Reaction of Bromonaphthofurans with Bis(pinacolato)diboron.

1999 ◽  
Vol 52 (11) ◽  
pp. 1021 ◽  
Author(s):  
Margaret A. Brimble ◽  
Fatiah Issa
Keyword(s):  
Late Stage ◽  
Diels Alder ◽  
Aryl Bromide ◽  
Reaction Conditions ◽  
Boronate Ester ◽  
Oxidative Rearrangement ◽  
Biaryl Coupling ◽  
Claisen Reaction

The synthesis of a dimeric pyranonaphthoquinone (8) was investigated focusing on a late-stage biaryl coupling of suitably functionalized bromonaphthofurans by using Suzuki–Miyaura methodology. Bromonaphthofuran (16) underwent reaction with bis(pinacolato)diboron in the presence of PdCl2(dppf) to afford boronate ester (21) and furonaphthofuran (22). ‘In situ’coupling of the boronate ester (21) with aryl bromide (16) to the desired dimer (11) was not realized. Bromonaphthofuran (17), prepared by Diels–Alder/retro-Claisen reaction of bromonaphthoquinone (24) with diene (25), underwent Suzuki–Miyaura coupling to naphthofuran (27) and boronate ester (28). Numerous attempts to alter the reaction conditions to effect homocoupling of bromide (17) to biaryl (19) were unsuccessful. Bromopyranonaphthoquinone (18) prepared by oxidative rearrangement of (17) failed to undergo Suzuki–Miyaura coupling.

Single wall carbon nanotube (SWCNT)–gold nanorod (AuNR) conjugates via thermally-mild reaction conditions

2017 ◽  
Vol 41 (21) ◽  
pp. 12392-12396 ◽  
Author(s):  
Siting Ni ◽  
Jun Zhu ◽  
Mohamed Amine Mezour ◽  
R. Bruce Lennox
Keyword(s):  
Carbon Nanotube ◽  
Covalent Binding ◽  
Alder Reaction ◽  
Diels Alder ◽  
Gold Nanorod ◽  
Reaction Conditions ◽  
Single Wall Carbon ◽  
Inverse Electron Demand ◽  
Diels Alder Reaction ◽  
Electron Demand

A thermally-mild method for covalent binding of SWCNTs to AuNRs, based on an inverse-electron-demand Diels–Alder reaction, is established and discussed.

Late-Stage Sulfoximination: Improved Synthesis of the Anticancer Drug Candidate Atuveciclib

Synthesis ◽  
2018 ◽  
Vol 51 (04) ◽  
pp. 971-975 ◽  
Author(s):  
Vincent Reboul ◽  
Thomas Glachet ◽  
Xavier Franck
Keyword(s):  
Anticancer Drug ◽  
Late Stage ◽  
Drug Candidate ◽  
Efficient Synthesis ◽  
Reaction Conditions

An efficient synthesis of racemic atuveciclib was accomplished in five steps with an excellent 51% overall yield, using cheap reagents and mild reaction conditions. The key sulfoximination reaction was realized during the last step of the synthesis from the corresponding sulfide.

scholarly journals Manganese-mediated reductive functionalization of activated aliphatic acids and primary amines

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Zhan Li ◽  
Ke-Feng Wang ◽  
Xin Zhao ◽  
Huihui Ti ◽  
Xu-Ge Liu ◽  
...  
Keyword(s):  
Carboxylic Acids ◽  
Late Stage ◽  
Materials Science ◽  
Reaction Pathway ◽  
Chemical Conversion ◽  
Primary Amines ◽  
Mechanistic Studies ◽  
Reaction Conditions ◽  
Aliphatic Acids ◽  
Redox Active

Abstract Alkyl carboxylic acids as well as primary amines are ubiquitous in all facets of biological science, pharmaceutical science, chemical science and materials science. By chemical conversion to redox-active esters (RAE) and Katritzky’s N-alkylpyridinium salts, respectively, alkyl carboxylic acids and primary amines serve as ideal starting materials to forge new connections. In this work, a Mn-mediated reductive decarboxylative/deaminative functionalization of activated aliphatic acids and primary amines is disclosed. A series of C-X (X = S, Se, Te, H, P) and C-C bonds are efficiently constructed under simple and mild reaction conditions. The protocol is applicable to the late-stage modification of some structurally complex natural products or drugs. Preliminary mechanistic studies suggest the involvement of radicals in the reaction pathway.

scholarly journals A Natural Diels‐Alder Biocatalyst Enables Efficient [4+2] Cycloaddition Under Harsh Reaction Conditions

ChemCatChem ◽  
2019 ◽  
Vol 11 (20) ◽  
pp. 5027-5031 ◽  
Author(s):  
Carl O. Marsh ◽  
Nicholas R. Lees ◽  
Li‐Chen Han ◽  
Matthew J. Byrne ◽  
Sbusisiwe Z. Mbatha ◽  
...  
Keyword(s):  
Diels Alder ◽  
Reaction Conditions

Involvement of Diels–Alder reactions in the biosynthesis of secondary natural products: the late stage of the biosynthesis of the phytotoxins solanapyrones

1999 ◽  
pp. 1225 ◽  
Author(s):  
Hideaki Oikawa ◽  
Yuichi Suzuki ◽  
Kinya Katayama ◽  
Akira Naya ◽  
Chiaki Sakano ◽  
...  
Keyword(s):  
Natural Products ◽  
Late Stage ◽  
Diels Alder ◽  
Secondary Natural Products

