Ads
related to: jacobsen epoxy catalyst
Search results
Results From The WOW.Com Content Network
Jacobsen's catalysts R = Alkyl, O-alkyl, O-trialkyl Best Jacobsen catalyst: R = t Bu Katsuki's catalysts R 1 = Aryl, substituted aryl R 2 = Aryl, Alkyl. The Jacobsen epoxidation, sometimes also referred to as Jacobsen-Katsuki epoxidation is a chemical reaction which allows enantioselective epoxidation of unfunctionalized alkyl- and aryl- substituted alkenes.
Jacobsen's catalyst is the common name for N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediaminomanganese(III) chloride, a coordination compound of manganese and a salen-type ligand. It is used as an asymmetric catalyst in the Jacobsen epoxidation , which is renowned for its ability to enantioselectively transform prochiral alkenes ...
In 1997, Jacobsen's group published a methodology which improved upon their earlier work, allowing for the use of water as the nucleophile in the epoxide opening. Utilizing a nearly identical catalyst, ee's in excess of 98% for both the recovered starting material epoxide and 1,2-diol product were observed.
The Jacobsen epoxidation, an alternative method to enantioselectively oxidise alkenes, overcomes this issue and tolerates a wider array of functional groups. [citation needed] For specifically glycidic epoxides, the Jørgensen-Córdova epoxidation avoids the need to reduce the carbonyl and then reoxidize, and has more efficient catalyst ...
Oxidation of epoxy alcohols generated via Sharpless epoxidation is a third method for the enantioselective synthesis of chiral α,β-epoxy carbonyl compounds. [30] Swern and Parikh-Doering conditions are most commonly applied to accomplish these oxidations. (14)
Jacobsen's catalyst is a manganese-based catalyst commonly used for the stereoselective epoxidation of alkenes. This epoxidation proceeds by a radical addition mechanism, which can be taken advantage of by introducing the radical TEMPO group into the reaction mixture.
A compound containing the epoxide functional group can be called an epoxy, epoxide, oxirane, and ethoxyline. Simple epoxides are often referred to as oxides. Thus, the epoxide of ethylene (C 2 H 4) is ethylene oxide (C 2 H 4 O). Many compounds have trivial names; for instance, ethylene oxide is called "oxirane".
A key use is as a catalyst for epoxy resin chemistry. It can be used as a homopolymerization catalyst for epoxy resins and also as an accelerator with epoxy resin curing agents. It is then further used in coatings, [5] sealants, composites, [6] adhesives [7] and elastomers. It has been stated that it is probably the most widely used room ...