A novel reduction of sodium alkyl thiosulfates with InCl3(cat.)/Sm(0) system in aqueous media has been developed, which generates the corresponding disulfides in good yields.

In saturated NH4CI (aq.)-THF solution at room temperature, metallic samaritan promoted reductive dimerization cyclization of gem-diactivated alkenes, reductive debromination of vic-dibromides, and reduction of sodium alkyl thiosulfates occur to afford corresponding functionalized cyciopentenes, (E)-alkenes, and disulfides. respectively in good yield. Only sub-stoichiometric quantities of samarium are employed in the former reactions and the trans-or trans, trans-form isomer is the majority product of the polysubstituted cyclopentene products.

The reductive coupling cyclization of 1, 1-dicyanoalkenes was performed with metallic samarium in saturated aqueous NH4C1-THF solution at room temperature. Sub-stoichiometric quantities of samarium could be employed and trans-isomer was the major product.

The Sonogashira coupling reaction catalyzed by ultrafine nickel(0) powder has been developed; terminal alkynes couple with aryl, alkenyl iodide and aryl bromide in the presence of cuprous iodide, triphenylphosphine, potassium hydroxide and ultrafine particle nickel(0) to provide the corresponding crosscoupling products with high yields.

A microwave-enhanced, solventless Mannich condensation of terminal alkynes, primary amines with paraformaldehyde on cuprous iodide doped alumina has been investigated. The struc-tures of products depend on the ratio of alkyne to amine and paraformaldehyde.