736184-66-0Relevant academic research and scientific papers
Enantioselective Construction of Axially Chiral Amino Sulfide Vinyl Arenes by Chiral Sulfide-Catalyzed Electrophilic Carbothiolation of Alkynes
Ji, Jieying,Jiang, Quanbin,Liang, Yaoyu,Luo, Jie,Zhang, Xiaoyan,Zhao, Xiaodan
supporting information, p. 4959 - 4964 (2020/02/11)
The enantioselective construction of axially chiral compounds by electrophilic carbothiolation of alkynes is disclosed for the first time. This enantioselective transformation is enabled by the use of a Ts-protected bifunctional sulfide catalyst and Ms-protected ortho-alkynylaryl amines (Ts=tosyl; Ms=mesyl). Both electrophilic arylthiolating and electrophilic trifluoromethylthiolating reagents are suitable for this reaction. The obtained products of axially chiral vinyl–aryl amino sulfides can be easily converted into biaryl amino sulfides, biaryl amino sulfoxides, biaryl amines, vinyl–aryl amines, and other valuable difunctionalized compounds.
Palladium-Catalyzed Ligand-Free Double Cyclization Reactions for the Synthesis of 3-(1′-Indolyl)-phthalides
Yuan, Shuo,Zhang, Dan-Qing,Zhang, Jing-Ya,Yu, Bin,Liu, Hong-Min
supporting information, p. 814 - 817 (2020/02/04)
Indole and phthalide are privileged heterocyclic scaffolds in numerous natural products and bioactive molecules. The synthesis and biological evaluation of the compounds combining these two scaffolds have rarely been reported. Herein, we repot the first palladium-catalyzed ligand-free double cyclization reactions that enable efficient synthesis of 3-(1′-indolyl)-phthalides (42 examples, up to 96% yield) under mild conditions. Notably, only 1.0 mol % of catalyst loading is used, suggesting high efficiency. Late-stage elaborations give highly functionalized analogues.
A Synthetic Route to Chiral Benzo-Fused N-Heterocycles via Sequential Intramolecular Hydroamination and Asymmetric Hydrogenation of Anilino-Alkynes
Xu, Cong,Feng, Yu,Li, Faju,Han, Jiahong,He, Yan-Mei,Fan, Qing-Hua
supporting information, p. 3979 - 3990 (2019/11/14)
An efficient sequential intramolecular hydroamination/asymmetric hydrogenation reaction under catalysis of a single chiral ruthenium complex or a binary system consisting of achiral gold complex and chiral ruthenium complex has been reported. A diverse range of enantioenriched benzo-fused N-heterocycles, including 1,2,3,4-tetrahydroquinoline, indoline, and 2,3,4,5-tetrahydro-1H-benzo[b]azepine derivatives, were obtained from anilino-alkynes in high yields (up to 98%) with moderate to excellent enantioselectivities (up to 98% ee) under mild conditions. This protocol features good functional group tolerance and high atom economy. Furthermore, this catalytic protocol is applicable to gram-scale synthesis of a naturally occurring alkaloid, (-)-Angustureine.
Gold-catalyzed tandem reaction of 2-alkynylanilines followed by 1,6-conjugate addition to: P -quinone methides: Efficient access to unsymmetrical diarylindolylmethanes
Jillella, Raveendra,Oh, Dong Hwan,Oh, Chang Ho
supporting information, p. 16886 - 16890 (2018/10/23)
A simple, mild, efficient and chemoselective catalytic method for the straightforward synthesis of an interesting class of 2-aryl/alkyl-substituted-3-diaryl indolyl methanes in high yield is reported. This atom-efficient method proceeds via a gold-catalyzed one-pot sequential intramolecular hydroamination (C-N bond formation) of 2-alkynylanilines followed by a 1,6-conjugate addition to p-quinonemethides. The p-quinonemethides, which contain aldehyde functional groups, preferentially participate in 1,6-conjugate addition, while the aldehyde functional group remains unreactive.
