Reagents for Chemical Synthesis
Reagents for organic synthesis at abcr
Learn more about the broad product portfolio available from abcr in the field of reagents for organic synthesis. These include:
- Fluorinating reagents and fluoroalkylation
- Brominating reagents
- Organometallic reagents: Grignard and organozinc compounds
- Organometallic reagents: Organolithium compounds
- Derivatising reagents
- Protecting group chemistry
- Boronic acids & esters
- Oxidising agents
- Reducing agents
- Ionic liquids
- Other reagents at abcr
Fluorinating reagents and fluoroalkylation
The introduction of fluorine atoms or fluoroalkyl groups intoleads to greater effectiveness in many cases. This step frequently occurs in a late stage of synthesis. This process is reflected in the term “late-stage-fluorination”.
Gaseous fluorine, hydrogen fluoride,halogen fluorides (e.g. iodine pentafluoride), sulfonylfluorides, (SF4) and derivates such as or quaternary ammonium fluorides are available to the chemist as reagents for fluorination, amongst others. Recent developments represent (Deoxo-Fluor®), (Fluolead®) as well as (XtalFluor-E®) and (XtalFluor-M®).
Metal fluorides such as aluminium, antimony, silver, molybdenum orare used, depending on the substrate. You can also find gaseous fluorides such as (AsF5) or (ReF6) in the abcr catalogue.
You can also choose between the following for the fluoroalkylation of diverse reagents:
(FIM) represents an easy to handle reagent for the introduction of fluoromethyl groups. or difluoromethyl groups can typically be transferred via so-called These hypervalent iodine compounds act as electrophilic CF3 sources, having been continuously refined over the years.
Besides electrophilic CH2F, CHF2 and CF3 sources, nucleophilic, radical or carbenoid sources are also used. Many of these reagents are based on sulfonium or sulfonyl compounds, thus for instance the
Other examples of trifluoromethylation reagents are represented by(TMSCF3), (CHF3), (CF3I) and (CF3SO2Na). On account of its instability, trifluoromethyllithium (CF3Li) is not available to synthesis chemists. Complexed trifluorumethyl copper reagents provide alternatives here.
You can also find a series of trifluorumethoxy- or trifluoromethylthio-substitutedin the abcr catalogue.
Althoughare long known, the corresponding pentafluoroethyl compounds have only become accessible recently. For the introduction of pentafluoroethyl groups, abcr recommends the new reagent This is available as a solid with long-term stability and does not require any gaseous educts.
and have long been known as common However, these substances exhibit certain disadvantages in respect to their handling, dosing and toxicity. abcr offers you a safe and also highly selective alternative in the form of tetraalkylammonium nonabromide salts. These salts that are both stable in air and good to dose enable high selectivity when brominating double bonds, triple bonds or heterocycles.
Organometallic reagents: Grignard and organozinc compounds
Organic chemists have been utilising organometallic reagents for over 100 years. The organomagnesium halide compounds developed by the French chemist Victor Grignard are among the best known organometallic compounds under the collective termsVictor Grignard received the Nobel Prize for Chemistry in 1912 for his research.
The Grignard reaction represents one of the most important reactions for linking carbon-carbon bonds. The linking of carbon-phosphorus, carbon-silicon or carbon-boron bonds is also possible via Grignard reagents.
Alkyl- or aryl-magnesium halides react here as nucleophiles with electrophilic groups such as cyano- or carbonyl groups:
Carboxylic acid esters
In combination with(Kumada coupling) or copper salts, Grignard reagents are used for aryl-alkyl coupling reactions.
Grignard reagents are accessible from many alkyl and aryl halides. In many cases, however, electronic effects, steric hindrance or particularly high reactivity impede synthesis of the desired Grignard compounds. A complementary alternative exists in the form of organozinc halides in many of these cases.
are primarily used in the transfer of alkenyl, benzyl, pyridyl or As nickel or cross-coupling, this reaction was named by the term “Negishi reaction”.
Organozinc halides are somewhat less reactive than Grignard reagents and therefore easier to handle.
Organometallic reagents: Organolithium compounds
Organolithium compounds serve in organic chemistry as strong bases for deprotonation with simultaneous lithiation of the substrates or as alkylating reagents. A defined lithiation of aromatic compounds is typically obtained by ortho-directing groups such as amino or methoxy groups.
Like Grignard reagents, organolithium compounds react with electrophiles such as aldehydes, ketones and carboxylic acid esters. Brominations, iodinations and carboxylations are possible through reaction of the lithium organyls with elementary bromine and iodine or solid carbon dioxide (“dry ice”).
The best known representatives among the organolithium compounds are methyllithium (MeLi) as well as n-butyllithium (n-BuLi) and tert-butyllithium (t-BuLi). You can find these and other lithium organyls as solutions in various solvents in the abcr catalogue.
are used in GC, GC/MS and NMR analytics. For applications in coupled gas chromatography/mass spectrometry, silylated and fluorinated amides such as (BSTFA), or (MSTFA) are used for derivatisation. Highly volatile or less stable substances are accessible to analytics in many cases by the introduction of a A mixture known as a trimethylsilylation solution is also used in industry.
