Mischmetall, an alloy of the light lanthanides, has been used in a variety of organicreactions, either as a coreductant in samarium(II)-mediated reactions (Barbier and Grignard-type reactions, pinacoliccouplingreactions) 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
A benzofuran-based cage-shaped borate showed a higher degree of Lewis acidity and exhibited photo-activated catalytic activity under black-light irradiation.
Diiodosamarium an excellent catalyst precursor for Aldolisation and Michael reactions.
作者:Pierre Van de Weghe、Jacqueline Collin
DOI:10.1016/s0040-4039(00)79253-7
日期:1993.6
SmI2 is the precursor of efficient catalysts for the aldolisationreactions of aldehydes and ketones with enol silanes. α,β-unsaturated ketones give 1,4-addidtions selectively.
Chemoselective Aldol Reaction of Silyl Enolates Catalyzed by MgI<sub>2</sub> Etherate
作者:Wei-Dong Z. Li、Xing-Xian Zhang
DOI:10.1021/ol026585e
日期:2002.10.1
Mukaiyama-type aldol coupling of typical silyl enolates 2-4 with aryl or vinyl aldehydes and acetals was realized in the presence of 1-5 mol % of MgI(2) etherate (1) in a mild, efficient, and highly chemoselective manner. Iodide counterion, weakly coordinating peripheral ethereal ligands (Et(2)O) of Mg(II), and a noncoordinating reactionmedia (i.e. CH(2)Cl(2)) are among the critical factors for the
Mukaiyama aldol and Michael reactions catalyzed by lanthanide iodides
作者:Nicolas Giuseppone、Pierre Van de Weghe、Mohamed Mellah、Jacqueline Collin
DOI:10.1016/s0040-4020(98)00791-1
日期:1998.10
Samariumdiiodide is an efficient catalyst precursor which allows the formation of condensation products between various carbonylcompounds and ketene silyl acetals or enoxysilanes. With α,β-unsaturated carbonylcompounds, 1,2- or 1,4-additions are observed according to the structure of the substrate. α,β-Unsaturated ketones yield to enoxysilanes by selective Michael additions. Aldol poducts are isolated