19224-28-3Relevant academic research and scientific papers
Reduction of diesters of 1,2-diols. Regioselective C-O bond cleavage of the anionic forms
Macias-Ruvalcaba, Norma A.,Moy, Cheryl L.,Zheng, Zi-Rong,Evans, Dennis H.
, p. 4829 - 4834 (2007/10/03)
The electrochemical reduction of benzoate diesters of glycols has been studied in acetonitrile and N,N-dimethylformamide as solvents. The reductions occur in two closely spaced one-electron steps, and it was found that the dianion diradicals decompose by one of two routes, depending on the substituents on the ethylene moiety: cleavage of two benzoates to produce alkene or formation of benzil by way of a postulated cyclic intermediate to produce also the dianion of the diol. These correspond to cleavage of the R-OC(O)Ar bonds and the RO-C(O)Ar bonds, respectively. When the radical formed by the former cleavage is a primary or secondary radical, the reaction is too slow to compete with the latter reaction that produces benzil. However, when that radical is either tertiary or benzylic, the former cleavage reaction is fast and no benzil is detected. The dianions of p-cyano- and p-nitrobenzoate esters are rather stable on the voltammetric time scale. However, the addition of lithium ions results in detectable formation of 4,4′-dicyanobenzil from four different p-cyanobenzoate diesters.
The Phenyldimethylsilyl Group as a Masked Hydroxy Group
Fleming, Ian,Henning, Rolf,Parker, David C.,Plaut, Howard E.,Sanderson, Philip E. J.
, p. 317 - 338 (2007/10/02)
A phenyldimethylsilyl group attached to carbon can be converted into hydroxy group 1->5, with retention of configuration at the migrating carbon, by any of three main methods.The first involves protodesilylation, to remove the phenyl ring from the silicon atom, followed by oxidation of the resulting functionalized silicon atom using peracid or hydrogen peroxide.The second uses mercuric acetate for the same purpose, and can be combined in one pot with the oxidative step using peracetic acid.This method has a variant in which the mercuric ion is combined with palladium(II) acetate, both in less than stoichiometric amounts.The third uses bromine, which can also be used in one pot in conjuction with peracetic acid.In this method, but not in the method based on mercuric acetate, the peracetic acid may be buffered with sodium acetate.The method using bromine as the electrophile for removing the benzene ring has a more agreeable variant in which it is administered in the form of potassium bromide, which is oxidised to bromine by the peracetic acid.The scope and limitations of each of these methods are reported with a range of examples possessing between them many of the common functional groups.Simple benzene rings, alcohols, ethers, esters, amides and nitriles are compatible with all three methods, and ketones do not undergo Baeyer-Villiger reaction under any of the conditions.Amines, however, are oxidised to amine oxides.Ketones may be brominated in the third of the three main species.The absence of acid in the third method makes it especially valuable when the phenyldimethylsilyl group has a neighbouring nucleofugal group such as hydroxy or acetoxy.Carbon-carbon double bonds are incompatible with the methods, except for terminal monosubstituted double bonds, which can survive the conditions used in the first of the three methods.
Studies on the Synthesis of Heterocyclic Compounds. VII. Action of Acyl Halides on Heterocyclic Compounds Containing the O-M-O (M = P, As, Sb) Bond in the Ring
Anchisi, Carlo,Corda, Luciana,Maccioni, Antonio,Podda, Gianni
, p. 141 - 144 (2007/10/02)
The action of acyl halides on heterocyclic compounds of five-membered rings containing an O-M-O (M = P, As, Sb) linkage is described.The reactions were either carried out in the presence of a solvent (benzene or toluene) or by direct heating of the reagent with the substrate.In the case of arsole, stibole and stannole derivatives, the cleavage of O-M bond and the formation of the respective mono- and diesters were always obtained, while with the phospholes, no cleavage of the compounds was observed.The products IIa-c (M = Sb) have been obtained in excellent yields starting from VIa-c and antimony trichloride.The structure of the compounds which were prepared was determined by analytical and spectroscopic methods and also by comparations with authentic samples where possible.
