In chemical synthesis, click chemistry is a class of simple, atom-economy reactions commonly used for joining two molecular entities of choice. Click chemistry is not a single specific reaction, but describes a way of generating products that follow examples in nature, which also generates substances by joining small modular units. In many applications, click reactions join a biomolecule and a reporter molecule. Click chemistry is not limited to biological conditions: the concept of a "click" reaction has been used in chemoproteomic, pharmacological, biomimetic and molecular machinery applications. However, they have been made notably useful in the detection, localization and qualification of biomolecules.
In organic chemistry, helicenes are ortho-condensed polycyclic aromatic compounds in which benzene rings or other aromatics are angularly annulated to give helically-shaped chiral molecules. The chemistry of helicenes has attracted continuing attention because of their unique structural, spectral, and optical features.
Tetrazoles are a class of synthetic organic heterocyclic compound, consisting of a 5-member ring of four nitrogen atoms and one carbon atom. The name tetrazole also refers to the parent compound with formula CH2N4, of which three isomers can be formulated.
Corannulene is a polycyclic aromatic hydrocarbon with chemical formula C20H10. The molecule consists of a cyclopentane ring fused with 5 benzene rings, so another name for it is [5]circulene. It is of scientific interest because it is a geodesic polyarene and can be considered a fragment of buckminsterfullerene. Due to this connection and also its bowl shape, corannulene is also known as a buckybowl. Buckybowls are fragments of buckyballs. Corannulene exhibits a bowl-to-bowl inversion with an inversion barrier of 10.2 kcal/mol (42.7 kJ/mol) at −64 °C.
Isatin, also known as tribulin, is an organic compound derived from indole with formula C8H5NO2. The compound was first obtained by Otto Linné Erdman and Auguste Laurent in 1840 as a product from the oxidation of indigo dye by nitric acid and chromic acids.
Hexacene is an aromatic compound consisting of six linearly-fused benzene rings. It is a blue-green, air-stable solid with low solubility.
Organozinc chemistry is the study of the physical properties, synthesis, and reactions of organozinc compounds, which are organometallic compounds that contain carbon (C) to zinc (Zn) chemical bonds.
Heptacene is an organic compound and a polycyclic aromatic hydrocarbon and the seventh member of the acene or polyacene family of linear fused benzene rings. This compound has long been pursued by chemists because of its potential interest in electronic applications and was first synthesized but not cleanly isolated in 2006. Heptacene was finally fully characterized in bulk by researchers in Germany and the United States in 2017.
[n]Radialenes are alicyclic organic compounds containing n cross-conjugated exocyclic double bonds. The double bonds are commonly alkene groups but those with a carbonyl (C=O) group are also called radialenes. For some members the unsubstituted parent radialenes are elusive but many substituted derivatives are known.
The Zincke reaction is an organic reaction, named after Theodor Zincke, in which a pyridine is transformed into a pyridinium salt by reaction with 2,4-dinitro-chlorobenzene and a primary amine.
In organic chemistry, organocatalysis is a form of catalysis in which the rate of a chemical reaction is increased by an organic catalyst. This "organocatalyst" consists of carbon, hydrogen, sulfur and other nonmetal elements found in organic compounds. Because of their similarity in composition and description, they are often mistaken as a misnomer for enzymes due to their comparable effects on reaction rates and forms of catalysis involved.
Asymmetric hydrogenation is a chemical reaction that adds two atoms of hydrogen to a target (substrate) molecule with three-dimensional spatial selectivity. Critically, this selectivity does not come from the target molecule itself, but from other reagents or catalysts present in the reaction. This allows spatial information to transfer from one molecule to the target, forming the product as a single enantiomer. The chiral information is most commonly contained in a catalyst and, in this case, the information in a single molecule of catalyst may be transferred to many substrate molecules, amplifying the amount of chiral information present. Similar processes occur in nature, where a chiral molecule like an enzyme can catalyse the introduction of a chiral centre to give a product as a single enantiomer, such as amino acids, that a cell needs to function. By imitating this process, chemists can generate many novel synthetic molecules that interact with biological systems in specific ways, leading to new pharmaceutical agents and agrochemicals. The importance of asymmetric hydrogenation in both academia and industry contributed to two of its pioneers — William Standish Knowles and Ryōji Noyori — being collectively awarded one half of the 2001 Nobel Prize in Chemistry.
Within the area of organocatalysis, (thio)urea organocatalysis describes the use of ureas and thioureas to accelerate and stereochemically alter organic transformations. The effects arise through hydrogen-bonding interactions between the substrate and the (thio)urea. Unlike classical catalysts, these organocatalysts interact by non-covalent interactions, especially hydrogen bonding. The scope of these small-molecule H-bond donors termed (thio)urea organocatalysis covers both non-stereoselective and stereoselective applications.
Kekulene is a polycyclic aromatic hydrocarbon which consists of 12 fused benzene rings arranged in a circle. It is therefore classified as a [12]-circulene with the chemical formula C48H24. It was first synthesized in 1978, and was named in honor of August Kekulé, the discoverer of the structure of the benzene molecule.
Kim Kimoon is a South Korean chemist and professor in the Department of Chemistry at Pohang University of Science and Technology (POSTECH). He is the first and current director of the Center for Self-assembly and Complexity at the Institute for Basic Science. Kim has authored or coauthored 300 papers which have been cited more than 30,000 times and he holds a number of patents. His work has been published in Nature, Nature Chemistry, Angewandte Chemie, and JACS, among others. He has been a Clarivate Analytics Highly Cited Researcher in the field of chemistry in 2014, 2015, 2016.
Proline organocatalysis is the use of proline as an organocatalyst in organic chemistry. This theme is often considered the starting point for the area of organocatalysis, even though early discoveries went unappreciated. Modifications, such as MacMillan’s catalyst and Jorgensen's catalysts, proceed with excellent stereocontrol.
A borylene is the boron analogue of a carbene. The general structure is R-B: with R an organic moiety and B a boron atom with two unshared electrons. Borylenes are of academic interest in organoboron chemistry. A singlet ground state is predominant with boron having two vacant sp2 orbitals and one doubly occupied one. With just one additional substituent the boron is more electron deficient than the carbon atom in a carbene. For this reason stable borylenes are more uncommon than stable carbenes. Some borylenes such as boron monofluoride (BF) and boron monohydride (BH) the parent compound also known simply as borylene, have been detected in microwave spectroscopy and may exist in stars. Other borylenes exist as reactive intermediates and can only be inferred by chemical trapping.
The parent metallacyclobenzene has the formula LnM(CH)5. They can be viewed as derivatives of benzene wherein a CH center has been replaced by a transition metal complex. Most metallabenzenes do not feature the M(CH)5 ring itself, but, instead, some of the H atoms are replaced by other substituents.
Jieping Zhu is an organic chemist specializing in natural product total synthesis and organometallics. He is a professor of chemistry at EPFL and the head of the Laboratory of Synthesis and Natural Products.
An organic azide is an organic compound that contains an azide functional group. Because of the hazards associated with their use, few azides are used commercially although they exhibit interesting reactivity for researchers. Low molecular weight azides are considered especially hazardous and are avoided. In the research laboratory, azides are precursors to amines. They are also popular for their participation in the "click reaction" between an azide and an alkyne and in Staudinger ligation. These two reactions are generally quite reliable, lending themselves to combinatorial chemistry.
