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. The product is a substituted alkene with the double bond shifted to the allylic position.[1]
Figure 1 - the ene reaction
This transformation is a group transfer pericyclic reaction,[2] and therefore, usually requires highly activated substrates and/or high temperatures.[3] Nonetheless, the reaction is compatible with a wide variety of functional groups that can be appended to the ene and enophile moieties. Many useful Lewis acid-catalyzed ene reactions have been also developed, which can afford high yields and selectivities at significantly lower temperatures, making the ene reaction a useful C–C forming tool for the synthesis of complex molecules and natural products.
^Alder, K.; Pascher, F; Schmitz, A. "Über die Anlagerung von Maleinsäure-anhydrid und Azodicarbonsäure-ester an einfach ungesättigte Koh an einfach ungesättigte Kohlenwasserstoffe. Zur Kenntnis von Substitutionsvorgängen in der Allyl-Stellung". Ber. Dtsch. Chem. Ges. 7: 2. doi:10.1002/cber.19430760105.
^Mikami, K.; Shimizu, M. (1992). "Asymmetric ene reactions in organic synthesis". Chem. Rev. 92 (5): 1021. doi:10.1021/cr00013a014.
^Snider, B. B. (1980). "Lewis-acid catalyzed ene reactions". Acc. Chem. Res. 13 (11): 426. doi:10.1021/ar50155a007.
organic chemistry, the enereaction (also known as the Alder-enereaction by its discoverer Kurt Alder in 1943) is a chemical reaction between an alkene with...
transfer reactions can sometimes be difficult to identify when separate reactant molecules combine into a single product molecule (like in the enereaction)....
reactions. The major classes of pericyclic reactions are given in the table below (the three most important classes are shown in bold). Enereactions...
involved in the Enereaction and the Thiol-enereaction -ene, a suffix used in the names of certain organic compounds (alkenes) Ene, Spanish abbreviation...
aldol reaction, and various pericyclic processes that proceed slowly at room temperature, such as the Diels-Alder reaction and the enereaction. In addition...
transfer of an allyl proton to the carbonyl group which in effect is an enereaction in scheme 6. in green: capture of the carbocation by additional carbonyl...
of the enereaction between singlet oxygen and olefins". Accounts of Chemical Research. 13 (11): 419–425. doi:10.1021/ar50155a006. This reaction is not...
place is much smaller, for example the enereaction or aldol reaction. Another approach to organic reactions is by type of organic reagent, many of them...
common in drug synthesis. Common reaction types include Diels–Alder reactions, the enereaction, [2+2] cycloaddition reactions, hydrocyanation of aldehydes...
describe this last step as a [3,3]-sigmatropic reaction in the original report but call it a retro-enereaction in another publication. (Note: The IUPAC defines...
generated from thiols RSH. Thiyl radicals are intermediates in the thiol-enereaction, which is the basis of some polymeric coatings and adhesives. They are...
applications in organic chemistry. For example, it can catalyse the enereaction, such as the addition of 3-buten-2-one (methyl vinyl ketone) to carvone:...
via rearrangement reactions. Besides olefin metathesis (described above), many pericyclic reactions can be used such as the enereaction and the Cope rearrangement...
the 2-norbornyl cation. Being a strained ene, norbornenes react readily with thiols in the thiol-enereaction to form thioethers. This makes norbornene-functionalized...
referred to simply as Click reactions Thiol-enereaction Diels-Alder reaction and inverse electron demand Diels-Alder reaction [4+1] cycloadditions between...
anchoring the hydrophobic group to the surface. ASA is prepared by the enereaction of unsaturated hydrocarbons with maleic anhydride. In 1901, Edgar Wedekind...
are produced by autoxidation, the direct reaction of O2 with a hydrocarbon. Autoxidation is a radical reaction that begins with the abstraction of an H...
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