1727-86-2Relevant academic research and scientific papers
Lactones; XIII. Grignard Reaction Followed by Phase-Transfer Oxidation: A Convenient Synthesis of γ,γ-Disubstituted γ-Butyrolactones from γ-Butyrolactone
Lehmann, Jochen,Marquardt, Norbert
, p. 1064 - 1067 (1987)
Grignard reaction of γ-butyrolactones, followed by oxidation of the resulting reaction mixture produces symmetrically γ,γ-dialkylated diarylated γ-butyrolactones.Phase transfer oxidation with potassium permanganate in benzene/water proves to be the best out of twelve examined oxidation methods.The synthesis is unsuccessful with sterically hindered or oxidizable Grignard reagents.
Chiral phosphoric acid-catalyzed enantioselective and diastereoselective spiroketalizations
Sun, Zhankui,Winschel, Grace A.,Borovika, Alina,Nagorny, Pavel
supporting information; experimental part, p. 8074 - 8077 (2012/07/14)
Catalytic enantioselective and diastereoselective spiroketalizations with BINOL-derived chiral phosphoric acids are reported. The chiral catalyst can override the inherent preference for the formation of thermodynamic spiroketals, and highly selective formation of nonthermodynamic spiroketals could be achieved under the reaction conditions.
Boronic acid catalysis as a mild and versatile strategy for direct carbo- and heterocyclizations of free allylic alcohols
Zheng, Hongchao,Ghanbari, Sina,Nakamura, Shinji,Hall, Dennis G.
supporting information; experimental part, p. 6187 - 6190 (2012/08/13)
BAC to the future: Boronic acid catalysis (BAC) was applied to the direct activation of alcohols leading to the preparation of carbocycles (see scheme), benzofurans, tetrahydrofurans, pyrrolidines, pyrans, piperidines, and various polycyclic compounds. The reactions proceed under mild conditions that circumvent the use of reactive leaving groups like halides. Copyright
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.
Catalytic Barbier-type reactions of lactones and esters mediated by the Mischmetall/SmI2(cat.) system or the Mischmetall/[SmI2/NiI2(cat'.)](cat.) system
Lannou, Marie-Isabelle,Hélion, Florence,Namy, Jean-Louis
, p. 8007 - 8010 (2007/10/03)
Barbier-type reactions using SmI2 in catalytic amounts together with Mischmetall as a coreductant, involving lactones or esters and a variety of organic halides (allylic, benzylic and alkyl), have been performed. With alkyl halides and five- or six-membered ring lactones, catalytic quantities of nickel diiodide (with respect to SmI2) must be added to achieve reactions. Thus, a 'two-stage catalysis' is carried out. Unexpectedly, it was found that with esters or an unstrained lactone the Mischmetall/SmI2 (catalytic) system is more reactive than samarium diiodide in stoichiometric amounts. Tentative interpretations of the catalytic role of NiI2 are proposed.
Barbier/Grignard-type allylation or benzylation mediated by the mischmetall/SmI2(cat.) system
Di Scala, Aurore,Garbacia, Stefania,Helion, Florence,Lannou, Marie-Isabelle,Namy, Jean-Louis
, p. 2989 - 2995 (2007/10/03)
Barbier- and Grignard-type allylation and benzylation have been achieved by the use of samarium diiodide in catalytic amounts together with mischmetall (an alloy of the light lanthanides) as a coreductant. Plausible catalytic schemes are proposed. In addition, organocerium and -lanthanum reagents have been obtained from samarium diiodide catalysed reactions between organic halides and cerium or lanthanum metal, giving a new route to organolanthanoid compounds. It also appears that trivalent benzyl and allyl organometallic compounds of cerium and lanthanum are much more stable than the corresponding samarium ones. Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002.
