75488-41-4Relevant academic research and scientific papers
Rhodium-Catalyzed meta-Selective C?H Carboxylation Reaction of 1,1-Diarylethylenes via Hydrorhodation-Rhodium Migration
Caner, Joaquim,Iwasawa, Nobuharu,Saito, Takanobu,Toriumi, Naoyuki
supporting information, p. 23349 - 23356 (2021/09/18)
A meta-selective C?H carboxylation reaction of 1,1-diarylethylene derivatives with CO2 by using a rhodium catalyst with NaOiPr as a stoichiometric reductant has been achieved. Together with hydrogenation of the ethylene moiety, a carboxyl group was introduced to the meta-position of the aryl ring with high selectivity over the ortho-positions. Experimental and computational mechanistic studies indicate that this carboxylation reaction proceeds via hydrorhodation on the ethylene moiety, followed by 1,4-rhodium migration and successive 1,2-rhodium migration on the aryl ring. The use of a bulky phosphine ligand seems to be the key to this unusual aryl-to-aryl 1,2-rhodium shift.
Photoredox-Catalyzed α-Aminomethyl Carboxylation of Styrenes with Sodium Glycinates: Synthesis of γ-Amino Acids and γ-Lactams
Zhou, Cong,Li, Miao,Sun, Jianwei,Cheng, Jiang,Sun, Song
supporting information, p. 2895 - 2899 (2021/05/05)
A visible-light photoredox-catalyzed reductive α-aminomethyl carboxylation of styrenes with sodium glycinates and CO2 has been developed to synthesize a series of α,α-disubstituted γ-amino acids and γ-lactams with high efficiency and regioselectivity. Notably, CO2 released from the decarboxylation step can be reused for the subsequent carboxylation. Distinct from the previous reactions with the same type of substrates leading to simple decarboxylation and olefin hydroalkylation, this process involves additional CO2 sequestration, thus leading to olefin α-aminomethyl carboxylation. These findings not only provide new access to α,α-disubstituted γ-amino acids and γ-lactams but also serve as a proof of concept for CO2 reutilization in decarboxylation reactions.
Base-promoted addition of DMA with 1,1-diarylethylenes: Application to a total synthesis of (-)-sacidumlignan B
Luo, Zhen-Biao,Peng, Yu,Wang, Ya-Wen
supporting information, p. 2054 - 2057 (2020/03/27)
A base-promoted addition of DMA (N,N-dimethylacetamide) to 1,1-diarylethylenes has been developed, and it provides a new strategy for the synthesis of N,N-dimethyl-4,4-diarylbutanamides from 1,1-diarylethylenes at room temperature. This method allows us to achieve the goal of synthesizing (-)-sacidumlignan B, and provides simple operation and broad substrate scope by avoiding the use of transition metal catalysts.
Spherical hollow mesoporous silica supported phosphotungstic acid as a promising catalyst for α-arylstyrenes synthesis via Friedel-Crafts alkenylation
Wang, Xianhui,Zhao, Zhongkui
, p. 729 - 734 (2018/09/21)
In this work, a spherical hollow mesoporous silica (SHMS) with high surface area (902 m2/g) and large mesopore volume (1.31 cm3/g) was prepared via a facile and scalable two-step soft-hard dual template-assisted sol-gel approach (OSD
Nickel-Catalyzed Direct Synthesis of Aryl Olefins from Ketones and Organoboron Reagents under Neutral Conditions
Lei, Chuanhu,Yip, Yong Jie,Zhou, Jianrong Steve
supporting information, p. 6086 - 6089 (2017/05/08)
Nickel-catalyzed addition of arylboron reagents to ketones results in aryl olefins directly. The neutral condition allows acidic protons of alcohols, phenols, and malonates to be present, and fragile structures are also tolerated.
Supported phosphotungstic acid catalyst on mesoporous carbon with bimodal pores: A superior catalyst for Friedel-Crafts alkenylation of aromatics with phenylacetylene
Zhao, Zhongkui,Wang, Xianhui
, p. 139 - 146 (2016/09/02)
Supported phosphotungstic acid (PTA) catalysts on diverse carriers containing the modified commercially available activated carbon (AC), classical mesoporous carbon via SBA-15 hard template method (CMK-3), and the mesoporous carbon with high surface area and bimodal pores through evaporation-induced tri-constituent co-assembly approach (MC) by using a facile wet impregnation method were employed as solid acid catalysts for Friedel-Crafts alkenylation of p-xylene with phenylacetylene. N2 adsorption–desorption, X-ray diffraction (XRD), and NH3 temperature-programmed desorption (NH3-TPD) characterization techniques were employed to reveal the structure-performance relationship. PTA/MC exhibits much superior catalytic performance to the previously reported PTA/AC, and even to PTA/CMK-3. The PTA/MC catalysts were optimized by varying the PTA loading, and the optimum PTA loading is 35%. The close to 100% of conversion towards phenylacetylene can be achieved in the presence of 2.67% of the 35% PTA/MC solid acid catalyst. It is also found that catalytic properties of the solid acids are strongly depended on acidic properties that affected by the textural properties of supports and PTA loading, as well as the accessibility of active sites affected by specific surface area and pore structure of catalyst. Moreover, the 35?wt.% PTA/MC catalyst has demonstrated outstanding catalytic performance for the Friedel-Crafts alkenylation of diverse aromatics to their corresponding α-arylstyrenes.
