36776-32-6Relevant academic research and scientific papers
Palladium-Catalyzed [5 + 2] Annulation of Vinylethylene Carbonates with Barbiturate-Derived Alkenes
Chen, Yuehua,Deng, Hao,Gao, Xing,Guo, Hongchao,Jiang, Feng,Wang, Wei,Wu, Yongjun,Zhu, Dongyu
supporting information, p. 7158 - 7163 (2020/10/02)
A palladium/XantPhos-catalyzed [5 + 2] annulation of VECs with electron-deficient alkenes having an isolated carbon-carbon double bond has been developed to afford spirobarbiturate-tetrahydrooxepines. This study provides an expedient assembly of biologically interesting spirobarbiturate-tetrahydrooxepines. The easy scalability and versatile transformability of the reaction products were also exhibited.
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
, 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.
Spiro[indene-1,4′-oxa-zolidinones] Synthesis via Rh(III)-Catalyzed Coupling of 4-Phenyl-1,3-oxazol-2(3 H)-ones with Alkynes: A Redox-Neutral Approach
Liu, Zhongsu,Zhang, Wenjing,Guo, Shan,Zhu, Jin
, p. 11945 - 11957 (2019/10/02)
Transition-metal-catalyzed C-H activation synthesis of heterocyclic spiro[4,4]nonanes has persistently witnessed the use of additional stoichiometric transition-metal oxidant when employing C=C bond as the spiro ring closure site. Herein, we have addressed the issue by reporting a redox-neutral strategy for spiro[indene-1,4′-oxa-zolidinones] synthesis via Rh(III)-catalyzed coupling of 4-phenyl-1,3-oxazol-2(3H)-ones with alkynes. The synthesis features a broad substrate scope and high regiospecificity.
Palladium-Catalyzed (Z)-Selective Allylation of Nitroalkanes: Access to Highly Functionalized Homoallylic Scaffolds
Cristòfol, àlex,Escudero-Adán, Eduardo C.,Kleij, Arjan W.
, p. 9978 - 9990 (2018/09/06)
Nitroalkanes undergo decarboxylative allylation in the presence of vinyl-substituted cyclic carbonates, providing a wide variety of functionalized homoallylated compounds with exquisite stereocontrol. This Pd-mediated procedure features operational simplicity, versatile substrate combinations, and also allows for the sequential introduction of different allyl groups in the nitroalkane scaffolds with high levels of stereocontrol through the intermediacy of a (Z)-configured palladacyclic intermediate. As far as we know, the developed protocol is the first general Pd-mediated methodology toward (Z)-configured homoallylic nitroalkanes with attractive functional group diversity.
Divergent synthesis of N-heterocycles by Pd-catalyzed controllable cyclization of vinylethylene carbonates
Yang, Yuwen,Yang, Weibo
, p. 12182 - 12185 (2018/11/21)
Here, we report a palladium-catalyzed controllable cyclization of vinyl ethylene carbonates that proceeds through formal migration [2+3] and [5+2] cycloadditions, respectively, under mild conditions. The transformation described here affords a series of synthetically versatile 5,7-membered N-heterocycles which are found in natural products and pharmaceuticals with biological and medicinal properties.
Chiral Ion-Pair Organocatalyst-Promoted Efficient Enantio-selective Reduction of α-Hydroxy Ketones
Zhang, Yiliang,He, Li,Shi, Lei
supporting information, p. 1926 - 1931 (2018/03/27)
The enantioselective reduction of α-hydroxy ketones with catecholborane has been developed employing 5 mol% of an 1,1′-bi-2-naphthol (BINOL)-derived ion-pair organocatalyst. This methodology provides a straightforward access to the corresponding aromatic 1,2-diols in high yields (up to 90%) with excellent enantioselectivities (up to 97%). Furthermore, the α-amino ketones also could be reduced with moderate ee values under mild reaction condition. (Figure presented.).
Direct Aerobic Oxidative Reactions of 2-Hydroxyacetophenones
Sahoo, Subas Chandra,Nath, Utpal,Pan, Subhas Chandra
supporting information, p. 4434 - 4438 (2017/08/23)
Valuable and direct aerobic oxidation reactions of 2-hydroxyacetophenones were explored. The concept was based on the in situ treatment of small quantities of aerobically formed α-keto aldehydes that drove the reactions to the corresponding products. This new strategy was applied for a variety of oxidative reactions of 2-hydroxyacetophenones, and valuable products such as phthalides, quinoxalines, and α-keto amides were obtained in good to high yields.
Tetrazolinone compound and application for same
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Paragraph 0694; 0695; 0696; 0697; 0730; 0731; 0732; 0733, (2016/10/08)
Provided is a tetrazolinone compound given by formula (1) (wherein E represents a 5-membered aromatic hetero group, such as the pyrazolyl group, the thiazolyl group, or the imidazolyl group; R4 and R5 represent hydrogen atoms or the like; R6 represents a C1-12 alkyl group; R7, R8, and R9 represent hydrogen atoms or the like; R10 represents a C1-3 alkyl group, or a C1-3 haloalkyl group; Y represents an oxygen atom or the like; and Q represents an oxygen atom or the like), and having exceptional efficacy in controlling harmful organisms.
Selective Debromination and α-Hydroxylation of α-Bromo Ketones Using Hantzsch Esters as Photoreductants
Jung, Jaehun,Kim, Jun,Park, Gyurim,You, Youngmin,Cho, Eun Jin
supporting information, p. 74 - 80 (2016/01/25)
Two transformations initiated by photoinduced one-electron transfer to α-bromo ketones have been demonstrated. Hantzsch esters donate one electron to α-bromo ketones under photoirradiation, promoting reductive debromination. Subsequent reactions of the resulting radical species of the ketones with molecular oxygen and Hantzsch esters lead to α-hydroxylation or debromination, respectively. The relative dominance of the two pathways depends profoundly on the reaction conditions, including solvent, O2 levels, and the concentration of the Hantzsch esters. The synthetic protocols feature advantages because they require the environmentally benign sources, molecular oxygen and visible light.
Ruthenium(0) Catalyzed Endiyne-α-Ketol [4 + 2] Cycloaddition: Convergent Assembly of Type II Polyketide Substructures via C-C Bond Forming Transfer Hydrogenation
Saxena, Aakarsh,Perez, Felix,Krische, Michael J.
supporting information, p. 5883 - 5886 (2015/05/27)
Upon exposure of 3,4-benzannulated 1,5-diynes (benzo-endiynes) to α-ketols (α-hydroxyketones) in the presence of Ru(0) catalysts derived from Ru3(CO)12 and RuPhos or CyJohnPhos, successive redox-triggered C-C coupling occurs to gener
