73839-44-8Relevant academic research and scientific papers
Alkenylation and Arylation of Peptides via Ni-Catalyzed Reductive Coupling of α- C-Tosyl Peptides with Csp2Triflates/Halides
Chen, Yunrong,Gong, Hegui,Ma, Guobin,Qian, Qun,Song, Yanhong,Sun, Deli,Tao, Xianghua
supporting information, p. 7418 - 7422 (2021/10/12)
A Ni-catalyzed reductive cross-coupling between α-C-tosyl peptides and Csp2 triflates/halides has been developed. This protocol enables the formation of various unnatural di- and tripeptides containing vinyl and aryl side chains, and it expands the applications of Ni-catalyzed reductive cross-coupling in late-stage diversification of peptides.
Illuminatinganti-hydrozirconation: controlled geometric isomerization of an organometallic species
Gilmour, Ryan,Hostmann, Theresa,Nevesely, Tomá?
, p. 10643 - 10648 (2021/08/20)
A general strategy to enable the formalanti-hydrozirconation of arylacetylenes is reported that mergescis-hydrometallation using the Schwartz Reagent (Cp2ZrHCl) with a subsequent light-mediated geometric isomerization atλ= 400 nm. Mechanistic delineation of thecontra-thermodynamic isomerization step indicates that a minor reaction product functions as an efficientin situgenerated photocatalyst. Coupling of theE-vinyl zirconium species with an alkyne unit generates a conjugated diene: this has been leveraged as a selective energy transfer catalyst to enableE→Zisomerization of an organometallic species. Through anUmpolungmetal-halogen exchange process (Cl, Br, I), synthetically useful vinyl halides can be generated (up toZ?:?E= 90?:?10). This enabling platform provides a strategy to access nucleophilic and electrophilic alkene fragments in both geometric forms from simple arylacetylenes.
A Simplified Protocol for the Stereospecific Nickel-Catalyzed C-S Vinylation Using NiX 2 Salts and Alkyl Phosphites
Larin, Egor M.,Lautens, Mark,Marchese, Austin D.,Mirabi, Bijan
, p. 311 - 319 (2019/12/28)
A Ni-catalyzed C-S cross-coupling using only NiI 2 (0.5-2.5 molpercent) and P(O i Pr) 3 (2.0-10.0 molpercent) is reported. Using an air-stable Ni(II) precatalyst, and a cheap and commercially available ligand, a scalable and robust method was developed to cross-couple various thiophenols and styryl bromides, including some sterically encumbered thiols, an α-bromocinnamaldehyde as well as a thiolation-cyclization.
Method for synthesizing beta-bromostyrene through metal-free catalysis
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Paragraph 0034-0036, (2020/02/06)
The invention discloses a method for synthesizing beta-bromostyrene through metal-free catalysis, and belongs to the technical field of organic chemistry. Substituted styrene 1 is used as a raw material and is reacted in the presence of a bromination reagent, sodium persulfate and dichloroethane, and the beta-bromostyrene compound 2 can be obtained in one step. The method is capable of solving thetechnical problem that in the traditional synthesis method, conversion into alkenyl boron, alkenyl silicon and other intermediates under the catalysis of noble metals and then further halogenation are needed; the defects of expensive reaction reagent, high catalytic cost, complex operation, incapability of large-scale preparation and the like in the traditional preparation method are avoided; byadopting the method, a series of beta-bromostyrene compounds can be obtained, and the method has a potential application prospect.
Facile Synthesis of β-Bromostyrenes by Direct Bromination of Styrenes with N -Bromosuccinimide and Sodium Persulfate
Chen, Xuenian,Gao, Yan,Jing, Yi,Ma, Yan-Na,Zhao, Qianyi
supporting information, (2020/09/09)
A new, direct, efficient, and transition-metal-free method is reported for the synthesis of β-bromostyrenes from styrenes by using N -bromosuccinimide as the brominating reagent and sodium persulfate (Na 2S 2O 8) as the oxidant. This convenient and concise reaction is practical, operationally simple, and can be adapted for large-scale syntheses.
