Osmium(III) and Osmium(V) Complexes Bearing a Macrocyclic Ligand: A Simple and Efficient Catalytic System for cis-Dihydroxylation of Alkenes with Hydrogen Peroxide
Osmium(III) and Osmium(V) Complexes Bearing a Macrocyclic Ligand: A Simple and Efficient Catalytic System for cis-Dihydroxylation of Alkenes with Hydrogen Peroxide
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带有大环配体的锇(III)和锇(V)配合物：一种简单高效的过氧化氢顺式二羟基化烯烃催化体系
DOI：
10.1002/asia.201300329
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发表时间：
2013
期刊：
影响因子：
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通讯作者：
Shinobu Itoh
中科院分区：
文献类型：
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作者：
Hideki Sugimoto;Kenji Ashikari;Shinobu Itoh
以[OsIII（OH）（H2O）（L-N4 Me 2）]（PF 6）2（1; L-N4 Me 2 =N，N′-二甲基-2，11-二氮杂[3.3]（2，6）吡啶并吡喃）为催化剂，H2 O2为末端氧化剂，合成了一个简单的烯烃顺式-1，2-二羟基化反应.含有吸电子基团的未官能化（或脂族）烯烃和烯烃/苯乙烯以良好至优异的产率（46- 99%）被选择性氧化成相应的邻位二醇。在催化反应中，烯烃与H2 O2的化学计量比为1：1，因此氧化剂效率非常高。对于环己烯的二羟基化反应，1的催化量可降低到0.01mol%，达到很高的转化数5500。 活性氧化剂被鉴定为OsV（O）（OH）物种（2），其通过氢过氧化物加合物形成，OsIII（OOH）物种。活性氧化剂2被成功地分离和晶体学表征。
A simple protocol that uses [OsIII(OH)(H2O)(L‐N4Me2)](PF6)2(1;L‐N4Me2=N,N′‐dimethyl‐2,11‐diaza[3.3](2,6)pyridinophane) as a catalyst and H2O2as a terminal oxidant for efficientcis‐1,2‐dihydroxylation of alkenes is presented. Unfunctionalized (or aliphatic) alkenes and alkenes/styrenes containing electron‐withdrawing groups are selectively oxidized to the corresponding vicinal diols in good to excellent yields (46–99 %). In the catalytic reactions, the stoichiometry of alkene:H2O2is 1:1, and thus the oxidant efficiency is very high. For the dihydroxylation of cyclohexene, the catalytic amount of1can be reduced to 0.01 mol % to achieve a very high turnover number of 5500. The active oxidant is identified as the OsV(O)(OH) species (2), which is formed via the hydroperoxide adduct, an OsIII(OOH) species. The active oxidant2is successfully isolated and crystallographically characterized.