86161-40-2Relevant articles and documents
An Amphiphilic (salen)Co Complex – Utilizing Hydrophobic Interactions to Enhance the Efficiency of a Cooperative Catalyst
Solís-Mu?ana, Pablo,Salam, Joanne,Ren, Chloe Z.-J.,Carr, Bronte,Whitten, Andrew E.,Warr, Gregory G.,Chen, Jack L.-Y.
supporting information, p. 3207 - 3213 (2021/06/01)
An amphiphilic (salen)Co(III) complex is presented that accelerates the hydrolytic kinetic resolution (HKR) of epoxides almost 10 times faster than catalysts from commercially available sources. This was achieved by introducing hydrophobic chains that increase the rate of reaction in one of two ways – by enhancing cooperativity under homogeneous conditions, and increasing the interfacial area under biphasic reaction conditions. While numerous strategies have been employed to increase the efficiency of cooperative catalysts, the utilization of hydrophobic interactions is scarce. With the recent upsurge in green chemistry methods that conduct reactions ‘on water’ and at the oil-water interface, the introduction of hydrophobic interactions has potential to become a general strategy for enhancing the catalytic efficiency of cooperative catalytic systems. (Figure presented.).
Palladium-catalyzed stereoselective (3 + 2) cycloaddition of vinylethylene carbonates with cyclicN-sulfonyl ketimines
Gao, Xing,Zhu, Dongyu,Jiang, Feng,Liao, Jianning,Wang, Wei,Wu, Yongjun,Zheng, Lufei,Guo, Hongchao
supporting information, p. 4877 - 4881 (2021/06/16)
A diastereoselective (3 + 2) cycloaddition ofN-sulfonyl ketimines with vinylethylene carbonates (VECs) in the presence of Pd2dba3·CHCl3and PPh3has been developed. The reaction of various substituted VECs and diverse cyclicN-sulfonyl ketimines proceeded smoothly under mild conditions, giving highly functionalized oxazolidine frameworks in good to excellent yields with moderate to good diastereoselectivities. With the use of spiroketal-based diphosphine SKP as a chiral ligand, an asymmetric version of the current (3 + 2) cycloaddition was achieved, and chiral products were obtained in >99% ee in most cases.
Preparation method of vinylethylene sulfite
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Paragraph 0033-0034, (2021/03/31)
The invention belongs to the field of additives, and particularly relates to a preparation method of vinylethylene sulfite. The invention discloses a preparation method of vinylethylene sulfite, whichcomprises the following step: reacting 3-butylene-1,2-diol with thionyl chloride to obtain vinylethylene sulfite. The preparation method has the advantages of simple operation, easily available raw materials, greenness, environmental protection, and great implementation value and social and economic benefits.
Iridium-Catalyzed Enantioselective Allylic Substitutions of Racemic, Branched Trichloroacetimidates with Heteroatom Nucleophiles: Formation of Allylic C?O, C?N, and C?S Bonds
Arachchi, Madhawee K.,Nguyen, Hien M.
supporting information, p. 4239 - 4246 (2021/07/16)
A broadly applicable methodology for the regio- and enantioselective construction of branched allylic carbon-heteroatom bonds from racemic, secondary allylic trichloroacetimidates has been developed. The branched allylic substrates undergo dynamic kinetic asymmetric substitution reactions with a number of unactivated anilines and carboxylic acids as well as unactivated aromatic thiols in the presence of a chiral bicyclo[3.3.0]octadiene-ligated iridium catalyst. The allylic C?O, C?N, and C?S bond containing products are obtained in synthetically useful yield and selectivity. Mechanistic studies suggest that the iridium-catalyzed enantioselective substitution reactions of heteroatom nucleophiles with allylic trichloroacetimidate substrates through an outer-sphere nucleophilic addition mechanism. In addition, the chiral diene-ligated iridium catalyst is effective at promoting asymmetric aminations of acyclic secondary anilines. Importantly, this catalytic iridium methodology enables the use of alkyl substituted allylic electrophiles. (Figure presented.).
