22090-26-2Relevant articles and documents
Dehydrogenation/(3+2) Cycloaddition of Saturated Aza-Heterocycles via Merging Organic Photoredox and Lewis Acid Catalysis
Xiao, Teng-Fei,Zhang, Yi-Fan,Hou, Wen-Tao,Yan, Pen-Ji,Hai, Jun,Xu, Peng-Fei,Xu, Guo-Qiang
supporting information, p. 8942 - 8946 (2021/11/24)
Herein, we report a photoinduced dehydrogenation/(3+2) cycloaddition reaction by merging organic photoredox and Lewis acid catalysis, providing a straightforward and efficient approach for directly installing a benzofuran skeleton on the saturated aza-heterocycles. In this protocol, we also describe a novel organic photocatalyst (t-Bu-DCQ) with the advantages of a wider redox potential, easy synthesis, and a low price. Furthermore, the stepwise activation mechanism of dual C(sp3)-H bonds was demonstrated by a series of experimental and computational studies.
Preparation method for series synthesis of phenylpyrrolidine derivative under metal catalysis
-
Paragraph 0015, (2020/09/16)
The invention relates to a preparation method for series synthesis of a phenylpyrrolidine derivative under metal catalysis. The structural formula of the prepared phenylpyrrolidine derivative is shownin the figure 1. The preparation method comprises the following steps: preparing an N, N-diallyl aniline compound, a Grubbs catalyst, reduced iron powder and a reaction solvent, setting the reactiontemperature to be 40 DEG C, and fully stirring and reacting for 8-10 hours in a hydrogen atmosphere; and quenching after the reaction is monitored by TLC, extracting by using an organic solvent, drying, filtering, concentrating, and purifying by column chromatography to obtain the phenylpyrrolidine derivative with the yield of 62-81%. According to the method, the phenylpyrrolidine derivative is synthesized through one-pot series connection, raw materials are easy to obtain, operation is easy, repeatability is good, reaction conditions are mild, and the method is suitable for industrial production.
Spin Delocalization, Polarization, and London Dispersion Forces Govern the Formation of Diradical Pimers
Ellern, Arkady,Peterson, Joshua P.,Winter, Arthur H.
supporting information, p. 5304 - 5313 (2020/04/08)
Some free radicals are stable enough to be isolated, but most are either unstable transient species or exist as metastable species in equilibrium with a dimeric form, usually a spin-paired sigma dimer or a pi dimer (pimer). To gain insight into the different modes of dimerization, we synthesized and evaluated a library of 15 aryl dicyanomethyl radicals in order to probe what structural and molecular parameters lead to σ- versus π-dimerization. We evaluated the divergent dimerization behavior by measuring the strength of each radical association by variableerature electron paramagnetic resonance spectroscopy, determining the mode of dimerization (σ- or π-dimer) by UV-vis spectroscopy and X-ray crystallography, and performing computational analysis. We evaluated three different hypotheses to explain the difference in the dimerization behavior: (1) that the dimerization behavior is dictated by radical spin densities; (2) that it is dictated by radical polarizability; (3) that it is dictated by London dispersion stabilization of the pimer. However, no single parameter model in itself was predictive. Two-parameter models incorporating either the computed degree of spin delocalization or the radical polarizability as well as computed estimates for the attractive London dispersion forces in the π-dimers lead to improved forecasts of σ- vs π-dimerization mode, and suggest that a balance of spin delocalization of the isolated radical as well as attractive forces between the stacked radicals, govern the formation of diradical pimers.
Aryl-Diadamantyl Phosphine Ligands in Palladium-Catalyzed Cross-Coupling Reactions: Synthesis, Structural Analysis, and Application
Sinai, ádám,Simkó, Dániel Cs.,Szabó, Fruzsina,Paczal, Attila,Gáti, Tamás,Bényei, Attila,Novák, Zoltán,Kotschy, András
supporting information, p. 1122 - 1128 (2020/03/03)
Synthesis, temperature-dependent NMR structure investigation and utilization of a new, stable and easily accessible aryl-diadamantylphosphine ligand family is reported. The bulky and electron-rich phosphorus center of the ligand enhances the catalytic activity of palladium in cross-coupling reactions of sterically demanding ortho-substituted aryl halides. In our study, we demonstrated the synthetic applicability of the new phosphine ligands in Buchwald-Hartwig and tosyl hydrazone coupling reactions.
