Metallic Samarium and Iodine in Alcohol. Deacylation and Dealkyloxycarbonylation of Protected Alcohols and Lactams

Highly Diastereoselective Samarium Diiodide Induced Ketyl Cyclisations of Indole and Pyrrole Derivatives – Scope and Limitations

“…For Nacylated indole precursors, SmI 2 -promoted N-acyl cleavage to afford methyl indole-3-carboxylate (2) was observed in varying ratios. [17] The mechanism of the SmI 2 -induced ketyl cyclisation is assumed to follow either the first pathway as illustrated in Scheme 7 or an alternative route shown in Scheme 8. In the first mechanism the samarium ketyl B is formed in equilibrium from SmI 2 and the ketone A.…”

CuFe2O4 Nanoparticles: A Magnetically Recoverable Catalyst for Selective Deacetylation of Carbohydrate Derivatives

“…Several homogeneous catalysis systems have been reported allowing the O-deacetylation in the presence of other esters, e.g. guanidine [7], Sm/I 2 [8], DBU [9], HCl/MeOH [10], HBF 4 .Et 2 O [11], p-TsOH [12], etc. However, these methods suffer a number of problems, such as expensive and toxic reagents, tedious separation, filtration or neutralization of the catalyst and hardly purification process.…”

Samarium Metal in Organic Synthesis

“…[46] Scheme 32 Selective 1,4-reduction of α,β-unsaturated carboxylic acid derivatives 107 and 108 to saturated derivatives 109 and 110 was performed by samarium and iodine in alcohol (Scheme 33). [47] These reactions supported a mechanism similar to the Birch-type reduction involving a radical-anion formation, followed by additional electron capture and subsequent protonation. Scheme 33 Reductive dimerization cyclization of 1,1-dicyanoalkenes 111 to functionalized cyclopentene 112 was achieved in a one-pot reaction by samarium in the presence of trimethylsilyl chloride and a trace amount of water (Scheme 34).…”