- Palladium-Catalyzed [4 + 3] or [2 + 2 + 3] Annulation via C-H Activation and Subsequent Decarboxylation: Access to Heptagon-Embedded Polycyclic Aromatic Hydrocarbons
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The construction of a seven-membered ring in the polycyclic aromatic hydrocarbon skeleton remains a notoriously difficult but attractive challenge. Herein a novel palladium-catalyzed [4 + 3] decarboxylative annulation of 2-iodobiphenyls with 2-(2-halophenyl)acrylic acids is reported, which provides an efficient approach for assembling various tribenzo[7]annulenes via a C-H activation and decarboxylation process. Moreover, tribenzo[7]annulenes can be also synthesized via a [2 + 2 + 3] decarboxylative annulation strategy by employing readily available 1,2-halobenzenes, phenylboronic acids, and 2-(2-halophenyl)acrylic acids.
- Yang, Xiumei,Chen, Xiahong,Xu, Yankun,Zhang, Minghao,Deng, Guobo,Yang, Yuan,Liang, Yun
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supporting information
p. 2610 - 2615
(2021/04/12)
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- Borylation of Unactivated C(sp3)-H Bonds with Bromide as a Traceless Directing Group
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A palladium-catalyzed alkyl C-H borylation with bromide as a traceless directing group is described, providing a convenient approach to access alkyl boronates bearing a β-all-carbon quaternary stereocenter. The protocol features a broad substrate scope, excellent site selectivity, and good functional group tolerance.
- Zhang, Ge,Li, Meng-Yao,Ye, Wen-Bo,He, Zhi-Tao,Feng, Chen-Guo,Lin, Guo-Qiang
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supporting information
p. 2948 - 2953
(2021/05/05)
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- Internal Nucleophilic Catalyst Mediated Cyclisation/Ring Expansion Cascades for the Synthesis of Medium-Sized Lactones and Lactams
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A strategy for the synthesis of medium-sized lactones and lactams from linear precursors is described in which an amine acts as an internal nucleophilic catalyst to facilitate a novel cyclisation/ring expansion cascade sequence. This method obviates the n
- Lawer, Aggie,Rossi-Ashton, James A.,Stephens, Thomas C.,Challis, Bradley J.,Epton, Ryan G.,Lynam, Jason M.,Unsworth, William P.
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supporting information
p. 13942 - 13947
(2019/08/28)
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- Development of a Divergent Synthetic Route to the Erythrina Alkaloids: Asymmetric Syntheses of 8-Oxo-erythrinine, Crystamidine, 8-Oxo-erythraline, and Erythraline
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A general synthetic methodology toward the erythrina alkaloids has been developed. Inspired by a proposed biosynthetic mechanism, the medium-sized chiral biaryl lactam was asymmetrically transformed into the common core A-D rings by a stereospecific singlet oxygen oxidation of the phenol moiety, followed by a transannular aza-Michael reaction to the dienone functionality. The late-stage manipulation of the oxidation and oxygenation states of the functional groups on the peripheral moieties enabled the flexible syntheses of the erythrina alkaloids. Then there were four: The fixed atropisomeric stereochemistry of a medium-sized biaryl intermediate was fully transferred to the central point chirality of a helical intermediate as a result of singlet oxygen oxidation and transannulation. This finding enabled the asymmetric synthesis of a common intermediate, which is amenable to a variety of oxidation-reduction transformations, thus giving rise to the first asymmetric syntheses of four erythrina alkaloids.
- Umihara, Hirotatsu,Yoshino, Tomomi,Shimokawa, Jun,Kitamura, Masato,Fukuyama, Tohru
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supporting information
p. 6915 - 6918
(2016/06/14)
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- Evaluation and synthesis of polar aryl- and heteroaryl spiroazetidine-piperidine acetamides as ghrelin inverse agonists
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Several polar heteroaromatic acetic acids and their piperidine amides were synthesized and evaluated as ghrelin or type 1a growth hormone secretagogue receptor (GHS-R1a) inverse agonists. Efforts to improve pharmacokinetic and safety profile was achieved
- Orr, Suvi T. M.,Beveridge, Ramsay,Bhattacharya, Samit K.,Cameron, Kimberly O.,Coffey, Steven,Fernando, Dilinie,Hepworth, David,Jackson, Margaret V.,Khot, Vishal,Kosa, Rachel,Lapham, Kimberly,Loria, Paula M.,McClure, Kim F.,Patel, Jigna,Rose, Colin,Saenz, James,Stock, Ingrid A.,Storer, Gregory,Von Volkenburg, Maria,Vrieze, Derek,Wang, Guoqiang,Xiao, Jun,Zhang, Yingxin
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supporting information
p. 156 - 161
(2015/03/04)
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- Urea-induced acid amplification: A new approach for metal-free insertion chemistry
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The enhanced catalytic activity of difluoroboronate ureas proved to be essential as an acidity amplifier to promote metal-free O-H and S-H insertion reactions of α-aryldiazoacetates in high yield. This methodology was found to be generally applicable to a
- Couch, Erica D.,Auvil, Tyler J.,Mattson, Anita E.
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supporting information
p. 8283 - 8287
(2014/07/08)
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- Facile synthesis of 4,5,6a,7-tetrahydrodibenzo[de,g]chromene heterocycles and their transformation to phenanthrene alkaloids
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Oxa-Pictet-Spengler cyclization and microwave-assisted C-H arylation have been implemented as key steps in the synthesis of new isochroman heterocycles containing a 4,5,6a,7-tetrahydrodibenzo[de,g]chromene motif. These isochromans may be easily transformed to phenanthrene alkaloids via acidic cleavage of the isochroman ring and standard synthetic manipulations thereafter. The route described is attractive in that it provides access to two biologically interesting scaffolds in simple and high yielding synthetic steps.
- Kapadia, Nirav,Harding, Wayne
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supporting information
p. 8914 - 8920
(2013/09/23)
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- 2,3-DIHYDRO-1H-INDEN-1-YL-2,7-DIAZASPIRO[3.5] NONANE DERIVATIVES
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The present invention provides a compound of Formula (I) or a pharmaceutically salt thereof wherein R1, R2, Ra, L, Z, Z1 and Z2 are as defined herein, that act as Ghrelin antagonists or inverse agonists; pharmaceutical compositions thereof; and methods of treating diseases, disorders, or conditions mediated by the antagonism of the Ghrelin receptor.
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Page/Page column 31
(2011/10/10)
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- Regioselective aryl radical cyclisation. Part 2. Synthesis of octahydro-1H-dibenzo[a,d]cycloheptenes through 7-endo ring closure
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A simple convergent synthesis of trans- and cis-octahydro-1H-dibenzo[a,d]cycloheptenes 15a-c and 16a-c and 20a-c and 21a-c through implementation of a regioselective 7-endo-trig-aryl radical cyclisation of the respective 2-(o-bromoarylethyl)-1-methylenecy
- Ghosh, Ajit K.,Mukhopadhyaya, Jayanta K.,Ghatak, Usha Ranjan
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p. 2747 - 2755
(2007/10/03)
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