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Development of polyoxometalate-based selective oxidation catalysts

多金属氧酸盐选择性氧化催化剂的开发

基本信息

批准号：
16206077
负责人：
MIZUNO Noritaka
金额：
$ 32.28万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
2004
资助国家：
日本
起止时间：
2004 至 2006
项目状态：
已结题

项目摘要

(1)Efficient epoxidation catalysts with hydrogen peroxide. (a) Peroxotungstate. The highly chemo-, regio-, and diastereoselective and stereospecific epoxidation of various allylic alcohols with only 1 equivalent of hydrogen peroxide in water could be efficiently catalyzed by an dinuclear peroxotungstate, [{W(=O)(O_2)_2(H_2O)}_2(μ-O)]^<2->. The peroxotungstate could be immobilized on ionic liquid-modified SiO_2. (b) Lacunary silicotungstate. The epoxidation with H_2O_2 catalyzed by lacunary silicodecatungstate ([γ-SiW_<10>O_<34>(H_2O)_2]^<4->) proceeded with 【greater than or equal】99% selectivity to epoxide, 【greater than or equal】99% efficiency of H_2O_2 utilization, high stereospecificity, and the easy recovery of the catalyst. A novel S-shaped disilicoeicosatungustate, [γ-SiW_<10>O_<32>(H_2O)_2)_2(μ-O)_2]^<4->, efficiently promoted the H_2O_2-based Baeyer-Villiger oxidations of cycloalkanones. (c) Di-vanadium or titanium-substituted silicotungstate. [γ-1,2-H_2SiV_2W_<10>O_<40>]^<4-> … More with the {VO-(μ-OH)_2-VO} core could catalyze epoxidation of olefins using only one equivalent H_2O_2 with the high epoxide yield and high efficiency of H_2O_2 utilization. Notably, this system showed unique stereospecificity, diastereoselectivity, and regioselectivity. A stereospecific epoxidation with hydrogen peroxide proceeded with a titanium-substituted silicotungstate cluster of [{γ-SiTi_2W_<10>O_<36>(OH)_2}_2(μ-O)_2]^<8->.(2)Bis (μ-oxo) bridged di-iron site on the lacunary POM as an efficient epoxidation catalyst with molecular oxygen. Bis (μ-oxo) bridged di-iron site on the lacunary POM has been used as catalysts for the oxygenation of alkenes in homogeneous reaction media using molecular oxygen as an oxygen donor. It is remarkable that selectivity to cyclooctene oxide and turnover number reached up to 98% and 10000, respectively, for the oxygenation of cyclooctene.(3)Microstructured POMs as a shape-selective catalyst. The Keggin-type POM, SiW_<12>O_<40>^<4->, and Cr(III) trinuclear cation, Cr_3O(OOCH)_6(H_2O)_3^+, assembled to create a channeled complex K_3[Cr_3O(OOCH)_6(H_2O)_3]SiW_<12>O_<40>・16H_2O with an opening of 0.5 x 0.8 nm. The complex reversibly absorbed water and polar organic molecules smaller than C2. The guest inclusion was highly selective and even a difference of one methylene group in the organic guest molecule was discriminated. Less

(1)高效的过氧化氢环氧化催化剂。 (a) Peroxotungstate.双核过氧钨酸盐[{W(=O)(O_2)_2(H_2O)}_2(μ-O)]^<2->可以有效地催化各种烯丙醇在水中仅用1当量过氧化氢进行的高度化学、区域、非对映选择性和立体定向环氧化。过氧钨酸盐可以固定在离子液体改性的SiO_2上。 (b) 空位硅钨酸盐。空位硅钨酸([γ-SiW_<10>O_<34>(H_2O)_2]^<4->)催化H_2O_2环氧化反应，环氧化物选择性【大于等于】99%，H_2O_2利用效率【大于等于】99%，立体定向性高，易于回收 of the catalyst.一种新型S形二硅二十碳酸盐[γ-SiW_<10>O_<32>(H_2O)_2)_2(μ-O)_2]^<4->有效促进了环烷酮的H_2O_2基Baeyer-Villiger氧化反应。 (c)二钒或钛取代的硅钨酸盐。以{VO-(μ-OH)_2-VO}为核心的[γ-1,2-H_2SiV_2W_<10>O_<40>]^<4-> … More可以仅使用1当量的H_2O_2催化烯烃环氧化反应，环氧化物收率高，H_2O_2利用效率高。值得注意的是，该系统表现出独特的立体特异性、非对映选择性和区域选择性。用过氧化氢进行立体定向环氧化反应，钛取代的硅钨酸盐簇[{γ-SiTi_2W_<10>O_<36>(OH)_2}_2(μ-O)_2]^<8->。(2)Bis (μ-oxo)桥接双铁位点在空位POM上作为有效的环氧化反应分子氧催化剂。缺位 POM 上的双 (μ-氧代) 桥接二铁位点已被用作在均相反应介质中使用分子氧作为氧供体进行烯烃氧化的催化剂。值得注意的是，对于环辛烯的氧化，氧化环辛烯的选择性和周转数分别达到98%和10000。(3)微结构POMs作为择形催化剂。 Keggin 型 POM SiW_<12>O_<40>^<4-> 和 Cr(III) 三核阳离子 Cr_3O(OOCH)_6(H_2O)_3^+ 组装形成通道复合物 K_3[Cr_3O(OOCH)_6(H_2O)_3]SiW_<12>O_<40>·16H_2O 孔径为 0.5 x 0.8 nm。该复合物可逆地吸收水和小于C2的极性有机分子。客体包含物具有高度选择性，甚至可以区分有机客体分子中一个亚甲基的差异。较少的