Bronsted acid-promoted sequential hydroarylation-hydroamidation of arene-tethered 1-(2-alkynylphenyl)ureas: Direct access to 4,4-spiro-3,4-dihydro- 2-(1H)-quinazolinones
Wang, Honggen,Zhao, Jiaji,Zhang, Jiancun,Zhu, Qiang
supporting information; experimental part, p. 2653 - 2658 (2011/12/01)
A Bronsted acid-promoted approach to 4,4-sipro-3,4-dihydro-2-(1H)- quinazolinones from arene-tethered 1-(2-alkynylphenyl)ureas has been developed. The reaction is initiated by intramolecular hydroarylation followed by hydroamidation, assisted by intramole
Kinetic resolutions of lndolines by a nonenzymatic acylation catalyst
Arp, Forrest O.,Fu, Gregory C.
, p. 14264 - 14265 (2008/03/13)
The first method for the kinetic resolution of indolines through catalytic N-acylation is described. To improve the selectivity factor, new planar-chiral PPY-derived catalysts were synthesized, wherein the chiral environment was systematically modified. This work provides a rare example of a nonenzyme-based acylation catalyst for the kinetic resolution of amines. Copyright
Biradicals/zwitterions from thermolysis of enyne-isocyanates. Application to the synthesis of 2(1H)-pyridones, benzofuro[3,2-c]pyridin-1(2H)-ones, 2,5-dihydro-1H-pyrido[4,3,-b]indol-1-ones, and related compounds
Li, Hongbin,Yang, Hua,Petersen, Jeffrey L.,Wang, Kung K.
, p. 4500 - 4508 (2007/10/03)
Thermolysis of benzannulated enyne-isocyanates 13 and enyne-isocyanates 36 and 37 promoted the cycloaromatization reactions to generate in situ O,4-didehydro-2-hydroxyquinolines and O,4-didehydro-2-hydroxypyridines, respectively, as reactive intermediates. These cycloaromatized intermediates could be captured either as biradicals and/or as zwitterions depending on the nature of the substituent at the alkynyl terminus. The intermediate derived from cycloaromatization of 13a bearing a phenyl substituent could be regarded as biradical 14, which then abstracts hydrogen atoms from γ-terpinene leading to 2(1H)-quinolinone 15. Alternatively, the same intermediate could also be regarded as zwitterion 14′, which then undergoes an initial hydride abstraction from γ-terpinene followed by protonation to produce 15. The presence of a 2-phenylethyl substituent in 13b and 37a or a 2-methylphenyl substituent in 37b also allowed the resulting intermediates to be captured intramolecularly either as biradicals or as zwitterions, producing 2(1H)-quinolinone 19, 2(1H)-pyridone 39, and benzopyranopyridine 43, respectively. On the other hand, with a 2-methoxyphenyl, a 2-(dimethylamino) phenyl, or a 3-methoxypropyl substituent, the chemical behavior of the cycloaromatized adduct could be best accounted for in terms of a zwitterionic intermediate leading to benzofuro [3,2-c]quinolin-6(5H)-one (20), 5,11-dihydro-11-methyl-6H-indolo-[3,2-c]quinolin-6-one (25), benzofuro[3,2-c]pyridin-1(2H)-one 44, 2,5-dihydro-2,5-dimethyl-1H-pyrido-[4,3-b] indol-1-one 46, and related compounds. Interestingly, thermolysis of 37f bearing a 2-(methoxymethyl)phenyl substituent at the alkynyl terminus produced the unexpected benzopyranopyridine 56 as the major product in a process involving the cleavage of the bond between the methoxyl oxygen and the adjacent methylene carbon. The efficiency and selectivity of the cycloaromatization reaction could also be enhanced by the introduction of 1.1 to 10 equiv of dimethylphenylsilyl chloride to the reaction mixture to capture the resulting zwitterion.
