Hydrosilylation of Aldehydes and Formates Using a Dimeric Manganese Precatalyst
作者:Tufan K. Mukhopadhyay、Chandrani Ghosh、Marco Flores、Thomas L. Groy、Ryan J. Trovitch
DOI:10.1021/acs.organomet.7b00423
日期:2017.9.25
afforded a signal consistent with two weaklyinteractingS = 1/2 Mn centers. At ambient temperature in the absence of solvent, [(Ph2PEtPDI)Mn]2 has been found to catalyze the hydrosilylation of aldehydes at loadings as low as 0.005 mol % (0.01 mol % relative to Mn) with a maximum turnover frequency of 9,900 min–1 (4,950 min–1 per Mn). Moreover, the [(Ph2PEtPDI)Mn]2-catalyzed dihydrosilylation of formates
通过用过量的Na / Hg还原(Ph2PEt PDI)MnCl 2可以合成形式上为零价的Mn二聚体[(Ph2PEt PDI)Mn] 2。单晶X射线衍射分析表明,[(Ph2PEt PDI)的Mn] 2具有一个κ 4有关每个锰中心-PDI螯合物,以及η 2横跨二聚体-亚胺协调。螯合韵律参数建议单电子还原PDI和EPR光谱分析,得到具有两个弱相互作用相一致的信号小号= 1 / 2的Mn中心。在无溶剂的环境温度下,[(Ph2PEt已发现PDI)Mn] 2以低至0.005 mol%(相对于Mn为0.01 mol%)的负载量催化醛的氢化硅烷化,最大转换频率为9,900 min –1(每Mn 4,950 min –1)。此外,已发现[(Ph2PEt PDI)Mn] 2催化的甲酸酯的二氢硅烷化反应以高达330 min –1的转换频率(相对于Mn为165 min –1)进行。这些量度可与用于该转化的主要Mn催化剂的丙烯桥连变体(Ph
Cesium Carbonate Catalyzed Chemoselective Hydrosilylation of Aldehydes and Ketones under Solvent-Free Conditions
作者:Mengdi Zhao、Weilong Xie、Chunming Cui
DOI:10.1002/chem.201403497
日期:2014.7.21
efficient and chemoselective catalyst for reduction of aldehydes and ketones to alcohols with one equivalent of Ph2SiH2 as the reductant under solvent‐free conditions. Most of the aldehydes employed can be effectively hydrosilated quantitatively to give the corresponding silyl ethers in 2 h at room temperature, whereas the hydrosilylation of ketones proceeded smoothly at 80 °C. The catalyst system tolerates
已发现Cs 2 CO 3是一种有效的化学选择催化剂,用于将醛和酮还原为一当量Ph 2 SiH 2的醇。在无溶剂条件下用作还原剂。所用的大多数醛可以在室温下2小时内有效地进行定量氢化硅化反应,得到相应的甲硅烷基醚,而酮的氢化硅烷化则在80°C进行得很顺利。催化剂体系可耐受许多官能团,包括卤素,烷氧基,烯烃,酯,硝基,氰基和杂芳族基团;可以通过温度有效地控制在酮存在下醛的选择性氢化硅烷化。α,β-不饱和羰基的氢化硅烷化产生了1,2-加成产物。合适的二羰基的催化氢化硅烷化可用于合成具有高分子量和窄分子分布的聚(甲硅烷基醚)。
[EN] FIRST-ROW TRANSITION METAL HYDROGENATION AND HYDROSILYLATION CATALYSTS<br/>[FR] CATALYSEURS D'HYDROGÉNATION ET D'HYDROSILYLATION À BASE DE MÉTAUX DE TRANSITION DE LA PREMIÈRE COLONNE
申请人:UNIV ARIZONA STATE
公开号:WO2014201082A1
公开(公告)日:2014-12-18
Transition metal compounds, and specifically transition metal compounds having a tetradentate and/or pentadentate supporting ligand are described, together with methods for the preparation thereof and the use of such compounds as hydrogenation and/or hydrosilylation catalysts.
A Pentacoordinate Mn(II) Precatalyst That Exhibits Notable Aldehyde and Ketone Hydrosilylation Turnover Frequencies
作者:Chandrani Ghosh、Tufan K. Mukhopadhyay、Marco Flores、Thomas L. Groy、Ryan J. Trovitch
DOI:10.1021/acs.inorgchem.5b01825
日期:2015.11.2
found to possess an intermediate-spin (S = 3/2) Mn(II) center by the Evans method and electron paramagnetic resonance spectroscopy. Furthermore, (κ5-N,N,N,N,N-PyEtPDEA)Mn was determined to be an effective precatalyst for the hydrosilylation of aldehydes and ketones, exhibiting turnover frequencies of up to 2475 min–1 when employed under solvent-free conditions. This optimization allowed for isolation
Catalytic and Stoichiometric Reactivity of β-Silylamido Agostic Complex of Mo: Intermediacy of a Silanimine Complex and Applications to Multicomponent Coupling
作者:Andrey Y. Khalimon、Razvan Simionescu、Georgii I. Nikonov
DOI:10.1021/ja111005r
日期:2011.5.11
reaction of complex (ArN═)(2)Mo(PMe(3))(3) (Ar = 2,6-diisopropylphenyl) with PhSiH(3) gives the β-agostic NSi-H···M silyamido complex (ArN═)Mo(SiH(2)Ph)(PMe(3))(η(3)-ArN-SiHPh-H) (3) as the first product. 3 decomposes in the mother liquor to a mixture of hydride compounds, including complex η(3)-SiH(Ph)-N(Ar)-SiHPh-H···}MoH(3)(PMe(3))(3) characterized by NMR. Compound 3 was obtained on preparative scale