New Development of Dioxygenase Model Complexes Complexes for Organic Synthesis

Cobalt（II） Schiff base Complexes， Co（II）（SB），其中显示了前解溶剂中的类似二氧化酶的活性，并发现了单氧化和脱氢酶依赖于反应介质、反应温度、物质和钴催化剂的结构。在二氧生成反应中，它被证明是这样的：在二氧化合物中观察到的二氧化合物加入到苯酸基物质中，只有当没有苯氧基激进中间体进入二氧化合物加入步骤时。Coordinately Saturated （HO）Co（III）（SB）已发现并建议将脂基氮化合物的氧化生成转化为相应的碳基产品，并提供了一个额外的示例Fpr的氧化反应。在另一手上，已经找到了协调不饱和的（HO）Co（III）（SB）导致单氧反应。例如，氧化物C-C-碳中芳香族氢化物和aliphatic硝基化合物的氧化生成结果 ... More d.清除以给予羧基酸甲基酯，并提供新的氧化反应。Furthermore，在60 ° C时，淀粉在酒精中被氧化化，给乙酸酮和l-苯甲酸酯。在协调不饱和的非平面（HO）Co（III）（SB）中，2-丙醇在l-苯甲酸醇的预先形成的结果中，在这种情况下，光学活性复合体的使用导致酒精产品中的对称性的诱导。使用Co（SB）的氧生成到二氮化合物（HO）Co（III）（SB）在丙酮腈中使用冷饱和度（HO）Co（III）（SB）的氧生成， （2）使用冷饱和度（HO）Co（III）（SB）在二氯甲烷中使用冷饱和度（HO）Co（III），（SB）在二氯甲烷中使用冷饱和度（VA）的氧生成，和（3）与t-BuOOH在coordinately saturated （HO）Co（III）（SB）中的氧化酒精到碳基化合物的存在。在氧化反应中扮演重要角色，即氢化复合体（HO）Co（III）（SB）扮演重要角色。（HO）Co（III）（SB）显示超酸和超基目录的可能性也是由一些初步实验提出的，将进行进一步的调查。Less（低）

Cobalt(II) Schiff base complexes, Co(II)(SB),which show dioxygenase-like activities in aprotic solvents, have been found to catalyze also monooxygenation and dehydrogenation depending on the nature of reaction medium,reaction temperature, substrate,and structure of the cobalt catalyst. In dioxygenation reactions,it has been demonstrated that the ortho regioselectivity observed in the dioxygn incorporation into phenolate substrates is accomplished only when no phenoxy radical intermediate is involved in the dioxygen incorporation step. Coordinately saturated (HO)Co(III)(SB) have been found to promote the oxygenation of aliphatic nitro compounds to corresponding carbonyl products, providing an additional example fpr the dioxygenase-type reactions. On the other hand, it has been found that coordinately unsaturated (HO)Co(III)(SB) lead to monooxygenation reactions. For example, the oxygenations of aromatic hydrazones and aliphatic nitro compounds in methanol result in the oxidative C-C bon … More d cleavage to give carboxylic acid methyl esters, providing new oxidation reactions. Furthermore, styrenes are oxidized in alcohols at 60 ゜C to give acetophenones and l-phenylethanols. The oxygenation of styrene with coordinately unsaturated nonplanar (HO)Co(III)(SB) in 2-propanol results in predominantly formation of l-phenylethanol, in this case the use of optically active complexes leads to the asymmetric induction in the alcohol product. Newly developed synthetically useful dehydrogenation rections using Co(SB) include (1) the oxygenation of aromatic hydrazones to diazo copounds using coordinately saturated (HO)Co(III)(SB) in acetonitrile, (2) the oxygenation of aliphatic hydrazones to l-alkenylcobalt complexes using coordinately unsaturated (HO)Co(III)(SB) in dichloromethane, and (3) the oxidation of alcohols to carbonyl compounds with t-BuOOH in the presence of coordinately saturated (HO)Co(III)(SB). As mentioned above, hydroxo complexes (HO)Co(III)(SB) play important roles in the oxidation reactions. The possibility that (HO)Co(III)(SB) may display superacid and superbase catalyses is also suggested by some preliminary experiments, which will be further investigated. Less