Metal Porphyrin-Catalyzed Redutive Oxygenation of Olefins and Its Application

在催化量的钴(II)卟啉存在下，α，β，γ，β-不饱和羰基化合物与分子氧(1atm)和三乙基硅烷的还原-氧化反应进行得很快，区域选择性地得到了高产率的α-羟基过氧基-α，β-不饱和化合物。用亚磷酸三甲酯还原得到的过氧化氢在一锅中转化为γ-羟基-α，β-不饱和羰基化合物，再用乙酸酐和4-(N，N-二甲氨基)吡啶处理得到γ-氧代-α，β-不饱和羰基化合物。应用这种还原氧化方法尝试了一些生物活性天然产物的合成。以D-葡萄糖为原料制备的(2E，4E，7S)-7-乙酰氧基-2，4-辛二烯酸乙酯为原料，经还原氧化合成了16元抗生素大环内酯类化合物(-)-派瑞诺林。以香草素为原料，高产率地合成了从生姜中分离得到的新的抗氧化剂6-羟基亚硝酸酯和相关的呋喃类化合物。此外，亚硝酸钴和三乙基硅烷分别催化二茂铁和α，β-不饱和酯的还原亚硝化反应，生成苯乙酮肟和α-羟基亚胺酯。这种硝化反应的进一步研究目前正在进行中。在这项研究中，通过钴(II)催化的分子氧和三乙基硅烷的区域选择性氧化反应，然后进行适当的处理，可以建立新的和广泛的方法将共轭烯烃转化为相应的过氧化氢、醇和酮。

Reduction-oxygenation of alpha, beta, gamma, delta-unsaturated carbonyl compounds with molecular oxygen (1 atm) and triethylsilane in the presence of a catalytic amount of cobalt (II) porphyrin proceeded rapidly and regioselectively to afford gamma-hydroperoxy-alpha, beta-unsaturated carbonyl compounds in good yields. The obtained hydroperoxides were converted in one pot into gamma-hydroxy-alpha, beta-unsaturated carbonyl compounds by reducing with trimethyl phosphite, and into gamma-oxo-alpha, beta-unsaturated carbonyl compounds by treating with acetic anhydride and 4- (N,N-dimethylamino) pyridine.Total synthese of some biologically active natural products were attempted by the application this reductive oxygenation. (-) -Pyrenophorin, a 16-membered antibiotic macrolide, was synthesized via the reductive oxygenation of ethyl (2E,4E,7S) -7-acetoxy-2,4-octadienoate prepared from D-glucose. 6-Hydroxyshojail and related furanoids, new antioxidative compounds isolated from Ginger, were also synthesized in good yields from vanillin.Furthermore, the reductive nitrosation of stirenes and alpha, beta-unsaturated esters with alkyl nitrite and triethylsilane was found to be catalyzed by cobalt (II) porphyrin, to produce acetophenone oximes and alpha-hydroxyimino esters, respectively. Further studies of this nitosation are now in progress in detail.In this reseach, novel and widespread methods for conversion of conjugated olefins into the correponding hydroperoxides, alcohols, and ketones could be established by cobalt (II) porphyrin-catalyzed regioselective oxygenation with molecular oxygen and triethylsilane followed by the appropriate treatment.