SiH and Me3GeH, including a mixture of α- and β-isomers of adducts of vinyltrimethylsilane addition to tetramethyldisiloxane: HSi(Me2)O(Me2)Si-C(Me)-SiMe3 and HSi(Me2)O(Me2)Si-(CH2)2-SiMe3, formed both according to Markovnikov's rule and against it, is discussed. We pay attention to the mismatch of values between the electronegativities of carbon, silicon, germanium and hydrogen atoms and the reactivity of C-H, Si-H, and Ge-H bonds. A spectral study of a mixture of α- and β-isomers was carried out. The effect of substituents at elements on its reactivity is discussed: hydrosilanes with chlorine atoms, alkyl and alkoxy groups on silicon are not active in the squalene hydrosilylation. In contrast to them, the α- and β-adducts and their mixture add well to squalene with an unambiguously unknown regioselectivity. The results obtained indicate the special behavior of squalene in electrophilic addition reactions catalyzed by metal complexes, in contrast to substituted ethylenes.