Ru(II)–NNO pincer‐type complexes catalysed E‐olefination of alkyl‐substituted quinolines/pyrazines utilizing primary alcohols

The Friedlander reaction is the most commonly used method to synthesis substituted quinolines, the essential intermediates in the medicine industry. A facile one-pot approach for synthesizing substituted quinolines by the reaction of isoxazoles, ammonium formate-Pd/C, concentrated sulfuric acid, methanol and ketones using Friedlander reaction conditions is reported. Procedures for the synthesis of quinoline derivatives were optimized, and the yield was up to 90.4%. The yield of aromatic ketones bearing electron-withdrawing groups was better than the ones with electron-donating substituents. The structures of eight substituted quinolines were characterized by MS, IR, H-NMR and 13CNMR, which were in agreement with the expected structures. The mechanism for the conversion was proposed, which involved the Pd/C catalytic hydrogen transfer reduction of unsaturated five-membered ring of isoxazole to produce ortho-amino aromatic ketones. Then the nucleophilic addition of with carbonyl of the ketones generated Schiff base in situ, which underwent an intermolecular aldol reaction followed by the elimination of H2O to give production of substituted quinolines. This new strategy can be readily applied for the construction of quinolines utilizing a diverse range of ketones and avoids the post-reaction separation of the o-amino aromatic ketone compounds. The conventionally used o-amino aromatic ketone compounds in Friedlander reaction to prepare substituted quinoline are laborious to synthesize and are apt to self-polymerize. While oxazole adopted in this work can be prepared at ease by the condensation of benzoacetonitrile and nitrobenzene derivatives under the catalysis of a strong base. Moreover, the key features of this protocol are readily available starting materials, excellent functional group tolerance, mild reaction conditions, operational simplicity, and feasibility for scaling up.

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A Review on the Synthesis and Anti-cancer Activity of 2-substituted Quinolines

Anti-Cancer Agents in Medicinal Chemistry ◽

10.2174/1871520615666141216125446 ◽

2015 ◽

Vol 15 (5) ◽

pp. 631-646 ◽

Cited By ~ 27

Author(s):

Kaalin Gopaul ◽

Suhas Shintre ◽

Neil Koorbanally

Keyword(s):

Substituted Quinolines ◽

Anti Cancer ◽

Cancer Activity

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Addition of primary alcohols to 3-chlorononafluoro-1,5-hexadiene and perfluoro-1,3,5-hexatriene

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19851714 ◽

1985 ◽

Vol 50 (8) ◽

pp. 1714-1726 ◽

Cited By ~ 3

Author(s):

Václav Dědek ◽

Igor Linhart ◽

Milan Kováč

Keyword(s):

Sulfuric Acid ◽

Primary Alcohols ◽

Principal Product ◽

Allyl Rearrangement ◽

Concentrated Sulfuric Acid ◽

Sodium Alkoxide

Sodium alkoxide-catalyzed addition of methanol, ethanol and propanol to 3-chlorononafluoro-1,5-hexadiene (I) proceeds at temperatures -35 °C to 8 °C with allyl rearrangement, affording 1,6-dialkoxy-1,1,2,3,4,4,5,6,6-octafluoro-2,4-hexadiene (V) as the principal product, along with 1,6-dialkoxy-1,2,3,3,4,5,6,6-octafluoro-1,5-diene (VI) and trans-1,6-dialkoxy-1,1,2,3,4,4,5,6,6-nonafluoro-2-hexene (VII). The ethers Va-Vc consist of the cis,trans- and trans,trans-isomers in about 3 : 1 ratio, whereas the ethers VIa-VIc have trans,trans-configuration. Ethers Vc and VIc react with concentrated sulfuric acid to give dipropyl 2,3,4,5-tetrafluoro-2,4-hexadienedioate (IX) and dipropyl 2,3,4,4,5-pentafluoro-2-hexenedioate (X), respectively, whereas the ether VIIc affords a mixture of propyl 6-propyloxy-2,3,4,4,5,6-heptafluoro-2-hexenoate (XI) and ester X. Addition of methanol to perfluoro-1,3,5-hexatriene (II) affords 1,1,2,3,4,5,6,6-octafluoro-1,6-dimethoxy-3-hexene (XIII) as the principal product.

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Cross β-alkylation of primary alcohols catalysed by DMF-stabilized iridium nanoparticles

Organic & Biomolecular Chemistry ◽

10.1039/d1ob00045d ◽

2021 ◽

Author(s):

Masaki Kobayashi ◽

Hiroki Yamaguchi ◽

Takeyuki Suzuki ◽

Yasushi Obora

Keyword(s):

Primary Alcohols ◽

Recycling Process ◽

Catalyst Recycling ◽

Simple Method ◽

Benzyl Alcohols ◽

Effective Catalyst ◽

Iridium Nanoparticles ◽

Highly Effective ◽

Linear Alcohols ◽

The Cross

A simple method for the cross β-alkylation of linear alcohols with benzyl alcohols in the presence of DMF-stabilized iridium nanoparticles was developed. Furthermore, a highly effective catalyst-recycling process was also developed.

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