The hydrodebromination of 1,1-dibromoalkenes via visible light catalysis
Sun, Wencheng,Teng, Qiaoling,Cheng, Dongping,Li, Xiaonian,Xu, Xiaoliang
, (2019/12/05)
Vinyl bromides are versatile synthetic intermediates and widely applied in organic synthesis and pharmaceuticals. Herein, a hydrodebromination reaction of 1,1-dibromoalkenes was established via visible light catalysis. A variety of structurally different vinyl bromides were obtained in moderate to excellent yields.
Zirconium-Catalyzed Synthesis of Alkenylaminoboranes: From a Reliable Preparation of Alkenylboronates to a Direct Stereodivergent Access to Alkenyl Bromides
Birepinte, Mélodie,Chabaud, Laurent,Liautard, Virginie,Pucheault, Mathieu
supporting information, p. 2838 - 2843 (2020/04/16)
A simple procedure has been optimized for the preparation of alkenylaminoborane from alkynes using diisopropylaminoborane and HZrCp2Cl. Coupled with a magnesium-catalyzed dehydrogenation, it allowed for the use of air- and moisture-stable diisopropylamine. This synthesis has been extended to a one-pot sequence leading directly to bromoalkenes with controlled stereochemistry. As such, it provides an easy, scalable, cheap process to access alkenylboronates and both (E)- and (Z)-bromoalkenes from commercially available alkynes.
Electrochemical intramolecular C-H/N-H functionalization for the synthesis of isoxazolidine-fused isoquinolin-1(2: H)-ones
Zhang, Lin-Bao,Geng, Rui-Sen,Wang, Zi-Chen,Ren, Guang-Yi,Wen, Li-Rong,Li, Ming
supporting information, p. 16 - 21 (2020/01/13)
A general and practical protocol for the construction of isoxazolidine-fused isoquinolin-1(2H)-ones has been described by electrochemical-oxidation-induced intramolecular annulation via amidyl radicals. In an undivided cell, isoquinolinones could be easily generated from various available amides bearing CONHOR groups under metal-free, additive-free and external oxidant-free conditions. Moreover, this transformation proceeded smoothly by using cheap 95% ethanol as the green solvent and could be extended to the gram scale.
Transition-Metal-Free α-Vinylation of Enolizable Ketones with β-Bromostyrenes
Zaid, Yassir,Mboyi, Clève Dionel,Drapeau, Martin Pichette,Radal, Léa,Chahdi, Fouad Ouazzani,Rodi, Youssef Kandri,Ollevier, Thierry,Taillefer, Marc
supporting information, p. 1564 - 1568 (2019/03/11)
An α-vinylation of enolizable ketones has been developed by using β-bromostyrenes and a KOtBu/NMP system. β,γ-Unsaturated ketones of E configuration were obtained in excellent yield and selectivity. Further synthetic possibilities are highlighted by one-pot functionalization via trapping of intermediate dienolates with alkyl, allyl, benzyl, and propargyl halides to generate quaternary centers. The reported transformation is believed to involve phenylacetylene and propargylic alcohol derivatives.
TsNBr2 promoted decarboxylative bromination of α,β-unsaturated carboxylic acids
Hazarika, Debojit,Phukan, Prodeep
supporting information, p. 4593 - 4596 (2018/11/23)
A rapid process for decarboxylative bromination of α,β-unsaturated carboxylic acids have been developed using N,N-dibromo-p-toluenesulfonamide (TsNBr2). Treatment of cinnamic acids with TsNBr2 in presence of potassium carbonate in acetonitrile produces corresponding β-bromostyrenes at room temperature. Exclusive formation of (E)-β-bromostyrenes was observed in a stereoselective manner within a very short period of time (5–15 min). This method was further extended for obtaining 1-bromoalkynes from corresponding propiolic acids. Instantaneous formation of bromoalkynes was observed when the reaction was carried out in presence of DBU as a base in acetonitrile at room temperature. A wide variety of cinnamic acids and propiolic acids could be converted to corresponding β-bromostyrenes and 1-bromoalkynes respectively under mild reaction condition with high to excellent yield.
