The reactions of organosulfur transfer reagents with Fe 2(CO) 9 and the synthesis of the Fe 2(CO) 6 derivative of α-lipoic acid

Abstract

Treatment of Fe 2(CO) 9 with sulfur-transfer reagents of the types ImideSSImide and RSSImide where H-imide = phthalimide, succinimide, benzimidazole, morpholine and piperazine, and R  CH 2Ph and CMe 3 leads to cleavage of both the sulfursulfur bond and the sulfurnitrogen bond to give Fe 3(CO) 9S 2 in varying yields, some Fe 2(CO) 6S 2 plus low yields of the appropriate dimers of the type Fe 2(CO) 6(SR)(SR′), where R = R′ = phthal imido, CH 2Ph, CMe 3 and R = CH 2Ph, CMe 3, R′ = phthalimido. The naturally occurring cyclic disulfide D,L-α-lipoic acid, its methyl ester and amide react with Fe 2(CO) 9 to give Fe 2(CO) 6 derivatives wherein the sulfursufur bond has been broken.