FUJIWARA Lanthanide reaction

FUJIWARA Lanthanide (Yb) reaction Use of ytterbium or other lanthanoids in substitution, reduction and 1,2 addition. 

The reaction of a lanthanide metal, ytterbium, has been explored by the group of Fujiwara [164-166]. Among the various processes (coupling, desul-furisation, etc.) which were evidenced, a nice application was achieved by successive reaction of thiobenzophenone with ytterbium, and treatment of the intermediate with a dihalide. Thiolanes, for instance, were thus obtained in an expedient manner. 

For a recent study concerning lanthanide triflates in hetero-Diels-Alder reactions of 2-azabutadienes see Makioka Y, Shindo T, Taniguchi Y, Takaki K, Fujiwara Y (1995) Synthesis 801... 

FUJI WAR A Lanthanide (Yb) reaction 136 FUJIWARA Aiylation, caiboxylation 137 FUJIWARA - HECK Coupling 138... 

Other examples and effects of lanthanide triflates are shown in Tables 8.16 and 8.17, respectively [59]. A vinyl sulfide, a vinyl ether and a silyl enol ether worked well as dienophiles to afford tetrahydroquinoline derivatives in high yields [60]. Fujiwara et al. reported a similar type of reaction [61]. As for the lanthanide triflates, heavy lanthanides such as Er, Tm and Yb gave better results. 

---