1578-79-6Relevant academic research and scientific papers
A Unified and Desymmetric Approach to Chiral Tertiary Alkyl Halides
Huang, Zhongxing,Low, Kam-Hung,Zhang, Suihan,Zheng, Yin,Zi, Weiwei
supporting information, p. 1951 - 1961 (2022/02/09)
Enantioenriched tertiary alkyl halides are prevalent in bioactive molecules and can serve as versatile synthetic intermediates to construct complex structures. While conventional access to these motifs often hinges on stereoselective carbon-halogen or carbon-carbon bond formation reactions, desymmetric approaches using halogenated and prochiral tetrasubstituted carbons are largely elusive in comparison. Here, we report that a suite of dinuclear zinc catalysts with a prolinol- or pipecolinol-derived tetradentate ligand can reductively desymmetrize a large collection of easily available halomalonic esters to α-halo-β-hydroxyesters. These polyfunctionalized tertiary alkyl fluorides, chlorides, and bromides proved to be useful intermediates toward fluorinated drug analogs and polyhalogenated monoterpenes. The facile intramolecular epoxidation of the chiral chloride and bromide products has also enabled expeditious access to natural products containing tertiary alcohol motifs.
Nickel-Catalyzed Benzylic Substitution of Benzyl Esters with Malonates as a Soft Carbon Nucleophile
Tsuji, Hiroaki,Hashimoto, Keisuke,Kawatsura, Motoi
, p. 8837 - 8841 (2019/11/11)
The nickel-catalyzed benzylic substitution of benzyl alcohol derivatives with a soft carbon nucleophile is extremely rare compared to that with a hard carbon nucleophile. We have achieved the nickel-catalyzed benzylic substitution of benzyl esters with malonates as a soft carbon nucleophile. Primary and secondary benzyl 2,3,4,5,6-pentafluorobenzoates as well as a wide variety of malonate derivatives were well tolerated in the nickel-catalyzed reaction, providing the corresponding alkylation products in 46-86% yields (34 examples). Additionally, we propose a possible reaction mechanism that would undergo via the ??1- A nd ??3-benzylnickel intermediates.
Methyl NFSI: Atom-economical alternative to NFSI shows higher fluorination reactivity under Lewis acid-catalysis and non-catalysis
Fukushi, Kazunobu,Suzuki, Satoru,Kamo, Tomohiro,Tokunaga, Etsuko,Sumii, Yuji,Kagawa, Takumi,Kawada, Kosuke,Shibata, Norio
supporting information, p. 1864 - 1868 (2016/04/19)
Me-NFSI was first reported in 1994. Despite its atom-economical structure and similarity to a well-explored fluorinating reagent, NFSI, Me-NFSI has not appeared in the literature in over 20 years. We disclose that Me-NFSI is more effective for the fluorination of active methines under Lewis acid-catalysis and non-catalysis than NFSI.
Enantioselective Suzuki cross-couplings of unactivated 1-fluoro-1-haloalkanes: Synthesis of chiral β-, γ-, δ-, and ε-fluoroalkanes
Jiang, Xiaojian,Gandelman, Mark
supporting information, p. 2542 - 2547 (2015/03/04)
The incorporation of fluorine atom into a stereogenic center is a highly challenging transformation with current methodologies offering access mainly to chiral α- and β-fluoroalkanes. In this article, the development of a novel general approach to constru
Diastereoselective Addition of Metal α-Fluoroenolates of Carboxylate Esters to N-tert-Butylsulfinyl Imines: Synthesis of α-Fluoro-β-amino Acids
Shang, Huaqi,Li, Ya,Li, Xiang,Ren, Xinfeng
supporting information, p. 8739 - 8747 (2015/09/15)
We report a diastereoselective addition reaction of fluoroacetate and α-alkylated fluoroacetate to N-tert-butylsulfinyl imines. This method provides a concise route to α-fluoro-β-amino acids containing fluorinated quaternary stereogenic carbon centers with very good yields and high diastereoselectivities. This protocol has the benefit of using abundant and readily accessible starting materials and is operationally simple. Additionally, the stereochemical outcome of the present reaction was different from that of the previously known addition of comparable nonfluorinated, brominated, and chlorinated enolates to N-sulfinyl imines, suggesting that an open transition state (rather than a closed one) is involved in the current fluoroalkylation reaction.
Efficient synthesis of secondary alkyl fluorides via suzuki cross-coupling reaction of 1-halo-1-fluoroalkanes
Jiang, Xiaojian,Sakthivel, Sekarpandi,Kulbitski, Kseniya,Nisnevich, Gennady,Gandelman, Mark
supporting information, p. 9548 - 9551 (2014/07/22)
Organofluorine compounds have found extensive applications in various areas of science. Consequently, the development of new efficient and selective methods for their synthesis is an important goal in organic chemistry. Here, we present the first Suzuki c
Asymmetric synthesis of chiral 2-fluorinated 1,3-propanediols and its application to the preparation of monofluorinated chiral synthon
Yokoyama, Hajime,Hyodo, Ryo,Nakada, Akiko,Yamaguchi, Seiji,Hirai, Yoshiro,Kometani, Tadashi,Goto, Michimasa,Shibata, Norio,Takeuchi, Yoshio
, p. 7741 - 7744 (2007/10/03)
Asymmetric synthesis of optically active 2-fluorinated 1,3-propanediols was achieved by enzymatical resolution and applied to obtain a chiral monofluorinated synthon for lignan derivatives.
Carbanion Fluorination with Xenon Difluoride in the Presence of Sulfur (II) Derivatives
Patrick, Timothy B.,Nadji, Sourena
, p. 415 - 420 (2007/10/02)
An electrophilic fluorination reagent capable of fluorinating carbanions in moderate yield is obtained from the reaction of xenon difluoride with Sulfur II derivatives such as dimethyl sulfide.
1-Fluoro-2-pyridone: A Useful Fluorinating Reagent
Purrington, Suzanne T.,Jones, Walda Ann
, p. 761 - 762 (2007/10/02)
1-Fluoro-2-pyridone (mp 50-53 degC) has been prepared by reaction of 5percent fluorine in nitrogen and 2-(trimethylsiloxy)pyridine in FCCl3 at -78 degC.After sublimation, the pyridone is used as a selective fluorinating agent in the preparation of some fl
