Recent developments in lanthanide mediated organic synthesis

New synthesis of mephenoxalone

“…Lanthanide reagents are frequently used in organic synthesis as catalysts in different reactions, [17][18][19][20][21][22] but lanthanide camphorates are typically used as chiral shift reagents for direct determination enantiomeric compositions by nuclear magnetic resonance. [23][24][25] Here, europium and ytterbium camphorates were used to establish their catalytic capacity and asymmetric induction in the addition of TMSCN to the carbonyl group.…”

Recent applications of rare-earth metal(III) triflates in cycloaddition and cyclization reactions

“…35,36 As was the case for DA reactions, rare-earth metal(III) triflates have also been successfully employed to promote heteroDiels-Alder reactions. [10][11][12][13][14][15] Below are notable examples of M(OTf) 3 -catalyzed HDA reactions published in the last five years.…”

“…73 Owing to their oxophilic character, water tolerability and pronounced Lewis acidic properties, lanthanide triflates were also successfully employed in a number of free radical processes. [10][11][12][13][14][15] Yang and co-workers have disclosed Yb(OTf) 3 -promoted 5-/6-exo-trig radical cyclization of α-phenylseleno amido esters 93 under UV irradiation to give rise to mono-and bicyclic nitogen heterocycles 94 (Scheme 26). 74 It was suggested that Yb(OTf) 3 played a two-fold role in promoting the radical process: increased electrophilicity of the α-radical intermediate via 1,3-dicarbonyl moiety chelation and accelerated PhSe group transfer.…”

“…[10][11][12][13][14][15] A selection of recent examples of these useful organic transformations, including Prins-type cyclization, three-component cyclization, and heterocycle syntheses, will be highlighted in this section. Sc(OTf) 3 can be successfully used as a promoter for intramolecular condensations of ynol ether-acetals.…”

“…[10][11][12][13][14][15] Therefore, the purpose of the present review is not to summarize all the efforts in the area comprehensively, but instead highlight a select number of important applications of rare-earth metal triflates in cyclization and cycloaddition reactions reported over the last five years, up to the first three quarters of 2013.…”