The preparation of organolanthanoid species from diorganomagnesium and lanthanoid salt is discussed. Treatment of cerium trichloride or ytterbium trichloride with diorganomagnesium gave the corresponding organolanthanoid species much more efficiently than treatment of the salt with organomagnesiumhalide.
In the presence of anhydrous cerium(III) chloride, Grignardreagents react with Ketones to afford addition products in high yields, even though the substrates are susceptible to abnormal reactions with Grignardreagents alone.
Transition-metal chloride mediated addition reaction of diorganomagnesium to easily enolizable ketones
作者:Mutsumi Sada、Seijiro Matsubara
DOI:10.1016/j.tet.2011.02.009
日期:2011.4
is difficult to perform with Grignardreagent (RMgX) or with diorganomagnesium (R2Mg), because a deprotonation to form a magnesium enolate occurs predominantly. To avoid the prior enolization, a complex reagent of a transition-metal salt and R2Mg was examined: A combination of R2Mg with iron(II) chloride (FeCl2) or ytterbium(III) chloride (YbCl3) gave a complex reagent that can realize a nucleophilic
A Formal Intermolecular Iodolactonization Reaction Based on a Radical-Ionic Sequence
作者:David F. León-Rayo、Maricela Morales-Chamorro、Alejandro Cordero-Vargas
DOI:10.1002/ejoc.201600051
日期:2016.3
report herein a method based on a radical-ionic sequence between an allylic alcohol and an α-iodo acid in the presence of substoichiometric amounts of lauroyl peroxide (DLP) to produce an atom transfer radical addition (ATRA) adduct, which subseqently underwent an acid-mediated lactonization. This approach can be described as a free radical reaction followed by an intermolecular iodolactonization. Twenty-two