53484-48-3Relevant academic research and scientific papers
Electrochemical generation of low-valent lanthanides
Parrish,Little
, p. 7767 - 7770 (2001)
A new method is presented to produce divalent lanthanides (including the popular reductant samarium(II) iodide) from the corresponding trivalent triflate salts. This novel route to low-valent lanthanides suggests the development of a catalytic system empl
A new preparation of samarium dibromide and its use in stoichiometric and catalytic pinacol coupling reactions
Hélion, Florence,Lannou, Marie-Isabelle,Namy, Jean-Louis
, p. 5507 - 5510 (2007/10/03)
A new convenient preparation of samarium dibromide in THF is reported. Pinacol coupling reactions using SmBr2 in catalytic amounts together with mischmetall as a coreductant have been performed with a variety of carbonyl compounds.
Some uses of mischmetall in organic synthesis
Lannou, Marie-Isabelle,Hélion, Florence,Namy, Jean-Louis
, p. 10551 - 10565 (2007/10/03)
Mischmetall, an alloy of the light lanthanides, has been used in a variety of organic reactions, either as a coreductant in samarium(II)-mediated reactions (Barbier and Grignard-type reactions, pinacolic coupling reactions) or as the promoter of Reformatsky-type reactions. It has been also employed as the starting material for easy syntheses of lanthanide trihalides, the reactivity of which has been explored in Imamoto and Luche-Fukuzawa reactions and in Mukaiyama aldol reactions.
Facile reduction of aromatic aldehydes, ketones, diketones and oxo aldehydes to alcohols by an aqueous TiCl3/NH3 system: Selectivity and scope
Clerici, Angelo,Pastori, Nadia,Porta, Ombretta
, p. 3326 - 3335 (2007/10/03)
A simple and rapid procedure for the almost quantitative reduction of aromatic aldehydes, ketones, diketones and oxo aldehydes to alcohols by use of TiCl3/NH3 in aqueous methanol solution is reported. The reducing system distinguishes between different classes of aldehydes and/or ketones, and many functionalities that usually do not survive under reducing conditions are tolerated well. The concept of reversal of chemoselectivity has also been developed. A mechanism based on two sequential one-electron transfers from TiIII to the carbonyl carbon atom is proposed, the second SET becoming operative only in the presence of ammonium ion (either added or formed in situ). Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002.
Diastereoselective pinacol coupling of alkyl aryl ketones with rare earth metals in the presence of chlorosilanes
Ogawa, Akiya,Takeuchi, Hiroki,Hirao, Toshikazu
, p. 7113 - 7114 (2007/10/03)
Rare earth metals (Ln) are found to act as useful reducing agents for the pinacol coupling reaction of alkyl aryl ketones in the presence of chlorosilanes. Although the hitherto known pinacol coupling reaction using rare earth reducing agents generally exhibits very low diastereoselectivities, the present pinacol coupling by use of a Ln/R3SiCl system usually indicates higher diastereoselectivities. In particular, a Yb/Me3SiCl system attains the diastereoselective pinacol coupling of primary alkyl aryl ketones with the dl/meso ratio of 8/2~9/1.
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.
