Palladium-Catalyzed Carbon-Carbon Bond Formation and Cleavage of Organo(hydro)fullerenes

Palladium-Catalyzed Three-Component 1,4-Alkoxyarylation Reaction of [60]Fullerene

The palladium-catalyzed three-component alkoxyarylation reaction of [60]fullerene with primary/secondary alcohols and aryl iodides generates a series of 1,4-(alkoxy)(aryl)[60]fullerene derivatives. Plausible reaction pathways for the formation of 1,4-(alkoxy)(aryl)[60]fullerenes are proposed. In addition, the electrochemical properties of the synthesized 1,4-alkoxyarylation adducts are investigated.

Palladium-catalyzed three-component 1,4-aminoarylation of [60]fullerene with aryl iodides and N-methoxysulfonamides, and further transformations

The palladium-catalyzed three-component 1,4-aminoarylation of [60]fullerene afforded 1,4-(aryl)(sulfonamide)[60]fullerenes, of which the sulfonamide group could be replaced by a (hetero)aryl, malonate ester or allyl group in the presence of FeCl3.

An "Umpolung Relay" Strategy: One-Pot, Twice Polarity Inversion Cascade Synthesis of Diversified [60]Fulleroindoles

An "umpolung relay" strategy, which includes an one-pot, twice polarity inversion cascade of C₆₀ via carbanion and carbocation polarity reversed relay pathway, has been developed for the synthesis of a diverse range of novel [60]fulleroindole derivatives.

Transition metal-catalyzed synthesis of spirooxindoles

Spirooxindole is a principal bioactive agent and is observed in several natural products including alkaloids. They are broadly studied in the pharmaceutical field and have a significant role in the evolution of drugs such as anti-viral, anti-cancer, anti-microbial etc. In organic chemistry, an indispensable role is presented by transition metal catalysts. An effective synthetic perspective to spirooxindoles is the use of transition metals as the catalyst. This review discusses the synthesis of spirooxindoles catalyzed by transition metals and covers literature up to 2020.

One-pot, three-component regioselective coupling reaction of triphenylamine/carbazole derivatives with [60]fullerene and indoles via an “umpolung relay” strategy

An “umpolung relay” three-component regioselective coupling reaction of triphenylamine/carbazole derivatives with C60 and indoles was developed, which features high regioselectivity, broad substrate scope, and excellent functional group tolerance.

General One-step Synthesis of Symmetrical or Unsymmetrical 1,4-Di(organo)fullerenes from Organo(hydro)fullerenes through Direct Oxidative Arylation

A general one-step synthesis of symmetrical or unsymmetrical 1,4-di(organo)fullerenes from organo(hydro)fullerenes (RC₆₀H) is realized by direct oxidative arylation. The new combination of catalytic trifluoromethanesulfonic acid (TfOH) and stoichiometric o-chloranil is the first to be used to directly generate an R-C₆₀⁺ intermediate from common RC₆₀H. Unexpectedly, the in situ generated R-C₆₀⁺ intermediate is shown to be quite stable in whole ¹³C NMR spectroscopy characterization in the absence of cation quenching reagents. Because the direct oxidation of common RC₆₀H to form the corresponding R-C₆₀⁺ has never been realized, the present combination of TfOH and o-chloranil solves the challenges associated with the formation of stable RC₆₀⁺ cations from common RC₆₀H without any coordination of an R group.

Functionalization of [60]fullerene through fullerene cation intermediates

Fullerene cations, namely [60]fullerene radical cation (C₆₀˙⁺) and organo[60]fullerenyl cation (RC₆₀⁺), open paths for the efficient derivatization of a great variety of fullerenes.

Oxidative deamination of azafulleroids into C60 by peracids

Oxidation of azafulleroids with peracids regenerate C₆₀via oxidation of the bridged nitrogen, depending on the basicity of N-substituents.

Toward controlled synthesis of carbon nanotubes and graphenes

A bottom-up synthesis of structurally uniform carbon nanotubes (CNTs) and graphenes is recognized as one of the greatest challenges of primary importance in nanocarbon science. This paper highlights our efforts to address these challenges since 2005. These endeavors have led to (i) modular, size-selective, and scalable synthesis of [n]cycloparapheneylenes (CPPs), the shortest segment of armchair CNTs, (ii) design and synthesis of the shortest segment of chiral CNTs, and (iii) efficient synthesis of carbon nanosheets through catalytic C–H bond arylation of polycyclic aromatic hydrocarbons (PAHs). We consider these works as a possible first step toward a controlled synthesis of structurally uniform CNTs and nanographenes.

Selective introduction of organic groups to C60 and C70 using organoboron compounds and rhodium catalyst: a new synthetic approach to organo(hydro)fullerenes

A Rh-catalyzed reaction of C(60) and C(70) with organoboron compounds is described. This new catalytic method enables introduction of various organic groups onto C(60) and C(70). [Rh(cod)(MeCN)(2)]BF(4) proved to be the most effective catalyst in terms of productivity and selectivity. The reaction generally proceeds with a high regioselectivity and in a mono-addition selective manner. It was found that water is an essential additive to promote the reaction. By X-ray crystal structure analysis, we have confirmed the reaction site of organometallic-based hydroarylation of C(70) for the first time. Various functional fullerenes, such as fullerene-tagged amino acids and fullerene-capped π systems, can be synthesized. The X-ray crystal structure of biphenyl-attached C(60) revealed an interesting opportunity for the well-organized alignment of bucky balls by taking advantage of CH-π interactions.