65926-98-9Relevant academic research and scientific papers
Geometric requirements in the ferriin oxidation of benzylic 1,2-diols
Penn, John H.,Plants, Robert C.,Liu, An
, p. 2359 - 2360 (2007/10/03)
The rates of ferriin [i.e. tris(1,10-phenanthroline)iron(III)] oxidation of cis- and trans-1,2-diphenylcyclohexane-1,2-diol have been found to be dramatically different; cis-1,2-diphenylcyclohexane-1,2-diol reacts a minimum of 104 times faster than the corresponding trans-isomer; implications for the oxidation of benzylic diols by ferriin are discussed.
Oxidative Cleavage of vic-Diols Using Copper(II) Bromide-Lithium t-Butoxide: A New Route to Unsymmetrical 1,5- and 1,6-Diketones
Fujiwara, Tooru,Tsuruta, Yumiko,Arizono, Ko-Ichi,Takeda, Takeshi
, p. 962 - 964 (2007/10/03)
Unsymmetrical 1,6-diketones were obtained by the copper(II) bromide-lithium t-butoxide oxidation of 1,2-disubstituted 1,2-cyclohexanediols. The diols were easily prepared by the addition of Grignard reagents to 2-trimethylsiloxy-2-cyelohexenone followed by the hydrolysis and treatment of the resulting 2-hydroxycyclohexanones with the second Grignard reagents. Similarly, 1,5-Diketones were obtained using 2-trimethylsiloxy-2-cyclopentenone as a starting material.
"Site Selective" Formation of Low-Valent Titanium Reagents: An "Instant" Procedure for the Reductive Coupling of Oxo Amides to Indoles
Fuerstner, Alois,Hupperts, Achim,Ptock, Arne,Janssen, Edo
, p. 5215 - 5229 (2007/10/02)
Aromatic acylamido carbonyl compounds are readily cyclized to indole derivatives upon treatment with low-valent titanium reagents of the formal oxidation states 0, +1, and +2.Other strong reducing agents such as SmI2 and low-valent zirconium, niobium, and tungsten complexes are also capable of effecting such intramolecular alkylidenation reactions of amides.From the preparative point of view these heterocycle syntheses are best effected with an active titanium species which is prepared in the presence of the carbonyl compound upon coordination of TiCln (n = 3, 4) to the oxo amide substrate and reduction of this complex with zinc dust ("instant" method).This procedure turned out to be as effective as the titanium-graphite-based methodology previously described but is much easier to perform as all hazardous reagents are avoided. "Instant" cyclizations can also be run in nonetheral solvents such as DMF, ethyl acetate, or acetonitrile and turned out to be compatible with many functional groups.The method was used to cyclize oxo amide 15 to (+)-aristoteline, and it applies nicely to the synthesis of strained indole derivatives, the formation of benzofurans, conventional McMurry reactions of aldehydes and ketones, and the dimerization of alkynes.Metals such as zirconium can also be activated in situ by reduction of ZrCl4 in the presence of a carbonyl compound.On the basis of the results obtained with substrates bearing appropriate structural probes a mechanism for such intramolecular keto-amide coupling processes is proposed.Carbonyl dianions, formed upon two-electron reduction of the keto group, are the most likely reactive intermediates.Electrochemical investigations support this mechanistic interpretation.
Synthesis and Enantiomer Recognition of Crown Ethers containing Cyclohexane-1,2-diol Derivatives as the Chiral Centre and Enzymatic Resolution of the Chiral Subunits
Naemura, Koichiro,Miyabe, Hajime,Shingai, Yasuhiro
, p. 957 - 959 (2007/10/02)
The cyclohexane-1,2-diol derivatives 1 and 4 of high optical purity have been prepared by enantioselective hydrolysis of their acetates (+/-)-2 and (+/-)-5 using pig liver esterase.The enantiomer recognition behaviour of the chiral crown ethers 11, 14, 15
SOME ORGANIC REACTIONS PROMOTED BY SAMARIUM DIIODIDE
Souppe, J.,Danon, L.,Namy, J.L.,Kagan, H.B.
, p. 227 - 236 (2007/10/02)
Various homoallylic alcohols and homobenzylic alcohols were prepared by the reaction between aldehydes and allylic or benzylic halides in the presence of samarium diiodide.This iodide is also a very good reagent for formation of pinacols from aldehydes or ketones.The reactions are especially fast and selective in the case of substituted benzaldehydes.The reactivities of various nitrogen functional groups (imine, oxime, nitro, azo, cyano) towards SmI2 were also examined.
