在钌催化剂存在下,使用来自南极念珠菌的固定化脂肪酶研究了底物外消旋条件下仲醇的酶促拆分。发现专门设计的酰基供体 4-氯苯乙酸酯与两种催化剂均相容,并导致有效的动态动力学拆分。在不同溶剂中的反应研究表明,非极性溶剂的结果最好。通过该过程,各种外消旋仲醇转化为相应的对映异构纯乙酸酯,有效利用所有原材料。在大多数情况下,反应以 >99% ee 和良好的收率进行。
Herein, we report a diaminocyclopentadienone ruthenium tricarbonyl complex-catalyzed synthesis of mono- or dialkylated acyl hydrazide compounds using the borrowing hydrogen strategy in the presence of various substituted primary and secondary alcohols as alkylating reagents. Deuterium labeling experiments confirm that the alcohols were the hydride source in this cascade process. Density functional
The borrowing hydrogen strategy has been applied in the synthesis of nonsymmetric N,N-dialkylated acyl hydrazides via a tandemthree-componentreaction catalyzed by a phosphine free diaminocyclopentadienone ruthenium tricarbonyl complex. This strategy represents the first direct one-pot approach to nonsymmetric functionalized acyl hydrazides. Different aromatic acyl hydrazides underwent dialkylation
Tandem Hydroformylation/Hydrogenation of Alkenes to Normal Alcohols Using Rh/Ru Dual Catalyst or Ru Single Component Catalyst
作者:Kohei Takahashi、Makoto Yamashita、Kyoko Nozaki
DOI:10.1021/ja307998h
日期:2012.11.14
The catalystsystem for tandemhydroformylation/hydrogenation of terminal alkenes to the corresponding homologated normal alcohol was developed. The reaction mechanism for the Rh/Rudualcatalyst was investigated by real-time IR monitoring experiments and (31)P NMR spectroscopy, which proved the mutual orthogonality of Rh-catalyzed hydroformylation and Ru-catalyzed hydrogenation. Detailed investigation
A one-pot three-step reaction, isomerization/hydroformylation/hydrogenation of internal alkenes to n-alcohols, was accomplished by employing a Rh/Ru dual-catalyst system. By using a combination of Rh(acac)(CO)2/bisphosphite and Shvo's catalyst, (Z)-2-tridecene was converted to 1-tetradecanol in 83% yield with high normal/iso selectivity (n/i = 12). The method was applicable to other internal alkenes
Solvent-free hydrogenation of levulinic acid to γ-valerolactone using a Shvo catalyst precursor: optimization, thermodynamic insights, and life cycle assessment
作者:Christian A. M. R. van Slagmaat、Marie A. F. Delgove、Jules Stouten、Lukas Morick、Yvonne van der Meer、Katrien V. Bernaerts、Stefaan M. A. De Wildeman
DOI:10.1039/c9gc02088h
日期:——
which were further evaluated by means of density functional theory (DFT) calculations, and compared with catalytic concepts that consume formic acid or isopropylalcohol as hydrogen donor. Ultimately, this alternative reaction procedure was subjected to a life cycle assessment (LCA) in comparison with the transfer hydrogenation methodologies, in order to verify its contribution towards a practice of