在中性反应条件下,用H 2 O 2进行的第一次锰催化的有机硅烷氧化为硅烷醇。可以耐受具有烷基,芳基,炔基和杂环取代基的多种有机硅烷,以及受阻位有机硅烷。氧化似乎是通过涉及氢过氧化锰物质的协同过程进行的。该方案具有温和的反应条件,快速的氧化作用,并且没有废副产物,可实现硅烷醇和硅烷二醇的低成本,生态友好的合成。
Enantioselective Si–H Insertion Reactions of Diarylcarbenes for the Synthesis of Silicon-Stereogenic Silanes
作者:Jake R. Jagannathan、James C. Fettinger、Jared T. Shaw、Annaliese K. Franz
DOI:10.1021/jacs.0c04533
日期:2020.7.8
silanes. Adding an ortho substituent on one phenyl ring of a prochiral diazo enhances enantioselectivity up to 95:5 er with yields up to 98 %. Using in situ IR spectroscopy, the impact of the off-cycle azine formation is supported based on the structural dependence for relative rates of diazo decomposition. A catalytic cycle is proposed with the Si-H insertion as the rate-determining step, supported by kinetic
STABILIZATION OF ACTIVE METAL CATALYSTS AT METAL-ORGANIC FRAMEWORK NODES FOR HIGHLY EFFICIENT ORGANIC TRANSFORMATIONS
申请人:The University of Chicago
公开号:US20180361370A1
公开(公告)日:2018-12-20
Metal-organic framework (MOFs) compositions based on post¬synthetic metalation of secondary building unit (SBU) terminal or bridging OH or OH
2
groups with metal precursors or other post-synthetic manipulations are described. The MOFs provide a versatile family of recyclable and reusable single-site solid catalysts for catalyzing a variety of asymmetric organic transformations, including the regioselective boryiation and siiylation of benzyiic C—H bonds, the hydrogenation of aikenes, imines, carbonyls, nitroarenes, and heterocycles, hydroboration, hydrophosphination, and cyclization reactions. The solid catalysts can also be integrated into a flow reactor or a supercritical fluid reactor.
Iridium(III)-salen complexes were found to efficiently catalyze enantioselective carbene Si-H bond insertion. Highly enantioselective Si-H insertion with alpha-alkyl-alpha-diazoacetates (>or=97% ee) was achieved for the first time by using the iridium complex 4 (aR,S), Ar = 4-TBDPSC(6)H(4)} bearing a concave-shaped salen ligand as the catalyst. Formation of a chiral silicon center was also achieved
The cobalt(II) complex of a new tridentate Schiff-base ligand as a catalyst for hydrosilylation of olefins
作者:Adam Gorczyński、Maciej Zaranek、Samanta Witomska、Aleksandra Bocian、Artur R. Stefankiewicz、Maciej Kubicki、Violetta Patroniak、Piotr Pawluć
DOI:10.1016/j.catcom.2016.02.009
日期:2016.3
new, tridentate Schiff-base ligand L, which readily reacts with CoCl2 to form a monometallic [CoLCl2] complex that, upon reduction, functions as active hydrosilylation catalyst. The ligand and the [CoLCl2] catalyst have been characterized spectroscopically (MS, NMR, FTIR) and by single crystal X-ray diffraction techniques. The results of preliminary catalytic experimentation show that the cobalt complex
1-甲基-2-咪唑甲醛与2-(1-甲基肼基)吡啶的缩合导致合成新的三齿席夫碱配体L,该配体容易与CoCl 2反应形成单金属[Co L Cl 2 ]配合物还原后,用作活性氢化硅烷化催化剂。所述配体和[Co L Cl 2 ]催化剂已经通过光谱法(MS,NMR,FTIR)和通过单晶X射线衍射技术进行了表征。初步催化实验的结果表明,取决于所用的氢硅烷底物,钴配合物可引起烯烃的氢化硅烷化和脱氢甲硅烷基化。