Iron-Catalyzed Hydroamination and Hydroetherification of Unactivated Alkenes
作者:Paul T. Marcyk、Silas P. Cook
DOI:10.1021/acs.orglett.9b00427
日期:2019.3.1
The hydrofunctionalization of alkenes, explored for over 100 years, offers the potential for a direct, atom-economical approach to value-added products. While thermodynamically favored, the kinetic barrier to such processes necessitates the use of catalysts to control selectivity and reactivity. Modern variants typically rely on noble metals that require different ligands for each class of hydrofunctionalization
Ether Synthesis through Reductive Cross-Coupling of Ketones with Alcohols Using Me2SiHCl as both Reductant and Lewis Acid
作者:Bill Morandi、Yong Lee
DOI:10.1055/s-0036-1590838
日期:2017.11
We report that a Lewis acidic silane, Me2SiHCl, can mediate the direct cross-coupling of a wide range of carbonyl compounds with alcohols to form dialkyl ethers. The reaction is operationally simple, tolerates a range of polar functional groups, can be utilized to make stericallyhindered ethers, and is extendable to sulfur and nitrogen nucleophiles.
Palladium-Catalyzed Hydrolytic Cleavage of Aromatic C−O Bonds
作者:Meng Wang、Hui Shi、Donald M. Camaioni、Johannes A. Lercher
DOI:10.1002/anie.201611076
日期:2017.2.13
with and without incorporation of H218O, the pathway was concluded to be initiated by palladium metal catalyzed partial hydrogenation of the phenyl group to an enol ether. Water then rapidly adds to the enol ether to form a hemiacetal, which then undergoes elimination to cyclohexanone and phenol/alkanol products. A remarkable feature of the reaction is that the stronger Ph−O bond is cleaved rather than
在相对温和的温度和H 2压力下,金属钯表面在促进芳族醚在水相中的还原水解方面具有很高的选择性。在定量转化时,观察到PhOR醚对水解产物的选择性范围为50%(R = Ph)至大于90%(R = n- C 4 H 9,环己基和PhCH 2 CH 2)。通过分析加入和不加入H 2 18的产物的演变○,该途径被认为是由钯金属催化的苯基部分氢化为烯醇醚引发的。然后将水快速加入到烯醇醚中,形成半缩醛,然后将其消除为环己酮和苯酚/链烷醇产物。该反应的显着特征是,更强的Ph-O键被裂解,而不是较弱的脂族O-R键被裂解。
Selective hydrogenation of lignin-derived compounds under mild conditions
作者:Lu Chen、Antoine P. van Muyden、Xinjiang Cui、Gabor Laurenczy、Paul J. Dyson
DOI:10.1039/d0gc00121j
日期:——
processes used in their production. Here, we show that well-defined Rh nanoparticles dispersed in sub-micrometer size carbon hollow spheres, are able to hydrogenate lignin derived products undermildconditions (30 °C, 5 bar H2), in water. The optimum catalyst exhibits excellent selectivity and activity in the conversion of phenol to cyclohexanol and other related substrates including aryl ethers.
木质素衍生化学品生产中的关键挑战是减少其生产中使用的能源密集型过程。在这里,我们显示了分散在亚微米尺寸的碳空心球中的定义明确的Rh纳米粒子能够在温和条件下(30°C,5 bar H 2)在水中氢化木质素衍生产品。最佳催化剂在苯酚向环己醇和其他相关底物(包括芳基醚)的转化中表现出出色的选择性和活性。
Reductive fractionation of woody biomass into lignin monomers and cellulose by tandem metal triflate and Pd/C catalysis
作者:Xiaoming Huang、Olivia M. Morales Gonzalez、Jiadong Zhu、Tamás I. Korányi、Michael D. Boot、Emiel J. M. Hensen
DOI:10.1039/c6gc02962k
日期:——
A catalytic process for the upgrading of woody biomass into mono-aromatics, hemi-cellulose sugars and a solid cellulose-rich carbohydrate residue is presented.