Functional groups cerium ammonium nitrate

SOMO catalysis, which has been the subject of considerable attention in recent years, is a unique and versatile activation mode that can participate in bond construction with various n-rich nucleophiles. The first asymmetric intramolecular a-arylation of aldehydes was reported by Nicolaou in 2009 using organo-SOMO catalysis [17a]. The authors applied imidazolidinone 23 as catalyst and cerium ammonium nitrate (CAN) as the oxidant Various 5-oxopentylbenzenes 36, or indole derivatives 38, could furnish the cyclic products 37 or 39, respectively, in good yields and with excellent ees (Scheme 36.11). Later, MacMillan disclosed similar research [17b], and a theoretical study of the intramolecular a-arylation of aldehydes was also reported by the same group via density functional theory [17c],... 

Oxidative functionalization of alkenes. Activated by cerium(IV) ammonium nitrate in methanol Ph2Se2 initiates addition to an alkene. Some unsaturated alcohols undergo phenylselenocycloetherification, and in case that the activation is by a photoinduced electron transfer process the phenylseleno group of the products can be replaced. 

Oxidation and Bromination of Other Functional Groups. Selective oxidation of alcohols may be achieved using a 1 1 complex of NBS and tetrabutylammonium iodide, whereas 1,2-diols are converted into 1,2-diketones using iV-bromosuccini-mide. An efficient and mild procedure has been reported for the preparation of benzoic acids via oxidation of aromatic carbonyl compounds by employing NBS and mercuric acetate. Selective and efficient oxidation of sulfides to sulfoxides has been achieved with NBS in the presence of /3-cyclodextrin in water. Epoxides and aziridines are conveniently oxidized to the corresponding a-hydroxy or Q -amino ketones using cerium(IV) ammonium nitrate and NBS. ... 

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