α-酯甲基硫桥羰基铁配合物(μ-RS)[μ-EtO<(O)CH2S]-Fe2(CO)6的合成及构象分析

通过μ-S2Fe2(CO)6的S-S键被Grignard试剂的还原断裂反应及中间物(μ-RS)(μ-XMgS)Fe2(CO)6(2)对氯代乙酸乙酯的亲核取代反应,合成了一系列铁硫原子簇配合物(μ-RS)μ-EtOC(O)CH2S]Fe2(CO)6(1).1也可由2经三氟醋酸酸解及中月物(μ-RS)(μ-HS)Fe2(CO)6(3)在三乙胺存在下与氯代乙酸乙酯缩合制得.然而前法较后法既操作简便又原料便宜易得.构象分析表明,各配合物一般为ae.ee和ea三种或其中构象体以一定比例存在的混和物.

Synthesis and conformational analysis of \a\-ethoxycarbonyl-methyl substituted sulfur-bridged iron carbonyl complexes (.mu.-Rs)[.mu.-EtOC (O)CH2S]Fe2(CO)6

Fe2(CO)6(m-RS)m-EtOC(O)CH2S] (I; R = Me, Et, Pr, CHMe2, Bu, CMe3, Ph, PhCH2, CH2:CHCH2, cyclopentyl, cyclohexyl) were prepared by reductive cleavage of an S-S bond of Fe2(m-S2)(CO)6 with Grignard reagents, followed by nucleophilic substitution of the intermediates, Fe2(m-SR)(m-SMgX)(CO)6 (II) with ClCH2C(O)OEt. I were also prepared by CF3CO2H-acidolysis of II, followed by condensation of Fe2(m-RS)(m-HS)(CO)6 with ClCH2C(O)OEt in the presence of Et3N. For the former method, however, the manipulation is more convenient. Conformational anal., indicates that I is a mixture of either 3 conformers (ae, ee, and ea) or 2 conformers in a given ratio.