6246-96-4Relevant academic research and scientific papers
FRUSTRATED LEWIS PAIR-IMPREGNATED POROUS MATERIALS AND USES THEREOF
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Page/Page column 85; 87-89, (2021/01/23)
Described herein are compositions composed of frustrated Lewis pairs impregnated in porous materials such as, for example, metal-organic frameworks, and their uses thereof. These compositions may allow new applications of frustrated Lewis pairs in catalysis by sequestering and protecting the frustrated Lewis pair within the nanospace of the porous material. Also provided are methods of hydrogenating an organic compound having at least one unsaturated functional group comprising using the compositions described herein.
Formal Aza-Wacker Cyclization by Tandem Electrochemical Oxidation and Copper Catalysis
Yi, Xiangli,Hu, Xile
supporting information, p. 4700 - 4704 (2019/03/07)
In oxidative electrochemical organic synthesis, radical intermediates are often oxidized to cations on the way to final product formation. Herein, we describe an approach to transform electrochemically generated organic radical intermediates into neutral
Promoting Frustrated Lewis Pairs for Heterogeneous Chemoselective Hydrogenation via the Tailored Pore Environment within Metal–Organic Frameworks
Niu, Zheng,Zhang, Weijie,Lan, Pui Ching,Aguila, Briana,Ma, Shengqian
, p. 7420 - 7424 (2019/04/27)
Frustrated Lewis pairs (FLPs) have recently been advanced as efficient metal-free catalysts for catalytic hydrogenation, but their performance in chemoselective hydrogenation, particularly in heterogeneous systems, has not yet been achieved. Herein, we demonstrate that, via tailoring the pore environment within metal–organic frameworks (MOFs), FLPs not only can be stabilized but also can develop interesting performance in the chemoselective hydrogenation of α,β-unsaturated organic compounds, which cannot be achieved with FLPs in a homogeneous system. Using hydrogen gas under moderate pressure, the FLP anchored within a MOF that features open metal sites and hydroxy groups on the pore walls can serve as a highly efficient heterogeneous catalyst to selectively reduce the imine bond in α,β-unsaturated imine substrates to afford unsaturated amine compounds.
Palladium-catalyzed aerobic oxidative coupling of allylic alcohols with anilines in the synthesis of nitrogen heterocycles
Kumar, Gangam Srikanth,Singh, Diksha,Kumar, Manish,Kapur, Manmohan
supporting information, p. 3941 - 3951 (2018/04/14)
We report herein an unprecedented and expedient Pd-catalyzed oxidative coupling of allyl alcohols with anilines to afford β-amino ketones which are converted into substituted quinolines in a one-pot fashion. The exclusive preference for N-alkylation over N-allylation makes this approach unique when compared to those reported in literature. Detailed mechanistic investigations reveal that the conjugate addition pathway was the predominant one over the allylic amination pathway. The notable aspects of the present approach are the use of readily available, bench-stable allyl alcohols and molecular oxygen as the terminal oxidant, in the process dispensing the need for unstable and costly enones. Further, we explored the synthetic utility of β-amino ketones through an intramolecular α-arylation methodology and a one-pot domino annulation, thereby providing rapid access to indolines and quinolines.
Aza-Wittig Rearrangements of N-Benzyl and N-Allyl Glycine Methyl Esters. Discovery of a Surprising Cascade Aza-Wittig Rearrangement/Hydroboration Reaction
Everett, Renata K.,Wolfe, John P.
, p. 9041 - 9056 (2015/09/28)
Treatment of N-(arylmethyl)-N-aryl or N-allyl-N-aryl glycine methyl ester derivatives with nBu2BOTf and iPr2NEt effects an aza-Wittig rearrangement that provides N-aryl phenylalanine methyl ester derivatives and N-aryl allylglycine methyl ester derivatives, respectively, in good yield with moderate to good diastereoselectivity. Under similar conditions, analogous substrates bearing N-carbonyl groups are converted to 1,4,2-oxazaborole derivatives. Additionally, N-allyl-N-aryl glycine methyl ester derivatives subjected to similar conditions at elevated temperatures undergo an aza-[2,3]-Wittig rearrangement, followed by a subsequent hydroboration oxidation reaction, to afford substituted amino alcohol products.
