Water accelerated Sm/TMSCl reduction system: Pinacolic coupling of aromatic carbonyl compounds and reductive dimerization cyclization of 1,1- dicyanoalkenes

Article abstract of DOI:10.1016/S0040-4020(98)00666-8

By action of Sm/TMSCl in THF at room temperature, aromatic carbonyl compounds produce the corresponding 1,2-diols via reductive coupling reaction and 1,1-dicyanoalkenes produce the functionalized cyclopentenes through reductive dimerization followed by intramolecular cyclization in one-pot. The former gives approximately equal amounts of (dl)- and (meso)-1,2-diols and the later gives the major trans-form products. Added micro amounts of water to the system not only can accelerate the reaction, but also increase the yields of products. Moreover, only substoichiometric quantities of metallic samarium are employed.