Search results
Results From The WOW.Com Content Network
The rule states that with the addition of a protic acid HX or other polar reagent to an asymmetric alkene, the acid hydrogen (H) or electropositive part gets attached to the carbon with more hydrogen substituents, and the halide (X) group or electronegative part gets attached to the carbon with more alkyl substituents. This is in contrast to ...
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.
Transfer hydrogenation usually occurs at mild temperature and pressure conditions using organic or organometallic catalysts, many of which are chiral, allowing efficient asymmetric synthesis. It uses hydrogen donor compounds such as formic acid, isopropanol or dihydroanthracene, dehydrogenating them to CO 2, acetone, or anthracene respectively. [1]
Enantioselective synthesis, also called asymmetric synthesis, [1] is a form of chemical synthesis. It is defined by IUPAC as "a chemical reaction (or reaction sequence) in which one or more new elements of chirality are formed in a substrate molecule and which produces the stereoisomeric ( enantiomeric or diastereomeric ) products in unequal ...
Allylic strain in an olefin. Allylic strain (also known as A 1,3 strain, 1,3-allylic strain, or A-strain) in organic chemistry is a type of strain energy resulting from the interaction between a substituent on one end of an olefin (a synonym for an alkene) with an allylic substituent on the other end. [1]
Alkenes react with percarboxylic acids and even hydrogen peroxide to yield epoxides: RCH=CH 2 + RCO 3 H → RCHOCH 2 + RCO 2 H. For ethylene, the epoxidation is conducted on a very large scale industrially using oxygen in the presence of silver-based catalysts: C 2 H 4 + 1/ 2 O 2 → C 2 H 4 O. Alkenes react with ozone, leading to the scission ...
In organic chemistry, the ene reaction (also known as the Alder-ene reaction by its discoverer Kurt Alder in 1943) is a chemical reaction between an alkene with an allylic hydrogen (the ene) and a compound containing a multiple bond (the enophile), in order to form a new σ-bond with migration of the ene double bond and 1,5 hydrogen shift.
Usually the substrate is an alkene and the product is a nitrile. The reaction proceeds via the oxidative addition of HCN to a low-valent metal complex to give a hydrido cyanide complex. Subsequent binding of the alkene gives the intermediate M(H)(CN)L n (alkene), which then undergoes migratory insertion to give an alkylmetal