2396-79-4Relevant academic research and scientific papers
Preparation, crystal structure and reactivity of bis(methylacrylate)(pyridine)nickel(0)
Sustmann, Reiner,Hopp, Peter,Boese, Roland
, p. 259 - 264 (1989)
The preparation, crystal structure and reactivity of bis(methyl acrylate)(pyridine)nickel(0) are reported.This complex reacts with E,Z-1-bromo-1-propene in the presence of water to give the conjugate addition product.Complexes of this type seem to be invo
Selective Production of Terminally Unsaturated Methyl Esters from Lactones Over Metal Oxide Catalysts
Brentzel, Zachary J.,Ball, Madelyn R.,Dumesic, James A.
, p. 3072 - 3081 (2018/08/22)
Metal oxide catalysts were studied for their selectivity for the production of a terminally unsaturated methyl ester, methyl 5-hexenoate (M5H), from a 6 carbon, 6-membered ring lactone, δ-hexalactone (DHL). A 15?wt% Cs/SiO2 catalyst had a selectivity of 55% to M5H. This selectivity was the highest of the metal oxide catalysts studied, which were Cs/SiO2, MgO, SrO, CeO2, ZrO2, Ta2O5, MgAl2O4, and a Mg–Zr mixed oxide. The Cs/SiO2 catalyst was utilized for the ring-opening of γ-valerolactone (GVL), a 5 carbon, 5-membered ring lactone. The catalyst was 88% selective to the terminally unsaturated methyl ester, methyl 4-pentenoate (M4P). Weight hourly space velocity studies determined that the unsaturated ester distributions remained constant and no C=C double bond isomerization occurred. Liquid phase transesterification reactions with DHL and methanol and nuclear magnetic resonance spectroscopy confirmed that DHL undergoes ring-opening transesterification to produce an?ω-1 hydroxy methyl ester, methyl 5-hydroxyhexanoate (M5HH). Liquid phase transesterification reactions and thermochemistry calculations established that the equilibrium for GVL transesterification with methanol was favored towards the ring-closed lactone instead of the ring-opened hydroxy ester because of the decreased ring strain of GVL compared to DHL. The difference in terminally unsaturated methyl ester selectivity between GVL and DHL manifests from the difference in ring-strain energy. DHL passes through the M5HH intermediate as a result of greater ring strain, while the production of M4P from GVL most likely occurs through a direct, concerted mechanism. Graphical Abstract: [Figure not available: see fulltext.].
Linear Selective Isomerization/Hydroformylation of Unsaturated Fatty Acid Methyl Esters: A Bimetallic Approach
Gaide, Tom,Bianga, Jonas,Schlipk?ter, Kim,Behr, Arno,Vorholt, Andreas J.
, p. 4163 - 4171 (2017/06/19)
Herein, we report about the development of an isomerization/hydroformylation tandem reaction to selectively convert fatty acid methyl esters into asymmetric α,ω-functionalized aldehyde esters. An orthogonal tandem catalytic system consisting of a palladium-based isomerization catalyst and a rhodium-based hydroformylation catalyst was developed, using methyl 3-hexenoate as a model substrate. Using this catalyst, high yields (81% at 99% conversion) and regioselectivities (l/b-ratio of 98/2) toward the desired terminal hydroformylation product are obtained in the conversion of methyl 3-hexenoate under mild conditions. Ethyl 4-decenoate was subsequently applied as a second model substrate to identify challenges associated with the longer chain length of the unsaturated ester. Finally, methyl oleate was converted using the developed catalyst system. High aldehyde yields of 74% (at 99% conversion) with an l/b-ratio of 91/9 are obtained.
Dienyne ring-closing metathesis approach for the construction of taxosteroids
Aldegunde, Maria J.,Garcia-Fandino, Rebeca,Castedo, Luis,Granja, Juan R.
, p. 5135 - 5150 (2008/02/11)
A cascade dienyne ring-closing metathesis approach has been applied to the synthesis of the tetracyclic carbon framework of a new class of hybrid compounds - the taxosteroids - possessing carbon frameworks incorporating moieties characteristic of both tax
