Cookies disclaimer

I agree Our site saves small pieces of text information (cookies) on your device in order to deliver better content and for statistical purposes. You can disable the usage of cookies by changing the settings of your browser. By browsing our website without changing the browser settings you grant us permission to store that information on your device.

Carbonyl chemistry: have you used all five of these important reactions?

Jan. 3, 2019

The carbonyl bond is one of the most synthetically important functional groups in the whole of organic chemistry, and is present in aldehydes, ketones, esters, amides and many other carboxylic acid derivatives. Consisting of a carbon atom joined to an oxygen atom by a double bond, the carbonyl group is key to the versatile chemistry these compounds can undergo.

What makes carbonyl chemistry so interesting?

It’s all about the carbonyl bond. The more electronegative oxygen atom draws electron density from the carbon, increasing the polarity of the bond. As a result, the carbon atom is a good electrophile and is more vulnerable to attack by marauding nucleophiles such as negatively charged ions or molecules with a lone pair of electrons. This electrophilic nature means carbonyl groups can be involved in a range of transformations, including simple addition reactions (where the double bond is broken) and addition–elimination reactions (where the double bond...

Read more ...


Oxidation reactions: transformations that deserve the oxygen of publicity

Nov. 7, 2018

Oxidation reactions are chemical transformations that result in a substrate losing electrons and increasing its oxidation state. They involve the use of an oxidizing agent or oxidant—a reagent in its higher oxidation state that is capable of gaining electrons, and is itself reduced in the reaction.

The term oxidation takes its name from the process of adding oxygen to compounds using oxygen gas (the first known oxidizing agent). But while the addition of oxygen in this way meets the modern definition of oxidation, oxygen gas is far from the only oxidizing agent. A wide range of oxidants exist, including reagents as diverse as hydrogen peroxide, permanganate salts, chromate salts and osmium tetroxide, to name just a few. Even reagents that don’t include oxygen atoms, such as halogens like fluorine and chlorine, can be powerful oxidants.

Amongst the earliest named oxidation reactions to be developed is the Tishchenko...

Read more ...


Test your metal: How many of these transition metal-catalyzed couplings have you used?

Oct. 23, 2018

Transition metal-catalyzed coupling reactions are an important family of chemical transformations that are commonly used to create new carbon-carbon and carbon-heteroatom bonds from structurally useful building blocks. These convenient reactions offer chemists a synthetic short-cut to a broad range of pharmaceutical, agrochemical and industrial compounds.

Without transition metal-catalyzed coupling reactions, many of the chemicals used in everyday life couldn’t be produced anywhere near as quickly or cost-effectively (or even at all). They’re so valuable, in fact, that the 2010 Nobel Prize in Chemistry was awarded to Richard F. Heck, Ei-ichi Negishi and Akira Suzuki in recognition of their remarkable contributions to the development of palladium-catalyzed cross-coupling reactions (more on these award-winning transformations below!).

Transition metal-catalyzed coupling reactions fall into two broad categories: homocouplings and heterocouplings (also known as cross-coupling reactions). Homocoupling reactions bring two identical structures together to form a new product, while cross-couplings react two different reagents. Palladium is...

Read more ...


Heterocyclic compound formation (if you like it, put a ring on it)

Aug. 29, 2018

A heterocyclic compound is a ring-structured molecule that contains at least two different elements as members of the ring. The sizes can vary, from highly strained, three-membered ring compounds, to larger molecules with eight, nine, or ten-membered ring structures. That being said, five and six-membered rings are usually the most common heterocyclic compounds, as they are less strained and thus more stable, especially in the case of aromatic heterocyclics. This structural variation in heterocycles (from ring size to the constituent elements) gives them a wide range of chemical properties and is a key reason what they have so many applications in organic chemistry.

Heterocyclic molecules make up many of the materials that are vital to life. For example, the fundamental building blocks of DNA (nucleic acids) are heterocyclic compounds, as are most naturally occurring antibiotics, vitamins, and pigments. In fact, heterocycles constitute nearly 50% of known organic compounds and almost 90%...

Read more ...


Nucleophilic substitution: A powerful strategy for creating diverse chemical structures

Aug. 7, 2018

Nucleophilic substitution reactions are amongst the most widely-used transformations in organic chemistry. They facilitate the interconversion of functional groups, typically at a saturated aliphatic carbon, allowing chemists to swap specific features on one molecule for more desirable ones on another. When it comes to synthetic manipulation, there really isn’t a substitute for nucleophilic substitution!

In this blog, we consider why these reactions are so useful and take a brief look at the history of some of the most important examples.

What is nucleophilic substitution?

Nucleophilic substitution reactions involve the interaction of an electron rich nucleophile (Nuc) with the positive or partially positive charge of one or more atoms on a substrate (R-LG). The neutral or negatively charged nucleophile forms a new bond with the substrate, replacing the neutral or positively charged leaving group (LG). The most general form of the reaction is as follows:

Nuc + R-LG → R-Nuc + LG

Some of...

Read more ...


Chemicals

Life Science

Metals & Materials

Catalysts

Analytical & Labware