17913-10-9Relevant academic research and scientific papers
t-BuCl-NaI as a Reagent for the Selective Reduction of Olefinic Double Bond of β-Phenyl α,β-Unsaturated Carbonyl Compounds
Sakai, Takashi,Miyata, Kazuyoshi,Hondo, Kazuomi,Utaka, Masanori,Takeda, Akira
, p. 3421 - 3422 (1987)
β-Phenyl α,β-unsaturated carbonyl compounds were conveniently reduced to the corresponding saturated aromatic compounds by heating with t-BuCl-NaI in acetonitrile.
On the Way to Chiral Copper(I) Arenethiolate Catalysts for the Enantioselective Conjugate Addition of Methyl Lithium and Methyl Magnesium Iodide to Benzylideneacetone
Lambert, Francois,Knotter, D. Martin,Janssen, Maurits D.,Klaveren, Mayra van,Boersma, Jaap,Koten, Gerard van
, p. 1097 - 1100 (1991)
Selective conjugate addition (0 percent enantiomeric excess (e.e)) of organoarenethiolatocuprates (from methyl lithium and 2-phenylthiolatocopper(I), CuSAr*) to benzylideneacetone (BA) is found up to a LiMe/CuSAr* ratio of 2/1
Environmentally responsible, safe, and chemoselective catalytic hydrogenation of olefins: ppm level Pd catalysis in recyclable water at room temperature
Gallou, Fabrice,Gao, Eugene S.,Lipshutz, Bruce H.,Takale, Balaram S.,Thakore, Ruchita R.
supporting information, p. 6055 - 6061 (2020/10/14)
Textbook catalytic hydrogenations are typically presented as reactions done in organic solvents and oftentimes under varying pressures of hydrogen using specialized equipment. Catalysts new and old are all used under similar conditions that no longer reflect the times. By definition, such reactions are both environmentally irresponsible and dangerous, especially at industrial scales. We now report on a general method for chemoselective and safe hydrogenation of olefins in water using ppm loadings of palladium from commercially available, inexpensive, and recyclable Pd/C, together with hydrogen gas utilized at 1 atmosphere. A variety of alkenes is amenable to reduction, including terminal, highly substituted internal, and variously conjugated arrays. In most cases, only 500 ppm of heterogeneous Pd/C is sufficient, enabled by micellar catalysis used in recyclable water at room temperature. Comparison with several newly introduced catalysts featuring base metals illustrates the superiority of chemistry in water.
Asymmetric Umpolung Hydrogenation and Deuteration of Alkenes Catalyzed by Nickel
Guo, Siyu,Wang, Xiuhua,Zhou, Jianrong Steve
supporting information, p. 1204 - 1207 (2020/02/04)
Nickel-catalyzed asymmetric hydrogenation of several types of alkenes proceeds in high enantioselectivity, using acetic acid or water as the hydrogen source and indium powder as electron donor. The scope of alkenes herein include α,β-unsaturated esters, n
Capturing the Monomeric (L)CuH in NHC-Capped Cyclodextrin: Cavity-Controlled Chemoselective Hydrosilylation of α,β-Unsaturated Ketones
Bistri-Aslanoff, Olivia,Derat, Etienne,Leloux, Sébastien,Leyssens, Tom,Ménand, Micka?l,Meijide Suárez, Jorge,Riant, Olivier,Roland, Sylvain,Sollogoub, Matthieu,Xu, Guangcan,Zhang, Pinglu,Zhang, Yongmin
supporting information, p. 7591 - 7597 (2020/03/23)
The encapsulation of copper inside a cyclodextrin capped with an N-heterocyclic carbene (ICyD) allowed both to catch the elusive monomeric (L)CuH and a cavity-controlled chemoselective copper-catalyzed hydrosilylation of α,β-unsaturated ketones. Remarkably, (α-ICyD)CuCl promoted the 1,2-addition exclusively, while (β-ICyD)CuCl produced the fully reduced product. The chemoselectivity is controlled by the size of the cavity and weak interactions between the substrate and internal C?H bonds of the cyclodextrin.
