Studies on the Condensation Pathway to and Properties of Diiron Azadithiolate Carbonyls.
Studies on the Condensation Pathway to and Properties of Diiron Azadithiolate Carbonyls.
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DOI：
10.1021/om0611150
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发表时间：
2007-03
期刊：
影响因子：
2.8
通讯作者：
J. Stanley;T. Rauchfuss;S. Wilson
中科院分区：
文献类型：
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作者：
J. Stanley;T. Rauchfuss;S. Wilson
在NH(3)存在下，Fe(2)(SH)(2)(CO)(6)与HCHO反应生成Fe(2)[(SCH(2))(2)NH](CO)(6)，得到可能的中间体Fe(2)(SCH(2)OH)(2)(CO)(6)。Fe(2)(SCH(2)OH)(2)(CO)(6)与氨和胺反应生成Fe(2)[(SCH(2))(2)NR](CO)(6)(R=H，烷基)。Fe(2)(SH)(2)(CO)(6)与RC(O)C(O)R(R=H，Ph，4-F-C(6)H(4))反应生成相应的半硫代缩醛中间体。对C(2)对称的苯并衍生物Fe(2)[S(2)C(2)(OH)(2)Ph(2)](CO)(6)也进行了结晶学表征。通过Li(2)Fe(2)S(2)(CO)(6)与(ClCH2)(2)NC(O)Me反应，合成了酰化氮杂二硫酸酯Fe(2)[(SCH(2))(2)NaC](CO)(6)。D核磁共振实验表明，Fe(2)[(Sch(2))(2)NAc](CO)(6)和Fe(2)[(Sch(2))(2)NAc](CO)(4)(PME(3))(2)的酰胺键转动活化能是相同的，这表明铁中心上的配体对氮的碱性影响不大。作为对照，我们发现硫代酰胺Fe(2)[(SCH(2))(2)NC(S)Me](CO)(6)确实表现出明显更高的旋转势垒，这是由于N-C(S)键的双键性质增加所致。
Reaction of Fe(2)(SH)(2)(CO)(6) and HCHO, which gives Fe(2)[(SCH(2))(2)NH](CO)(6) in the presence of NH(3), affords the possible intermediate Fe(2)(SCH(2)OH)(2)(CO)(6), which has been characterized crystallographically as its axial-equatorial isomer. Fe(2)(SCH(2)OH)(2)(CO)(6) was shown to react with ammonia and amines to give Fe(2)[(SCH(2))(2)NR](CO)(6) (R = H, alkyl). Related hemithioacetal intermediates were generated by treatment of Fe(2)(SH)(2)(CO)(6) with RC(O)C(O)R (R = H, Ph, 4-F-C(6)H(4)) to give cycloadducts. The benzil derivative Fe(2)[S(2)C(2)(OH)(2)Ph(2)](CO)(6), a C(2)-symmetric species, was also characterized crystallographically. The acylated azadithiolate Fe(2)[(SCH(2))(2)NAc](CO)(6) was prepared by reaction of Li(2)Fe(2)S(2)(CO)(6) with (ClCH(2))(2)NC(O)Me. DNMR experiments show that the free energies of activation for rotation of the amide bond are the same for Fe(2)[(SCH(2))(2)NAc](CO)(6) and Fe(2)[(SCH(2))(2)NAc](CO)(4)(PMe(3))(2), which implies that the ligands on the iron centers do not strongly affect the basicity of the nitrogen. As a control, we showed that the thioamide Fe(2)[(SCH(2))(2)NC(S)Me](CO)(6) does exhibit a significantly higher barrier to rotation, attributable to the increased double-bond character of the N-C(S) bond.