16432-53-4Relevant articles and documents
Ester hydrogenation catalyzed by a ruthenium(II) complex bearing an N-heterocyclic carbene tethered with an "nH2" group and a DFT study of the proposed bifunctional mechanism
O, Wylie W.N.,Morris, Robert H.
, p. 32 - 40 (2013)
A ruthenium(II) catalyst containing an NHC-amine (NHC = Nheterocyclic carbene) ligand (C-NH2) catalyzes the H2-hydrogenation of various esters and lactones at 50 °C and 25 bar of H2 pressure, mild reaction conditions compared with other reported catalysts. A maximum turnover frequency of 1510 h-1 for the hydrogenation of phthalide with a conversion of 96% is achieved in 4 h. DFT calculations suggest a concerted, asynchronous bifunctional mechanism for homogeneous ester hydrogenation; a proton transfer step from the N-H group of a ruthenium hydride-amine complex to the carbonyl group has the largest energy barrier in the catalytic cycle. A surprising observation is that methyl pivalate ( tBuCOOCH3) is hydrogenated much more rapidly than is tert-butyl acetate (CH3COOtBu). This is explained by the energetics of the rate-determining step of the proposed Ru-H/N-H bifunctional mechanism.
Overman
, p. 1196 (1972)
Hemilabile Benzyl Ether Enables Γ-C(sp3)-H Carbonylation and Olefination of Alcohols
Tanaka, Keita,Ewing, William R.,Yu, Jin-Quan
supporting information, p. 15494 - 15497 (2019/10/16)
Pd-catalyzed C(sp3)-H activation of alcohol typically shows β-selectivity due to the required distance between the chelating atom in the attached directing group and the targeted C-H bonds. Herein we report the design of a hemilabile directing group which exploits the chelation of a readily removable benzyl ether moiety to direct Γ- or δ-C-H carbonylation and olefination of alcohols. The utility of this approach is also demonstrated in the late-stage C-H functionalization of β-estradiol to rapidly prepare desired analogues that required multi-step syntheses with classical methods.
Method for synthesizing diene compounds based on aldehyde-ketone condensation reaction
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Paragraph 0185; 0189; 0190, (2019/05/08)
The invention provides a method for synthesizing diene compounds based on an aldehyde-ketone condensation reaction. The method comprises the following steps: firstly, under the action of a condensation catalyst, performing a condensation reaction on ketone compounds and aldehyde compounds to obtain condensation products; then, under the action of a reduction catalyst, performing a reduction reaction on the condensation products obtained in the previous step to obtain reduction products; under the action of a catalyst, performing a dehydration reaction on the reduction products obtained in theprevious step to obtain the diene compounds. According to the method, ketone, aldehyde as well as homologues of ketone and aldehyde which are cheap and easy to obtain can be used as raw materials forsynthesizing the diene compounds such as butadiene, piperylene as well as homologues of butadiene and piperylene, experimental conditions are mild, the operation is simple, and a large-scale synthesisprospect is achieved.
