7642-17-3Relevant academic research and scientific papers
Rhodium-Catalyzed Alkenylation of Toluene Using 1-Pentene: Regioselectivity to Generate Precursors for Bicyclic Compounds
Liebov, Nichole S.,Zhu, Weihao,Chen, Junqi,Webster-Gardiner, Michael S.,Schinski, William L.,Gunnoe, T. Brent
supporting information, p. 3844 - 3851 (2019/10/16)
Rhodium catalysts for arene alkenylation reported by our group (e.g., Science 2015, 348, 421; J. Am. Chem. Soc. 2017, 139, 5474; J. Am. Chem. Soc. 2018, 140, 17007) have demonstrated selectivity for 1-aryl alkenes over y-aryl alkenes (y > 1). This selectivity is notable because 1-aryl alkenes or 1-aryl alkanes cannot be generated using acid-based Friedel-Crafts arene alkylation or acidic zeolite catalysts. Herein, we report the extension of Rh arene alkenylation catalysis to generate 1-tolyl-1-pentenes, which are potential precursors for bicyclic compounds. The olefin concentration, copper(II) oxidant identity and concentration, reaction temperature, and rhodium concentration for the alkenylation of toluene with 1-pentene have been optimized using [Rh(Η2-C2H4)2(μ-OAc)]2 as the catalyst precursor. The rhodium-based catalysis achieves up to 12(1):1 anti-Markovnikov selectivity for 1-tolyl-1-pentenes over 2-tolyl-2-pentenes and is selective for alkenylation in the meta and para positions.
Method for synthesizing olefin compound by photo-induced one-pot process
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Paragraph 0137-0139, (2018/11/03)
The invention discloses a method for synthesizing an olefin compound by a photo-induced one-pot process. The method comprises the following step of subjecting a halohydrocarbon and an aldehyde compound to a reaction under the condition of irradiation in an inert atmosphere by taking alkali metal carbonate as a base, taking an organic phosphine compound as an adjuvant and taking a photosensitizer as a catalyst, thereby obtaining the olefin compound. According to the method disclosed by the invention, the olefin compound is produced from the halohydrocarbon and the aldehyde compound in a high-yield manner under the condition of irradiation in the inert atmosphere under normal-temperature reaction conditions by taking acetonitrile, DMF (N,N-dimethylformamide) or DMA (N,N-dimethylacetamide) asa solvent, taking an organic phosphine reagent as a reaction adjuvant, taking the alkali metal carbonate as the base and taking the photosensitizer as the catalyst. Compared with the conventional olefin synthesis methods, the method disclosed by the invention has the obvious advantages that the reaction raw materials are readily available, the tolerance to a variety of functional groups on halohydrocarbons and aldehydes is high, the yield is high, the separation and purification of a product are simple and convenient, and the like.
Improvements and Applications of the Transition Metal-Free Asymmetric Allylic Alkylation using Grignard Reagents and Magnesium Alanates
Grassi, David,Alexakis, Alexandre
supporting information, p. 3171 - 3186 (2015/11/03)
Two new N-heterocyclic carbene (NHC) ligands have been synthesized and employed in the transition metal-free asymmetric allylic alkylation (AAA) mediated by Grignard reagents and magnesium alanates. The employment of these ligands showed high yields and improved regio- and enantioselectivity in the formation of tertiary and quaternary stereocenters. Moreover, the low catalyst loading (up to 0.3 mol%) and high scalability (up to 10 mmol) of this improved methodology provide a convenient access to biologically active compounds and synthetically valuable intermediates.
Copper-free asymmetric allylic alkylation with a grignard reagent: Design of the ligand and mechanistic studies
Grassi, David,Dolka, Chrysanthi,Jackowski, Olivier,Alexakis, Alexandre
supporting information, p. 1466 - 1475 (2013/02/25)
The Cu-free asymmetric allylic alkylation, catalysed by NHC, with Grignard reagents is reported on allyl bromide derivatives with good results. The enantioselectivity was quite homogeneous (around 85 % ee) on large and various substrates, regardless of the nature of the Grignard reagent. The formation of stereogenic quaternary centres was highly regioselective for both aliphatic and aromatic derivatives with good enantiomeric excess (up to 92 % ee). The methodology developed was found to be complementary with the Cu-catalysed version. Several new NHCs were tested with improved efficiency. In addition, mechanistic studies, using NMR spectroscopy, led to the discovery of the catalytically active species. Copyright
Furanoside phosphite-phosphoroamidite and diphosphoroamidite ligands applied to asymmetric Cu-catalyzed allylic substitution reactions
Magre, Marc,Mazuela, Javier,Dieguez, Montserrat,Pamies, Oscar,Alexakis, Alexandre
experimental part, p. 67 - 71 (2012/05/20)
A phosphite-phosphoroamidite and diphosphoroamidite ligand library was applied in the Cu-catalyzed allylic substitution of a range of cinnamyl-type substrates using several organometallic nucleophiles. Results indicated that selectivity depended strongly on the ligand parameters (position of the phosphoroamidite group at either C-5 or C-3 of the furanoside backbone, as well as the configuration of C-3, the introduction of a second phosphoroamidite moiety, the substituents and configurations in the biaryl phosphite/ phosphoroamidite moieties), the nature of the leaving group of the substrate and the alkylating reagent. Good enantioselectivities (up to 76%) and activity combined with high regioselectivities were obtained.
A tandem Aldol-Grob reaction of ketones with aromatic aldehydes
Kabalka, George W.,Tejedor, David,Li, Nan-Sheng,Malladi, Rama R.,Trotman, Sarah
, p. 15525 - 15532 (2007/10/03)
Aromatic aldehydes react with ketones to produce (E)-1-aryl-1-alkenesvia a tandem Aldol-Grob cleavage reaction sequence. The reaction, initiated by boron trifluoride, also produces a carboxylic acid fragment.
REACTIONS EN MILIEU HETEROGENE SOLIDE-LIQUIDE FAIBLEMENT HYDRATE : LA REACTION DE WITTIG DANS LE SYSTEME HYDROXIDES ALCALINS/SOLVANT ORGANIQUE APROTIQUE
Le Bigot, Yves,Delmas, Michel,Gaset, Antoine
, p. 1057 - 1072 (2007/10/02)
The Wittig reaction carried out in a slightly hydrated solid-liquid media constituted by a solid alkaline hydroxide and an organic phase which includes the phosphonium salt and the aldehyde leads easily to the corresponding alkene with very good yields specially with furanic aldehydes.The ylide formation at the interface appears as the most important step of this condensation.