Organocatalytic Cascade β-Functionalization/Aromatization of Pyrrolidines via Double Hydride Transfer
An, Xiao-De,Li, Xian-Jiang,Liu, Qing,Shao, Chang-Lun,Xiao, Jian,Yang, Shuo,Zhou, Lan
supporting information, (2020/02/15)
An unprecedented cascade β-functionalization/aromatization reaction of N-arylpyrrolidines was established. A series of β-substituted arylpyrroles embedded with trifluoromethyl groups are provided directly from N-arylpyrrolidines. The deuterium-labeling experiments indicate that sequential double hydride transfer processes serve as the key steps in this transformation.
BIPHENYL COMPOUND AS CCR2/CCR5 RECEPTOR ANTAGONIST
-
Paragraph 0177, (2019/11/21)
Provided is a CCR2/CCR5 receptor antagonist and the use thereof in the preparation of a drug for treating diseases associated with the CCR2/CCR5. In particular, disclosed are a compound represented by formula (I) and a pharmaceutically acceptable salt thereof
Electrochemical Regioselective Bromination of Electron-Rich Aromatic Rings Using n Bu 4 NBr
Bai, Ya,Che, Xin,Liu, Nian,Ning, Shulin,Shi, Lingling,Wang, Shutao,Wang, Siyu,Xiang, Jinbao,Xie, Wenxia
supporting information, p. 1313 - 1316 (2019/06/20)
Electrochemical regioselective bromination of electron-rich aromatic rings using stoichiometric tetrabutylammonium bromide (n Bu 4 NBr) has been accomplished under mild conditions. This protocol provides an environmentally friendly and simple way for the construction of C-Br bond in moderate to high yields with wide functional group tolerance.
Utilization of Cyclic Amides as Masked Aldehyde Equivalents in Reductive Amination Reactions
Prince, Robin J.,Gao, Fang,Pazienza, Jessica E.,Marx, Isaac E.,Schulz, Jurgen,Hopkins, Brian T.
, p. 7936 - 7949 (2019/06/27)
An operationally simple protocol has been discovered that couples primary or secondary amines with N-aryl-substituted lactams to deliver differentiated diamines in moderate to high yields. The process allows for the partial reduction of a lactam in the presence of Cp2ZrHCl (Schwartz's reagent), followed by a reductive amination between the resulting hemiaminal and primary or secondary amine. These reactions can be telescoped in a one-pot fashion to significantly simplify the operation. The scope of amines and substituted lactams of various ring sizes was demonstrated through the formation of a range of differentiated diamine products. Furthermore, this methodology was expanded to include N-aryl pyrrolidinone substrates with an enantiopure ester group at the 5-position, and α-amino piperidinones were prepared with complete retention of stereochemical information. The development of this chemistry has enabled the consideration of lactams as useful synthons.
Dual C(sp3)?H Bond Functionalization of N-Heterocycles through Sequential Visible-Light Photocatalyzed Dehydrogenation/[2+2] Cycloaddition Reactions
Xu, Guo-Qiang,Xu, Ji-Tao,Feng, Zhi-Tao,Liang, Hui,Wang, Zhu-Yin,Qin, Yong,Xu, Peng-Fei
supporting information, p. 5110 - 5114 (2018/03/27)
Herein we describe a mild method for the dual C(sp3)?H bond functionalization of saturated nitrogen-containing heterocycles through a sequential visible-light photocatalyzed dehydrogenation/[2+2] cycloaddition procedure. As a complementary approach to the well-established use of iminium ion and α-amino radical intermediates, the elusive cyclic enamine intermediates were effectively generated by photoredox catalysis under mild conditions and efficiently captured by acetylene esters to form a wide array of bicyclic amino acid derivatives, thus enabling the simultaneous functionalization of two vicinal C(sp3)?H bonds.
Room-Temperature Practical Copper-Catalyzed Amination of Aryl Iodides
Deldaele, Christopher,Evano, Gwilherm
, p. 1319 - 1328 (2016/04/20)
An efficient and highly practical procedure is reported for the Ullmann-Goldberg-type copper-catalyzed amination of aryl iodides. By using a combination of copper iodide and proline in the presence of an excess of an amine, a wide range of aryl iodides can be readily aminated at room temperature. The reaction proceeds well regardless of the electronic properties of the starting aryl iodide and the amination products can be obtained without the need for purification by column chromatography in most cases. Owing to its efficiency and the mildness of the reaction conditions, this amination could also be extended to the amination of complex aryl iodides at room temperature.