Dinuclear Manganese Complexes Containing Chiral 1,4,7-Triazacyclononane-Derived Ligands and Their Catalytic Potential for the Oxidation of Olefins, Alkanes, and Alcohols
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- 作者：Vladimir B. Romakh ; Bruno Therrien ; Georg Sü ; ss-Fink ; Georgiy B. Shul'pin
- 刊名：Inorganic Chemistry
- 出版年：2007
- 出版时间：February 19, 2007
- 年：2007
- 卷：46
- 期：4
- 页码：1315 - 1331
- 全文大小：429K
- 年卷期：v.46,no.4(February 19, 2007)
- ISSN：1520-510X
文摘
Five new 1,4,7-triazacyclononane-derived compounds, sodium 3-(4,7-dimethyl-1,4,7-triazacyclononan-1-yl)propionate(Na[LMe2R']) as well as the enantiopure derivatives (S)-1-(2-methylbutyl)-4,7-dimethyl-1,4,7-triazacyclononane (S-LMe2R''), SS-trans-2,5,8-trimethyl-2,5,8-triazabicyclo[7.4.01,9]tridecane (SS-LBMe3), (S)-1-(2-hydroxypropyl)-4,7-dimethyl-1,4,7-triazacyclononane (S-LMe2R), and (R)-1-(2-hydroxypropyl)-4,7-dimethyl-1,4,7-triazacyclononane (R-LMe2R), havebeen synthesized. Reaction of manganese dichloride with the chiral macrocycles S-LMe2R and R-LMe2R in aqueousethanol gives, upon oxidation with hydrogen peroxide, the brown dinuclear Mn(III)-Mn(IV) complexes which areenantiomers, [Mn2(S-LMe2R)2(
-O)2]3+ (S,S-1) and [Mn2(R-LMe2R)2(-O)2]3+ (R,R-1). The single-crystal X-ray structureanalyses of [S,S-1][PF6]3·0.5(CH3)2CO and [R,R-1][PF6]3·0.5(CH3)2CO show both enantiomers to contain Mn(III)and Mn(IV) centers, each of which being coordinated to three nitrogen atoms of a triazacyclononane ligand andeach of which being bridged by two oxo and by two chiral hydroxypropyl pendent arms of the macrocycle. Theenantiomeric complexes S,S-1 and R,R-1 were found to catalyze the oxidation of olefins, alkanes, and alcoholswith hydrogen peroxide. In the epoxidation of indene the enantiomeric excess values attain 13%. The bond selectivitiesof the oxidation of linear and branched alkanes suggest the crucial step in this process to be the attack of asterically hindered high-valent manganese-oxo species on the C-H bond.
-O)2]3+ (S,S-1) and [Mn2(R-LMe2R)2(-O)2]3+ (R,R-1). The single-crystal X-ray structureanalyses of [S,S-1][PF6]3·0.5(CH3)2CO and [R,R-1][PF6]3·0.5(CH3)2CO show both enantiomers to contain Mn(III)and Mn(IV) centers, each of which being coordinated to three nitrogen atoms of a triazacyclononane ligand andeach of which being bridged by two oxo and by two chiral hydroxypropyl pendent arms of the macrocycle. Theenantiomeric complexes S,S-1 and R,R-1 were found to catalyze the oxidation of olefins, alkanes, and alcoholswith hydrogen peroxide. In the epoxidation of indene the enantiomeric excess values attain 13%. The bond selectivitiesof the oxidation of linear and branched alkanes suggest the crucial step in this process to be the attack of asterically hindered high-valent manganese-oxo species on the C-H bond.