Supported phosphotungstic acid catalyst on modified activated carbon for Friedel-Crafts alkenylation of diverse aromatics to their corresponding α-arylstyrenes
Zhao, Zhongkui,Wang, Xianhui
, p. 103 - 110 (2015/08/06)
Abstract The supported phosphotungstic acid catalysts on modified activated carbon (PTA/AC) prepared by a facile wet impregnation method were employed for Friedel-Crafts alkenylation of diverse aromatics with phenylacetylene to synthesize their corresponding α-arylstyrenes. Reaction results demonstrate that the fabricated PTA/AC catalyst with 30 wt.% PTA loading exhibits outstanding catalytic performance. The 100% conversion of phenylacetylene with 95.7% selectivity towards α-(2,5-dimethylphenyl) styrene can be achieved over the developed 30 wt.% PTA/AC catalyst under optimized reaction conditions, and no visible loss in catalytic performance can be observed after it suffers from several times recycling. The various characterization techniques including X-ray diffraction, N2 adsorption-desorption, Fourier transform infrared spectroscopy, and NH3 temperature-programmed desorption were employed to reveal the relationship between the catalysts nature and catalytic properties. Moreover, the results on the scope of aromatics for the Friedel-Crafts alkenylation illustrate that the developed PTA/AC alkenylation catalyst can be efficiently catalyze the diverse aromatics and even for the electron deficient chlorobenzene. The developed PTA/AC catalyst, using the modified low-cost and sustainable AC as support, may be a robust and promising candidate for highly-efficient and clean α-arylstyrenes production through Friedel-Crafts alkenylation of diverse aromatics including electron-donating and electron-withdrawing groups substituted benzene derivatives as well as heterocyclic and polypolycyclic arenes with phenylacetylene.
Immobilized palladium nanoparticles on potassium zirconium phosphate as an efficient recoverable heterogeneous catalyst for a clean Heck reaction in flow
Petrucci, Chiara,Cappelletti, Matteo,Piermatti, Oriana,Nocchetti, Morena,Pica, Monica,Pizzo, Ferdinando,Vaccaro, Luigi
, p. 27 - 34 (2015/03/30)
Palladium nanoparticles on layered potassium α-zirconium phosphate (PdNP/α-ZrPK) with high palladium loading (10.6 wt%) have been prepared and used as catalyst in low amount (0.1 mol% of Pd) in the Heck reaction of methyl acrylate and styrene with a series of aryl iodides in CH3CN/H2O azeotrope as a green medium. The procedure has been optimized under flow conditions obtaining an extremely low waste production (E-factor) and allowing to isolate the final product with very low residual palladium content without any purification step.
Electronic polarizability-based stereochemical model for Sharpless AD reactions
Han, Peng,Wang, Ruji,Wang, David Zhigang
supporting information; experimental part, p. 8873 - 8878 (2011/12/02)
Softness really is the hard force! Reported here was the critical yet long-overlooked role of electronic polarizability (i.e., softness) effect in controlling absolute stereochemical courses of general asymmetric induction events. Thus, a sensitive dependence of the sense of chiral induction on an alkene substrate's substituent electronic polarizability character was uncovered from a range of structurally highly comparable Sharpless asymmetric dihydroxylation (AD) systems, from which a new polarizability-based stereochemical model of predictive power was suggested.
Synthesis of dihydrofurans containing trifluoromethyl ketone and heterocycles by radical cyclization of fluorinated 1,3-dicarbonyl compounds with 2-thienyl and 2-furyl substituted alkenes
Ylmaz, Mehmet
experimental part, p. 8255 - 8263 (2011/11/12)
Manganese(III) acetate based radical cyclization of various fluorinated 1,3-dicarbonyl compounds with 2-thienyl and 2-furyl substituted alkenes produced 3-trifluoroacetyl and 2-trifluoromethyl-dihydrofurans in good yields. The radical cyclizations of 2-methyl-5-[(E)-2-phenylvinyl]furan 2b and 2-[(E)-2-phenylvinyl]thiophene 2c led to the formations of 5-(5-methyl-2-furyl)- 4,5-dihydrofuran and 5-(2-thienyl)-4,5-dihydrofuran, respectively. In the reactions of 1,3-dicarbonyls with alkenes, 2-thienyl substituted alkenes formed 4,5-dihydrofurans in higher yields than 2-furyl substituted alkenes.