Olefin reaction in the catalyst and the olefin production
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Paragraph 0145-0146; 0149, (2020/10/31)
PROBLEM TO BE SOLVED: To provide a catalyst for obtaining an olefin in high selectivity with a vicinal diol as a raw material.SOLUTION: A catalyst for olefination reaction for use in a reaction to produce an olefin by a reaction of a polyol, having two adjacent carbon atoms each having a hydroxy group, with hydrogen comprises: a carrier; at least one oxide selected from the group consisting of oxides of the group 6 elements and oxides of the group 7 elements supported on the carrier; and at least one metal selected from the group consisting of silver, iridium, and gold supported on the carrier.SELECTED DRAWING: None
Asymmetric Synthesis of N-Fused 1,3-Oxazolidines via Pd-Catalyzed Decarboxylative (3+2) Cycloaddition
Ahn, Hye-In,Cho, Ho-Jun,Kim, Ju Hyun,Park, Jong-Un,Xuan, Zi
supporting information, (2020/04/22)
Efficient synthesis of optically active N-fused 1,3-oxazolidines containing quaternary and tertiary stereocenters was achieved via Pd-catalyzed asymmetric (3+2) cycloadditions of sulfamate-derived cyclic imines and vinylethylene carbonates. Using a chiral phosphoramidite ligand, the cycloadditions proceeded effectively providing sulfamidate-fused 1,3-oxazolidines in high yields (up to 96%) with stereoselectivities (up to 25:1 dr; >99% ee). Additionally, the scale-up reaction and further transformations of the product were also achieved demonstrating the synthetic utility toward the construction of useful heterocycles such as chiral oxazoline bearing a quaternary stereocenter. (Figure presented.).
Pd-Catalyzed Decarboxylative Olefination: Stereoselective Synthesis of Polysubstituted Butadienes and Macrocyclic P-glycoprotein Inhibitors
Chen, Xiangyang,Hao, Jiping,Houk, K. N.,Li, Yingzi,Lou, Liguang,Quan, Haitian,Song, Bichao,Wang, Lu,Xia, Yuanzhi,Xie, Peipei,Xu, Zhongliang,Yang, Weibo
supporting information, p. 9982 - 9992 (2020/06/27)
The efficient and stereoselective synthesis of polysubstituted butadienes, especially the multifunctional butadienes, represents a great challenge in organic synthesis. Herein, we wish to report a distinctive Pd(0) carbene-initiated decarboxylative olefination approach that enables the direct coupling of diazo esters with vinylethylene carbonates (VECs), vinyl oxazolidinones, or vinyl benzoxazinones to afford alcohol-, amine-, or aniline-containing 1,3-dienes in moderate to high yields and with excellent stereoselectivity. This protocol features operational simplicity, mild reaction conditions, a broad substrate scope, and gram-scalability. Notably, a structurally unique allylic Pd(II) intermediate was isolated and characterized. DFT calculation and control experiments demonstrated that a rare Pd(0) carbene intermediate could be involved in this reaction. Moreover, the polysubstituted butadienes as novel building blocks were unprecedentedly assembled into macrocycles, which efficiently inhibited the P-glycoprotein and dramatically reversed multidrug resistance in cancer cells by 190-fold.
The Role of Trichloroacetimidate to Enable Iridium-Catalyzed Regio- And Enantioselective Allylic Fluorination: A Combined Experimental and Computational Study
Sorlin, Alexandre M.,Mixdorf, Jason C.,Rotella, Madeline E.,Martin, Robert T.,Gutierrez, Osvaldo,Nguyen, Hien M.
supporting information, p. 14843 - 14852 (2019/10/11)
Asymmetric allylic fluorination has proven to be a robust and efficient methodology with potential applications for the development of pharmaceuticals and practical synthesis for 18F-radiolabeling. A combined computational (dispersion-corrected
Transfer hydrogenation of cyclic carbonates and polycarbonate to methanol and diols by iron pincer catalysts
Liu, Xin,De Vries, Johannes G.,Werner, Thomas
, p. 5248 - 5255 (2019/10/11)
Herein, we report the first example on the use of an earth-abundant metal complex as the catalyst for the transfer hydrogenation of cyclic carbonates to methanol and diols. The advantage of this method is the use of isopropanol as the hydrogen source, thus avoiding the handling of flammable hydrogen under high pressure. The reaction offers an indirect route for the reduction of CO2 to methanol. In addition, poly(propylene carbonate) was converted to methanol and propylene glycol. This methodology can be considered as an attractive opportunity for the chemical recycling of polycarbonates.
Functionalizable Stereocontrolled Cyclopolyethers by Ring-Closing Metathesis as Natural Polymer Mimics
Alkattan, Mohammed,Prunet, Jo?lle,Shaver, Michael P.
supporting information, p. 12835 - 12839 (2018/09/25)
Whereas complex stereoregular cyclic architectures are commonplace in biomacromolecules, they remain rare in synthetic polymer chemistry, thus limiting the potential to develop synthetic mimics or advanced materials for biomedical applications. Herein we