Iridium-Catalyzed Alkene-Selective Transfer Hydrogenation with 1,4-Dioxane as Hydrogen Donor
Zhang, Deliang,Iwai, Tomohiro,Sawamura, Masaya
supporting information, p. 5867 - 5872 (2019/08/26)
The iridium-catalyzed transfer hydrogenation of alkenes using 1,4-dioxane as a hydrogen donor is described. The use of 1,2-bis(dicyclohexylphosphino)ethane (DCyPE), featuring bulky and highly electron-donating properties, led to high catalytic activity. A polystyrene-cross-linking bisphosphine PS-DPPBz produced a reusable heterogeneous catalyst. These homogeneous and heterogeneous protocols achieved chemoselective transfer hydrogenation of alkenes over other potentially reducible functional groups such as carbonyl, nitro, cyano, and imino groups in the same molecule.
In Situ Generated Gold Nanoparticles on Active Carbon as Reusable Highly Efficient Catalysts for a Csp3 ?Csp3 Stille Coupling
Holz, Julia,Pfeffer, Camilla,Zuo, Hualiang,Beierlein, Dennis,Richter, Gunther,Klemm, Elias,Peters, René
supporting information, p. 10330 - 10334 (2019/06/27)
Gold nanoparticle catalysts are important in many industrial production processes. Nevertheless, for traditional Csp2-Csp2 cross-coupling reactions they have been rarely used and Pd catalysts usually give a superior performance. Herein we report that in situ formed gold metal nanoparticles are highly active catalysts for the cross coupling of allylstannanes and activated alkylbromides to form Csp3-Csp3 bonds. Turnover numbers up to 29 000 could be achieved in the presence of active carbon as solid support, which allowed for convenient catalyst recovery and reuse. The present study is a rare case where a gold metal catalyst is superior to Pd catalysts in a cross-coupling reaction of an organic halide and an organometallic reagent.
Rhenium-catalyzed α-alkylation of enol acetates with alcohols or ethers
Umeda, Rui,Takahashi, Yuuki,Yamamoto, Takaaki,Iseki, Hideki,Osaka, Issey,Nishiyama, Yutaka
supporting information, p. 92 - 101 (2018/11/01)
When benzylic and allylic alcohols were treated with enol acetate in the presence of a catalytic amount of a rhenium complex, ReBr(CO)5, the carbon-carbon bond formation of the alcohols and enol acetate smoothly proceeded to give the corresponding ketones and aldehyde in moderate to good yields. For the reaction of allylic alcohols, γ,δ-unsaturated carbonyl compounds were obtained in good yields. When ethers were used instead of alcohols as the alkylated agent, two alkyl moieties on the ethers were utilized on the reaction.
Palladium-catalyzed site-selective arylation of aliphatic ketones enabled by a transient ligand
Pan, Lei,Yang, Ke,Li, Guigen,Ge, Haibo
supporting information, p. 2759 - 2762 (2018/03/21)
Transition metal-catalyzed direct C-H bond functionalization enabled by transient ligands has become an attractive topic. Here we report a palladium-catalyzed site-selective arylation of β-C(sp3)-H bonds in aliphatic ketones with β-alanine as the transient ligand.
Direct conversion of cinnamate esters into β,β-disubstituted ketones mediated by cyano-magnesio cuprates
Genna, Douglas T.,Posner, Gary H.
, p. 5968 - 5971 (2016/09/14)
The clean synthesis of unsymmetrical ketones from carboxylic acid derivatives has been a challenge in the organic community dating back over 80 years. Herein we report the conversion of simple alkyl cinnamates to β,β-disubstituted ketones with cyano-magnesio cuprates in high yields with no observation of tertiary alcohol byproduct. The lack of tertiary alcohol is attributed to a putative enolate intermediate that serves as a ketone protecting group. A distinctive steric inhibition trend was observed related to both the size of the R group on the parent ester and the nucleophilic cuprate. Lastly, we demonstrate that this reaction can be coupled with known copper mediated allylic substitution reactions yielding β,γ-disubstituted ketone (8) from parent α-chloro-β,γ-ethylenic ester (7).