Bioinspired Total Synthesis of the Dimeric Indole Alkaloid (+)-Haplophytine by Direct Coupling and Late-Stage Oxidative Rearrangement

2016 ◽  
Vol 128 (48) ◽  
pp. 15381-15385
Author(s):  
Hitoshi Satoh ◽  
Ken-ichi Ojima ◽  
Hirofumi Ueda ◽  
Hidetoshi Tokuyama
Keyword(s):  
Total Synthesis ◽  
Late Stage ◽  
Indole Alkaloid ◽  
Direct Coupling ◽  
Oxidative Rearrangement

Einfache Synthese von 2,2-Diethoxy-2,5-dihydrofuranen, 2(5 H)Furanonen und 2-Ethoxy-furanen.Kristall-und Molekülstruktur eines Barrelenon Diels-Aider Produktes [1] / Convenient Synthesis of 2,2-Diethoxy-2,5-dihydrofurans, 2(5 H)Furanones and 2-Ethoxyfurans.Crystal and Molecular Structure of a Barrelenone Diels-Alder Product [1]

1994 ◽  
Vol 49 (3) ◽  
pp. 389-406 ◽  
Author(s):  
Rolf W. Saalfrank ◽  
Wieland Hafner ◽  
Joachim Markmann ◽  
Andreas Welch ◽  
Karl Peters ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Maleic Anhydride ◽  
Structure Analysis ◽  
Diels Alder ◽  
Dimethyl Acetylenedicarboxylate ◽  
Reaction Conditions ◽  
X Ray ◽  
Convenient Synthesis

AbstractReaction of 1,2-hydroxyketones 5 with (2,2-diethoxyvinylidene)triphenylphosphorane (2) or (2,2-diethoxyvinyl)triphenylphosphonium tetrafluoroborates 6 yields the 2,2-diethoxy- 2.5-dihydrofurans 9. Depending on the reaction conditions used, the orthoesters 9 can be hydrolized to give 2(5 H)furanones 10 and 2-ethoxyfurans 11, respectively. 4,5-Dimethyl- 5.6-dihydro-2-pyranone (20) and 8-methoxycoumarin (23) are prepared, starting from (2,2-diethoxyvinyl)triphenylphosphonium tetrafluoroborate (6 a) and 1-hydroxy-2-methyl- 3-butanone (16) or 2-hydroxy-3-methoxy-benzaldehyde (21). The 2-ethoxyfuranes 11 readily undergo Diels-Alder reactions with 2-chloracrylonitrile (24), maleic anhydride (26), N-phenyl-1,2,4-triazoline-3,5-dione (28) and dimethyl acetylenedicarboxylate (30) to give the corresponding Diels-Alder products 25, 27, 29 and 31, respectively. Contrary to 2-ethoxyfuran 11b , 11a reacts with two equivalents of acetylene 30, to yield barrelenone 34. The structure of 34 unequivocally is established by X-ray structure analysis.

Late Stage of Biosynthesis of Intermolecular Diels-Alder Type Adducts in Morus alba L. Cell Cultures

Heterocycles ◽  
1999 ◽  
Vol 51 (2) ◽  
pp. 231 ◽  
Author(s):  
Taro Nomura ◽  
Yoshio Hano ◽  
Shinichi Ueda
Keyword(s):  
Cell Cultures ◽  
Late Stage ◽  
Diels Alder ◽  
Morus Alba ◽  
L Cell

scholarly journals Synthetic studies on the bioactive tetramic acid JBIR-22 using a late stage Diels–Alder reaction

2015 ◽  
Vol 13 (42) ◽  
pp. 10527-10531 ◽  
Author(s):  
A. R. Healy ◽  
N. J. Westwood
Keyword(s):  
Late Stage ◽  
Alder Reaction ◽  
Diels Alder ◽  
Tetramic Acid ◽  
Diels Alder Reaction ◽  
Synthetic Studies

A successful late-stage Diels–Alder cyclisation in the synthesis of JBIR-22 highlights it as a viable biosynthetic event.

scholarly journals Tyrosine and Drug-like Late-stage Benzylic Functionalization via Photoredox Catalysis

2020 ◽  
Author(s):  
Tobias Brandhofer ◽  
Volker Derdau ◽  
María Mendez ◽  
Christoph Pöverlein ◽  
Olga Garcia Mancheno
Keyword(s):  
Natural Products ◽  
Visible Light ◽  
Late Stage ◽  
Medicinal Chemistry ◽  
Functional Group ◽  
Reaction Conditions ◽  
Site Selectivity ◽  
Wide Range ◽  
High Yields ◽  
Therapeutic Compounds

Abstract Visible light mediated late-stage functionalization is a rising field in synthetic and medicinal chemistry, allowing the fast and diversified modification of valuable, potentially therapeutic compounds such as peptides. However, there are relatively few mild methodologies for the C(sp3)-H functionalization of complex peptides. Herein, we report a visible light mediated photocatalytic protocol for the benzylic C-H modification of tyrosine and related C-H bonds. The embraced radical-cation/deprotonation strategy enables an incorporation of a wide range of valuable functional groups in high yields and chemoselectivity. The mild reaction conditions, site-selectivity and high functional group tolerance was highlighted by the functionalization of complex peptides, drugs and natural products, providing a promising synthetic platform in medicinal chemistry.

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