In NMR analytics, enantiomer mixtures – in which both enantiomers exhibit the same NMR spectra in many cases – can be characterised by the addition of a suitable enantiomericallyThe resultant diastereomers exhibit different NMR spectra, thereby enabling a quantification of the enantiomers, determination of the ee value (“enantiomeric excess”) and optical purity. The of (R) or (S)-α-methoxy-α-(trifluormethyl)phenylacetic acid have proven effective for determining the enantiomeric purity of chiral amines and alcohols. These are also referred to as Mosher’s acid chlorides.
Electrochemical and UV detectors are used amongst others in HPLC. The products are derivatised for electrochemical detection, e.g. withare used for derivatisation for UV detection.
Protecting group chemistry
The use of protecting groups has become firmly established in the field ofin particular. Amino and carboxy groups can be blocked selectively by using BOC (tert-butyloxycarbonyl), FMOC (fluorenylmethyloxycarbonyl), Cbz (benzyloxycarbonyl) or Trt (trityl) protecting groups. This enables the targeted build-up of
The carboxy groups are activated by activating reagents such asor active esters of (HOBt), (HOOBt) and (HOSu).
You can also find other coupling reagents such asor in the abcr catalogue.
Depending on the substrate, the protecting groups is eliminated in a hydrogenolytic, basic or acidic manner. These different reaction conditions correspond to the orthogonality principle, according to which each protecting group can be eliminated individually and in any order when using different protecting groups, without one or the other protecting group being attacked.
Protecting groups are also used in organic synthesis. Hydroxy groups can be blocked with reagents such asor can be stabilised as by reaction with diols.
Boronic acids & esters
Suzuki coupling has become established as one of the most versatile cross-coupling reactions in organic chemistry. After discovering it, Aguri Suzuki received the Nobel Prize for Chemistry in 2010 together with Richard Heck and Ei-ichi Negishi.
For Suzuki coupling, aryl, alkenyl or alkyl boronic acids are reacted with aryl halides or vinyl halides viawhereby new carbon-carbon bonds are linked. In case of reactive or unstable boronic acids, the corresponding boronic acid pinacol esters are available as a substitute. round off the pallet of boronic acids.
The abcr catalogue contains a broad spectrum of more than 8000 different boronic acids, pinacol esters and trifluoroborate salts. N-heterocyclic boronic acid MIDA esters are also part of our portfolio.
Use our structural search to find theor of your choice!
The main application ofof the formula BxHy lies in hydroboration. Born-hydrogen bonds add double and triple bonds by forming organoboranes. Although these organoboranes can be isolated, these are mostly reacted further in a further reaction step (e.g. an oxidation). are derived from in this way.
Free borane (BH3) is highly reactive, but can be stabilised well in the form of adducts.or are available to chemists in the laboratory as easy to handle sources for BH3.
The pinacol boranesand serve for the production of
Familiar examples of oxidising agents areand Chromium (VI) compounds are also used in industry, but are problematic on account of their high toxicity. silver (II) salts as well as halogen oxoacids and their salts (e.g. hypochlorite, periodate, bromate) are also used to a large extent in oxidation reactions.
In gunpowder,forms the oxidizing component. Besides nitrate salts, and peroxo-sulfuric acids are also used for oxidation purposes.
Hydride reagents such as lithium aluminium hydride (LiAlH4) or(NaBH4) are used actively as reducing agents in organic syntheses. known by the trade name Vitride® represents an easy to handle alternative to pure hydrides. Pure also have a strongly reductive effect, for instance in the Birch reduction of aromatic compounds.
In combination withsuch as Pd/C or Pt/C, elementary hydrogen is used for reductions in industrial applications.
In the Fischer-Tropsch process, synthesis gas (mixture comprising CO/H2) is converted into a series of gaseous or liquid hydrocarbons by heterogeneous iron or cobalt catalysis. Amongst other applications, these serve as low-sulfur synthetic fuels and engine oils.
In analytical chemistry,and are used for redox titrations.
Finally,is used as rocket fuel in aerospace.
You can find all common organicfrom A for acetone to X for xylene in the abcr catalogue, in practical small containers for your application in the laboratory. For applications in or biochemistry, we provide solvents in special purities.
is the name given to molten salts with a melting temperature below 100 °C. They primarily comprise iminium cations and complex halide anions or other very weakly coordinated anions. The cations in ionic liquids are mostly substituted imidazolium, pyridinium, pyrrolidinium, guanidinium, piperidinium, morpholinium, ammonium or phosphonium ions. Triflates, tosylates, tetrafluoroborates, halides, trifluoroacetates, hexafluorophosphates or also amides are used as anions.
Ionic liquids are used asfor organic, inorganic and polymer synthesis. They also serve as as well as in metallurgy.
Typical applications of ionic liquids in process technology include use as parting agents, lubricants and hydraulic fluids. On account of their ability to store and transfer heat, they are also used as
Other reagents at abcr
The Burgess reagentwas first described as a mild dehydration reagent in 1970. This reagent allows the production of from and from amides.
reacts with alkene via hydrozirconation. The resultant alkyl zirconium complexes can typically be oxidised during hydroboration.
decay after absorption of (UV) light (= photolysis) in reactive species, which can start (initiate) a (chain) reaction. Photoinitiators such as triaryl sulfonium, ferrocenium, diaryliodonium, or diazonium salts are therefore used as starters for radical or cationic