887027-36-3Relevant academic research and scientific papers
Azide Radical Initiated Ring Opening of Cyclopropenes Leading to Alkenyl Nitriles and Polycyclic Aromatic Compounds
Muriel, Bastian,Waser, Jerome
supporting information, p. 4075 - 4079 (2021/01/18)
We report herein a radical-mediated amination of cyclopropenes. The transformation proceeds through a cleavage of the three-membered ring after the addition of an azide radical on the strained double bond and leads to tetrasubstituted alkenyl nitrile derivatives upon loss of N2. With 1,2-diaryl substituted cyclopropenes, this methodology could be extended to a one-pot synthesis of highly functionalized polycyclic aromatic compounds (PACs). This transformation allows the synthesis of nitrile-substituted alkenes and aromatic compounds from rapidly accessed cyclopropenes using only commercially available reagents.
Borane catalysed cyclopropenation of arylacetylenes
Dasgupta, Ayan,Heard, Matthew J.,Melen, Rebecca L.,Stefkova, Katarina
supporting information, p. 6736 - 6739 (2021/07/13)
Triarylboranes have gained substantial attention as catalysts for C-C bond forming reactions due to their remarkable catalytic activities. Herein, we report B(C6F5)3catalysed cyclopropenation of a wide variety of arylacetylenes using donor-acceptor diazoesters. A mild reaction protocol has been developed for the synthesis of functionalised cyclopropenes (33 examples) in good to excellent yields.
Insertion of Diazo Esters into C-F Bonds toward Diastereoselective One-Carbon Elongation of Benzylic Fluorides: Unprecedented BF3Catalysis with C-F Bond Cleavage and Re-formation
Wang, Fei,Nishimoto, Yoshihiro,Yasuda, Makoto
supporting information, p. 20616 - 20621 (2021/11/23)
Selective transformation of C-F bonds remains a significant goal in organic chemistry, but C-F insertion of a one-carbon-atom unit has never been established. Herein we report the BF3-catalyzed formal insertion of diazo esters as one-carbon-atom sources into C-F bonds to accomplish one-carbon elongation of benzylic fluorides. A DFT calculation study revealed that the BF3 catalyst could contribute to both C-F bond cleavage and re-formation. This elongation provided α-fluoro-α,β-diaryl esters with a high level of diastereoselectivity. Various benzylic fluorides and diazo esters were applicable. The synthetic utility of this method was demonstrated by the synthesis of a fluoro analogue of a compound that is used as a transient receptor and potential canonical channel inhibitor.
Photochemical Doyle-Kirmse Reaction: A Route to Allenes
Or?owska, Katarzyna,Rybicka-Jasińska, Katarzyna,Krajewski, Piotr,Gryko, Dorota
supporting information, p. 1018 - 1021 (2020/01/31)
This Letter describes the metal-free, blue-light-induced [2,3]-sigmatropic rearrangement of sulfonium ylides generated from donor/acceptor diazoalkanes and propargyl sulfides. The reaction furnishes highly functionalized allenes from a broad range of starting materials in decent yield. Mechanistic experiments supported by the literature data suggest singlet carbenes as intermediates in this reaction.
Diazo Activation with Diazonium Salts: Synthesis of Indazole and 1,2,4-Triazole
Li, Xuming,Ye, Xiaohan,Wei, Chiyu,Shan, Chuan,Wojtas, Lukasz,Wang, Qilin,Shi, Xiaodong
supporting information, p. 4151 - 4155 (2020/06/05)
A donor/acceptor diazo activation strategy, processing via condensation using diazonium salts without the addition of any other catalysts or reagents, is reported. The diazenium intermediate was found to undergo cyclization to give indazoles in excellent yields. Alternatively, in the presence of nitriles, substituted 1,2,4-triazoles were obtained in good to excellent yields. This interesting diazenium route provides a new approach to achieve complex heterocycle synthesis under mild conditions.
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.
Photochemical, Metal-Free Sigmatropic Rearrangement Reactions of Sulfur Ylides
Yang, Zhen,Guo, Yujing,Koenigs, Rene M.
supporting information, p. 6703 - 6706 (2019/05/10)
Sigmatropic rearrangement reactions constitute one of the most fundamental reactions of carbenes. While state-of-the-art synthetic methods require the use of expensive precious metal catalysts, the application of visible light for the photolysis of α-aryldiazoacetates is much less investigated and provides an operationally simple entry to carbenes under mild reaction conditions. Herein, we report on blue-light induced sigmatropic rearrangement reactions of sulfur compounds with α-aryldiazoacetates. This process, depending on the substitution pattern of the sulfide, opens up formal insertion reactions of carbenes into S?N, S?C, or C?H bonds.
Norcaradiene Synthesis via Visible-Light-Mediated Cyclopropanation Reactions of Arenes
Guo, Yujing,Nguyen, Thanh Vinh,Koenigs, Rene M.
supporting information, p. 8814 - 8818 (2019/11/03)
Cyclopropanation reactions of carbenes with arenes provide a straightforward pathway to norcaradienes or cycloheptatrienes. This reaction normally requires harsh reaction conditions or transition-metal catalysts. In this report, we describe the metal-free visible-light photolysis of aryl diazoacetates in aromatic solvents, which provides access to the norcaradiene ring system in a highly regio- and stereoselective manner. The mild reaction conditions of this approach also allow chemoselective cyclopropanation of substituted arenes without competing C-H functionalization reactions.
Method for synthesizing alpha-diazoesters compound by using microwave at normal pressure
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Paragraph 0029-0031, (2018/11/22)
The invention discloses a method for synthesizing an alpha-diazoesters compound by using microwave at normal pressure. An esters compound and P-toluenesulfonyl azide are used as initial raw materials,1,8-diazabicyclo[5.4.0]undec-7-ene(DBU) is used as a catalyst, the alpha-diazoesters compound can be generated in 30 minutes by virtue of a diazo transfer reaction under a microwave assisting heating condition, and the alpha-diazoesters compound can further generate a functional product. The organic reaction rate of the method is multiple times faster than the traditional heating method, the reaction efficiency is high, the operation is simple and convenient, the synthetic reaction condition is mild, the product type is rich, and the functional group is diversified.
Pd-Catalyzed Three-Component Domino Reaction of Vinyl Benzoxazinanones for Regioselective and Stereoselective Synthesis of Allylic Sulfone-Containing Amino Acid Derivatives
Hao, Jiping,Xu, Yi,Xu, Zhongliang,Zhang, Zhiqiang,Yang, Weibo
supporting information, p. 7888 - 7892 (2019/01/04)
A Pd-catalyzed, highly regioselective and stereoselective three-component domino allylic substitution/N-H carbene insertion reaction under mild conditions is described. This reaction demonstrates a wide substrate scope and satisfactory functional group tolerance, providing a broad range of allylic sulfone-containing amino acid derivatives. Moreover, DBU mediates highly diastereoselective cross-dehydrogenative coupling annulation of allylic sulfones without using peroxides or any metal oxidants. This developed protocol affords 7-membered ring heterocyclic compounds incorporating both sulfone-containing amino acid esters and one quaternary carbon center. Mechanistic studies indicate that an unusual umpolung of glycine occurred in this annulation.