A computationally designed titanium-mediated amination of allylic alcohols for the synthesis of secondary allylamines
Sun, Zunming,Wang, Qingxia,Xu, Yi,Wang, Zhihong
, p. 84284 - 84289 (2015/10/28)
A computational design was inspired by previous mechanistic studies and the DFT-guided reactions were implemented in the synthesis of secondary allylamines. The participation of titanium imido intermediates facilitated the reaction and the closed transiti
Hydrogen-bond-assisted activation of allylic alcohols for palladium-catalyzed coupling reactions
Gumrukcu, Yasemin,Debruin, Bas,Reek, Joost N. H.
, p. 890 - 896 (2014/03/21)
We report direct activation of allylic alcohols using a hydrogen-bond-assisted palladium catalyst and use this for alkylation and amination reactions. The novel catalyst comprises a palladium complex based on a functionalized monodentate phosphoramidite ligand in combination with urea additives and affords linear alkylated and aminated allylic products selectively. Detailed kinetic analysis show that oxidative addition of the allyl alcohol is the rate-determining step, which is facilitated by hydrogen bonds between the alcohol, the ligand functional group, and the additional urea additive. Hydrogen Bond Rule(s): Direct activation of allylic alcohols and subsequent alkylation and amination reactions are reported. The new catalyst is based on functionalized palladium and phosphoramidite ligands to allow hydrogen bond-assisted activation. Kinetic data are in line with this mechanism as the oxidative addition is the rate-determining step.
Enantioselective hydroformylation of aniline derivatives
Joe, Candice L.,Tan, Kian L.
supporting information; experimental part, p. 7590 - 7596 (2011/11/12)
We have developed a ligand that reversibly binds to aniline substrates, allowing for the control of regioselectivity and enantioselectivity in hydroformylation. In this paper we address how the electronics of the aniline ring affect both the binding of the substrate to the ligand and the enantioselectivity in this reaction.
Nucleophilic substitution reactions of alcohols with use of montmorillonite catalysts as solid Bronsted acids
Motokura, Ken,Nakagiri, Nobuaki,Mizugaki, Tomoo,Ebitani, Kohki,Kaneda, Kiyotomi
, p. 6006 - 6015 (2008/02/10)
(Chemical Equation Presented) We have developed an environmentally benign synthetic approach to nucleophilic substitution reactions of alcohols that minimizes or eliminates the formation of byproducts, resulting in a highly atom-efficient chemical process. Proton- and metal-exchanged montmorillonites (H- and Mn+-mont) were prepared easily by treating Na +-mont with an aqueous solution of hydrogen chloride or metal salt, respectively. The H-mont possessed outstanding catalytic activity for nucleophilic substitution reactions of a variety of alcohols with anilines, because the unique acidity of the H-mont catalyst effectively prevents the neutralization by the basic anilines. In addition, amides, indoles, 1,3-dicarbonyl compounds, and allylsilane act as nucleophiles for the H-mont-catalyzed substitutions of alcohols, which allowed efficient formation of various C-N and C-C bonds. The solid H-mont was reusable without any appreciable loss in its catalytic activity and selectivity. Especially, an Al3+-mont showed high catalytic activity for the α-benzylation of 1,3-dicarbonyl compounds with primary alcohols due to cooperative catalysis between a protonic acid site and a Lewis acidic Al3+ species in its interlayer spaces.
Direct use of allylic alcohols for platinum-catalyzed monoallylation of amines
Utsunomiya, Masaru,Miyamoto, Yoshiki,Lpposhi, Junji,Ohshima, Takashi,Mashima, Kazushi
, p. 3371 - 3374 (2008/02/12)
A new direct catalytic amination of allylic alcohols promoted by the combination of platinum and a large bite-angle ligand DPEphos was developed in which the allylic alcohol was effectively converted to a π-allylplatinum intermediate without the use of an activating reagent. The use of the DPEphos ligand was essential for obtaining high catalyst activity and high monoallylation selectivity of primary amines, allowing the formation of a variety of monoallylation products in good to excellent yield.
